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Temperate riverside forests without alder trees in the north-west of the Iberian Peninsula: ecology, phytosociological profile and interest for preservation policies.

INTRODUCTION

A substantial part of the forests growing along the river watercourses of the Atlantic area of the extreme northwest of the Iberian Peninsula are dominated by alder trees (Alnus glutinosa Gaertn.). Four phytosociological forest associations dominated by this species have so far been described as growing in this ecological environment (AMIGO & al., 1987; Romero Bujan, 1993; Diaz Gonzalez & Fernandez Prieto, 1994; Honrado & al., 2002), which is characterized by river flooding in autumn and winter, but with soils remaining fairly well aerated in summer.

However, there are other tree communities present in this biogeographical environment which tend to naturally colonize the river banks and where the above mentioned tree species are usually absent. These include some types of willow forests, a couple of types of birch tree forests and a type of mixed forest often dominated by ash trees (Fraxinus excelsior) (Izco & al., 1986; DIAZ Gonzalez & Fernandez Prieto, 1994; Honrado & al., 2003; Amigo, 2006). These tree formations grow mostly in the Cantabrian Cordillera range (Orocantabric Subprovince sensu Rivas-Martinez, 2007) although some are even found in the central and eastern part of the Cantabrian coast (Cantabrian-Atlantic Subprovince) beside river watercourses which are particularly well suited to their development, but not at all suited to alder trees (Diaz Gonzalez & Fernandez Prieto, 1994; LoiDi & al., 1997; Amigo, 2006) (Table 1).

With regards riverside alder tree forests, the data previously available (Table 1) revealed that the territories at the western end of the Cantabrian coast and of the northern half of the Artabrian Gulf show a particularly high biodiversity rate as compared with other Iberian environments in the northwest. Not only do they include the widespread alder tree forests belonging to the Valeriano pyrenaicae-Alnetum glutinosae association, but also some Galician-Portuguese (Senecioni bayonensis-Alnetum glutinosae subass. fraxinetosum excelsioris) and Ovetense (Hyperico androsaemi-Alnetum glutinosae subass. osmundetosum regalidis) enclaves of alder tree forests towards the western and eastern ends respectively (Amigo & al., 1987; Diaz Gonzalez & Fernandez Prieto, 1994). However, there is no information on the possible existence of other typologies of riverside forests where the alder tree might be absent.

Over the last ten years, our field research in this geographical area has revealed the occurrence of other riverside tree communities where Alnus glutinosa is absent. Some of these communities have been briefly described in a previous paper (Rodriguez Guitian, 2005). This current paper aims not only to determine the phytosociological profile of this riverside tree vegetation growing at the western end of Cantabria, but also to assess its role as a suitable habitat for the preservation of vascular plant populations currently under legal protection.

STUDY AREA AND METHODS

This paper concentrates on the area comprising basically the western Cantabrian Subsector (Galician-Asturian Sector, Cantabrian-Atlantic Subprovince, Atlantic European Province, Eurosiberian Region) according to the biogeographical units described for the Iberian NW by Rodriguez Guitian & Ramil-Rego (2008). This biogeographical unit coincides largely with the so-called "Northern Galician-Asturian Subsector" of Rivas-Martinez (1987) or the Northern Galician and Northern Asturian districts combined in the mapping published by Vazquez & Diaz (2005).

[FIGURE 1 OMITTED]

Generally speaking, the territory under study is formed by metamorphic and igneous-siliceous rocky outcrops occasionally covered by detrital, non-consolidated sediments which produce soils which are poor in nutrients and frequently quite stony (Alvarez & Diaz-Fierros, 1995; Macias & Calvo de Anta, 1999). The general orographical profile is a succession of variably oriented ranges with more or less encased valleys and small sedimentary depressions in between (Valdovino-Naron, San Sadurnino, As Pontes, O Valadouro, valleys of Mondonedo and Lourenza, etc.). Nevertheless, this biogeographical unit makes contact to the south with topographically flat or slightly undulating territories (namely, the regions of Teixeiro-Curtis in the province of A Coruna and Terra Cha in the province of Lugo). At the easternmost point of the territory, the southern limit coincides with topographically rugged mountainous areas within the river basins of the Navia and the Narcea (Figure 1).

With regards bioclimatology, the thermotemperate belt extends from sea level to an altitude of about 150 m. Above this altitude we find the mesotemperate belt, whose highest level reaches an altitude of 650-800 m (the lower record corresponds to windward and the higher to leeward exposures). At still higher altitudes we find the supratemperate belt (Rodriguez Guitian, 2005; Rodriguez Guitian & Ramil-Rego, 2007).

In each of the sites we made floristic releves using the sigmatist phytosociological methods of Zurich-Montpellier (Braun-Blanquet, 1979). The environmental data recorded included not only hydrological values but also topographical (altitude, slope, exposure) and soil (lithology, soil developmental state) values. The impact of human action was also recorded. With the aid of the thermometric gradients provided by Rodriguez Guitian (2004) we calculated the Compensated Thermicity Index (CTi) value for each site in order to determine the particular thermotype following the methods proposed by Rivas-Martinez (2007). The information collected in the field was later checked against the available bibliographical references and is here shown in synthetic tables to enable discussion of the results. For taxonomical purposes we basically followed the suggestions of Flora Iberica (Castroviejo & al., 1986-2009) and European Flora (Tutin & al., 1960-1980) for vascular plants and Brugues & al. (2007), Casas & al. (2006) and Smith (1990) for briophytes. Because the distribution of Hedera species is still not well-known in the NW Iberian Peninsula, we maintain the original determinations established by the authors of the references used in the discussion paragraph. Nevertheless following Sahuquillo & al. (2001) H. hibernica could be the only taxon of this genus present in the study area. Finally, our syntaxonomical discussion relies heavily on the arrangement of phytosociological units and groups of characteristic species published by Rivas-Martinez & al. (2001, 2002).

[FIGURE 2 OMITTED]

RESULTS AND DISCUSSION

From a physiognomical perspective, the riverside vegetation reveals the occurrence of three clearly distinguishable communities with regards their respective dominant tree-like species (ash, hazel-willow and birch tree forests). This paper concentrates not only on the floristic and structural features of these communities but also on their ecological and phytosociological profiles. The CTI index values reckoned for each of the sites under study (Figure 2) indicate that these three tree-like formations are thermotypically widely spread. Nevertheless there is also a certain bioclimatic segregation, as ash tree forests and hazel-willow tree forests tend to grow at mesotemperate and thermotemperate levels, whereas birch tree forests grow preferably in mesotemperate and supratemperate thermotypes.

Riverside ash tree forests

Most of the rivers flowing into the Cantabrian Sea cover a relatively broad altitudinal range with short watercourses. Consequently, given the high rainfall rates recorded, heavily concentrated in the winter season, river flow rates are extremely variable and river banks tend to be unstable and liable to erosion, or even mostly cut out of the rock in many fluvial stretches. These conditions are not very suitable for the development of the root system of alder trees and prevail along the high and middle water courses, although they can be present locally in the lower courses. under these adverse circumstances for alder trees, riverside galleries tend to be formed by a wide spectrum of tree-like species, such as ash trees (Fraxinus escelsior), sycamore maples (Acer pseudoplatanus), wych elm trees (Ulmus glabra) and oak trees (Quercus robur, Quercus petraea, Quercus x rosacea), with occasional occurrences of beech (Fagus sylvatica), sweet chestnut (Castanea sativa), wild cherry (Prunus avium) or yew (Taxus baccata). Since the ash tree (Fraxinus excelsior) is the most frequently dominant species in these riverside forests, we have given them the name of "riverside ash tree forests". It is however true that these forests can exhibit a somewhat variable physiognomy and an average size which ranges from 12 to 24 m (Tables 2, 3 and 4).

In the scrub stratum (1.5-4 m) of these forests, hazel trees (Corylus avellana), grey willows (Salix atrocinerea), glossy buckthorns (Frangula alnus) and Plymouth pear (Pyrus cordata) tend to occur frequently. In the undergrowth there is an abundance of the nemoral grasses frequently found in riverside alder tree forests (Athyrium filix-femina, Brachypodium sylvaticum, Carex remota, Carex elata subsp. reuteriana, Circaea lutetiana, Hypericum androsaemum, Polystichum setiferum, Ranunculus ficaria, Scrophularia auriculata, Symphytum tuberosum) and a variety of climatophilous forests (Aquilegia vulgaris, Blechnum spicant, Dryopteris affinis, Dryopteris dilatata, Dryopteris filix-mas, Euphorbia amygdaloides, Hedera hibernica, Holcus mollis, Hyacinthoides non-scripta, Lonicera periclymenum, Luzula sylvatica subsp. henriquesii, Oxalis acetosella, Polypodium vulgare, Sanicula europaea, Saxifraga spathularis, Stellaria holostea, Teucrium scorodonia, Vaccinium myrtillus, Viola riviniana). In this respect, the large number of characteristic species of the Fagetalia sylvaticae order thriving in these forests (Carex sylvatica, Euphorbia dulcis, Helleborus viridis subsp. occidentalis, Lysimachia nemorum, Melica uniflora, Mercurialisperennis, Milium efussum, Primula acaulis, Ranunculus tuberosus, Scrophularia alpestris) is particularly worth noting. The average number of species is very high (38 taxa), well above the number recorded in the typical facies of the riverside alder tree forests of the Valeriano pyrenaicae-Alnetum glutinosae association studied by Amigo & al. (1987) and Mayor & Fernandez (2007).

From a physiognomical and ecological point of view, these ash tree forests are related to the riparian forests described for the nearby Orocantabrian territories included in the Festuco giganteae-Fraxinetum excelsioris association, the only one of this particular profile so far described (Diaz Gonzalez & Fernandez Prieto 1994, Rodriguez Guitian & al. 2001). However, the presence of mesothermophilous taxa, such as Quercus robur, Carex pendula, Ruscus aculeatus, Rubia peregrina or Arbutus unedo in the Cantabrian-Atlantic ash tree forests we have studied, allows a clear-cut distinction as compared to the previous (Tables 2, 3, 4 and 7). Given their peculiar floristic profile and the clearly disjointed distribution of these forests as compared to the Orocantabrian riverside ash tree forests, we propose that they should be included in the new Valeriano pyrenaicae-Fraxinetum excelsioris associatio nova hoc loco association, whose holotypus can be seen in releve 9 of Table 2.

The floristic data recorded for this community and their correlation with a number of ecological factors suggest the presence of syntaxonomical units within it, with a rank lower than that of an association. On the one hand, the presence/absence of some thermophilous species allows us to distinguish two subassociations within these ash tree forests. The floristic composition of the most typical (fraxinetosum excelsioris) comprises taxa which are vulnerable to cold temperatures, such as Arbutus unedo, Asplenium onopteris, Carex pendula, Laurus nobilis, Phyllitis scolopendrium, Rubia peregrina, Ruscus aculeatus or Tamus communis. Meanwhile, in areas far from the coast, especially within the upper mesotemperate and supratemperate thermotypes, not only is the group of thermophilous species absent, but there is also an increase in the frequency of Saxifraga lepismigena and some megaforbic species, such as Adenostyles hybrida, Allium victorialis, Angelica major. For this second ecological profile, we propose the subassociation adenostyletosum hybridae subass. nova hoc loco (holotypus releve 10, Table 4).

On the other hand, when the general hyperoceanic character of the climate in the area under study is accompanied in specific places by a deep encasement of the watercourses, with abundant rapids and waterfalls inducing high atmospheric humidity in the environment, these forests tend to show exuberant populations of hygrosciophilous pteridophytes, such as Woodwardia radicans, Culcita macrocarpa, Hymenophyllum tunbrigense or Stegnogramma pozoi (Table 3). These situations, relatively frequent in the thermotemperate and lower mesotemperate distributional levels of these ash tree forests, represent what we have called the hyperhygrophilous variant of the typical subassociation already mentioned.

Finally, these forests also include a facies with Alnus glutinosa, which marks a transitional phase from this kind of forests towards the Valeriano pyrenaicae-Alnetum glutinosae alder tree forests, a community which usually makes contact with the riverside ash tree forests. Despite the existence of the black alder in these facies of the ash woodlands, they differ from the latter by the presence of many plants that are absent or are very rare in them, such as Ajuga reptans, Cardamine impatiens, Castanea sativa, Erica arborea, Heracleum sphondylium, Holcus mollis, Hyacinthoides nonscripta, Ilex aquifolium, Mercurialis perennis, Oxalis acetosella, Polypodium vulgare, Primula acaulis, Quercus robur, Ranunculus tuberosus, Ruscus aculeatus, Sorbus aucuparia, Ulmus glabra, Vaccinium myrtillus, Valeriana montana and Woodwardia radicans, but are very common in the ash tree woodlands as a whole (Table 7). In addition, a number of species very frequent in the black alder woodlands, such as Carex reuteriana, Circaea lutetiana, Equisetum arvense, Eupatorium cannabinum, Geum urbanum, Lythrum salicaria, Osmunda regalis, Poa nemoralis and Solanum dulcamara, are scarce or absent in the ash woodlands.

From a syntaxonomical point of view, the presence of species such as Festuca gigantea, Hypericum androsaemum, Senecio nemorensis, Culcita macrocarpa or Woodwardia radicans in these forests allow us to include them in the suballiance Hyperico androsaemi-Alnenion glutinosae, belonging to the Alnion incanae alliance, Populetalia albae order and Salici-Populetea nigrae class (Table 7, Rivas-Martinez & al., 2002).

Riverside hazel-willow tree forests

Up river near the headwaters, the river flow rates vary to such an extent throughout the year that most of the characteristic tree-like species of the ash tree forests no longer find suitable growing conditions on the riverbanks. These circumstances produce microforests of usually 6-10 m high, mainly dominated by hazel trees (Corylus avellana) and black willow trees (Salix atrocinerea, Figure 2). As a result of their particular hydrological location, these hazel-willow tree forests tend to spread through the mesotemperate belt. However, they can also be found in thermotemperate areas where there are small streams.

As part of the canopy of these plant formations, some scattered trees may also be found which are less demanding of the soil moisture frequent in ash tree forests. This is the case, for example, of oak trees (Quercus robur), sweet chestnut (Castanea sativa), holly (Ilex aquifolium), beech (Fagus sylvatica) and downy birch (Betula pubescens). However, the flora of the groundlevel of these forests is considerably poorer compared to that of these formations. The impact is particularly notable on the species belonging to the Fagetalia sylvaticae order and the Salici-Populetea class (Table 5). By contrast, the occurrence and abundance of species such as Agrostis capillaris, Avenella flexuosa, Dryopteris aemula, Vaccinium myrtillus, Erica arborea, Lastrea limbosperma or Sorbus aucuparia are noticeably higher in these microforests. These acidophilous species are frequently recorded in the climatophilous oak woods with which they usually make lateral contact, but they rarely occur or are absent in the riverside ash tree forests.

From a phytosociological point of view, the floristic differences between the hazel-willow tree forests and the riverside ash tree forests, together with their very different ecological profile, lead us to propose the inclusion of the former in a new plant association, namely the Hyperico androsaemi-Coryletum avellanae associatio nova hoc loco, whose holotypus we have stated in releve 10 of Table 5.

In addition to the typical subassociation, whose distribution is mainly upper mesotemperate and supratemperate, there is another thermophilous subassociation (ruscetosum aculeati subass. nova hoc loco, holotypus releve 17, Table 5) characterized by species such as Arbutus unedo, Carex pendula, Laurus nobilis, Ruscus aculeatus or Tamus communis, which tend to grow in the thermotemperate and lower mesotemperate belts. There are two variants within both subassociations: the typical one and a hyperhygrophilous one, this latter being characterized by the occurrence of thermophilous and hygrophilous ferns, such as Woodwardia radicans, Culcita macrocarpa or Hymenophyllum tunbrigense. This last floristic combination takes place in either heavily encased enclaves or near small waterfalls.

As occurs in the case of riverside ash tree forests, the presence of taxa such as Hypericum androsaemum, Senecio nemorensis, Festuca gigantea or Woodwardia radicans in these riverside hazel-willow tree forests supports their inclusion in the Hyperico androsaemi-Alnenion glutinosae suballiance (Alnion glutinosae alliance, Populetalia albae order, Salici-Populetea nigrae class).

Riverside birch tree forests

In the highest sites of the northern Galician ranges and in the Sierra de la Bobia in Asturias, usually at altitudes of 400 or 500 m to 900 m, in connection with the upper mesotemperate and lower supratemperate thermotypes, the vegetation associated with the banks of streams becomes dominated by downy birches (Betula pubescens), sometimes accompanied by black willow trees (Salix atrocinerea), oak trees (Quercus robur), glossy buckthorns (Frangula alnus), hazel (Corylus avellana) holly (Ilex aquifolium) and mountain ash (Sorbus aucuparia). These are lineal forests usually 12-18 m high, whose undergrowth normally includes not only Erica arborea but also some acidophilous species frequently recorded in the nearby climatophilous forests (Avenella flexuosa, Blechnum spicant, Dryopteris affinis, Dryopteris dilatata, Euphorbia dulcis, Hedera hibernica, Holcus mollis, Lonicera periclymenum, Luzula henriquesii, Omphalodes nitida, Oxalis acetosella, Polypodium vulgare, Saxifraga spathularis, Stellaria holostea, Teucrium scorodonia, Vaccinium myrtillus or Viola riviniana). Plants usually found in the nearby more or less hygrophilous or hygroturfophilous scrublands and grasslands are also abundant. These are, e. g., Agrostis capillaris, Arrhenatherum bulbosum, Carex laevigata, C. binervis, Centaurea nigra, Crocus serotinus, Dactylis glomerata, Deschampsia cespitosa, Juncus effusus, Molinia caerulea, Peucedanum lancifolium, Prunella vulgaris, Ranunculus repens or Rumex acetosa.

These edaphohygrophilous riverside birch forests must not be confused with the widespread secondary climatophilous thermo-mesotemperate birch forests belonging to the association Holco mollis-Betuletum celtibericae (Betulion fontqueri-celtibericae, Betulo-Populetalia tremulae, Querco-Fagetea) described by Amigo & Romero (1998) and typified more recently by Rivas-Martinez & al. (2002). These seral birch forests substitute several climatophilous oak forests of the suballiance Quercenion robori-pyrenaicae present in the NW Iberian Peninsula.

So far, two riverside tree-like communities dominated by downy birches

had previously been described for the extreme NW of the Iberian Peninsula:

--Luzulo henriquesii-Betuletum celtibericae subas. salicetosum atrocinereae, occurring at the supratemperate levels of the Galician-Leonese ranges of Courel and Ancares (Western Orocantabrian sector in the Rodriguez Guitian & Ramil-Rego biogeographical classification), and distinguishable from the typical subassociation by the presence of plants such as Salix atrocinerea, Blechnum spicant, Chaerophyllum hirsutum, Cirsium palustre, Adenostyles hybrida and Athyrium filix-femina (IZCO& al., 1986).

--Carici reuterianae-Betuletum celtibericae, distributed throughout the mountains near the Galician-Portuguese limit (Galician-Portuguese and Rias Baixas sectors in the Rodriguez Guitian & Ramil-Rego biogeographical classification) and in contrast to the previous birch tree forests, characterized by the presence, among other plants, of Allium scorzonerifolium, Anemone trifolia subsp. albida, Aquilegia vulgaris subsp. dichroa, Calamagrostis arundinacea, Carex elata subsp. reuteriana, Epilobium obscurum, Galium broterianum or Paradisea lusitanica (Honrado & al., 2003).

As compared to these two communities, the riverside birch tree forests present the differentially exclusive presence of taxa such as Ajuga reptans, Angelica major, Avenella flexuosa, Dryopteris aemula or Senecio nemorensis (Tables 6 and 7). In addition, not only do these birch tree forests lack the species differentiating the Xuresian from the Orocantabrian birch tree forests, but also others which are characteristic taxa of these latter (Chaerophyllum hirsutum, Daphne laureola, Poa nemoralis, Polygonatum verticillatum and Valeriana montana). Consequently, it seems clear that this kind of riverside birch tree forests is a new phytosociological association for which we propose the name Violo palustris-Betuletum pubescentis associatio nova hoc loco (holotypus rel. 3 Table 6).

The presence of species such as Athyrium filixfemina, Brachypodium sylvaticum, Frangula alnus, Osmunda regalis and Ranunculus ficaria in the riverside birch tree forests of this new association supports their inclusion in the Populetalia albae order, Salici-Populetea nigrae class (cf. Rivas-Martinez & al., 2002). However, contrary to the proposal made by Honrado & al. (2003) for the Xuresian riverside birch tree forests, which they include in the Osmundo-Alnion alliance due to their lack of the characteristic species of the Alnion incanae alliance, the birch tree forests should be included in that alliance due to the presence of species such as Carex remota or Festuca gigantea, and, within this alliance, in the Hyperico androsamei-Alnenion suballiance, as they include species characteristic of that syntaxonomical unit, such as Hypericum androsaemum or Senecio nemorensis (Rivas-Martinez & al. 2002).
SYNTAXONOMICAL SCHEME

  The syntaxonomical scheme of the plant communities mentioned in
  this paper is shown below.

Salici-Populetea nigrae (Rivas-Martinez & Canto ex Rivas-Martinez,
  Bascones, T.E. Diaz, FernandezGonzalez & Loidi 1991)
  Rivas-Martinez & Canto 2002
 Populetalia albae Br.-Bl. ex Tchou 1948
  Alnion incanae Pawlowski in Pawlowski, Sokolowski & Wallisch 1928
   Hyperico androsaemi-Alnenion glutinosae Amigo, Guitian & F. Prieto
   1987
    Festuco giganteae-Fraxinetum excelsioris F. Prieto & Bueno in T.E.
    Diaz & F. Prieto 1994
    Hyperico androsaemi-Alnetum glutinosae (Br.-Bl. 1967)
       Rivas-Martinez
     in Loidi 1983 osmundetosum regalidis Amigo, Guitian & F. Prieto
     1987
     Valeriano pyrenaicae-Alnetum glutinosae Amigo, J. Guitian & F.
     Prieto 1987
     Valeriano pyrenaicae-Fraxinetum excelsioris ass. nova
     fraxinetosum excelsioris
      typical variant
       typical facies
        Alnus glutinosa facies
      hyperhygrophilous variant
       typical facies
        Alnus glutinosa facies
      subass. adenostyletosum hybridae nova
       typical facies
       Alnus glutinosa facies
      Hyperico androsaemi-Coryletum avellanae ass. nova
       coryletosum avellanae
        typical variant
        hyperhygrophilous variant
       ruscetosum aculeati nova
        typical variant
        hyperhygrophilous variant
      Violo palustris-Betuletum pubescentis ass. nova
       typical variant
        typical facies
        Salix atrocinerea facies
       Alnus glutinosa variant
        typical facies
        Salix atrocinerea facies

    Osmundo-Alnionglutinosae (Br.-Bl., P. Silva & Rozeira 1956)
    Dierschke & Rivas-Martinez in Rivas-Martinez 1975

      Galio broteriani-Alnetum glutinosae Rivas-Martinez, Fuente &
      Sanchez-Mata 1986

      Scrophulario scorodoniae-Alnetum glutinosae Br.-Bl., P.
      Silva & Rozeira 1956

      Senecioni bayonensis-Alnetum glutinosae Amigo, J. Guitian & F.
           Prieto 1987 (=Narcisso cyclaminei-Alnetum
           glutinosae Honrado, P. Alves, R. Pereira & F.B. Caldas
           in Honrado, P. Alves, H.N. Alves &
           F.B. Caldas 2004)

           Carici reuterianae-Betuletum celtibericae Honrado, P. Alves,
           Aguiar, Ortiz & F.B. Caldas ex Honrado 2004
      Salicetalia purpureae Moor 1958

        Salicion salviifoliae Rivas-Martinez, T.E. Diaz, F. Prieto,
        Loidi & Penas 1984

        Salicetum salviifoliae Oberdorfer & Tuxen in Tuxen & Oberdorfer
        1958

        Salicetum lambertiano-salviifoliae Rivas-Martinez 1965 corr.
        Rivas-Martinez, Fernandez-Gonzalez &
        Sanchez-Mata 1986

    Querco-Fagetea Br.-Bl. & Vlieger in Vlieger 1937

     Betulo pendulae-Populetalia tremulae Rivas-Martinez & Costa 2002

      Betulion fontqueri-celtibericae Rivas-Martinez & Costa 2002

       Luzulo henriquesii-Betuletum celtibericae Rivas-Martinez 1965
         salicetosum atrocinereae Izco, Amigo & J. Guitian 1986


Interest of the forests under study for a preservation policy

A correct assessment of the interest of a given kind of habitat for a preservation policy is a complex issue which requires profound knowledge not only of the different biotic factors involved but also of their geographical distribution (Loidi, 2008). When there is little of this information available, researchers often resort to assessments based on the vulnerability level or endemicity rate of animals and plants living in that ecological environment. Although this kind of assessment is very common, the results obtained from a consideration of the plant elements tend to underestimate the interest of a given ecological environment for a preservation policy, as certain plants, especially geophytes, may have phenological cycles which make it very difficult to clearly identify the plants outside the flowering or fruiting periods.

Conscious of this difficulty, we offer a tentative assessment of the conservation interest of these riverside forests as part of a preservation policy of natural heritage. For this purpose we not only take into account floristic criteria (lists of species under legal protection) but also the typology of habitats (according to Appendix I of the Directive 92/43/EEC). We also assume that the forest samples in our releves faithfully represent their floristic composition throughout their recognised distribution area.

Floristic criteria

In this section we have used the occurrence rate, in each of the described forest associations, of plant species currently under legal protection, both at the EU level (Appendix of the Directive 92/43/EEC) and at the level of the Spanish autonomous regions, i.e., Galicia and Principado de Asturias, two regions which have their own catalogues of endangered species: CGEA (Anonymous, 2007) and CREAPA (Anonymous, 1997) (Table 8). The results reveal that the riverside forests under study include up to 8 vascular plant species under protection and 1 moss genus, with a notable proportion of pteridophytes (4 species). Although it was not recorded in our releves, Hymenophyllum wilsonii, whose only population known so far in the Iberian Peninsula grows precisely in a riverside forest similar to the hazel-willow tree forests described here, must be added to this list (Sonora & al., 1992, Quintanilla & al., 2002). The low occurrence rate of some species, such as Culcita macrocarpa or Taxus baccata, in the communities under study is due to their very meagre natural populations in the territory in question. However, in other cases, such as that of Narcissus asturiensis, the low occurrence rate must be put down to the difficulty of detection when field sampling: conspicuously prevernal, this species can easily be overlooked during its vegetative period. With regard to the briophytes of the Sphagnum genus, as occurs with the rest of the non-vascular flora, they are frequently dismissed in the research depicting the phytocoenoses dominated by superior plants, which prevents them from being correctly assessed as far as preservation policy is concerned.

The data recorded suggest that the three kinds of riverside forests described are typical of ecological environments suitable for the development of plant species populations under protection. In this respect, the hazel-willow tree forests include the largest number of protected plants, specifically three species from Appendix II, two from Appendix V of Directive 92/43/EEC, two ranked as vulnerable (VU) in the CGEA, and one ranked as being of special interest (SI) and included in the CREAPA (Table 8).

Typology according to Annex I of the Directive 92/43/EEC

In addition to the criteria based on the presence of endangered species under legal protection, since the passing and publication in 1992 of Directive 92/43/EEC, the list of habitats shown in Annex I is being used as a criterion for determining the interest of types of vegetation characteristic of specific ecological environments for a preservation policy.

According to the guidelines of the EUR-27 version of the "Interpretation Manual of European Union Habitats" (EC 2007), all the forests described here should be included in the priority habitat "91E0* Alnus glutinosa and Fraxinus excelsior riverside forests (Alno-Padion, Alnion incanae, Salicion albae)" not only because they are riverside forests growing in the temperate zone dominated by alder tree or ash tree (as happens with the riverside ash tree forests), but also because their floristic composition includes many species considered characteristic of this kind of habitat (Alnus glutinosa, Angelica sylvestris, Betula pubescens, Cardamine pratensis, Carex pendula, Carex remota, C. sylvatica, Fraxinus excelsior, Lysimachia nemorum, Salix fragilis, Ulmus glabra, Urtica dioica), a criterion which supports their inclusion in the case of the hazel-willow tree forests and the birch tree forests. In addition, as we have already explained, the ash tree, hazel-willow and birch tree forests are ascribed, from a syntaxonomical point of view, to the Alnion incanae alliance, the reference unit alluded to in the declaration of the above-mentioned type of habitat.

CONCLUSIONS

Our paper has documented the existence of different types of riverside forests in which alder trees are absent or have a very small presence within the westernmost Cantabrian territories. In the headwaters of the rivers and in the steep-banked stretches of the middle and low altitude river watercourses, these riverside forests (ash , hazel-willow and birch forests) take the place of the alder tree forests of the Valeriano-pyrenaicae-Alnetum glutinosae association for hydrological and bioclimatic reasons. The plant communities occur in ecological environments considered as habitats in great need of protection within the EU, and are particularly suitable for the survival of a large number of plant species under protection. Consequently, accurate knowledge of the distribution of these forests is very useful for an efficient mapping and management of areas of interest for a preservation policy to protect the natural heritage of the territory we have studied.

doi: 10.5209/rev_LAZA.2010.v31.1

ACKNOWLEDGEMENTS

I would like to thank the reviewers for their comments to improve the original manuscript and Javier Ferreiro da Costa, Gabriel Lijo Pose, Miguel A. Negral Fernandez, Jose A. Penin Franco, Javier Pereira-Espinel, Pablo Ramil-Rego and Rosa Romero Franco for their valuable help during the field research activities. Carlos Real determined the briophytes.

Recibido: 26 junio 2009

Aceptado: 11 enero 2010

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Manuel Antonio Rodriguez Guitian (*)

* Departamento de Produccion Vexetal. Escola Politecnica Superior. Universidade de Santiago de Compostela. Campus Universitario s/n. E-27002-Lugo. E-mail: manuelantonio.rodriguez@usc.es
Table 1

Biogeographical distribution of the riparian forests described in
the NW Iberian Peninsula. Acronyms of the biogeographical units.
Sectors: G-A: Galician-Asturian; G-P: Galician-Portuguese; Gint:
Interior Galician; B-V: Bercian-Valdeorresean; N-A:
Narceensian-Ancaresian; G-D: Galician-Duriensian. Subsectors: Co:
Western Cantabrian; O: Ovetensian; F: Fisterranean; RB: Rias
Baixas; Ch: Chairego; OL: Ourensian-Lucensian; N: Naviano; UD:
Ulloa-Deza; P: Penedense; X: Xuresian; V: Valdeorresean; B:
Bercian; Al: Altonarceensian; om: omanes; An: Ancaresian; C:
Courelian; Q: Queixense; S: Sanabrensian. The asterisks (*)
represents the forests type studied.

Subprovince                         Cantabo-Atlantic

Sector                              G-A         G-P
Subsector                        Co     O     F    RE

Alder tree forests
  Hyperico androsaemi-            a     b
    Alnetum glutinosae
  Valeriano pyrenaicae-           b
    Alnetum glutinosae
  Senecioni bayonensis-           a           b     b
    Alnetum glutinosae
  Galio broterianae-
    Alnetum glutinosae
Willow tree forests
  Salicetum angustifolio-
    salviifoliae
  Salicetum angustifolio-albae          a
  Salicetum salviifoliae                            a
Birch tree forests
  Luzulo henriquesii-Betuletum
    celtibericae
  subass. salicetosum
    atrocinereae
  Carici reuterianae-Alnetum
    glutinosae
  * Violo palustris-Betuletum     b
    pubescentis
Ash tree forests
  Festuco giganteae-
    Fraxinetum excelsioris
  * Valeriano pyrenaicae-         b
    Fraxinetum excelsioris
Hazel tree-willow tree forests
  * Hyperico androsaemi-          b
    Coryletum avellanae
  Number of associations          6     2     1     2

Subprovince                                Cantabo-Atlantic

Sector                                 Gint              Gint
Subsector                        Ch    OL     N    UD     P     X

Alder tree forests
  Hyperico androsaemi-
    Alnetum glutinosae
  Valeriano pyrenaicae-                 a     b
    Alnetum glutinosae
  Senecioni bayonensis-           b     b           b
    Alnetum glutinosae
  Galio broterianae-                                      ?     b
    Alnetum glutinosae
Willow tree forests
  Salicetum angustifolio-
    salviifoliae
  Salicetum angustifolio-albae
  Salicetum salviifoliae
Birch tree forests
  Luzulo henriquesii-Betuletum
    celtibericae
  subass. salicetosum
    atrocinereae
  Carici reuterianae-Alnetum                              b     b
    glutinosae
  * Violo palustris-Betuletum     a
    pubescentis
Ash tree forests
  Festuco giganteae-
    Fraxinetum excelsioris
  * Valeriano pyrenaicae-
    Fraxinetum excelsioris
Hazel tree-willow tree forests
  * Hyperico androsaemi-
    Coryletum avellanae
  Number of associations          2     2     1     1    2?     2

Subprovince                                    Cantabo-Atlantic

Sector                                              Gint
Subsector                                     Ch    OL     N

Alder tree forests
  Hyperico androsaemi-Alnetum glutinosae
  Valeriano pyrenaicae-Alnetum glutinosae            a     b
  Senecioni bayonensis-Alnetum glutinosae      b     b
  Galio broterianae-Alnetum glutinosae
Willow tree forests
  Salicetum angustifolio-salviifoliae
  Salicetum angustifolio-albae
  Salicetum salviifoliae
Birch tree forests
  Luzulo henriquesii-Betuletum celtibericae
  subass. salicetosum atrocinereae
  Carici reuterianae-Alnetum glutinosae
  * Violo palustris-Betuletum pubescentis      a
Ash tree forests
  Festuco giganteae-Fraxinetum excelsioris
  * Valeriano pyrenaicae-Fraxinetum
    excelsioris
Hazel tree-willow tree forests
  * Hyperico androsaemi-Coryletum avellanae
  Number of associations                       2     2     1

                                  Cantabo-
Subprovince                       Atlantic         Orocantabric

Sector                              B-V               N-A
Subsector                         V     B    Al    On    An     C

Alder tree forests
  Hyperico androsaemi-
    Alnetum glutinosae
  Valeriano pyrenaicae-                       b     b     b     b
    Alnetum glutinosae
  Senecioni bayonensis-                 b
    Alnetum glutinosae
  Galio broterianae-
    Alnetum glutinosae
Willow tree forests
  Salicetum angustifolio-               a
    salviifoliae
  Salicetum angustifolio-albae    a     a
  Salicetum salviifoliae
Birch tree forests
  Luzulo henriquesii-Betuletum
    celtibericae
  subass. salicetosum                         ?     ?     b     a
    atrocinereae
  Carici reuterianae-Alnetum
    glutinosae
  * Violo palustris-Betuletum
    pubescentis
Ash tree forests
  Festuco giganteae-                          b     b     b     a
    Fraxinetum excelsioris
  * Valeriano pyrenaicae-
    Fraxinetum excelsioris
Hazel tree-willow tree forests
  * Hyperico androsaemi-
    Coryletum avellanae
  Number of associations          1     3    3?    3?     3     3

Subprovince                      Orocantabric

Sector                               G-D
Subsector                         Q      S

Alder tree forests
  Hyperico androsaemi-
    Alnetum glutinosae
  Valeriano pyrenaicae-
    Alnetum glutinosae
  Senecioni bayonensis-
    Alnetum glutinosae
  Galio broterianae-              ?      b
    Alnetum glutinosae
Willow tree forests
  Salicetum angustifolio-
    salviifoliae
  Salicetum angustifolio-albae
  Salicetum salviifoliae
Birch tree forests
  Luzulo henriquesii-Betuletum
    celtibericae
  subass. salicetosum             ?      a
    atrocinereae
  Carici reuterianae-Alnetum
    glutinosae
  * Violo palustris-Betuletum
    pubescentis
Ash tree forests
  Festuco giganteae-
    Fraxinetum excelsioris
  * Valeriano pyrenaicae-
    Fraxinetum excelsioris
Hazel tree-willow tree forests
  * Hyperico androsaemi-
    Coryletum avellanae
  Number of associations          2?     2

Table 2

Valerianopyrenaicae-Fraxinetum excelsioris ass. nova
typical facies (1-15); Alnus glutinosa facies (16-20)
(Hyperico androsaemi-Alnenion glutinosae, Alnion incanae, Populetalia
albae, Salici-Populetea)

Altitude (m)                    560    745    780    480    400
Exposition                       N     NNE     NW     N     NNW
Slope ([grados])                 4      16     15     4      2
Tree height (m)                  16     8      25     18     18
Tree cover (>1.5m, %)           100    100    100     95     95
Understory cover (<1.5m, %)      70     90     90     70     70
Area ([m.sup.2])                250    200    200    120    200
Number of taxa                   47     29     41     35     30
N.                               1      2      3      4      5

Characteristics of association and upper units

Corylus avellana                 4      5      3      2      3
Athyrium filix-femina            1      2      2      +      2
Dryopteris affinis               1      3      1      1      2
Saxifraga spathularis            1      1      1      1      .
Blechnum spicant                 +      +      1      .      1
Hedera hibernica                 1      .      1      .      .
Fraxinus excelsior               3      .      .      4      2
Oxalis acetosella                +      .      1      1      .
Salix atrocinerea                2      .      1      2      3
Acer pseudoplatanus              2      1      1      2      .
Lonicera periclymenum            1      .      1      .      .
Luzula henriquesii               1      2      1      .      1
Euphorbia dulcis                 .      1      1      +      +
Valeriana pyrenaica              1      1      1      2      2
Polystichum setiferum            1      .      1      2      1
Ilex aquifolium                  1      1      1      .      .
Primula acaulis                  .      1      .      .      +
Holcus mollis                    +      .      +      +      +
Hypericum androsaemum            +      .      .      .      .
Polypodium vulgare               +      +      r      +      .
Viola riviniana                  .      +      1      .      +
Mercurialis perennis             +      1      .      1      .
Chrysosplenium oppositifolium    1      2      1      1      .
Castanea sativa                  1      .      .      .      3
Dryopteris dilatata              +      1      .      .      .
Brachypodium sylvaticum          .      .      .      +      1
Ulmus glabra                     3      .      .      2      1
Festuca gigantea                 .      .      +      .      +
Carex remota                     +      .      .      .      1
Ranunculus ficaria               +      .      +      +      .
Scrophularia auriculata          .      .      .      .      1
Circaea lutetiana                .      .      .      .      .
Malus sylvestris                 .      .      .      .      .

Differentials of Festuco-Fraxinetum

Ajuga reptans                    .      2      1      +      1
Crataegus monogyna               1      1      .      .      1
Quercus robur                    1      .      .      .      .
Heracleum sphondylium            2      .      .      1      .
Cardamine raphanifolia           1      .      .      .      .
Senecio nemorensis               .      .      +      .      .
Osmunda regalis                  .      .      .      .      .
Sambucus nigra                   +      .      .      +      .
Viola palustris                  .      2      .      .      .
Angelica sylvestris              +      .      .      +      .
Cardamine impatiens              +      .      +      +      .
Deschampsia cespitosa            .      .      .      .      .
Pyrus cordata                    .      .      .      .      .
Frangula alnus                   .      .      .      .      .
Arum italicum                    +      .      .      +      .
Anemone nemorosa                 .      .      .      .      .
Dryopteris aemula                .      .      .      .      .
Avenella flexuosa                .      .      .      .      .
Narcissus asturiensis            .      .      .      .      .

Differentials of typical subassociation

Carex pendula                    .      +      +      .      1
Ruscus aculeatus                 +      .      .      .      .
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      .
Phyllitis scolopendrium          .      .      .      +      .
Asplenium onopteris              .      .      .      .      .

Diferentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions
Rubus sp.                        .      2      +      +      +
Stellaria holostea               .      +      .      .      .
Geranium robertianum             1      1      .      .      +
Scrophularia alpestris           1      .      r      +      .
Betula pubescens                 1      .      1      .      .
Cardamine pratensis              .      .      +      1      .
Chaerophyllum hirsutum           3      1      1      1      .
Dryopteris filix-mas             +      .      .      .      .
Euphorbia amygdaloides           +      .      .      .      .
Fragaria vesca                   .      .      +      +      .
Vaccinium myrtillus              .      .      +      .      .
Dactylis glomerata               .      .      .      .      .
Geum urbanum                     1      .      .      +      +
Teucrium scorodonia              .      .      .      .      .
Silene dioica                    .      +      .      .      .
Carexreuteriana                  .      .      .      .      +
Hyacinthoides non-scripta        .      .      1      +      .
Oenanthe crocata                 .      .      .      .      1
Aquilegia vulgaris               .      .      +      .      .
Carex sylvatica                  .      +      .      .      .
Omphalodes nitida                +      .      .      .      .
Caltha palustris                 .      .      .      .      .
Urtica dioica                    +      .      .      +      .
Melica uniflora                  .      .      .      .      .
Sorbus aucuparia                 .      .      +      .      .
Quercus x rosacea                .      .      .      .      .
Taxus baccata                    .      .      .      .      .
Ranunculus repens                .      .      .      .      .
Lamium maculatum                 .      .      .      .      .
Lapsana communis                 .      .      .      .      .
Lysimachia nemorum               .      .      .      .      .
Brachypodium rupestre            .      .      .      .      .
Carex laevigata                  .      .      .      .      .
Erica arborea                    .      .      .      .      .
Rumex acetosa                    .      .      .      .      .
Arrhenatherum bulbosum           .      .      .      .      .
Ranunculus tuberosus             .      .      .      .      .
Umbilicus rupestris              1      .      .      .      .
Sanicula europaea                +      +      1      .      .

Altitude (m)                    430    415    590    210    535
Exposition                      NNW    WNW     E      NE     N
Slope ([grados])                 2      4      20     2      2
Tree height (m)                  18     10     12     12     12
Tree cover (>1.5m, %)           100     90     95     90    100
Understory cover (<1.5m, %)      60     80     30     80     85
Area ([m.sup.2])                100    200    100    100    200
Number of taxa                   35     47     31     35     52
N.                               6      7      8      9      10

Characteristics of association and upper units

Corylus avellana                 3      2      4      4      1
Athyrium filix-femina            .      2      1      1      3
Dryopteris affinis               +      1      3      1      +
Saxifraga spathularis            1      1      1      1      +
Blechnum spicant                 +      1      1      +      +
Hedera hibernica                 +      1      +      1      1
Fraxinus excelsior               +      3      2      3      1
Oxalis acetosella                +      1      +      .      1
Salix atrocinerea                .      2      3      1      .
Acer pseudoplatanus              .      1      .      1      1
Lonicera periclymenum            +      1      .      1      +
Luzula henriquesii               1      .      1      2      3
Euphorbia dulcis                 .      1      +      +      +
Valeriana pyrenaica              .      .      1      1      1
Polystichum setiferum            3      .      2      2      1
Ilex aquifolium                  +      1      .      .      1
Primula acaulis                  .      .      .      r      .
Holcus mollis                    +      2      +      .      .
Hypericum androsaemum            r      +      .      +      +
Polypodium vulgare               +      .      .      .      +
Viola riviniana                  .      1      .      .      +
Mercurialis perennis             +      .      +      .      +
Chrysosplenium oppositifolium    .      .      1      +      +
Castanea sativa                  4      .      +      1      3
Dryopteris dilatata              .      .      .      .      +
Brachypodium sylvaticum          .      .      .      2      1
Ulmus glabra                     1      .      .      1      1
Festuca gigantea                 +      .      +      +      +
Carex remota                     .      .      .      .      1
Ranunculus ficaria               .      .      .      .      .
Scrophularia auriculata          .      +      .      .      .
Circaea lutetiana                .      .      .      .      +
Malus sylvestris                 .      .      .      .      1

Differentials of Festuco-Fraxinetum

Ajuga reptans                    r      +      1      .      +
Crataegus monogyna               1      .      +      1      +
Quercus robur                    .      1      .      1      .
Heracleum sphondylium            .      .      +      .      .
Cardamine raphanifolia           2      .      +      +      1
Senecio nemorensis               .      .      +      .      .
Osmunda regalis                  .      1      .      2      .
Sambucus nigra                   .      .      .      .      .
Viola palustris                  .      1      .      .      .
Angelica sylvestris              r      .      .      .      .
Cardamine impatiens              .      .      +      .      .
Deschampsia cespitosa            .      1      .      .      .
Pyrus cordata                    +      1      .      .      +
Frangula alnus                   .      +      .      .      .
Arum italicum                    .      .      .      .      .
Anemone nemorosa                 .      .      .      .      .
Dryopteris aemula                .      +      .      .      .
Avenella flexuosa                .      +      .      .      .
Narcissus asturiensis            .      .      .      .      .

Differentials of typical subassociation

Carex pendula                    .      .      .      1      .
Ruscus aculeatus                 .      .      +      .      +
Laurus nobilis                   .      +      .      .      .
Tamus communis                   .      .      .      +      +
Phyllitis scolopendrium          .      .      .      .      .
Asplenium onopteris              +      .      .      .      .

Diferentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions
Rubus sp.                        1      +      1      +      1
Stellaria holostea               .      .      .      .      +
Geranium robertianum             .      .      .      +      1
Scrophularia alpestris           r      .      .      .      .
Betula pubescens                 .      .      .      .      .
Cardamine pratensis              .      .      .      .      .
Chaerophyllum hirsutum           .      .      +      .      .
Dryopteris filix-mas             1      .      .      1      2
Euphorbia amygdaloides           .      .      +      +      .
Fragaria vesca                   +      .      .      .      +
Vaccinium myrtillus              .      1      .      r      .
Dactylis glomerata               .      +      .      +      .
Geum urbanum                     r      .      .      .      r
Teucrium scorodonia              .      +      .      .      .
Silene dioica                    .      .      .      .      .
Carexreuteriana                  .      1      .      .      .
Hyacinthoides non-scripta        .      .      .      .      .
Oenanthe crocata                 .      r      .      .      .
Aquilegia vulgaris               .      .      r      .      +
Carex sylvatica                  .      .      .      .      +
Omphalodes nitida                .      .      .      .      .
Caltha palustris                 .      1      .      .      .
Urtica dioica                    .      .      .      .      +
Melica uniflora                  .      .      .      .      +
Sorbus aucuparia                 .      .      .      .      .
Quercus x rosacea                1      .      .      .      .
Taxus baccata                    +      .      .      .      .
Ranunculus repens                r      .      .      .      .
Lamium maculatum                 .      .      .      .      .
Lapsana communis                 .      +      .      .      .
Lysimachia nemorum               .      .      .      .      .
Brachypodium rupestre            .      1      .      .      .
Carex laevigata                  .      +      .      .      .
Erica arborea                    .      1      .      .      .
Rumex acetosa                    .      .      .      .      .
Arrhenatherum bulbosum           .      +      .      .      .
Ranunculus tuberosus             .      1      .      .      .
Umbilicus rupestris              +      .      .      .      .
Sanicula europaea                .      .      .      .      .

Altitude (m)                    450    340    110    485     95
Exposition                      NNE     S      W     WSW     NE
Slope ([grados])                 12     20     4      2      2
Tree height (m)                  16     20     14     20     15
Tree cover (>1.5m, %)           100    100     80    100    100
Understory cover (<1.5m, %)      40     80     70     85     95
Area ([m.sup.2])                100    120    180    300    200
Number of taxa                   35     27     34     44     56
N.                               11     12     13     14     15

Characteristics of association and upper units

Corylus avellana                 3      .      2      3      4
Athyrium filix-femina            +      2      1      1      1
Dryopteris affinis               .      2      1      .      1
Saxifraga spathularis            1      .      +      +      1
Blechnum spicant                 1      .      1      1      1
Hedera hibernica                 1      2      1      2      3
Fraxinus excelsior               .      3      .      3      2
Oxalis acetosella                1      1      1      1      2
Salix atrocinerea                .      2      2      2      4
Acer pseudoplatanus              2      5      3      1      .
Lonicera periclymenum            1      1      1      2      1
Luzula henriquesii               1      .      1      +      .
Euphorbia dulcis                 1      .      +      .      2
Valeriana pyrenaica              +      .      .      3      .
Polystichum setiferum            1      .      .      3      1
Ilex aquifolium                  1      .      .      +      .
Primula acaulis                  1      +      .      .      1
Holcus mollis                    .      1      .      .      1
Hypericum androsaemum            .      +      +      +      +
Polypodium vulgare               +      .      +      .      .
Viola riviniana                  .      .      +      +      +
Mercurialis perennis             1      .      .      +      2
Chrysosplenium oppositifolium    .      2      .      +      +
Castanea sativa                  .      .      .      +      .
Dryopteris dilatata              1      1      +      1      1
Brachypodium sylvaticum          1      .      1      .      1
Ulmus glabra                     2      .      .      .      .
Festuca gigantea                 .      .      .      .      .
Carex remota                     .      .      .      +      1
Ranunculus ficaria               .      .      .      .      2
Scrophularia auriculata          .      .      .      .      .
Circaea lutetiana                .      .      .      .      +
Malus sylvestris                 .      .      .      +      .

Differentials of Festuco-Fraxinetum

Ajuga reptans                    +      .      1      1      1
Crataegus monogyna               1      .      .      1      .
Quercus robur                    +      .      3      +      .
Heracleum sphondylium            .      .      .      +      1
Cardamine raphanifolia           1      .      .      +      .
Senecio nemorensis               .      .      .      .      +
Osmunda regalis                  .      .      2      .      .
Sambucus nigra                   .      .      .      +      1
Viola palustris                  .      .      1      .      .
Angelica sylvestris              .      .      .      .      1
Cardamine impatiens              .      +      .      .      .
Deschampsia cespitosa            .      .      .      .      .
Pyrus cordata                    .      .      .      .      .
Frangula alnus                   .      .      .      .      .
Arum italicum                    +      .      .      .      .
Anemone nemorosa                 .      .      .      .      2
Dryopteris aemula                .      .      .      .      .
Avenella flexuosa                .      .      .      .      .
Narcissus asturiensis            .      .      .      .      .

Differentials of typical subassociation

Carex pendula                    +      1      .      .      +
Ruscus aculeatus                 +      .      .      +      .
Laurus nobilis                   .      1      1      .      1
Tamus communis                   .      .      +      +      +
Phyllitis scolopendrium          .      .      .      +      +
Asplenium onopteris              .      .      .      .      .

Diferentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions
Rubus sp.                        1      +      1      +      1
Stellaria holostea               +      .      .      r      1
Geranium robertianum             +      .      .      +      +
Scrophularia alpestris           +      +      +      .      .
Betula pubescens                 .      .      1      .      1
Cardamine pratensis              .      1      .      +      +
Chaerophyllum hirsutum           .      .      .      +      1
Dryopteris filix-mas             1      .      .      1      .
Euphorbia amygdaloides           .      .      .      r      .
Fragaria vesca                   .      +      +      .      .
Vaccinium myrtillus              +      .      .      .      .
Dactylis glomerata               .      .      .      .      r
Geum urbanum                     .      .      .      .      .
Teucrium scorodonia              .      .      .      .      +
Silene dioica                    .      1      .      .      1
Carexreuteriana                  .      .      .      .      .
Hyacinthoides non-scripta        .      .      .      .      1
Oenanthe crocata                 .      .      .      +      2
Aquilegia vulgaris               .      .      +      .      .
Carex sylvatica                  +      .      .      .      .
Omphalodes nitida                .      .      +      .      .
Caltha palustris                 1      .      .      .      .
Urtica dioica                    .      .      +      .      .
Melica uniflora                  .      .      .      .      .
Sorbus aucuparia                 .      .      .      .      .
Quercus x rosacea                .      .      1      .      .
Taxus baccata                    .      .      .      .      .
Ranunculus repens                .      .      .      .      .
Lamium maculatum                 .      +      .      .      .
Lapsana communis                 .      .      .      .      +
Lysimachia nemorum               .      1      .      .      +
Brachypodium rupestre            .      .      .      .      .
Carex laevigata                  .      .      .      .      .
Erica arborea                    .      .      .      .      .
Rumex acetosa                    .      +      .      .      .
Arrhenatherum bulbosum           .      .      .      .      r
Ranunculus tuberosus             .      +      .      .      .
Umbilicus rupestris              .      +      .      .      .
Sanicula europaea                .      .      .      .      .

Altitude (m)                    570    425    450    270    635
Exposition                      ---     N     WNW    WNW     W
Slope ([grados])                 <2     4      4      6      5
Tree height (m)                  15     12     18     16     14
Tree cover (>1.5m, %)           100     90    100    100    100
Understory cover (<1.5m, %)     100     80     90     90     90
Area ([m.sup.2])                200    200    400    200    100
Number of taxa                   45     51     56     45     40
N.                               16     17     18     19     20

Characteristics of association and upper units

Corylus avellana                 1      1      1      3      4
Athyrium filix-femina            1      +      2      1      1
Dryopteris affinis               1      1      2      1      2
Saxifraga spathularis            1      1      2      +      1
Blechnum spicant                 1      1      2      1      +
Hedera hibernica                 +      1      2      3      2
Fraxinus excelsior               1      3      1      2      2
Oxalis acetosella                +      +      .      1      +
Salix atrocinerea                3      4      3      3      1
Acer pseudoplatanus              3      1      2      1      1
Lonicera periclymenum            1      1      1      1      .
Luzula henriquesii               1      +      3      .      2
Euphorbia dulcis                 1      .      2      3      1
Valeriana pyrenaica              1      1      +      .      1
Polystichum setiferum            +      .      .      .      2
Ilex aquifolium                  +      .      1      .      1
Primula acaulis                  1      1      1      1      +
Holcus mollis                    +      2      .      .      .
Hypericum androsaemum            .      +      +      .      .
Polypodium vulgare               .      +      .      1      +
Viola riviniana                  .      +      1      .      +
Mercurialis perennis             .      +      .      .      1
Chrysosplenium oppositifolium    .      .      .      .      .
Castanea sativa                  2      .      .      .      2
Dryopteris dilatata              .      .      .      1      .
Brachypodium sylvaticum          +      .      .      .      1
Ulmus glabra                     .      .      .      .      .
Festuca gigantea                 .      .      .      .      +
Carex remota                     1      .      .      .      .
Ranunculus ficaria               .      .      .      3      .
Scrophularia auriculata          .      .      +      .      .
Circaea lutetiana                .      .      .      .      .
Malus sylvestris                 .      .      .      .      .

Differentials of Festuco-Fraxinetum

Ajuga reptans                    1      1      .      1      +
Crataegus monogyna               +      1      .      +      2
Quercus robur                    3      2      3      r      .
Heracleum sphondylium            1      +      +      .      +
Cardamine raphanifolia           .      .      .      .      .
Senecio nemorensis               +      +      2      1      .
Osmunda regalis                  .      1      3      2      .
Sambucus nigra                   .      1      .      .      .
Viola palustris                  .      .      2      1      .
Angelica sylvestris              .      +      .      .      .
Cardamine impatiens              .      .      .      .      .
Deschampsia cespitosa            .      1      1      +      .
Pyrus cordata                    .      .      .      +      .
Frangula alnus                   .      1      1      .      .
Arum italicum                    .      .      .      .      .
Anemone nemorosa                 .      .      .      .      .
Dryopteris aemula                .      .      +      .      .
Avenella flexuosa                .      .      .      .      .
Narcissus asturiensis            .      +      .      .      .

Differentials of typical subassociation

Carex pendula                    +      +      .      .      +
Ruscus aculeatus                 .      .      .      .      +
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      .
Phyllitis scolopendrium          .      .      .      .      .
Asplenium onopteris              .      .      +      .      .

Diferentials of Alnus glutinosa facies

Alnus glutinosa                  1      1      1      1      1
Companions
Rubus sp.                        1      1      1      +      2
Stellaria holostea               2      .      1      1      +
Geranium robertianum             .      .      +      .      .
Scrophularia alpestris           r      .      .      .      +
Betula pubescens                 1      1      3      .      .
Cardamine pratensis              +      1      .      1      .
Chaerophyllum hirsutum           .      .      .      2      .
Dryopteris filix-mas             .      .      .      .      1
Euphorbia amygdaloides           .      1      +      .      +
Fragaria vesca                   1      .      .      .      .
Vaccinium myrtillus              .      +      +      .      +
Dactylis glomerata               +      .      +      +      .
Geum urbanum                     .      .      .      .      .
Teucrium scorodonia              +      1      1      +      .
Silene dioica                    .      .      +      .      .
Carexreuteriana                  .      1      1      +      .
Hyacinthoides non-scripta        .      +      .      +      .
Oenanthe crocata                 .      .      1      .      .
Aquilegia vulgaris               +      .      .      .      .
Carex sylvatica                  .      .      .      .      .
Omphalodes nitida                .      .      .      1      .
Caltha palustris                 .      +      .      +      .
Urtica dioica                    .      .      .      .      .
Melica uniflora                  1      .      .      .      +
Sorbus aucuparia                 +      .      .      .      1
Quercus x rosacea                .      .      .      .      2
Taxus baccata                    1      .      .      +      .
Ranunculus repens                .      .      +      +      .
Lamium maculatum                 .      .      +      1      .
Lapsana communis                 .      .      .      1      .
Lysimachia nemorum               .      .      .      +      .
Brachypodium rupestre            .      1      1      .      .
Carex laevigata                  .      +      +      .      .
Erica arborea                    .      +      +      .      .
Rumex acetosa                    2      .      +      .      .
Arrhenatherum bulbosum           .      1      .      .      .
Ranunculus tuberosus             .      +      .      .      .
Umbilicus rupestris              .      .      .      .      .
Sanicula europaea                .      .      .      .      .

Companions: Pulmonaria longifolia and Salix caprea + in 1; Lastrea
limbosperma and Polygonatum verticillatum + in 2; Epilobium sp.,
Polygonatum odoratum, Polygonatum verticillatum and Prunus avium +
in 3; Asplenium trichomanes and Cystopteris fragilis + in 4; Milium
effusum and Myosotis sp. + and Lastrea limbosperma 1 in 5; Asplenium
trichomanes and Valeriana montana + in 6; Conopodium majus r, Crocus
serotinus, Daboecia cantabrica, Juncus effusus, Lithodora prostrata
and Solidago virgaurea + in 7; Valeriana montana +, Allium ursinum 1
in 8; Picris hieracioides r in 9; Melittis melissophyllum r, Euphorbia
hyberna, Milium effusum, Prunus avium, Meconopsis cambric and
Pimpinella major +, Quercuspetraea 1, Fagus sylvatica 2 in 10;
Centaurea nigra, Cystopteris fragilis and Digitalis purpurea + in 11;
Helleborus foetidus, Helleborus occidentalis and Rosa gr. canina +,
Fagus sylvatica 1 in 14; Anthoxanthum amarum, Cardamine flexuosa,
Cruciata glabra, Galium aparine, Irispseudacorus, Ligus-trum
ovalifolum, Potentilla sterilis, Stachys sylvatica and Veronica
chamaedrys + in 15; Anthoxanthum odoratum r, Pteridum aquilinum +,
Euphorbia hyberna and Prunus spinosa 1 in 16; Asphodelus sp. r,
Angelica major, Crepis lampsanoides, Daboecia cantabrica, Picris
hieracioides and Stachys officinalis +, Succisa pratensis 1 in 17;
Crocus serotinus, Digitalis purpurea, Galium palustre, Potentilla
sterilis, Prunella vulgaris and Veronica chamaedrys +; Adenostyles
hybrida and Staachys officinalis 1 in 18; Asphodelus sp. r, Pteridum
aquilinum + and Veronica montana 1 in 19; Helleborus foetidus and H.
occidentalis + in 20.

Locations (sq. 1x1km UTM coord. are indicated): 1: Fraga de Turia,
Taramundi, Asturias, 654/4797; 2: Estornin, Monte da Mermella, Baleira,
Lugo, 644/4766; 3: Rego da Cabana, downstream from Padornelo, Baleira,
Lugo, 646/4772; 4: Rego do Bao do Medio, between Fontangordo and
Vilaeimil, A Pontenova, Lugo, 649/4795; 5: Rio das Covas, in front to
Teixeira de Pacios, A Fonsagrada, Lugo, 650/4782; 6: Fraga de Murias,
Meira, Lugo, 643/4789; 7: Rego de Santar, between Muroas and Lombao,
Muras, Lugo, 604/4820; 8: Rego de Romeor, Mte. As Paleiras, Baleira,
Lugo, 642/4776; 9: Fraga de Reigadas, A Pontenova, Lugo, 650/4796,
holotypus assoc.; 10: Rio do Couso, Monte da Marronda, Baleira, Lugo,
642/4775; 11: Fraga de Reigadas, A Pontenova, Lugo, 650/4794; 12: Rego
de Toxoso, between Igrexa and A Beira da Fraga, Ourol, Lugo, 601/4823;
13: Rio de Bravos, between A Lagoa and Tinade, Ourol, Lugo, 607/4825;
14: Rio de Muina, Monte da Marronda, Baleira, Lugo, 641/4775; 15: Rego
de Reboredo, downstream from Debesos, Ortigueira, A Coruna, 596/4832;
16: Fraga de Santestebo, A Fonsagrada, Lugo, 653/4779; 17: Porcia
river, upstream from Aguillon, Castropol, Asturias, 666/4809; 18: Rio
Eume, between Casateita and Goibetas, Muras, Lugo, 601/4813; 19: Rio
Grande de Xubia, between O Couto and O Teixeiro, As Somozas, A Coruna,
585/4816; 20: Fraga de Ferreirola, Rego dos Muinos de Branas, A
Fonsagrada, Lugo, 649/4774.

Table 3

Valerianopyrenaicae-Fraxinetum excelsioris typical subass.,
hyperhygrophilous variant typical facies (1-18); Alnus glutinosa
facies (19-22). (Hyperico androsaemi-Alnenion glutinosae, Alnion
incanae, Populetalia albae, Salici-Populetea)

Altitude (m)                     75    410    340    350    470
Exposition                      NNW     NE    WNW     N      NE
Slope ([grados])                 12     26     5      6      18
Tree height (m)                  14     18     16     16     16
Tree cover (>1,5m)(%)            90     90     85     90    100
understory cover (<1,5m)(%)      40     70     80     85     90
Area ([m.sup.2])                300    120    120    300    120
Number of taxa                   43     29     38     48     40
N.                               1      2      3      4      5

Characteristics of association and upper units

Corylus avellana                 3      1      1      4      4
Athyrium filix-femina            2      +      1      1      1
Dryopteris affinis               1      1      2      1      1
Saxifraga spathularis            1      1      +      2      1
Oxalis acetosella                1      .      +      1      1
Blechnum spicant                 +      1      +      1      1
Hedera hibernica                 2      +      .      2      +
Lonicera periclymenum            1      +      1      2      1
Hypericum androsaemum            +      +      +      +      +
Fraxinus excelsior               3      1      2      3      2
Luzula henriquesii               .      4      2      2      +
Ulmus glabra                     .      1      4      .      2
Holcus mollis                    +      +      +      +      1
Polystichum setiferum            1      3      1      1      .
Dryopteris dilatata              +      1      +      .      +
Chrysosplenium oppositifolium    .      .      1      1      +
Salix atrocinerea                1      1      .      2      +
Polypodium vulgare               +      +      +      1      .
Euphorbia dulcis                 1      .      .      +      +
Carex remota                     +      .      +      +      +
Castanea sativa                  1      3      2      3      .
Viola riviniana                  +      .      .      +      2
Valeriana pyrenaica              .      .      +      1      .
Acer pseudoplatanus              .      +      3      2      .
Mercurialis perennis             .      +      1      .      1
Brachypodium sylvaticum          .      .      r      .      .
Scrophularia alpestris           .      .      +      .      .
Festuca gigantea                 .      .      .      .      .
Circaea lutetiana                .      .      .      .      .
Ranunculus ficaria               .      .      .      .      +
Symphytum tuberosum              .      .      .      +      .

Differentials of Festuco-Fraxinetum

Quercus robur                    .      1      .      .      .
Primula acaulis                  +      .      .      +      1
Angelica sylvestris              r      .      +      .      +
Ajuga reptans                    .      +      .      +      1
Anemone nemorosa                 +      .      .      .      +
Cardamine raphanifolia           .      1      +      1      .
Heracleum sphondylium            1      .      .      .      .
Osmunda regalis                  1      .      .      +      .
Viola palustris                  +      .      .      +      .
Sambucus nigra                   .      .      .      .      +
Cardamine impatiens              .      .      +      .      1
Crataegus monogyna               .      .      .      .      .
Arum italicum                    .      +      1      .      .
Narcissus asturiensis            .      .      .      .      +
Dryopteris aemula                .      .      .      .      .
Avenella flexuosa                .      .      .      +      .
Deschampsia cespitosa            .      .      .      +      .
Pyrus cordata                    .      .      .      1      .
Senecio nemorensis               .      .      .      .      .
Frangula alnus                   .      .      .      .      .

Differentials of typical subassociation

Ruscus aculeatus                 +      .      .      .      .
Carex pendula                    .      .      r      .      .
Laurus nobilis                   1      .      .      .      .
Tamus communis                   .      +      .      +      1
Phyllitis scolopendrium          .      .      1      .      .
Arbutus unedo                    .      .      .      .      .
Rubia peregrina                  .      .      .      .      .
Asplenium onopteris              .      .      .      .      .

Differentials of hyperhygrophilous var.

Woodwardia radicans              .      1      1      2      2
Hymenophyllum tunbrigense        +      .      .      .      .
Culcita macrocarpa               .      .      .      .      .
Stegnogramma pozoi               .      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions:
Rubus sp.                        +      +      1      1      .
Geranium robertianum             +      .      +      .      1
Omphalodes nitida                1      .      .      .      +
Ranunculus tuberosus             +      .      .      +      1
Rumex acetosa                    r      .      .      .      .
Ilex aquifolium                  .      .      .      1      1
Aquilegia vulgaris               .      .      .      +      .
Vaccinium myrtillus              .      .      .      +      .
Teucrium scorodonia              +      .      .      +      .
Cystopteris fragilis             .      .      +      .      .
Cardamine pratensis              +      .      .      .      .
Digitalis purpurea               .      .      .      .      +
Polygonatum verticillatum        .      .      .      .      .
Quercus petraea                  .      1      .      .      .
Crepis lampsanoides              .      .      .      .      .
Stellaria holostea               .      .      .      .      +
Betula pubescens                 .      .      .      .      .
Dryopteris filix-mas             .      1      1      .      .
Euphorbia amygdaloides           +      .      .      .      .
Adenostyles hybrida              .      .      .      .      .
Allium victorialis               .      .      .      .      .
Oenanthe crocata                 .      .      .      .      .
Silene dioica                    .      .      .      .      .
Umbilicus rupestris              .      +      .      .      .
Urtica dioica                    .      .      +      .      .
Veronica chamaedrys              .      .      .      .      .
Sanicula europaea                .      .      .      .      .
Lapsana communis                 .      .      .      .      +
Pulmonaria longifolia            .      .      .      .      1

Altitude (m)                    480    400    430    150    470
Exposition                      ENE    SSE    NNE     SE     E
Slope ([grados])                 36     6      12     2      48
Tree height (m)                  8      8      16     18     12
Tree cover (>1,5m)(%)            80     90     90    100    100
understory cover (<1,5m)(%)      85     60     90     90     90
Area ([m.sup.2])                100    200    100    120    100
Number of taxa                   38     47     28     29     30
N.                               6      7      8      9      10

Characteristics of association and upper units

Corylus avellana                 4      5      3      3      4
Athyrium filix-femina            1      1      2      1      1
Dryopteris affinis               +      +      1      2      1
Saxifraga spathularis            3      1      1      .      1
Oxalis acetosella                1      +      +      +      .
Blechnum spicant                 2      1      +      .      .
Hedera hibernica                 2      1      2      .      1
Lonicera periclymenum            1      +      .      1      +
Hypericum androsaemum            .      +      +      .      +
Fraxinus excelsior               +      2      2      .      2
Luzula henriquesii               +      1      4      .      .
Ulmus glabra                     3      .      .      .      2
Holcus mollis                    .      +      .      .      .
Polystichum setiferum            .      .      .      2      .
Dryopteris dilatata              .      .      1      1      +
Chrysosplenium oppositifolium    .      +      1      1      1
Salix atrocinerea                .      1      2      2      .
Polypodium vulgare               +      +      .      +      .
Euphorbia dulcis                 +      +      .      .      .
Carex remota                     .      .      .      .      +
Castanea sativa                  .      .      1      3      .
Viola riviniana                  .      .      .      .      +
Valeriana pyrenaica              .      .      +      +      .
Acer pseudoplatanus              .      .      2      1      1
Mercurialis perennis             .      .      .      .      +
Brachypodium sylvaticum          .      .      .      .      .
Scrophularia alpestris           .      .      .      +      .
Festuca gigantea                 .      .      .      .      .
Circaea lutetiana                .      .      .      .      .
Ranunculus ficaria               .      .      .      .      .
Symphytum tuberosum              .      .      .      .      +

Differentials of Festuco-Fraxinetum

Quercus robur                    .      1      2      2      +
Primula acaulis                  +      +      .      .      1
Angelica sylvestris              .      r      .      .      +
Ajuga reptans                    +      .      1      1      .
Anemone nemorosa                 1      +      .      +      .
Cardamine raphanifolia           1      .      .      .      .
Heracleum sphondylium            1      1      +      .      +
Osmunda regalis                  .      .      .      .      .
Viola palustris                  1      +      .      .      .
Sambucus nigra                   .      r      .      2      .
Cardamine impatiens              .      .      .      1      .
Crataegus monogyna               +      .      .      .      1
Arum italicum                    .      .      .      .      .
Narcissus asturiensis            .      .      .      .      .
Dryopteris aemula                .      +      .      .      .
Avenella flexuosa                .      .      r      .      .
Deschampsia cespitosa            .      +      .      .      .
Pyrus cordata                    +      .      .      .      .
Senecio nemorensis               .      .      .      .      .
Frangula alnus                   .      .      .      .      .

Differentials of typical subassociation

Ruscus aculeatus                 +      r      .      .      r
Carex pendula                    .      .      1      1      +
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      +
Phyllitis scolopendrium          .      .      .      .      .
Arbutus unedo                    .      .      .      .      .
Rubia peregrina                  .      .      .      .      .
Asplenium onopteris              .      .      .      .      .

Differentials of hyperhygrophilous var.

Woodwardia radicans              2      2      3      4      5
Hymenophyllum tunbrigense        .      .      .      .      .
Culcita macrocarpa               .      .      .      .      .
Stegnogramma pozoi               .      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions:
Rubus sp.                        1      .      1      1      2
Geranium robertianum             .      r      .      +      .
Omphalodes nitida                +      r      .      .      .
Ranunculus tuberosus             +      .      .      .      .
Rumex acetosa                    .      +      .      .      .
Ilex aquifolium                  +      .      .      .      .
Aquilegia vulgaris               +      .      .      .      .
Vaccinium myrtillus              +      +      r      .      .
Teucrium scorodonia              r      .      .      .      .
Cystopteris fragilis             .      .      .      .      .
Cardamine pratensis              1      1      .      .      .
Digitalis purpurea               .      r      .      .      .
Polygonatum verticillatum        1      +      .      .      +
Quercus petraea                  .      .      2      .      1
Crepis lampsanoides              r      +      .      .      .
Stellaria holostea               .      .      .      .      .
Betula pubescens                 .      1      .      .      .
Dryopteris filix-mas             .      .      +      .      .
Euphorbia amygdaloides           .      .      .      .      .
Adenostyles hybrida              .      .      1      .      .
Allium victorialis               +      r      .      .      .
Oenanthe crocata                 .      .      .      .      .
Silene dioica                    .      .      .      +      .
Umbilicus rupestris              .      .      .      .      .
Urtica dioica                    .      .      .      .      .
Veronica chamaedrys              .      +      .      .      +
Sanicula europaea                +      .      .      .      .
Lapsana communis                 .      .      .      .      .
Pulmonaria longifolia            .      r      .      .      .

Altitude (m)                    120    310    435    405    315
Exposition                      ESE    ---    ---     NW    ---
Slope ([grados])                 30     <2     <2     12     <2
Tree height (m)                  10     18     16     19     20
Tree cover (>1,5m)(%)            80    100     95    100     80
understory cover (<1,5m)(%)     100     50     70     90     70
Area ([m.sup.2])                120    200    180    120    350
Number of taxa                   27     38     52     38     50
N.                               11     12     13     14     15

Characteristics of association and upper units

Corylus avellana                 3      3      2      2      3
Athyrium filix-femina            2      1      +      2      3
Dryopteris affinis               +      +      +      2      2
Saxifraga spathularis            +      +      1      1      1
Oxalis acetosella                1      +      1      1      1
Blechnum spicant                 +      +      +      2      1
Hedera hibernica                 2      +      +      1      1
Lonicera periclymenum            1      1      +      1      1
Hypericum androsaemum            1      +      +      1      +
Fraxinus excelsior               .      3      1      1      +
Luzula henriquesii               .      +      2      3      1
Ulmus glabra                     1      2      4      3      1
Holcus mollis                    .      .      1      1      2
Polystichum setiferum            2      1      +      .      .
Dryopteris dilatata              +      .      1      1      1
Chrysosplenium oppositifolium    .      1      +      .      +
Salix atrocinerea                1      .      .      3      +
Polypodium vulgare               .      +      +      1      .
Euphorbia dulcis                 .      .      +      +      1
Carex remota                     +      +      1      .      +
Castanea sativa                  .      .      .      2      +
Viola riviniana                  .      r      1      +      +
Valeriana pyrenaica              .      1      1      .      1
Acer pseudoplatanus              .      1      .      4      .
Mercurialis perennis             .      +      1      +      +
Brachypodium sylvaticum          +      r      .      .      +
Scrophularia alpestris           .      .      .      1      .
Festuca gigantea                 .      .      1      .      1
Circaea lutetiana                .      +      .      .      .
Ranunculus ficaria               .      .      +      .      .
Symphytum tuberosum              .      .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    .      .      +      2      2
Primula acaulis                  +      .      +      +      +
Angelica sylvestris              +      .      +      .      +
Ajuga reptans                    .      .      +      .      .
Anemone nemorosa                 .      .      +      .      1
Cardamine raphanifolia           .      r      1      .      .
Heracleum sphondylium            .      .      +      .      1
Osmunda regalis                  .      .      .      r      1
Viola palustris                  .      .      .      .      .
Sambucus nigra                   .      +      +      .      .
Cardamine impatiens              .      .      .      .      1
Crataegus monogyna               .      .      .      .      +
Arum italicum                    .      .      .      .      .
Narcissus asturiensis            .      .      r      .      +
Dryopteris aemula                .      .      .      .      .
Avenella flexuosa                .      .      .      .      .
Deschampsia cespitosa            .      .      .      .      .
Pyrus cordata                    .      .      .      .      .
Senecio nemorensis               .      .      .      .      .
Frangula alnus                   1      .      .      .      .

Differentials of typical subassociation

Ruscus aculeatus                 +      +      .      +      .
Carex pendula                    2      +      .      .      .
Laurus nobilis                   2      1      .      .      .
Tamus communis                   .      .      +      .      +
Phyllitis scolopendrium          .      1      .      .      .
Arbutus unedo                    .      .      .      .      .
Rubia peregrina                  +      .      .      .      .
Asplenium onopteris              .      .      .      .      .

Differentials of hyperhygrophilous var.

Woodwardia radicans              5      +      2      1      2
Hymenophyllum tunbrigense        .      .      +      +      +
Culcita macrocarpa               .      .      .      .      .
Stegnogramma pozoi               .      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      .      .
Companions:
Rubus sp.                        +      r      +      1      .
Geranium robertianum             .      +      .      .      .
Omphalodes nitida                +      .      +      .      +
Ranunculus tuberosus             .      .      +      +      .
Rumex acetosa                    .      .      +      r      .
Ilex aquifolium                  .      .      1      .      1
Aquilegia vulgaris               1      .      .      .      +
Vaccinium myrtillus              .      .      r      r      .
Teucrium scorodonia              .      .      +      +      .
Cystopteris fragilis             .      +      .      +      .
Cardamine pratensis              1      .      .      r      .
Digitalis purpurea               .      .      +      .      r
Polygonatum verticillatum        .      .      .      +      +
Quercus petraea                  .      1      .      .      .
Crepis lampsanoides              .      .      +      .      .
Stellaria holostea               .      .      +      1      +
Betula pubescens                 .      .      .      .      1
Dryopteris filix-mas             .      1      .      .      .
Euphorbia amygdaloides           .      .      +      .      1
Adenostyles hybrida              .      .      .      .      1
Allium victorialis               .      .      .      .      .
Oenanthe crocata                 .      .      .      .      .
Silene dioica                    .      +      +      .      .
Umbilicus rupestris              .      .      .      .      .
Urtica dioica                    .      r      .      .      .
Veronica chamaedrys              .      .      .      .      .
Sanicula europaea                .      .      .      .      +
Lapsana communis                 .      .      1      .      +
Pulmonaria longifolia            .      .      +      .      .

Altitude (m)                    165    390    250    180
Exposition                      ---     E      E      NE
Slope ([grados])                 <2     18     20     5
Tree height (m)                  15     8      25     12
Tree cover (>1,5m)(%)            90     85    100    100
understory cover (<1,5m)(%)      50     60     80     20
Area ([m.sup.2])                120    200    300    100
Number of taxa                   42     39     39     40
N.                               16     17     18     19

Characteristics of association and upper units

Corylus avellana                 3      3      4      3
Athyrium filix-femina            2      1      1      1
Dryopteris affinis               +      1      1      1
Saxifraga spathularis            1      1      1      1
Oxalis acetosella                1      +      1      +
Blechnum spicant                 +      +      .      1
Hedera hibernica                 1      1      1      2
Lonicera periclymenum            +      1      .      1
Hypericum androsaemum            1      1      +      +
Fraxinus excelsior               .      2      5      3
Luzula henriquesii               r      +      1      .
Ulmus glabra                     1      1      2      +
Holcus mollis                    +      +      1      1
Polystichum setiferum            1      1      3      1
Dryopteris dilatata              1      +      .      .
Chrysosplenium oppositifolium    1      .      1      .
Salix atrocinerea                r      2      1      1
Polypodium vulgare               +      +      .      .
Euphorbia dulcis                 .      +      +      1
Carex remota                     +      .      +      .
Castanea sativa                  .      .      2      2
Viola riviniana                  .      1      +      1
Valeriana pyrenaica              .      r      3      .
Acer pseudoplatanus              .      .      .      .
Mercurialis perennis             .      .      1      .
Brachypodium sylvaticum          .      +      1      .
Scrophularia alpestris           .      .      .      .
Festuca gigantea                 .      .      1      .
Circaea lutetiana                .      .      .      .
Ranunculus ficaria               .      .      .      .
Symphytum tuberosum              .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    3      2      .      2
Primula acaulis                  .      +      .      .
Angelica sylvestris              +      .      +      .
Ajuga reptans                    .      +      .      .
Anemone nemorosa                 .      .      .      +
Cardamine raphanifolia           1      .      .      .
Heracleum sphondylium            .      +      .      .
Osmunda regalis                  +      2      +      1
Viola palustris                  +      .      .      .
Sambucus nigra                   .      .      .      .
Cardamine impatiens              .      .      .      .
Crataegus monogyna               .      1      1      .
Arum italicum                    .      .      .      .
Narcissus asturiensis            .      .      .      .
Dryopteris aemula                .      .      +      .
Avenella flexuosa                .      .      .      .
Deschampsia cespitosa            .      .      .      .
Pyrus cordata                    .      .      .      .
Senecio nemorensis               .      .      .      .
Frangula alnus                   .      .      .      .

Differentials of typical subassociation

Ruscus aculeatus                 +      .      +      +
Carex pendula                    .      +      .      .
Laurus nobilis                   3      1      .      2
Tamus communis                   .      .      +      .
Phyllitis scolopendrium          .      .      +      .
Arbutus unedo                    +      .      .      1
Rubia peregrina                  .      .      .      +
Asplenium onopteris              +      .      .      .

Differentials of hyperhygrophilous var.

Woodwardia radicans              2      3      2      1
Hymenophyllum tunbrigense        2      1      1      .
Culcita macrocarpa               .      1      .      .
Stegnogramma pozoi               .      .      1      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                  .      .      .      1
Companions:
Rubus sp.                        1      1      1      +
Geranium robertianum             .      .      +      .
Omphalodes nitida                .      +      .      .
Ranunculus tuberosus             +      .      .      .
Rumex acetosa                    +      .      .      .
Ilex aquifolium                  .      .      1      1
Aquilegia vulgaris               .      +      .      1
Vaccinium myrtillus              .      .      .      .
Teucrium scorodonia              r      .      .      .
Cystopteris fragilis             +      .      .      .
Cardamine pratensis              .      .      .      .
Digitalis purpurea               +      .      .      .
Polygonatum verticillatum        .      .      .      .
Quercus petraea                  .      .      .      1
Crepis lampsanoides              r      .      .      .
Stellaria holostea               .      .      .      .
Betula pubescens                 .      .      1      1
Dryopteris filix-mas             .      .      .      .
Euphorbia amygdaloides           .      .      .      .
Adenostyles hybrida              .      +      .      1
Allium victorialis               .      1      .      1
Oenanthe crocata                 +      r      +      .
Silene dioica                    .      .      .      .
Umbilicus rupestris              1      .      +      .
Urtica dioica                    .      .      .      .
Veronica chamaedrys              .      .      .      .
Sanicula europaea                .      .      .      +
Lapsana communis                 .      .      .      .
Pulmonaria longifolia            .      .      .      .

Altitude (m)                    215    225     90
Exposition                       NW    ---    ENE
Slope ([grados])                 5      <2     18
Tree height (m)                  20     12     19
Tree cover (>1,5m)(%)            90     80    100
understory cover (<1,5m)(%)      75     40     45
Area ([m.sup.2])                150    120    200
Number of taxa                   42     42     30
N.                               20     21     22

Characteristics of association and upper units

Corylus avellana                 3      3      3
Athyrium filix-femina            3      1      3
Dryopteris affinis               1      1      1
Saxifraga spathularis            1      +      1
Oxalis acetosella                1      +      1
Blechnum spicant                 +      r      +
Hedera hibernica                 1      .      1
Lonicera periclymenum            1      .      2
Hypericum androsaemum            .      +      +
Fraxinus excelsior               .      3      .
Luzula henriquesii               1      +      +
Ulmus glabra                     .      2      3
Holcus mollis                    +      +      1
Polystichum setiferum            2      1      1
Dryopteris dilatata              +      1      2
Chrysosplenium oppositifolium    1      +      +
Salix atrocinerea                .      .      .
Polypodium vulgare               r      .      +
Euphorbia dulcis                 +      .      +
Carex remota                     +      +      .
Castanea sativa                  3      2      .
Viola riviniana                  +      .      .
Valeriana pyrenaica              .      +      .
Acer pseudoplatanus              1      .      .
Mercurialis perennis             .      +      .
Brachypodium sylvaticum          r      .      1
Scrophularia alpestris           .      +      .
Festuca gigantea                 .      1      +
Circaea lutetiana                .      +      .
Ranunculus ficaria               .      .      .
Symphytum tuberosum              .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    2      1      .
Primula acaulis                  +      .      .
Angelica sylvestris              +      .      +
Ajuga reptans                    +      +      .
Anemone nemorosa                 1      .      .
Cardamine raphanifolia           1      1      .
Heracleum sphondylium            .      .      1
Osmunda regalis                  .      .      .
Viola palustris                  1      .      +
Sambucus nigra                   +      .      .
Cardamine impatiens              .      +      .
Crataegus monogyna               .      .      .
Arum italicum                    .      +      .
Narcissus asturiensis            .      .      .
Dryopteris aemula                .      .      .
Avenella flexuosa                .      .      .
Deschampsia cespitosa            .      .      .
Pyrus cordata                    .      .      .
Senecio nemorensis               .      .      +
Frangula alnus                   .      .      .

Differentials of typical subassociation

Ruscus aculeatus                 +      .      .
Carex pendula                    +      1      +
Laurus nobilis                   3      .      1
Tamus communis                   1      .      .
Phyllitis scolopendrium          .      +      .
Arbutus unedo                    .      .      .
Rubia peregrina                  .      .      .
Asplenium onopteris              .      .      .

Differentials of hyperhygrophilous var.

Woodwardia radicans              2      1      1
Hymenophyllum tunbrigense        1      .      .
Culcita macrocarpa               .      .      1
Stegnogramma pozoi               .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                  1      2      2
Companions:
Rubus sp.                        2      +      1
Geranium robertianum             .      +      .
Omphalodes nitida                .      .      .
Ranunculus tuberosus             +      .      .
Rumex acetosa                    +      r      r
Ilex aquifolium                  .      .      .
Aquilegia vulgaris               .      r      .
Vaccinium myrtillus              .      .      .
Teucrium scorodonia              .      .      .
Cystopteris fragilis             r      +      .
Cardamine pratensis              .      .      .
Digitalis purpurea               .      .      .
Polygonatum verticillatum        .      .      .
Quercus petraea                  .      .      .
Crepis lampsanoides              r      .      .
Stellaria holostea               .      .      .
Betula pubescens                 .      .      .
Dryopteris filix-mas             .      .      .
Euphorbia amygdaloides           .      +      .
Adenostyles hybrida              .      .      .
Allium victorialis               .      .      .
Oenanthe crocata                 r      .      .
Silene dioica                    .      +      .
Umbilicus rupestris              2      .      .
Urtica dioica                    .      r      .
Veronica chamaedrys              .      +      .
Sanicula europaea                .      .      .
Lapsana communis                 .      .      .
Pulmonaria longifolia            .      .      .

Companions: Asphodelus sp. and Potentilla sterilis r, Carex
sylvatica, Conopodium majus, Euphorbia hyberna and Veronica
montana + in 1; Geum urbanum and Melica uniflora +, Myosotis sp.
1 in 3; Erica arborea and Picris hieracioides r, Arrhenatherum
bulbosum, Carex laevigata, Crocus serotinus, Milium effusum,
Pteridium aquilinum, Stachys officinalis and Ulex europaeus + in
4; Fragaria vesca and Physospermum cornubiense + in 5; Asphodelus
sp., Lysimachia nemorum and Parnassia palustris + in 6; Caltha
palustris, Cardamine hirsute, Carex echinata, Parnassia palustris,
Ranunculus repens, Sorbus aucuparia +, Narthecium ossifragum 1 in
7; Taxus baccata 1 in 8; Saxifraga hirsuta +, Angelica major 1,
Chaerophyllum hirsutum and Prunus laurocerasus 2, Fagus sylvatica 3
in 9; Chaerophyllum hirsutum + in 10; Asplenium trichomanes and
Clematis vitalba + in 12; Hypericum sp. r, Hyacinthoides non-scripta
1 in 13; Melittis melissophyllum + in 14; Caltha palustris r, Hypericum
sp. and Lysimachia nemorum + in 15; Lamium maculatum and Erica arborea
r in 16; Prunella vulgaris + in 17; Picris hieracioides + in 18;
Pteridium aquilinum and Wahlenbergia hederacea r, Carexpilulifera
and Carex sylvatica +, Prunella vulgaris 1; in 19; Ranunculus repens
r, Prunus avium 2 in 21. Releve sites (sq. 1x1km UTM coord. Are
indicated): 1: Fragas do Eume Natural Park, Rego de Cal de Vinas,
Monfero, A Coruna, 574/4806; 2: Fraga de Murias, Meira, Lugo, 643/4789;
3: Sanxes, Mte. O Cabanal, A Pontenova, Lugo, 652/4795; 4: Rio
Lagarteira, between Restrepo and Palacio, Vegadeo, Asturias, 661/4808;
5: Rio da Fraga das Lerias, O Valadouro, Lugo, 621/4819; 6: Rio da
Fraga das Lerias, O Valadouro, Lugo, 620/4819; 7: Rio da Fraga das
Lerias, O Valadouro, Lugo, 620/4820; 8: Fraga de Vilapena, Trabada,
Lugo, 644/4807; 9: Esqueiro river, between Foyedo and La Mafalla,
Valdes, Asturias, 717/4823; 10: Fraga de Reigadas, A Pontenova, Lugo,
650/4794; 11: Rio Mera, Fraga dos Casas, Cerdido, A Coruna, 588/4826;
12: Regueiro de Bounote, Fraga de Reigadas, A Pontenova, Lugo,
650/4794; 13: Fraga das Lerias, O Valadouro, Lugo, 620/4819; 14:
Fraga de Vilapercide, Trabada, Lugo, 643/4810; 15: Rio da Fraga das
Lerias, O Valadouro, Lugo, 621/4818; 16: Fraga de Tanxauga, Viveiro,
Lugo, 617/4829; 17: Rego Pequeno, Carino, A Coruna, 586/4835; 18:
Freixido, Rio da Fraga das Lerias, O Valadouro, Lugo, 621/4818; 19:
Rio Quiza, upstream from O Seixo, Carino, A Coruna, 586/4838; 20:
Fraga de Tanxauga, Viveiro, Lugo, 617/4829; 21: Fraga de Reigadas,
A Pontenova, Lugo, 651/4796; 22: Fragas do Eume Natural Park, Rego
do Rodeiro, Monfero, A Coruna, 576/4806.

Tabla 4

Valeriano pyrenaicae-Fraxinetum excelsioris subass. adenostyletosum
hybridae nova typical facies (1-16); Alnus glutinosa facies (17-18)
(Hyperico androsaemi-Alnenion glutinosae, Alnion incanae, Populetalia
albae, Salici-Populetea)

Altitude (m)                     570    630    635    775    325
Exposition                       NNE     N     WSW    SSW     SE
Slope ([grados])                  10     18     4      4      10
Tree height (m)                   16     9      12     10     18
Tree cover (>1,5m)(%)            100     95     95    100     90
Understory cover (<1,5m)(%)       75     65     60     70     50
Area (m2)                        100    200    100    100    300
Number of taxa                    24     36     24     36     34
N.                                1      2      3      4      5

Characteristic taxa of association and upper units

Corylus avellana                  2      5      2      2      1
Athyrium flix-femina              1      +      .      1      1
Saxifraga spathularis             1      1      1      1      1
Hedera hibernica                  +      1      1      1      .
Dryopteris affinis                2      1      1      2      1
Blechnum spicant                  .      1      1      1      1
Lonicera periclymenum             .      1      1      .      1
Fraxinus excelsior                3      2      2      3      .
Oxalis acetosella                 1      1      .      1      1
Acer pseudoplatanus               2      .      2      2      .
Luzula henriquesii                2      2      .      1      1
Salix atrocinerea                 .      1      4      3      1
Holcus mollis                     .      1      +      +      .
Dryopteris dilatata               1      1      .      .      1
Chrysosplenium oppositifolium     1      1      .      .      1
Polypodium vulgare                .      +      1      +      1
Euphorbia dulcis                  .      .      .      1      .
Betula pubescens                  .      .      1      .      .
Viola riviniana                   .      .      .      1      .
Valeriana pyrenaica               1      1      .      .      1
Polystichum setiferum             3      1      .      .      3
Hypericum androsaemum             .      .      .      .      +
Castanea sativa                   .      .      2      .      3
Festuca gigantea                  +      +      .      .      .
Mercurialis perennis              1      r      .      .      .
Ulmus glabra                      3      .      .      .      .
Carex remota                      1      .      .      .      +
Brachypodium sylvaticum           .      .      .      +      +
Scrophularia alpestris            .      .      .      .      r
Frangula alnus                    .      .      .      .      .
Scrophularia auriculata           .      r      .      .      .
Ranunculus ficaria                .      .      .      .      .
Malus sylvestris                  .      .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                     .      1      2      2      3
Ajuga reptans                     .      +      .      +      1
Heracleum sphondylium             1      +      +      1      .
Cardamine raphanifolia            2      1      .      .      1
Anemone nemorosa                  .      .      +      +      .
Angelica sylvestris               .      +      .      .      .
Deschampsia caespitosa            .      .      .      .      .
Osmunda regalis                   .      .      .      .      .
Senecio nemorensis                .      .      .      .      .
Viola palustris                   .      .      .      .      .
Crataegus monogyna                .      .      .      .      +
Sambucus nigra                    .      .      .      .      1
Cardamine impatiens               .      .      .      .      .
Avenella flexuosa                 .      .      .      .      .
Dryopteris aemula                 .      .      .      .      .
Narcissus asturiensis             .      .      .      +      .
Pyrus cordata                     .      .      .      .      .

Differentials of adenostyletosum hybridae

Adenostyles hybrida               .      +      .      .      +
Saxifraga lepismigena             .      .      +      +      .
Allium victorialis                .      .      .      r      .
Angelica major                    +      .      .      .      .
Veratrum album                    .      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                   .      .      .      .      .

Companions:

Rubus sp.                         1      .      .      1      1
Stellaria holostea                .      .      .      +      1
Vaccinium myrtillus               .      1      .      +      .
Crepis lampsanoides               .      +      .      .      .
Ilex aquifolium                   .      .      .      1      .
Hyacinthoides non-scripta         .      +      .      +      .
Teucrium scorodonia               .      .      .      .      .
Erica arborea                     .      +      .      1      .
Rumex acetosa                     .      .      .      .      .
Oenanthe crocata                  .      .      .      .      .
Silene dioica                     .      +      .      .      .
Primula acaulis                   .      .      .      .      +
Chaerophyllum hirsutum            1      1      .      .      .
Geranium robertianum              +      .      .      .      r
Euphorbia amygdaloides            .      .      .      .      .
Ranunculus repens                 .      +      .      .      .
Ranunculus tuberosus              .      .      .      .      .
Umbilicus rupestris               .      .      .      .      .
Pteridum aquilinum                .      .      .      .      .
Anthoxanthum amarum               .      .      .      .      .
Arrhenatherum bulbosum            .      .      .      .      .
Carex reuteriana                  .      .      .      .      .
Cardamine pratensis               .      .      .      .      .
Dactylis glomerata                .      .      .      .      .
Caltha palustris                  .      .      .      .      .
Omphalodes nitida                 .      .      .      .      .
Sanicula europaea                 .      r      .      .      .
Quercus petraea                   .      .      .      .      1

Altitude (m)                     435    530    460    515    440
Exposition                        NW     W      W      SW    NNE
Slope ([grados])                  4      24     5      <2     2
Tree height (m)                   14     16     15     20     22
Tree cover (>1,5m)(%)             85    100    100     90    100
Understory cover (<1,5m)(%)       80     70     60    100     95
Area (m2)                        180    100    200    200    500
Number of taxa                    35     33     27     48     45
N.                                6      7      8      9      10

Characteristic taxa of association and upper units

Corylus avellana                  3      4      4      1      3
Athyrium flix-femina              1      1      1      2      2
Saxifraga spathularis             +      +      .      1      1
Hedera hibernica                  1      1      1      .      2
Dryopteris affinis                .      2      .      2      2
Blechnum spicant                  1      2      .      .      1
Lonicera periclymenum             1      +      1      1      2
Fraxinus excelsior                2      2      2      1      1
Oxalis acetosella                 1      1      .      1      .
Acer pseudoplatanus               2      .      .      2      2
Luzula henriquesii                .      +      1      2      3
Salix atrocinerea                 1      1      .      3      1
Holcus mollis                     1      .      .      +      .
Dryopteris dilatata               +      1      .      +      .
Chrysosplenium oppositifolium     .      .      1      1      .
Polypodium vulgare                .      .      .      .      +
Euphorbia dulcis                  1      .      +      2      1
Betula pubescens                  1      1      .      3      .
Viola riviniana                   .      +      .      +      +
Valeriana pyrenaica               .      .      1      1      .
Polystichum setiferum             .      1      1      .      .
Hypericum androsaemum             +      +      .      .      .
Castanea sativa                   .      2      2      .      .
Festuca gigantea                  +      .      1      .      .
Mercurialis perennis              .      1      .      .      .
Ulmus glabra                      .      .      3      .      .
Carex remota                      .      .      .      .      .
Brachypodium sylvaticum           .      .      .      1      .
Scrophularia alpestris            .      .      1      .      .
Frangula alnus                    .      .      .      +      1
Scrophularia auriculata           .      .      .      +      +
Ranunculus ficaria                1      .      .      .      .
Malus sylvestris                  .      .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                     2      2      2      1      3
Ajuga reptans                     1      +      +      1      .
Heracleum sphondylium             .      .      .      +      .
Cardamine raphanifolia            .      1      1      .      .
Anemone nemorosa                  .      .      .      .      .
Angelica sylvestris               .      .      +      +      .
Deschampsia caespitosa            .      .      .      1      1
Osmunda regalis                   .      1      .      .      3
Senecio nemorensis                .      .      .      2      1
Viola palustris                   .      .      .      .      1
Crataegus monogyna                .      .      .      .      1
Sambucus nigra                    .      .      .      .      .
Cardamine impatiens               .      .      r      .      .
Avenella flexuosa                 +      .      .      .      .
Dryopteris aemula                 1      .      .      .      .
Narcissus asturiensis             .      .      .      .      .
Pyrus cordata                     .      .      .      .      .

Differentials of adenostyletosum hybridae

Adenostyles hybrida               +      .      .      1      +
Saxifraga lepismigena             +      +      +      .      .
Allium victorialis                .      .      .      .      1
Angelica major                    .      .      .      +      .
Veratrum album                    .      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                   .      .      .      .      .

Companions:

Rubus sp.                         +      .      +      2      +
Stellaria holostea                .      +      .      +      +
Vaccinium myrtillus               1      .      +      .      .
Crepis lampsanoides               .      .      r      .      +
Ilex aquifolium                   1      .      .      .      +
Hyacinthoides non-scripta         .      1      .      .      .
Teucrium scorodonia               .      .      .      2      2
Erica arborea                     +      .      .      .      .
Rumex acetosa                     .      .      .      .      +
Oenanthe crocata                  .      .      +      +      1
Silene dioica                     .      .      .      .      +
Primula acaulis                   1      .      .      1      .
Chaerophyllum hirsutum            .      .      .      .      .
Geranium robertianum              .      .      .      .      .
Euphorbia amygdaloides            .      .      .      1      1
Ranunculus repens                 .      .      .      1      .
Ranunculus tuberosus              .      .      .      .      .
Umbilicus rupestris               .      .      .      .      .
Pteridum aquilinum                .      .      .      1      1
Anthoxanthum amarum               +      .      .      +      .
Arrhenatherum bulbosum            +      r      .      .      +
Carex reuteriana                  .      .      .      +      2
Cardamine pratensis               1      .      .      .      .
Dactylis glomerata                .      .      .      +      .
Caltha palustris                  1      .      .      .      .
Omphalodes nitida                 .      +      .      +      1
Sanicula europaea                 .      +      .      .      .
Quercus petraea                   .      .      .      .      .

Altitude (m)                     455    430    475    470    530
Exposition                       ESE    ESE     NE     S     NNE
Slope ([grados])                  2      5      4      10     16
Tree height (m)                   12     20     20    7-10   8-10
Tree cover (>1,5m)(%)            100    100    100     90    100
Understory cover (<1,5m)(%)       80     50    100     80     85
Area (m2)                        300    120    400    120    120
Number of taxa                    48     32     51     28     29
N.                                11     12     13     14     15

Characteristic taxa of association and upper units

Corylus avellana                  4      1      +      3      4
Athyrium flix-femina              2      3      2      1      1
Saxifraga spathularis             1      .      1      2      3
Hedera hibernica                  +      1      2      .      1
Dryopteris affinis                1      1      2      1      +
Blechnum spicant                  1      1      1      1      +
Lonicera periclymenum             1      1      2      1      .
Fraxinus excelsior                1      2      3      .      .
Oxalis acetosella                 1      +      1      1      1
Acer pseudoplatanus               .      4      2      1      1
Luzula henriquesii                1      2      3      2      +
Salix atrocinerea                 1      .      2      1      .
Holcus mollis                     .      .      1      2      2
Dryopteris dilatata               1      .      +      1      1
Chrysosplenium oppositifolium     1      +      1      .      1
Polypodium vulgare                +      .      +      +      .
Euphorbia dulcis                  +      +      2      .      .
Betula pubescens                  .      .      1      2      .
Viola riviniana                   +      .      .      .      .
Valeriana pyrenaica               .      .      .      .      .
Polystichum setiferum             1      .      .      .      .
Hypericum androsaemum             1      +      .      .      .
Castanea sativa                   2      .      .      .      .
Festuca gigantea                  1      1      .      .      .
Mercurialis perennis              1      .      .      .      .
Ulmus glabra                      3      2      .      .      .
Carex remota                      +      1      .      .      .
Brachypodium sylvaticum           .      +      .      .      .
Scrophularia alpestris            .      1      .      .      .
Frangula alnus                    +      .      .      1      .
Scrophularia auriculata           .      .      .      .      .
Ranunculus ficaria                .      .      .      .      .
Malus sylvestris                  .      .      +      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                     .      1      3      .      1
Ajuga reptans                     1      1      .      .      +
Heracleum sphondylium             1      1      +      .      .
Cardamine raphanifolia            +      .      .      .      .
Anemone nemorosa                  r      +      .      .      1
Angelica sylvestris               1      +      .      .      .
Deschampsia caespitosa            .      .      1      1      .
Osmunda regalis                   1      .      2      .      .
Senecio nemorensis                .      .      1      .      .
Viola palustris                   .      1      2      +      .
Crataegus monogyna                .      .      +      .      .
Sambucus nigra                    .      1      1      .      .
Cardamine impatiens               +      +      .      .      .
Avenella flexuosa                 .      .      .      1      +
Dryopteris aemula                 .      .      .      1      .
Narcissus asturiensis             .      .      .      .      .
Pyrus cordata                     .      .      1      .      .

Differentials of adenostyletosum hybridae

Adenostyles hybrida               .      .      1      .      1
Saxifraga lepismigena             +      1      .      +      .
Allium victorialis                .      .      1      .      .
Angelica major                    .      .      .      .      .
Veratrum album                    +      .      .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                   .      .      .      .      .

Companions:

Rubus sp.                         +      1      1      1      1
Stellaria holostea                .      1      1      +      +
Vaccinium myrtillus               .      .      .      1      .
Crepis lampsanoides               .      .      1      .      r
Ilex aquifolium                   .      .      1      .      .
Hyacinthoides non-scripta         .      .      .      .      +
Teucrium scorodonia               .      .      1      .      1
Erica arborea                     .      .      .      1      .
Rumex acetosa                     .      .      +      1      +
Oenanthe crocata                  .      .      1      .      .
Silene dioica                     r      .      .      .      1
Primula acaulis                   .      .      .      .      .
Chaerophyllum hirsutum            2      .      .      .      .
Geranium robertianum              1      +      .      .      .
Euphorbia amygdaloides            .      .      1      .      .
Ranunculus repens                 .      .      .      .      +
Ranunculus tuberosus              1      .      .      1      .
Umbilicus rupestris               +      .      +      .      +
Pteridum aquilinum                .      .      1      1      .
Anthoxanthum amarum               .      .      .      3      1
Arrhenatherum bulbosum            .      .      .      .      .
Carex reuteriana                  .      .      2      .      .
Cardamine pratensis               .      .      .      .      .
Dactylis glomerata                .      .      +      .      .
Caltha palustris                  .      .      .      .      .
Omphalodes nitida                 .      .      .      .      .
Sanicula europaea                 .      .      .      .      .
Quercus petraea                   1      .      .      .      .

Altitude (m)                     830    570    450
Exposition                       ENE     S     WNW
Slope ([grados])                  18     2      10
Tree height (m)                   10     12     14
Tree cover (>1,5m)(%)            100     85     90
Understory cover (<1,5m)(%)       70     80     75
Area (m2)                        100    120    200
Number of taxa                    28     41     39
N.                                16     17     18

Characteristic taxa of association and upper units

Corylus avellana                  4      2      4
Athyrium flix-femina              2      .      +
Saxifraga spathularis             1      1      1
Hedera hibernica                  1      1      2
Dryopteris affinis                .      1      1
Blechnum spicant                  2      +      +
Lonicera periclymenum             +      1      2
Fraxinus excelsior                .      .      3
Oxalis acetosella                 1      .      2
Acer pseudoplatanus               .      3      2
Luzula henriquesii                .      .      1
Salix atrocinerea                 1      .      1
Holcus mollis                     1      .      1
Dryopteris dilatata               1      .      +
Chrysosplenium oppositifolium     .      1      +
Polypodium vulgare                .      +      +
Euphorbia dulcis                  1      .      .
Betula pubescens                  2      .      1
Viola riviniana                   +      1      +
Valeriana pyrenaica               .      1      1
Polystichum setiferum             .      1      .
Hypericum androsaemum             .      +      +
Castanea sativa                   .      1      .
Festuca gigantea                  .      .      .
Mercurialis perennis              .      +      .
Ulmus glabra                      1      .      .
Carex remota                      .      +      .
Brachypodium sylvaticum           .      .      .
Scrophularia alpestris            +      .      .
Frangula alnus                    .      .      .
Scrophularia auriculata           .      .      .
Ranunculus ficaria                .      .      .
Malus sylvestris                  .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                     .      .      1
Ajuga reptans                     +      .      +
Heracleum sphondylium             .      .      .
Cardamine raphanifolia            .      1      +
Anemone nemorosa                  1      +      .
Angelica sylvestris               .      .      +
Deschampsia caespitosa            .      .      +
Osmunda regalis                   .      .      .
Senecio nemorensis                .      1      .
Viola palustris                   .      .      .
Crataegus monogyna                .      +      .
Sambucus nigra                    .      .      .
Cardamine impatiens               .      .      .
Avenella flexuosa                 .      .      .
Dryopteris aemula                 .      .      .
Narcissus asturiensis             .      .      +
Pyrus cordata                     .      .      .

Differentials of adenostyletosum hybridae

Adenostyles hybrida               1      +      +
Saxifraga lepismigena             .      .      .
Allium victorialis                .      1      .
Angelica major                    .      +      .
Veratrum album                    .      .      .

Differentials of Alnus glutinosa facies

Alnus glutinosa                   .      1      1

Companions:

Rubus sp.                         +      +      1
Stellaria holostea                .      .      +
Vaccinium myrtillus               +      r      1
Crepis lampsanoides               .      .      +
Ilex aquifolium                   1      1      .
Hyacinthoides non-scripta         +      +      .
Teucrium scorodonia               .      +      +
Erica arborea                     .      1      .
Rumex acetosa                     .      .      +
Oenanthe crocata                  .      1      .
Silene dioica                     .      .      +
Primula acaulis                   .      +      .
Chaerophyllum hirsutum            .      1      .
Geranium robertianum              .      .      .
Euphorbia amygdaloides            .      +      .
Ranunculus repens                 .      .      .
Ranunculus tuberosus              .      .      +
Umbilicus rupestris               .      .      .
Pteridum aquilinum                .      .      .
Anthoxanthum amarum               .      .      .
Arrhenatherum bulbosum            .      .      .
Carex reuteriana                  .      .      .
Cardamine pratensis               .      +      .
Dactylis glomerata                .      .      +
Caltha palustris                  .      1      +
Omphalodes nitida                 .      .      .
Sanicula europaea                 .      +      .
Quercus petraea                   .      2      .

Companions: Milium effusum + and Salix caprea 1 in 2; Asplenium
trichomanes r, Solidago virgaurea +, Valeriana montana 1 and Fagus
sylvatica 2 in 3; Aquilegia vulgaris, Dryopteris filix-mas, Scilla
verna and Valeriana montana +, Euphorbia hyberna and Sorbus
aucuparia 1, Sorbus aria 2 in 4; Asphodelus sp., Carex laevigata
and Carex pilulifera + in 6; Ceratocapnos claviculata and Fragaria
vesca r, Asphodelus sp., Pulmonaria longifolia + and Prunus avium 1
in 7; Polygonatum verticillatum +, Saxifraga hirsuta 2 and Fagus
sylvatica 3 in 8; Agrostis capillaris, Carex laevigata, Lysimachia
nemorum, Myosotis sp. and Valeriana dioica +, Lastrea limbosperma
and Stachys officinalis 1, Brachypodium rupestre 2; in 9; Centaurea
nigra, Crocus serotinus, Lamium maculatum, Lathyrus linifolius and
Rosa gr. canina + Agrostis capillaris, Myrica gale and Prunella
vulgaris 1 in 10; Solidago virgaurea r, Picris hieracioides and
Silene vulgaris +, Quercus x rosacea 1 in 11; Anthoxanthum odoratum
and Digitalis purpurea + in 13; Crocus serotinus, Lathyrus
linifolius, Prunella vulgaris, Rosa gr. canina, Veronica chamaedrys
and Tritonia x crocosmiflora +, Euphorbia hyberna and Stachys
officinalis 1, Brachypodium rupestre 2 in 14; Juncus effusus + and
Myrica gale 1 in 15; Prunus avium +, Dryopteris filix-mas,
Polygonatum verticillatum and Sorbus aucuparia 1 in 16; Aquilegia
vulgaris and Myosotis sp. +; Quercus x rosacea 1 in 17; Cystopteris
fragilis + in 18. Releve sites (sq. 1x1km UTM coord. are
indicated): 1: Fraga de Turia, Taramundi, Asturias, 654/4796; 2:
Rego de Ouroso, between Brataramundi and Cotarelo, Taramundi,
Asturias, 658/4801; 3: Rio Lloredo, between Muriellos and Penouta,
Allande, Asturias, 684/4797; 4: Arroyo de Carondio, Brana de Is,
Allande, Asturias, 681/4796; 5: Rego do Survial do Couso, Ribeira
de Piquin, Lugo, 644/4786; 6: Rego dos Carballas, downstream from
Carballosa, Muras, Lugo, 601/4818; 7: A Rebordela, Ribeira de
Piquin, Lugo, 648/4787; 8: Arroyo de Trieves, Faedo de Ayones,
Valdes, Asturias, 709/4810; 9: Rio Eume, between Painceira and
Invernes, Muras, Lugo, 605/4811; 10: Rio Eume, in front of Porto
dos Paus, Muras, Lugo, 601/4814, holotypus subass. adenostyletosum;
11: Rio Cabornel, Barandon, Villayon, Asturias, 682/4801; 12: Fraga
de Carreiracha, Trabada, Lugo, 644/4806; 13: Rio Eume, near to
industrial state of Muras, Muras, Lugo, 602/4810; 14: Rego da Fraga
Gorda, Ameixeiras, Muras, Lugo, 601/4819; 15: Rego Seco, Fraga de
Baos, Mondonedo, Lugo, 634/4804; 16: Rego de Lagos, Pedrouzos, A
Fonsagrada, Lugo, 652/4772; 17: Rego de Cubilledo, between Penas
and Suagranda, Baleira, Lugo, 645/4767; 18: Regueiro da Mina, in
front of Pumarega, Vegadeo, Asturias, 662/4805.

Table 5

Hyperico androsaemi-Coryletum avellanae ass. nova typical (1-11);
hyperhygrophilous variant (12-13); ruscetosum aculeati, typical var.
(14-17); ruscetosum aculeati, hyperhygrophilous var. (18-21)
(Hyperico androsaemi-Alnenion glutinosae, Alnion incanae, Populetalia
albae, Salici-Populetea)

Altitude (m)                    765    695    670    660    640
Exposition                       NW    ENE    SSE     SW    NNW
Slope ([grados])                 10     24     6      8      8
Tree height (m)                 8-10    6      8     8-12    8
Tree cover (>1,5m)(%)           100    100     80     90     60
Understory cover (<1,5m)(%)      85     80     90     85     60
Area ([m.sup.2])                300    100    100    240    100
Numer of taxa                    40     36     32     35     27
N.                               1      2      3      4      5

Characteristics of association and upper units

Corylus avellana                 3      5      4      4      4
Athyrium filix-femina            1      1      1      +      1
Blechnum spicant                 3      2      2      2      3
Hedera hibernica                 1      1      2      2      1
Oxalis acetosella                +      3      3      1      .
Lonicera periclymenum            1      1      1      2      .
Saxifraga spathularis            2      2      .      .      1
Holcus mollis                    1      1      1      3      2
Dryopteris afffinis              .      .      .      1      .
Dryopteris dilatata              1      1      +      +      .
Salix atrocinerea                4      1      1      .      .
Hypericum androsaemum            +      +      1      .      +
Euphorbia dulcis                 1      1      1      .      1
Viola riviniana                  .      +      .      .      +
Betula pubescens                 1      .      .      2      2
Carex remota                     .      .      .      .      .
Frangula alnus                   1      .      +      .      1
Polystichum setiferum            .      .      .      .      .
Scrophularia auriculata          .      .      .      +      .
Festuca gigantea                 .      .      .      .      .
Brachypodium sylvaticum          .      .      .      .      .
Malus sylvestris                 .      .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    1      .      1      2      +
Ajuga reptans                    .      1      1      1      .
Viola palustris                  1      +      2      .      1
Dryopteris aemula                1      1      .      .      .
Osmunda regalis                  .      .      .      .      .
Narcissus asturiensis            1      +      +      .      +
Crataegus monogyna               .      .      .      .      .
Pyrus cordata                    .      .      1      .      .
Avenella flexuosa                .      .      .      .      +
Anemone nemorosa                 .      .      .      .      .
Senecio nemorensis               +      .      .      1      .
Sambucus nigra                   .      .      .      +      .
Castanea sativa                  .      .      .      .      .
Angelica sylvestris              .      +      .      .      .
Deschampsia cespitosa            .      .      .      1      1

Differentials of ruscetosum aculeati

Ruscus aculeatus                 .      .      .      .      .
Carex pendula                    .      .      .      .      .
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      .
Arbutus unedo                    .      .      .      .      .

Differentials of the hyperhygrophilous variant

Woodwardia radicans              .      .      .      .      .
Hymenophyllum tunbrigense        .      .      .      .      .
Culcita macrocarpa               .      .      .      .      .
Companions
Rubus sp.                        1      +      1      2      1
Vaccinium myrtillus              +      +      +      +      2
Cardamine pratensis              .      1      +      1      .
Ilex aquifolium                  1      +      .      r      1
Luzula henriquesii               2      .      .      .      1
Teucrium scorodonia              .      .      1      +      +
Omphalodes nitida                .      .      +      +      .
Digitalis purpurea               r      +      +      .      .
Polypodium vulgare               +      .      .      +      .
Carex laevigata                  .      +      +      r      .
Adenostyles hybrida              1      +      1      1      +
Primula acaulis                  .      .      .      +      .
Chrysosplenium oppositifolium    +      .      .      .      .
Erica arborea                    .      .      r      1      .
Allium victorialis               2      .      .      .      .
Stellaria holostea               .      .      .      .      .
Polygonatum verticillatum        .      +      .      .      +
Sorbus aucuparia                 +      1      .      .      +
Agrostis capillaris              .      1      .      .      1
Rumex acetosa                    .      .      .      .      .
Lastrea limbosperma              .      1      .      .      2
Asphodelus sp.                   .      .      .      +      .
Aquilegia vulgaris               .      1      .      .      .
Valeriana pyrenaica              .      .      .      .      .
Hyacinthoides non-scripta        1      .      .      .      .
Ranunculus tuberosus             .      1      .      .      .
Cardamine raphanifolia           +      .      .      .      .
Crepis lampsanoides              .      .      .      .      .
Chaerophyllum hirsutum           +      +      .      .      .
Scrophularia alpestris           .      .      .      .      .
Brachypodium rupestre            .      +      +      1      .
Caltha palustris                 +      .      .      +      .
Molinia caerulea                 .      .      r      .      +
Umbilicus rupestris              .      .      .      .      .
Cardamine flexuosa               .      .      .      +      .
Silene dioica                    .      .      .      .      .
Geranium robertianum             .      .      .      .      .
Arrhenatherum bulbosum           1      .      .      .      .
Lysimachia nemorum               .      1      .      .      .

Altitude (m)                    600    595    550    535    530
Exposition                      NNE     NE     E     ENE    ESE
Slope ([grados])                 26     8      2      4      4
Tree height (m)                  10     10     5      8      10
Tree cover (>1,5m)(%)            85     90     90     90     85
Understory cover (<1,5m)(%)      95     90     85     60     70
Area ([m.sup.2])                200    200    100    300    100
Numer of taxa                    46     31     27     38     43
N.                               6      7      8      9      10

Characteristics of association and upper units

Corylus avellana                 4      4      4      4      5
Athyrium filix-femina            2      1      +      1      1
Blechnum spicant                 2      2      2      1      1
Hedera hibernica                 2      3      1      1      3
Oxalis acetosella                2      2      +      2      1
Lonicera periclymenum            1      2      .      1      1
Saxifraga spathularis            2      3      2      2      2
Holcus mollis                    2      1      .      1      1
Dryopteris afffinis              2      1      +      1      1
Dryopteris dilatata              1      2      1      1      1
Salix atrocinerea                1      2      +      1      1
Hypericum androsaemum            +      +      +      .      1
Euphorbia dulcis                 1      1      .      .      2
Viola riviniana                  +      .      .      +      1
Betula pubescens                 1      2      .      1      1
Carex remota                     +      .      +      .      .
Frangula alnus                   .      .      .      .      .
Polystichum setiferum            .      .      .      .      .
Scrophularia auriculata          .      .      .      +      .
Festuca gigantea                 .      .      .      .      .
Brachypodium sylvaticum          .      .      .      .      .
Malus sylvestris                 .      .      .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    .      +      1      1      1
Ajuga reptans                    1      .      .      +      +
Viola palustris                  1      3      .      2      2
Dryopteris aemula                .      3      1      +      +
Osmunda regalis                  .      .      +      +      +
Narcissus asturiensis            .      +      .      .      .
Crataegus monogyna               .      .      .      .      +
Pyrus cordata                    .      .      +      .      .
Avenella flexuosa                .      +      .      1      .
Anemone nemorosa                 .      .      .      .      +
Senecio nemorensis               +      .      .      .      +
Sambucus nigra                   .      .      .      .      .
Castanea sativa                  .      .      .      .      .
Angelica sylvestris              .      .      .      .      .
Deschampsia cespitosa            +      .      .      .      .

Differentials of ruscetosum aculeati

Ruscus aculeatus                 .      .      .      .      .
Carex pendula                    .      .      .      .      .
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      .
Arbutus unedo                    .      .      .      .      .

Differentials of the hyperhygrophilous variant

Woodwardia radicans              .      .      .      .      .
Hymenophyllum tunbrigense        .      .      .      .      .
Culcita macrocarpa               .      .      .      .      .
Companions
Rubus sp.                        1      +      2      1      +
Vaccinium myrtillus              +      1      1      +      .
Cardamine pratensis              1      1      +      1      .
Ilex aquifolium                  .      .      +      +      +
Luzula henriquesii               2      1      .      1      2
Teucrium scorodonia              .      .      .      +      +
Omphalodes nitida                +      .      .      .      .
Digitalis purpurea               .      .      .      .      +
Polypodium vulgare               .      +      .      +      .
Carex laevigata                  +      .      .      +      +
Adenostyles hybrida              1      .      .      .      1
Primula acaulis                  1      .      1      .      .
Chrysosplenium oppositifolium    1      .      .      .      1
Erica arborea                    1      .      .      r      .
Allium victorialis               .      +      .      .      1
Stellaria holostea               1      +      .      .      .
Polygonatum verticillatum        .      1      .      +      .
Sorbus aucuparia                 +      .      .      .      .
Agrostis capillaris              .      .      .      1      1
Rumex acetosa                    +      .      .      .      .
Lastrea limbosperma              .      .      .      +      1
Asphodelus sp.                   +      .      +      .      .
Aquilegia vulgaris               .      .      .      .      +
Valeriana pyrenaica              +      .      1      .      2
Hyacinthoides non-scripta        +      .      1      .      .
Ranunculus tuberosus             1      .      .      +      .
Cardamine raphanifolia           .      .      .      .      .
Crepis lampsanoides              +      .      .      .      +
Chaerophyllum hirsutum           3      .      .      .      .
Scrophularia alpestris           +      +      .      .      1
Brachypodium rupestre            .      .      .      .      1
Caltha palustris                 1      .      +      .      .
Molinia caerulea                 .      .      .      .      .
Umbilicus rupestris              +      .      .      .      .
Cardamine flexuosa               +      .      .      .      .
Silene dioica                    +      .      .      .      .
Geranium robertianum             +      .      .      .      .
Arrhenatherum bulbosum           1      .      .      .      .
Lysimachia nemorum               .      .      .      +      .

Altitude (m)                    400    460    620    665    355
Exposition                      ENE     NE    NNE     S     WNW
Slope ([grados])                 22     10     24     6      24
Tree height (m)                  10     10     6      10     10
Tree cover (>1,5m)(%)           100    100     90     85    100
Understory cover (<1,5m)(%)      60     70     75     65     60
Area ([m.sup.2])                300    150    200    200    100
Numer of taxa                    33     32     29     38     26
N.                               11     12     13     14     15

Characteristics of association and upper units

Corylus avellana                 5      5      5      4      4
Athyrium filix-femina            2      1      1      1      +
Blechnum spicant                 +      2      2      2      +
Hedera hibernica                 .      1      2      2      1
Oxalis acetosella                2      1      1      1      r
Lonicera periclymenum            1      1      2      1      1
Saxifraga spathularis            2      2      2      1      1
Holcus mollis                    1      +      1      1      .
Dryopteris afffinis              1      1      .      3      2
Dryopteris dilatata              1      1      1      .      .
Salix atrocinerea                .      .      .      1      .
Hypericum androsaemum            1      .      +      .      .
Euphorbia dulcis                 .      1      +      1      .
Viola riviniana                  .      +      .      +      .
Betula pubescens                 .      .      .      .      .
Carex remota                     +      +      .      .      .
Frangula alnus                   .      .      1      1      .
Polystichum setiferum            .      .      .      .      3
Scrophularia auriculata          .      .      .      .      .
Festuca gigantea                 .      .      .      +      .
Brachypodium sylvaticum          .      .      .      .      .
Malus sylvestris                 .      .      .      .      +

Differentials of Festuco-Fraxinetum

Quercus robur                    .      .      1      2      .
Ajuga reptans                    +      .      .      1      .
Viola palustris                  .      .      .      .      .
Dryopteris aemula                .      1      1      .      .
Osmunda regalis                  .      .      .      .      .
Narcissus asturiensis            .      +      +      .      .
Crataegus monogyna               .      1      .      +      +
Pyrus cordata                    .      1      .      .      .
Avenella flexuosa                .      .      +      .      .
Anemone nemorosa                 +      +      1      1      .
Senecio nemorensis               .      .      .      .      .
Sambucus nigra                   1      .      .      .      3
Castanea sativa                  1      .      .      .      .
Angelica sylvestris              .      .      .      .      .
Deschampsia cespitosa            .      .      .      .      .

Differentials of ruscetosum aculeati

Ruscus aculeatus                 .      .      .      +      +
Carex pendula                    .      .      .      .      .
Laurus nobilis                   .      .      .      .      .
Tamus communis                   .      .      .      .      .
Arbutus unedo                    .      .      .      .      .

Differentials of the hyperhygrophilous variant

Woodwardia radicans              .      .      .      .      .
Hymenophyllum tunbrigense        .      1      1      .      .
Culcita macrocarpa               .      .      .      .      .
Companions
Rubus sp.                        +      +      +      1      1
Vaccinium myrtillus              .      1      1      1      .
Cardamine pratensis              +      +      +      .      .
Ilex aquifolium                  +      .      .      1      .
Luzula henriquesii               2      .      .      3      .
Teucrium scorodonia              +      .      .      .      .
Omphalodes nitida                +      +      .      .      .
Digitalis purpurea               r      +      .      .      .
Polypodium vulgare               .      .      1      +      .
Carex laevigata                  .      .      +      +      .
Adenostyles hybrida              .      .      1      .      .
Primula acaulis                  .      +      .      +      1
Chrysosplenium oppositifolium    1      .      .      .      1
Erica arborea                    .      +      .      .      .
Allium victorialis               .      .      2      .      .
Stellaria holostea               .      .      .      1      .
Polygonatum verticillatum        .      .      +      .      .
Sorbus aucuparia                 .      .      +      .      .
Agrostis capillaris              .      .      .      .      .
Rumex acetosa                    .      .      .      .      r
Lastrea limbosperma              .      .      +      .      .
Asphodelus sp.                   .      1      .      .      .
Aquilegia vulgaris               .      +      .      1      .
Valeriana pyrenaica              1      .      .      .      .
Hyacinthoides non-scripta        .      +      .      +      .
Ranunculus tuberosus             .      +      +      .      .
Cardamine raphanifolia           .      .      .      1      +
Crepis lampsanoides              +      .      .      .      .
Chaerophyllum hirsutum           .      .      .      .      .
Scrophularia alpestris           1      .      .      .      .
Brachypodium rupestre            .      .      .      .      .
Caltha palustris                 .      .      .      .      .
Molinia caerulea                 .      .      .      .      .
Umbilicus rupestris              .      .      .      .      r
Cardamine flexuosa               .      .      .      .      .
Silene dioica                    .      .      .      .      1
Geranium robertianum             1      .      .      .      +
Arrhenatherum bulbosum           .      .      .      1      .
Lysimachia nemorum               .      +      .      .      .

Altitude (m)                    330     85     95
Exposition                      WSW    SSE    ENE
Slope ([grados])                 6      12     18
Tree height (m)                  8      10     14
Tree cover (>1,5m)(%)            90     90     80
Understory cover (<1,5m)(%)      85     80     90
Area ([m.sup.2])                120    120    240
Numer of taxa                    31     36     42
N.                               16     17     18

Characteristics of association and upper units

Corylus avellana                 4      4      4
Athyrium filix-femina            1      3      3
Blechnum spicant                 1      2      2
Hedera hibernica                 2      2      2
Oxalis acetosella                +      2      1
Lonicera periclymenum            1      2      2
Saxifraga spathularis            2      .      1
Holcus mollis                    .      1      +
Dryopteris afffinis              2      1      1
Dryopteris dilatata              2      1      1
Salix atrocinerea                .      3      1
Hypericum androsaemum            +      +      1
Euphorbia dulcis                 .      .      .
Viola riviniana                  .      +      +
Betula pubescens                 1      1      1
Carex remota                     +      .      1
Frangula alnus                   .      +      1
Polystichum setiferum            1      1      +
Scrophularia auriculata          .      .      .
Festuca gigantea                 .      .      +
Brachypodium sylvaticum          .      +      .
Malus sylvestris                 .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    .      .      +
Ajuga reptans                    .      +      +
Viola palustris                  .      1      .
Dryopteris aemula                .      .      .
Osmunda regalis                  .      1      1
Narcissus asturiensis            .      .      .
Crataegus monogyna               .      1      .
Pyrus cordata                    .      1      .
Avenella flexuosa                .      .      +
Anemone nemorosa                 .      1      .
Senecio nemorensis               .      .      +
Sambucus nigra                   .      .      .
Castanea sativa                  2      .      1
Angelica sylvestris              .      .      +
Deschampsia cespitosa            .      .      .

Differentials of ruscetosum aculeati

Ruscus aculeatus                 +      1      +
Carex pendula                    .      +      .
Laurus nobilis                   .      1      1
Tamus communis                   .      +      .
Arbutus unedo                    .      .      .

Differentials of the hyperhygrophilous variant

Woodwardia radicans              .      .      1
Hymenophyllum tunbrigense        .      .      .
Culcita macrocarpa               .      .      1
Companions
Rubus sp.                        1      +      1
Vaccinium myrtillus              +      .      .
Cardamine pratensis              1      1      .
Ilex aquifolium                  .      .      .
Luzula henriquesii               +      .      .
Teucrium scorodonia              .      1      +
Omphalodes nitida                .      +      +
Digitalis purpurea               +      r      r
Polypodium vulgare               +      .      +
Carex laevigata                  .      .      .
Adenostyles hybrida              .      .      .
Primula acaulis                  .      +      .
Chrysosplenium oppositifolium    1      .      .
Erica arborea                    .      .      +
Allium victorialis               .      .      .
Stellaria holostea               +      .      .
Polygonatum verticillatum        .      .      .
Sorbus aucuparia                 .      .      .
Agrostis capillaris              .      .      .
Rumex acetosa                    +      +      +
Lastrea limbosperma              .      .      .
Asphodelus sp.                   +      .      +
Aquilegia vulgaris               +      .      .
Valeriana pyrenaica              +      .      .
Hyacinthoides non-scripta        .      .      .
Ranunculus tuberosus             .      .      .
Cardamine raphanifolia           1      .      .
Crepis lampsanoides              +      .      .
Chaerophyllum hirsutum           +      .      .
Scrophularia alpestris           .      .      .
Brachypodium rupestre            .      .      .
Caltha palustris                 .      .      .
Molinia caerulea                 .      .      .
Umbilicus rupestris              .      .      +
Cardamine flexuosa               .      .      +
Silene dioica                    1      .      .
Geranium robertianum             .      .      .
Arrhenatherum bulbosum           .      .      .
Lysimachia nemorum               .      .      .

Altitude (m)                    270    460    230
Exposition                      NNW     N     ENE
Slope ([grados])                 8      15     12
Tree height (m)                  10     8      8
Tree cover (>1,5m)(%)           100    100    100
Understory cover (<1,5m)(%)      80     90     50
Area ([m.sup.2])                200    150     60
Numer of taxa                    40     32     30
N.                               19     20     21

Characteristics of association and upper units

Corylus avellana                 4      5      5
Athyrium filix-femina            2      1      1
Blechnum spicant                 1      2      1
Hedera hibernica                 2      +      1
Oxalis acetosella                3      1      1
Lonicera periclymenum            2      1      2
Saxifraga spathularis            2      1      +
Holcus mollis                    2      1      1
Dryopteris afffinis              1      +      1
Dryopteris dilatata              1      2      .
Salix atrocinerea                3      2      1
Hypericum androsaemum            1      .      .
Euphorbia dulcis                 2      +      +
Viola riviniana                  1      .      +
Betula pubescens                 .      .      1
Carex remota                     +      +      .
Frangula alnus                   .      .      .
Polystichum setiferum            .      .      .
Scrophularia auriculata          .      .      .
Festuca gigantea                 .      .      .
Brachypodium sylvaticum          .      .      .
Malus sylvestris                 .      .      .

Differentials of Festuco-Fraxinetum

Quercus robur                    1      1      1
Ajuga reptans                    .      .      +
Viola palustris                  1      +      .
Dryopteris aemula                +      2      .
Osmunda regalis                  2      +      .
Narcissus asturiensis            .      .      +
Crataegus monogyna               .      1      .
Pyrus cordata                    +      .      .
Avenella flexuosa                +      .      .
Anemone nemorosa                 .      .      .
Senecio nemorensis               .      .      .
Sambucus nigra                   .      .      +
Castanea sativa                  .      .      .
Angelica sylvestris              .      .      +
Deschampsia cespitosa            .      .      .

Differentials of ruscetosum aculeati

Ruscus aculeatus                 .      .      .
Carex pendula                    .      +      +
Laurus nobilis                   .      .      .
Tamus communis                   .      .      .
Arbutus unedo                    1      .      .

Differentials of the hyperhygrophilous variant

Woodwardia radicans              +      .      2
Hymenophyllum tunbrigense        .      +      .
Culcita macrocarpa               .      .      .
Companions
Rubus sp.                        +      1      1
Vaccinium myrtillus              1      +      .
Cardamine pratensis              .      .      +
Ilex aquifolium                  .      r      .
Luzula henriquesii               +      .      .
Teucrium scorodonia              +      1      .
Omphalodes nitida                .      r      +
Digitalis purpurea               +      .      .
Polypodium vulgare               .      .      +
Carex laevigata                  +      .      .
Adenostyles hybrida              .      .      .
Primula acaulis                  .      .      +
Chrysosplenium oppositifolium    .      +      .
Erica arborea                    +      .      .
Allium victorialis               .      1      1
Stellaria holostea               2      +      .
Polygonatum verticillatum        .      +      .
Sorbus aucuparia                 .      r      .
Agrostis capillaris              .      1      .
Rumex acetosa                    +      .      .
Lastrea limbosperma              2      .      .
Asphodelus sp.                   .      .      .
Aquilegia vulgaris               .      .      .
Valeriana pyrenaica              .      .      .
Hyacinthoides non-scripta        .      .      .
Ranunculus tuberosus             .      .      .
Cardamine raphanifolia           .      .      .
Crepis lampsanoides              .      .      .
Chaerophyllum hirsutum           .      .      .
Scrophularia alpestris           .      .      .
Brachypodium rupestre            .      .      .
Caltha palustris                 .      .      .
Molinia caerulea                 +      .      .
Umbilicus rupestris              .      .      .
Cardamine flexuosa               .      .      .
Silene dioica                    .      .      .
Geranium robertianum             .      .      .
Arrhenatherum bulbosum           .      .      .
Lysimachia nemorum               .      .      .

Companions: Hookeria lucens and Polytrichastrum formosum +, Fagus
sylvatica, Scapania undulata and Sphagnum fimbriatum 1 in 1;
Cirsium palustre and Wahlenbergia hederacea + in 2; Cirsium
palustre, Juncus heterophyllus, Oenanthe crocata and Pteridum
aquilinum + in 3; Acer pseudoplatanus, Angelica major, Myosotis sp.
and Pteridum aquilinum + in 4; Carex echinata and Juncus effusus +,
Pulmonaria longifolia 1 in 7; Carex sylvatica and Stachys
officinalis +, Dryopteris filix-mas 1 in 8; Daboecia cantabrica,
Erica mackaiana, Lapsana communis, Potentilla erecta + in 9; Carex
elata subsp. reuteriana, Crocus nudiflorus, Dactylis glomerata +,
Stachys officinalis 1 in 10; Fraxinus excelsior and Veronica
chamaedrys r, Cardamine hirsuta, Hypericum pulchrum and Ranunculus
repens +, Veronica montana 1 in 11; Anthoxanthum odoratum + in 12;
Acer pseudoplatanus, Euphorbia amigdaloides, Lathyrus linifolius,
Potentilla sterilis, Prunella vulgaris and Sanicula europaea +,
Euphorbia hyberna 1 in 14; Lamium maculatum and Mercurialis
perennis 1 in 15; Milium effusum and Solidago virgaurea +,
Narcissus triandrus 1 in 17; Euphorbia hyberna +, Valeriana montana
and Ulex europaeus 1 in 18; Carex sylvatica, Juncus effusus and
Solidago virgaurea +, Erica mackaiana and Taxus baccata 1,
Anthoxanthum odoratum 2 in 19; Potentilla erecta + in 20; Euphorbia
amygdaloides and Sanicula europaea +, Dryopteris filix-mas and
Heracleum sphondylium 1 in 21. Releve sites (sq. 1x1km UTM coord.
are indicated): 1: Monte da Marronda, Rego do Couso, Baleira, Lugo,
642/4772; 2: Rego dos Charcos, O Valadouro, Lugo, 618/4818; 3:
Vilapedre, Fraga do Curro, Vilalba, Lugo, 608/4807; 4: Irixoa, Rego
do Xuncal, Muras, Lugo, 608/4813; 5: Rego de Riobo, Fraga de Riobo,
Muras, Lugo, 610/4811, holotypus assoc.; 6: Rego Grande, between
San Fiz and Meiroi, Ribeira de Piquin, Lugo, 643/4784; 7:
Fragavella, Rego do Cal, Abadin, Lugo, 624/4811; 8: Estelo, Rego do
Cabo, Mondonedo, Lugo, 626/4810; 9: Rego das Canelas, O Valadouro,
Lugo, 619/4818; 10: Rego dos Agros, upstream from its confluence
with Rego do Pedrido, Abadin, Lugo, 625/4809; 11: Fraga de Baos,
Rego de Couto Redondo, Mondonedo, Lugo, 635/4805; 12: Guilfonso,
Fraga Muradoira, Alfoz, Lugo, 621/4813; 13: Fraga das Lerias, S
part, Mondonedo, Lugo, 621/4811; 14: San Paio, Monte O Freixido,
Rego dos Cabozos, Baleira, Lugo, 642/4771; 15: As Dureixas, Mte. do
Cadaval, Monfero, A Coruna, 585/4800; 16: Arroyo de Franjoz,
Taramundi, Asturias, 657/4803; 17: Fragas do Eume Natural Park,
Rego do Pozo, A Capela, A Coruna, 575/4808, holotypus ruscetosum
aculeati; 18: Fragas do Eume Natural Park, Rego da Vaca, close to
its confluence with Rio Eume, Monfero, A Coruna, 576/4806; 19: Rego
de Coto Grande, upstream from As Coruxeiras, Burela, Lugo,
627/4829; 20: Guilfonso, Fraga Muradoira, Alfoz, Lugo, 621/4813;
21: Serra de Moles, Rego de Vilarino, Ortigueira, A Coruna,
586/4834.

Table 6

Violo palustris-Betuletum pubescentis ass. nova
(Hyperico androsaemi-Alnenion glutinosae, Alnion incanae, Populetalia
albae, Salici-Populetea) typical var. and facies (1-29); typical var.,
Salix atrocinerea facies (30-37); Alnus glutinosa var., typical facies
(38-39) Alnus glutinosa var., Salix atrocinerea facies (40)

Altitude (m)                  295    205    575    545    620
Exposition                     4      2      4      4      6
Slope ([grados])               N     NNW    NNW     NE    ENE
Tree height (m)                23     18     16     12     14
Tree cover (>1,5m)(%)          90     90    100    100     95
Understory cover (<1,5m)(%)    80     80    100     75     80
Area ([m.sup.2])              200    300    300    300    400
Numer of taxa                  31     33     48     34     41
N.                             1      2      3      4      5

Characteristic taxa of association and upper units

Betula pubescens               5      5      5      5      4
Blechnum spicant               3      2      1      1      2
Holcus mollis                  1      1      2      +      +
Athyrium filix-femina          1      1      1      .      1
Deschampsia cespitosa          .      3      3      .      3
Quercus robur                  +      1      1      +      +
Teucrium scorodonia            1      1      +      1      1
Hedera hibernica               2      1      1      2      +
Dryopteris affinis             1      1      +      .      1
Viola palustris                1      1      +      1      2
Lonicera periclymenum          1      1      +      +      +
Saxifraga spathularis          2      1      .      +      2
Euphorbia dulcis               2      +      1      .      +
Carex reuteriana               .      2      +      +      .
Frangula alnus                 .      .      1      1      .
Oenanthe crocata               2      .      +      .      .
Dryopteris dilatata            +      .      .      1      1
Stellaria holostea             2      .      .      .      +
Osmunda regalis                +      .      .      .      .
Hypericum androsaemum          +      .      .      .      +
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      .      +      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              .      +      1      1      1

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             +      .      +      .      +
Ajuga reptans                  .      +      1      .      .
Avenella flexuosa              .      .      .      2      +
Angelica major                 .      .      +      +      +
Dryopteris aemula              .      +      .      1      .

Companions

Rubus sp.                      1      1      1      +      +
Erica arborea                  .      1      +      1      1
Pteridum aquilinum             +      +      +      +      +
Brachypodium rupestre          .      .      2      .      2
Polypodium vulgare             +      +      +      .      .
Arrhenatherum bulbosum         .      .      1      .      .
Vaccinium myrtillus            1      .      .      1      +
Carex laevigata                .      1      1      +      .
Crocus serotinus               .      .      +      +      +
Dactylis glomerata             .      1      1      1      .
Agrostis capillaris            .      .      .      2      1
Centaurea nigra                .      +      1      .      +
Digitalis purpurea             .      r      .      +      +
Oxalis acetosella              1      +      .      .      +
Pyrus cordata                  .      .      .      +      .
Omphalodes nitida              +      .      .      .      .
Luzula henriquesii             .      .      +      .      2
Corylus avellana               .      .      +      .      .
Ranunculus repens              .      .      .      .      +
Narcissus asturiensis          .      .      1      +      .
Viola riviniana                .      .      .      .      .
Ilex aquifolium                .      .      .      +      .
Adenostyles hybrida            .      .      2      .      .
Lamium maculatum               +      .      .      .      .
Prunella vulgaris              .      .      1      .      .
Juncus effusus                 .      +      +      .      .
Allium victorialis             .      .      1      .      1
Castanea sativa                1      .      .      .      .
Molinia coerulea               .      .      .      .      .
Cardamine pratensis            +      .      +      .      .
Stachys officinalis            .      .      .      .      +
Lastrea limbosperma            .      .      .      +      1
Rumex acetosa                  .      .      .      .      .
Crepis lampsanoides            .      .      .      .      +
Cystisus scoparius             .      .      .      .      .
Caltha palustris               .      +      .      .      .
Cirsium palustre               .      .      .      .      +
Peucedanum lancifolium         .      .      .      .      +
Veronica chamaedrys            .      .      .      .      .
Silene dioica                  .      .      .      .      .
Euphorbia amygdaloides         .      .      +      .      +
Primula acaulis                +      .      2      .      .
Polytrichum commune            .      .      1      .      .
Daboecia cantabrica            .      +      .      .      .
Sambucus nigra                 1      .      .      .      .
Scrophularia auriculata        .      .      .      .      .
Saxifraga lepismigena          .      1      .      .      .
Ranunculus tuberosus           +      .      .      .      .
Fraxinus excelsior             .      .      .      .      .
Heracleum sphondylium          .      .      1      .      .
Pulmonaria longifolia          .      .      +      .      .
Anthoxanthum amarum            2      .      +      .      .
Sorbus aucuparia               .      .      .      .      .
Asphodelus sp.                 .      .      .      .      .
Avenula sulcata                .      .      +      +      .
Crataegus monogyna             .      .      .      .      .
Acer pseudoplatanus            .      .      .      .      .
Galium palustre                .      .      .      .      .
Rumex obtusifolius             .      .      .      .      .
Umbilicus rupestris            .      .      .      .      .
Anemone nemorosa               .      .      .      +      .
Sphagnum sp.                   .      .      .      .      .
Ulex europaeus                 .      +      .      .      .
Ulex gallii                    .      .      +      .      .

Altitude (m)                  600    500    500    400    505
Exposition                     4      2      2      4      2
Slope ([grados])               SE     E      N      N      SW
Tree height (m)                16     14     14     16     14
Tree cover (>1,5m)(%)          90     90    100     95    100
Understory cover (<1,5m)(%)    90    100    100     85    100
Area ([m.sup.2])              200    300    200    300    300
Numer of taxa                  33     16     29     31     34
N.                             6      7      8      9      10

Characteristic taxa of association and upper units

Betula pubescens               5      5      4      4      4
Blechnum spicant               1      2      3      3      2
Holcus mollis                  1      2      3      1      1
Athyrium filix-femina          1      1      1      2      2
Deschampsia cespitosa          2      3      r      2      2
Quercus robur                  .      1      2      2      1
Teucrium scorodonia            +      2      3      1      1
Hedera hibernica               .      1      1      2      .
Dryopteris affinis             1      .      1      2      2
Viola palustris                2      .      +      2      2
Lonicera periclymenum          .      .      1      1      1
Saxifraga spathularis          1      r      .      .      .
Euphorbia dulcis               +      .      .      1      1
Carex reuteriana               3      .      r      2      1
Frangula alnus                 .      1      .      1      1
Oenanthe crocata               1      .      .      .      1
Dryopteris dilatata            +      .      +      .      +
Stellaria holostea             .      .      1      .      .
Osmunda regalis                .      .      .      1      .
Hypericum androsaemum          .      .      .      .      +
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              1      1      1      1      1

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             1      .      +      +      .
Ajuga reptans                  +      .      .      .      1
Avenella flexuosa              .      .      +      1      .
Angelica major                 .      .      +      .      +
Dryopteris aemula              .      1      .      .      .

Companions

Rubus sp.                      +      1      2      1      2
Erica arborea                  1      +      .      1      1
Pteridum aquilinum             .      .      2      1      1
Brachypodium rupestre          2      .      1      2      3
Polypodium vulgare             .      .      .      .      .
Arrhenatherum bulbosum         .      .      .      .      1
Vaccinium myrtillus            +      .      .      .      .
Carex laevigata                .      .      .      .      .
Crocus serotinus               +      .      +      +      +
Dactylis glomerata             .      .      +      .      1
Agrostis capillaris            +      .      .      1      .
Centaurea nigra                +      .      .      .      .
Digitalis purpurea             .      .      +      .      +
Oxalis acetosella              .      .      .      .      .
Pyrus cordata                  .      .      .      1      .
Omphalodes nitida              +      .      +      +      1
Luzula henriquesii             1      .      .      .      .
Corylus avellana               .      .      .      .      .
Ranunculus repens              +      .      .      .      .
Narcissus asturiensis          .      .      .      .      .
Viola riviniana                .      .      1      .      .
Ilex aquifolium                .      .      .      .      .
Adenostyles hybrida            1      .      .      .      .
Lamium maculatum               .      .      .      .      1
Prunella vulgaris              .      .      .      .      .
Juncus effusus                 +      .      .      .      .
Allium victorialis             1      .      .      .      .
Castanea sativa                .      .      .      +      .
Molinia coerulea               .      +      .      1      .
Cardamine pratensis            .      .      .      .      .
Stachys officinalis            .      .      .      .      +
Lastrea limbosperma            .      .      .      .      .
Rumex acetosa                  .      .      .      .      .
Crepis lampsanoides            .      .      .      .      .
Cystisus scoparius             .      .      +      +      .
Caltha palustris               .      .      .      .      +
Cirsium palustre               .      .      .      .      .
Peucedanum lancifolium         +      .      .      .      .
Veronica chamaedrys            .      .      .      .      .
Silene dioica                  .      .      .      .      .
Euphorbia amygdaloides         .      .      .      .      .
Primula acaulis                .      .      .      .      .
Polytrichum commune            .      2      .      .      .
Daboecia cantabrica            .      .      .      .      .
Sambucus nigra                 1      .      .      .      1
Scrophularia auriculata        +      .      .      .      .
Saxifraga lepismigena          .      .      .      +      .
Ranunculus tuberosus           .      .      .      .      .
Fraxinus excelsior             .      .      .      .      .
Heracleum sphondylium          .      .      .      .      .
Pulmonaria longifolia          .      .      .      .      .
Anthoxanthum amarum            .      .      .      .      .
Sorbus aucuparia               .      .      .      .      .
Asphodelus sp.                 .      .      .      .      .
Avenula sulcata                .      .      .      .      .
Crataegus monogyna             1      .      .      .      .
Acer pseudoplatanus            .      .      .      .      .
Galium palustre                .      .      .      .      .
Rumex obtusifolius             .      .      .      .      .
Umbilicus rupestris            .      .      .      .      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   .      .      .      .      .
Ulex europaeus                 .      .      .      .      .
Ulex gallii                    .      .      .      .      .

Altitude (m)                  580    640    365    595    540
Exposition                     4      4      4      4      4
Slope ([grados])              WNW    WNW     NE     NW     N
Tree height (m)                18     12     12     14     12
Tree cover (>1,5m)(%)          95    100     85    100    100
Understory cover (<1,5m)(%)    95    100     95    100     70
Area ([m.sup.2])              300    150    300    200    200
Numer of taxa                  48     32     26     37     26
N.                             11     12     13     14     15

Characteristic taxa of association and upper units

Betula pubescens               4      4      5      4      4
Blechnum spicant               1      1      2      1      1
Holcus mollis                  1      1      .      .      1
Athyrium filix-femina          1      2      +      2      +
Deschampsia cespitosa          2      .      2      3      +
Quercus robur                  1      .      1      1      1
Teucrium scorodonia            1      .      +      1      +
Hedera hibernica               1      .      1      1      .
Dryopteris affinis             1      2      .      1      .
Viola palustris                .      .      .      +      .
Lonicera periclymenum          1      .      1      .      .
Saxifraga spathularis          1      .      +      1      +
Euphorbia dulcis               +      +      .      2      .
Carex reuteriana               1      +      +      +      +
Frangula alnus                 .      .      2      .      1
Oenanthe crocata               +      1      .      1      .
Dryopteris dilatata            +      +      .      1      +
Stellaria holostea             .      .      .      1      .
Osmunda regalis                .      .      .      .      1
Hypericum androsaemum          .      .      .      .      .
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              2      2      2      2      2

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             1      +      .      1      .
Ajuga reptans                  1      +      +      .      .
Avenella flexuosa              .      .      .      .      1
Angelica major                 +      r      .      1      .
Dryopteris aemula              .      .      2      .      1

Companions

Rubus sp.                      1      1      1      1      .
Erica arborea                  r      .      2      +      1
Pteridum aquilinum             1      .      .      1      +
Brachypodium rupestre          3      .      .      4      .
Polypodium vulgare             .      1      .      +      .
Arrhenatherum bulbosum         1      +      .      1      .
Vaccinium myrtillus            .      .      1      +      1
Carex laevigata                .      .      r      +      +
Crocus serotinus               1      .      .      +      .
Dactylis glomerata             1      .      1      .      +
Agrostis capillaris            .      .      .      1      1
Centaurea nigra                +      .      +      .      .
Digitalis purpurea             .      .      .      +      .
Oxalis acetosella              +      +      .      +      .
Pyrus cordata                  1      .      +      .      .
Omphalodes nitida              .      .      .      .      .
Luzula henriquesii             2      .      +      .      1
Corylus avellana               .      2      .      .      .
Ranunculus repens              +      .      .      .      .
Narcissus asturiensis          1      .      .      1      .
Viola riviniana                .      .      .      1      .
Ilex aquifolium                .      .      +      .      2
Adenostyles hybrida            +      1      .      1      .
Lamium maculatum               +      .      .      .      .
Prunella vulgaris              .      .      .      .      .
Juncus effusus                 +      .      .      .      .
Allium victorialis             +      .      .      +      .
Castanea sativa                .      .      .      .      .
Molinia coerulea               .      .      .      .      1
Cardamine pratensis            .      1      .      .      .
Stachys officinalis            +      .      .      +      .
Lastrea limbosperma            .      .      .      .      .
Rumex acetosa                  .      .      .      .      .
Crepis lampsanoides            .      r      .      .      .
Cystisus scoparius             .      .      .      .      .
Caltha palustris               +      .      .      .      .
Cirsium palustre               +      .      .      .      .
Peucedanum lancifolium         .      .      .      .      .
Veronica chamaedrys            .      .      .      .      .
Silene dioica                  .      1      .      .      .
Euphorbia amygdaloides         .      .      .      .      .
Primula acaulis                .      1      .      .      .
Polytrichum commune            1      .      .      .      .
Daboecia cantabrica            .      .      1      .      .
Sambucus nigra                 .      .      .      .      .
Scrophularia auriculata        .      .      .      .      .
Saxifraga lepismigena          .      .      .      .      .
Ranunculus tuberosus           +      .      +      .      .
Fraxinus excelsior             1      1      .      .      .
Heracleum sphondylium          +      1      .      .      .
Pulmonaria longifolia          .      .      .      +      .
Anthoxanthum amarum            +      .      .      .      .
Sorbus aucuparia               .      .      .      .      1
Asphodelus sp.                 .      .      .      +      .
Avenula sulcata                .      .      .      .      .
Crataegus monogyna             .      .      .      .      .
Acer pseudoplatanus            .      2      .      .      .
Galium palustre                .      .      .      .      .
Rumex obtusifolius             .      .      .      .      .
Umbilicus rupestris            .      .      .      .      .
Anemone nemorosa               +      .      .      .      +
Sphagnum sp.                   +      .      .      .      .
Ulex europaeus                 .      .      .      .      .
Ulex gallii                    .      .      .      .      .

Altitude (m)                  595    410    620    455    435
Exposition                     2      4      4      2      <2
Slope ([grados])               NW    NNW     W     WNW     S
Tree height (m)                14     14     14     18     18
Tree cover (>1,5m)(%)         100    100     90    100     90
Understory cover (<1,5m)(%)   100     95    100     95    100
Area ([m.sup.2])              300    300    200    200    300
Numer of taxa                  39     31     39     38     39
N.                             16     17     18     19     20

Characteristic taxa of association and upper units

Betula pubescens               5      5      4      4      3
Blechnum spicant               1      2      1      .      2
Holcus mollis                  2      2      2      1      1
Athyrium filix-femina          1      1      2      3      3
Deschampsia cespitosa          3      3      3      1      +
Quercus robur                  +      1      1      1      3
Teucrium scorodonia            2      2      +      1      1
Hedera hibernica               .      1      .      1      1
Dryopteris affinis             1      1      +      2      2
Viola palustris                .      +      .      2      1
Lonicera periclymenum          2      1      .      .      +
Saxifraga spathularis          1      1      2      .      .
Euphorbia dulcis               1      +      +      2      1
Carex reuteriana               .      .      .      1      .
Frangula alnus                 1      1      +      1      .
Oenanthe crocata               1      .      1      2      .
Dryopteris dilatata            .      .      .      .      .
Stellaria holostea             1      .      +      +      1
Osmunda regalis                .      .      +      +      1
Hypericum androsaemum          .      .      .      .      .
Brachypodium sylvaticum        1      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              2      2      2      2      2

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             1      +      1      2      1
Ajuga reptans                  .      +      +      1      .
Avenella flexuosa              +      .      .      +      .
Angelica major                 +      .      .      .      +
Dryopteris aemula              .      .      .      .      .

Companions

Rubus sp.                      1      1      +      1      1
Erica arborea                  1      1      1      +      +
Pteridum aquilinum             1      .      1      +      .
Brachypodium rupestre          2      4      1      3      3
Polypodium vulgare             1      1      1      .      .
Arrhenatherum bulbosum         1      2      .      1      +
Vaccinium myrtillus            .      +      .      .      .
Carex laevigata                +      .      +      .      +
Crocus serotinus               +      .      +      +      +
Dactylis glomerata             +      1      1      .      +
Agrostis capillaris            1      .      2      1      1
Centaurea nigra                1      .      1      1      .
Digitalis purpurea             .      .      +      +      .
Oxalis acetosella              .      .      .      .      .
Pyrus cordata                  .      1      .      .      .
Omphalodes nitida              .      +      .      1      .
Luzula henriquesii             +      .      .      .      .
Corylus avellana               .      .      .      .      .
Ranunculus repens              .      .      +      .      .
Narcissus asturiensis          .      .      .      +      .
Viola riviniana                1      .      .      1      +
Ilex aquifolium                .      .      .      .      +
Adenostyles hybrida            .      .      1      .      .
Lamium maculatum               .      .      +      .      1
Prunella vulgaris              1      .      1      +      .
Juncus effusus                 .      .      .      .      .
Allium victorialis             .      .      +      .      .
Castanea sativa                .      .      .      .      .
Molinia coerulea               .      .      .      .      .
Cardamine pratensis            .      .      .      .      .
Stachys officinalis            +      .      .      1      .
Lastrea limbosperma            +      .      .      .      .
Rumex acetosa                  .      .      1      +      +
Crepis lampsanoides            .      .      .      .      .
Cystisus scoparius             .      .      .      .      .
Caltha palustris               .      .      .      .      .
Cirsium palustre               .      +      .      .      .
Peucedanum lancifolium         .      .      .      .      +
Veronica chamaedrys            .      .      1      .      +
Silene dioica                  .      .      .      +      1
Euphorbia amygdaloides         .      .      .      +      +
Primula acaulis                .      .      .      1      1
Polytrichum commune            .      .      .      .      .
Daboecia cantabrica            .      .      .      .      .
Sambucus nigra                 .      .      .      .      +
Scrophularia auriculata        .      .      .      .      .
Saxifraga lepismigena          .      .      .      .      .
Ranunculus tuberosus           .      .      .      .      .
Fraxinus excelsior             r      .      .      .      .
Heracleum sphondylium          +      .      .      .      .
Pulmonaria longifolia          .      .      .      .      .
Anthoxanthum amarum            .      1      .      .      .
Sorbus aucuparia               .      .      .      .      .
Asphodelus sp.                 .      .      .      .      .
Avenula sulcata                .      .      1      .      .
Crataegus monogyna             .      .      .      .      .
Acer pseudoplatanus            +      .      .      .      .
Galium palustre                .      .      .      .      .
Rumex obtusifolius             .      .      .      .      .
Umbilicus rupestris            .      1      .      .      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   .      .      .      .      .
Ulex europaeus                 .      .      .      .      .
Ulex gallii                    .      .      .      .      .

Altitude (m)                  940    355    420    435    790
Exposition                     6      4      2      4      6
Slope ([grados])               E     ENE     SW    NNE    ESE
Tree height (m)                18     18     10     16     14
Tree cover (>1,5m)(%)          85     90     90    100     85
Understory cover (<1,5m)(%)    70     95    100     90     90
Area ([m.sup.2])              120    200    200    200    120
Numer of taxa                  22     33     30     46     35
N.                             21     22     23     24     25

Characteristic taxa of association and upper units

Betula pubescens               5      3      4      4      4
Blechnum spicant               2      2      2      2      1
Holcus mollis                  3      1      2      1      2
Athyrium filix-femina          +      2      1      1      1
Deschampsia cespitosa          1      1      2      2      +
Quercus robur                  2      2      2      2      2
Teucrium scorodonia            .      .      1      1      +
Hedera hibernica               +      1      1      2      +
Dryopteris affinis             +      2      .      1      1
Viola palustris                .      +      +      2      .
Lonicera periclymenum          .      1      1      1      1
Saxifraga spathularis          1      2      +      +      1
Euphorbia dulcis               .      1      .      .      .
Carex reuteriana               .      .      +      2      .
Frangula alnus                 .      .      1      1      .
Oenanthe crocata               .      2      .      +      +
Dryopteris dilatata            1      +      .      1      +
Stellaria holostea             1      1      .      +      .
Osmunda regalis                .      1      .      +      .
Hypericum androsaemum          .      +      .      .      .
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      +
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              2      3      3      3      3

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             .      .      .      1      .
Ajuga reptans                  .      1      .      1      1
Avenella flexuosa              2      1      1      .      1
Angelica major                 .      .      .      .      .
Dryopteris aemula              .      1      1      +      .

Companions

Rubus sp.                      1      2      1      1      2
Erica arborea                  2      .      2      1      +
Pteridum aquilinum             1      .      2      .      1
Brachypodium rupestre          .      .      .      .      .
Polypodium vulgare             +      .      .      +      +
Arrhenatherum bulbosum         .      2      .      1      1
Vaccinium myrtillus            2      .      2      +      1
Carex laevigata                1      .      +      +      +
Crocus serotinus               .      .      .      .      .
Dactylis glomerata             .      .      .      .      1
Agrostis capillaris            .      .      .      1      .
Centaurea nigra                .      +      r      +      .
Digitalis purpurea             .      r      +      .      .
Oxalis acetosella              .      1      .      .      +
Pyrus cordata                  .      1      1      .      .
Omphalodes nitida              .      .      .      +      .
Luzula henriquesii             .      .      .      1      1
Corylus avellana               .      1      1      1      1
Ranunculus repens              .      1      .      +      .
Narcissus asturiensis          +      .      +      .      .
Viola riviniana                .      .      .      +      .
Ilex aquifolium                .      .      .      +      .
Adenostyles hybrida            .      1      .      .      .
Lamium maculatum               .      .      .      +      .
Prunella vulgaris              .      .      .      .      .
Juncus effusus                 1      .      .      +      +
Allium victorialis             .      .      .      1      .
Castanea sativa                .      2      .      +      .
Molinia coerulea               .      .      .      .      .
Cardamine pratensis            .      .      .      .      +
Stachys officinalis            .      .      .      .      .
Lastrea limbosperma            .      .      .      +      .
Rumex acetosa                  .      .      .      .      .
Crepis lampsanoides            .      .      .      .      +
Cystisus scoparius             .      .      +      .      .
Caltha palustris               .      .      .      .      +
Cirsium palustre               .      .      .      .      .
Peucedanum lancifolium         .      .      .      .      .
Veronica chamaedrys            .      .      .      .      .
Silene dioica                  .      .      .      .      .
Euphorbia amygdaloides         .      .      .      .      .
Primula acaulis                .      .      .      .      .
Polytrichum commune            .      .      .      .      +
Daboecia cantabrica            .      .      +      .      .
Sambucus nigra                 .      .      .      .      .
Scrophularia auriculata        .      .      .      .      .
Saxifraga lepismigena          .      .      +      +      +
Ranunculus tuberosus           .      .      .      +      .
Fraxinus excelsior             .      .      .      1      .
Heracleum sphondylium          .      .      .      .      .
Pulmonaria longifolia          .      .      .      .      .
Anthoxanthum amarum            .      .      .      .      .
Sorbus aucuparia               1      .      .      .      .
Asphodelus sp.                 .      .      .      .      +
Avenula sulcata                .      .      .      .      .
Crataegus monogyna             .      .      .      .      .
Acer pseudoplatanus            .      .      .      .      .
Galium palustre                .      .      .      .      .
Rumex obtusifolius             .      .      .      .      .
Umbilicus rupestris            .      .      .      +      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   .      .      .      .      .
Ulex europaeus                 .      .      .      .      .
Ulex gallii                    .      .      +      .      .

Altitude (m)                  790    610    660    440    440
Exposition                     6      8      4      2      <2
Slope ([grados])              ESE    WNW     W     SSW     S
Tree height (m)                18     10     8      14     12
Tree cover (>1,5m)(%)         100     90    100     90    100
Understory cover (<1,5m)(%)    95     85     95     90    100
Area ([m.sup.2])              200    200    200    300    400
Numer of taxa                  27     38     46     37     44
N.                             26     27     28     29     30

Characteristic taxa of association and upper units

Betula pubescens               4      3      3      3      3
Blechnum spicant               1      2      1      2      +
Holcus mollis                  3      1      2      2      1
Athyrium filix-femina          .      1      2      4      3
Deschampsia cespitosa          1      2      2      1      +
Quercus robur                  2      2      1      2      2
Teucrium scorodonia            .      1      +      1      2
Hedera hibernica               1      1      1      3      2
Dryopteris affinis             1      .      1      2      1
Viola palustris                .      2      3      2      2
Lonicera periclymenum          1      1      .      2      2
Saxifraga spathularis          1      1      1      .      .
Euphorbia dulcis               .      1      1      1      2
Carex reuteriana               .      2      1      1      1
Frangula alnus                 .      +      .      .      +
Oenanthe crocata               .      +      2      2      1
Dryopteris dilatata            .      .      1      .      .
Stellaria holostea             .      .      .      +      .
Osmunda regalis                .      .      +      1      2
Hypericum androsaemum          .      +      .      .      .
Brachypodium sylvaticum        .      .      +      .      .
Carex remota                   +      .      .      .      .
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              3      3      3      3      4

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             +      1      1      1      3
Ajuga reptans                  .      +      1      .      .
Avenella flexuosa              2      +      .      .      .
Angelica major                 .      .      +      +      1
Dryopteris aemula              .      1      .      .      .

Companions

Rubus sp.                      1      +      1      +      1
Erica arborea                  2      +      +      .      .
Pteridum aquilinum             +      +      +      .      +
Brachypodium rupestre          .      +      .      3      5
Polypodium vulgare             +      +      1      .      .
Arrhenatherum bulbosum         1      .      1      +      +
Vaccinium myrtillus            1      .      +      .      .
Carex laevigata                .      .      1      +      .
Crocus serotinus               .      .      1      +      +
Dactylis glomerata             .      .      1      1      1
Agrostis capillaris            .      1      .      .      +
Centaurea nigra                .      .      1      .      +
Digitalis purpurea             .      r      .      +      +
Oxalis acetosella              .      1      1      .      .
Pyrus cordata                  .      r      .      .      +
Omphalodes nitida              .      .      .      +      +
Luzula henriquesii             .      .      .      .      .
Corylus avellana               .      2      1      .      .
Ranunculus repens              .      .      1      .      +
Narcissus asturiensis          .      +      .      .      .
Viola riviniana                .      .      .      1      1
Ilex aquifolium                .      .      .      .      .
Adenostyles hybrida            .      1      .      .      .
Lamium maculatum               .      .      .      +      .
Prunella vulgaris              .      .      1      +      .
Juncus effusus                 +      .      .      .      .
Allium victorialis             .      .      .      .      .
Castanea sativa                .      .      .      .      .
Molinia coerulea               +      .      +      .      .
Cardamine pratensis            .      .      1      .      1
Stachys officinalis            .      .      .      .      .
Lastrea limbosperma            .      2      .      .      .
Rumex acetosa                  .      +      .      .      +
Crepis lampsanoides            +      .      +      .      .
Cystisus scoparius             .      .      +      .      .
Caltha palustris               +      .      .      .      .
Cirsium palustre               .      .      .      .      +
Peucedanum lancifolium         .      .      1      .      .
Veronica chamaedrys            .      .      +      +      +
Silene dioica                  .      .      2      2      .
Euphorbia amygdaloides         .      .      .      1      1
Primula acaulis                .      .      .      1      .
Polytrichum commune            1      .      .      .      .
Daboecia cantabrica            .      +      .      .      .
Sambucus nigra                 .      .      .      1      .
Scrophularia auriculata        .      .      .      +      +
Saxifraga lepismigena          .      .      .      .      .
Ranunculus tuberosus           .      .      .      .      .
Fraxinus excelsior             .      .      1      .      .
Heracleum sphondylium          .      .      +      .      .
Pulmonaria longifolia          .      .      +      .      .
Anthoxanthum amarum            .      .      .      .      .
Sorbus aucuparia               .      +      .      .      .
Asphodelus sp.                 .      .      .      .      .
Avenula sulcata                .      .      .      .      .
Crataegus monogyna             .      .      .      .      .
Acer pseudoplatanus            .      .      .      .      .
Galium palustre                .      .      .      .      1
Rumex obtusifolius             .      .      .      +      .
Umbilicus rupestris            .      .      .      .      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   .      .      .      .      .
Ulex europaeus                 .      .      .      .      .
Ulex gallii                    .      .      .      .      .

Altitude (m)                  525    450    680    980    550
Exposition                     4      <2     6      10     6
Slope ([grados])              ESE     NE    ESE    NNE     N
Tree height (m)                6      16     10     10    -10
Tree cover (>1,5m)(%)         100    100     90    100     85
Understory cover (<1,5m)(%)    80    100     90     95     95
Area ([m.sup.2])              120    300    100    200    200
Numer of taxa                  30     46     36     29     35
N.                             31     32     33     34     35

Characteristic taxa of association and upper units

Betula pubescens               1      2      .      2      2
Blechnum spicant               1      2      2      1      2
Holcus mollis                  .      1      1      2      1
Athyrium filix-femina          .      1      1      .      +
Deschampsia cespitosa          1      1      1      .      1
Quercus robur                  +      2      2      .      1
Teucrium scorodonia            .      1      1      +      +
Hedera hibernica               1      2      2      1      1
Dryopteris affinis             +      1      +      +      1
Viola palustris                1      +      2      .      .
Lonicera periclymenum          +      .      2      1      2
Saxifraga spathularis          .      .      .      .      .
Euphorbia dulcis               .      .      1      .      .
Carex reuteriana               .      .      .      .      .
Frangula alnus                 2      .      2      .      .
Oenanthe crocata               .      1      .      .      1
Dryopteris dilatata            +      +      .      2      1
Stellaria holostea             .      1      .      +      .
Osmunda regalis                +      .      .      .      .
Hypericum androsaemum          .      .      +      .      .
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      2      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      .      .      .

Differentials of Salix atrocinerea facies

Salix atrocinerea              4      4      4      4      5

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             .      +      .      .      .
Ajuga reptans                  .      .      1      2      1
Avenella flexuosa              1      .      +      1      .
Angelica major                 .      +      .      +      .
Dryopteris aemula              .      .      .      +      .

Companions

Rubus sp.                      +      2      1      2      2
Erica arborea                  1      1      .      1      +
Pteridum aquilinum             .      1      .      .      .
Brachypodium rupestre          +      4      .      .      2
Polypodium vulgare             +      +      .      .      +
Arrhenatherum bulbosum         .      1      .      1      1
Vaccinium myrtillus            1      .      +      1      .
Carex laevigata                .      +      1      .      +
Crocus serotinus               +      +      .      .      .
Dactylis glomerata             .      1      .      .      .
Agrostis capillaris            1      .      1      .      .
Centaurea nigra                .      +      .      .      1
Digitalis purpurea             .      .      +      .      .
Oxalis acetosella              +      .      2      .      .
Pyrus cordata                  +      .      1      .      +
Omphalodes nitida              .      2      +      .      .
Luzula henriquesii             1      .      .      4      .
Corylus avellana               .      .      2      2      .
Ranunculus repens              .      1      .      1      .
Narcissus asturiensis          .      +      +      +      .
Viola riviniana                .      +      .      .      .
Ilex aquifolium                +      .      +      .      +
Adenostyles hybrida            .      .      2      .      .
Lamium maculatum               .      1      .      .      .
Prunella vulgaris              .      +      .      .      1
Juncus effusus                 .      .      .      .      .
Allium victorialis             .      .      .      .      +
Castanea sativa                .      1      .      .      .
Molinia coerulea               2      .      +      .      .
Cardamine pratensis            .      .      +      .      .
Stachys officinalis            .      .      .      .      1
Lastrea limbosperma            .      .      .      .      .
Rumex acetosa                  +      +      .      .      .
Crepis lampsanoides            .      .      .      +      .
Cystisus scoparius             .      .      .      .      +
Caltha palustris               .      1      .      .      +
Cirsium palustre               .      +      .      +      +
Peucedanum lancifolium         .      .      .      .      .
Veronica chamaedrys            .      .      .      .      .
Silene dioica                  .      .      .      .      .
Euphorbia amygdaloides         .      .      .      .      .
Primula acaulis                .      .      .      .      .
Polytrichum commune            .      .      .      .      1
Daboecia cantabrica            +      .      .      .      .
Sambucus nigra                 .      .      .      .      .
Scrophularia auriculata        .      .      .      .      .
Saxifraga lepismigena          .      .      .      .      .
Ranunculus tuberosus           .      .      .      1      .
Fraxinus excelsior             .      .      .      .      .
Heracleum sphondylium          .      .      .      .      .
Pulmonaria longifolia          .      .      +      .      r
Anthoxanthum amarum            .      .      .      +      .
Sorbus aucuparia               .      .      .      1      .
Asphodelus sp.                 .      .      .      .      +
Avenula sulcata                .      .      .      .      +
Crataegus monogyna             .      1      .      .      .
Acer pseudoplatanus            .      1      .      .      .
Galium palustre                .      +      .      .      .
Rumex obtusifolius             .      1      .      .      .
Umbilicus rupestris            .      .      .      .      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   .      .      .      +      .
Ulex europaeus                 .      .      .      .      +
Ulex gallii                    +      .      .      .      .

Altitude (m)                  580    610    340    420    285
Exposition                     2      2      2      <2     6
Slope ([grados])              ENE     NE    NNW     S      NE
Tree height (m)                8      10     18     18     16
Tree cover (>1,5m)(%)          90     90     90    100    100
Understory cover (<1,5m)(%)   100     90     95    100     80
Area ([m.sup.2])              100    200    300    300    200
Numer of taxa                  34     42     40     34     39
N.                             36     37     38     39     40

Characteristic taxa of association and upper units

Betula pubescens               1      1      4      4      3
Blechnum spicant               1      1      2      .      2
Holcus mollis                  1      1      2      +      1
Athyrium filix-femina          2      1      2      3      2
Deschampsia cespitosa          .      3      3      1      1
Quercus robur                  .      .      3      1      1
Teucrium scorodonia            .      +      1      +      1
Hedera hibernica               2      +      3      1      2
Dryopteris affinis             .      1      1      +      .
Viola palustris                4      2      2      2      1
Lonicera periclymenum          1      1      1      1      1
Saxifraga spathularis          +      1      +      .      3
Euphorbia dulcis               .      +      1      .      1
Carex reuteriana               .      2      1      +      +
Frangula alnus                 1      .      3      .      +
Oenanthe crocata               .      1      .      1      +
Dryopteris dilatata            1      +      .      .      .
Stellaria holostea             .      +      .      .      .
Osmunda regalis                .      .      .      1      1
Hypericum androsaemum          .      .      .      .      .
Brachypodium sylvaticum        .      .      .      .      .
Carex remota                   .      .      .      .      .
Ranunculus ficaria             .      .      .      .      .

Differentials of Alnus glutinosa var.

Alnus glutinosa                .      .      1      1      1

Differentials of Salix atrocinerea facies

Salix atrocinerea              5      5      +      2      4

Differentials from xuresian and orocantabric birch riparian forests

Senecio nemorensis             .      1      1      1      .
Ajuga reptans                  .      .      .      +      1
Avenella flexuosa              1      .      .      .      1
Angelica major                 .      +      .      +      .
Dryopteris aemula              1      .      +      .      1

Companions

Rubus sp.                      +      1      +      1      1
Erica arborea                  +      +      1      .      +
Pteridum aquilinum             .      .      1      .      .
Brachypodium rupestre          .      2      3      4      .
Polypodium vulgare             +      +      +      .      +
Arrhenatherum bulbosum         .      .      1      .      2
Vaccinium myrtillus            +      .      +      .      +
Carex laevigata                1      +      .      .      .
Crocus serotinus               .      .      +      .      .
Dactylis glomerata             .      1      +      .      .
Agrostis capillaris            1      1      1      .      .
Centaurea nigra                .      1      .      .      +
Digitalis purpurea             +      +      .      .      .
Oxalis acetosella              1      .      .      .      1
Pyrus cordata                  +      .      1      .      1
Omphalodes nitida              .      .      .      .      +
Luzula henriquesii             .      3      2      .      +
Corylus avellana               1      .      1      .      3
Ranunculus repens              1      1      .      .      .
Narcissus asturiensis          .      .      .      .      .
Viola riviniana                .      .      .      +      .
Ilex aquifolium                +      .      .      .      r
Adenostyles hybrida            +      .      .      .      .
Lamium maculatum               .      +      .      .      .
Prunella vulgaris              .      1      .      .      .
Juncus effusus                 +      .      .      .      .
Allium victorialis             .      1      .      .      .
Castanea sativa                .      .      +      1      2
Molinia coerulea               .      .      2      .      .
Cardamine pratensis            .      .      .      .      1
Stachys officinalis            .      .      1      .      .
Lastrea limbosperma            1      +      .      .      .
Rumex acetosa                  .      .      .      .      .
Crepis lampsanoides            .      .      +      .      .
Cystisus scoparius             .      +      +      .      .
Caltha palustris               .      .      .      .      .
Cirsium palustre               .      .      .      .      .
Peucedanum lancifolium         +      .      +      .      .
Veronica chamaedrys            .      .      .      +      .
Silene dioica                  .      +      .      .      .
Euphorbia amygdaloides         .      .      .      .      .
Primula acaulis                .      .      .      .      .
Polytrichum commune            .      .      .      .      .
Daboecia cantabrica            .      .      .      .      .
Sambucus nigra                 .      .      .      .      .
Scrophularia auriculata        .      +      .      +      .
Saxifraga lepismigena          .      .      .      .      .
Ranunculus tuberosus           .      .      .      .      .
Fraxinus excelsior             .      .      .      .      .
Heracleum sphondylium          .      .      .      .      .
Pulmonaria longifolia          .      .      .      .      .
Anthoxanthum amarum            .      .      .      .      .
Sorbus aucuparia               .      .      .      .      .
Asphodelus sp.                 .      .      .      .      r
Avenula sulcata                .      .      .      .      .
Crataegus monogyna             .      .      1      .      .
Acer pseudoplatanus            .      .      .      .      .
Galium palustre                .      .      .      1      .
Rumex obtusifolius             .      +      .      .      .
Umbilicus rupestris            .      .      +      .      .
Anemone nemorosa               .      .      .      .      .
Sphagnum sp.                   2      .      .      .      .
Ulex europaeus                 .      +      .      .      .
Ulex gallii                    .      .      .      .      .

Companions: Laurus nobilis and Physospermum cornubiense + in 2;
Lathyrus linifolius r, Myosotis sp. + in 3; Juncus bulbosus,
Potentilla erecta and Ranunculus bulbosus + in 4; Hypericum
pulchrum and Physospermum cornubiense + in 5; Agrostis stolonifera
and Carex pilulifera + in 8; Pseudarrhenatherum longifolium + in 9;
Cirsium filipendulum and Epilobium sp. r in 10; Taraxacum gr.
officinale r, Conopodium sp. + in 11; Chrysosplenium oppositifolium,
Festuca gigantea, Hyacinthoides non-scripta and Irispseudacorus +,
Chaerophyllum hirsutum and Valerianapyrenaica 1 in 12; Arbutus unedo
+ in 13; Valerianapyrenaica + in 16; Prunus laurocerasus (pl.) r,
Hyacinthoides non-scripta + in 17; Genista florida, Potentilla erecta
and Succisa pratensis + in 18; Erica vagans + in 19; Ceratocapnos
claviculata, Linaria triornithophora and Rosa gr. canina + in 20;
Mercurialis perennis +, Aquilegia vulgaris 1 in 22; Valeriana dioica
+ in 24; Carex binervis +; Succisa pratensis 1 in 26; Solidago
virgaurea + in 27; Mercurialisperennis + in 28; Epilobium sp., Mentha
aquatica, Prunella grandiflora and Vicia sepium +, Lythrum salicaria 1
in 30; Anthoxanthum odoratum r, Solidago virgaurea + in 31; Taraxacum
gr. officinale r, Cardamine hirsuta, Iris pseudacorus, Pentaglottis
sempervirens and Urtica dioica + in 32; Aquilegia vulgaris, Carex
echinata, Carex lusitanica, Lysimachia nemorum and Scutellaria minor
+ in 33; Erica mackaiana + in 35; Carex echinata, Lotus pedunculatus
and Lysimachia nemorum +, Potamogeton natans 1 in 36; Cardamine
flexuosa +, Senecio aquaticus and Succisapratensis 1 in 37; Lysimachia
vulgaris, Mentha aquatica, Myosotis sp., Picris hieracioides, Polygonum
persicaria, Scutellaria minor and Senecio aquaticus + in 39; Angelica
sylvestris r, Hymenophyllum tunbrigense +, Lythrum salicaria and
Prunella grandiflora 1 in 40.

Releve sites (sq. 1x1km UTM coord. are indicated): 1: Rego de San
Miguel, downstream from O Lombao, Ortigueira, A Coruna, 597/4829; 2:
Rio de Fragacha, between Ambosores and Beira da Fraga, Ourol, Lugo,
602/4823; 3: Rego de Xestosa, between Leganitos and A Armada, Muras,
Lugo, 607/4818, holotypus assoc.; 4: Rego das Furnas, upstream from O
Cadramon, O Valadouro, Lugo, 617/4815; 5: Rego do Pedrido, in front of
Curro Vello, Abadin, Lugo, 620/4810; 6: Rego do Pedrido, downstream
from Ponte Xestido, Abadin, Lugo, 621/4809; 7: Rego do Gallel, As
Pontes, A Coruna, 582/4809; 8: Rio de Tordegos, in front of Os Miraces,
Xermade, Lugo, 594/4803; 9: Rio Frai Bermuz, downstream from the brigde
of the road Betanzos-Cabreiros, between Albite and Rubeiras, Monfero,
A Coruna, 584/4797; 10: Rego da Ponte das Ovellas, between Cambas and
A Vide, Aranga, A Coruna, 584/4790; 11: Rego de Coruxos, between Fra
and Cornido, Muras, Lugo, 612/4817; 12: Rego da Ribeira, between Doulfe
and O Porto dos Troncos, Vilalba, Lugo, 613/4806; 13: Rego de Tras
da Serra, in front of O Formigueiro, As Pontes, A Coruna, 601/4820;
14: Rio Landro, upstream from O Viveiro, Muras, Lugo, 611/4816; 15:
Rego das Furnas, Val das Furnas, O Cadramon, O Valadouro, Lugo,
617/4815; 16: Rio Eume, in front of Escourido, Vilalba, Lugo,
609/4811; 17: Rio Belelle, between As Felgueiras and O Seixo, As
Neves, A Coruna, 579/4810; 18: Rio Eume, between A Ponte and A
Balsa Pequena, Vilalba, Lugo, 611/4808; 19: Rego do Campo, between
Penachaina and O Campo, Xermade, Lugo, 600/4807; 20: Rego de San
Martino, Cabreiros, Xermade, Lugo, 598/4805; 21: Rego do Chao, near
Brananova, Villanueva de Oscos, As, 663/4802; 22: Rego de Candedos,
between O Foro and Casa da Bouza, As Pontes, A Coruna, 598/4821;
23: Rego de Tras da Serra, downstream from A Curiscada, As Pontes,
A Coruna, 601/4818; 24: Rego de Cauce Ancho, near Caneiro de
Abaixo, As Pontes, A Coruna, 598/4812; 25: Rego de los Vedules,
Illano, Asturias, 670/4802; 26: Arroyo de Vilanova, between
Penacoba and Bustapena, Villanueva de Oscos, As, 663/4800; 27: Rego
do Casal, between Orxas and Folgoso, Xermade Lugo, 605/4810; 28:
Rio Eume, near A Serra, Vilalba, Lugo, 614/ 4808; 29: Rego do
Campo, between O Chao and Nova, Xermade, Lugo, 598/4806; 30: Rio
Trimaz, Candamil, upstream from the bigde of the road to Xermade,
Xermade, Lugo, 598/4801; 31: Rio das Furnas, Val das Furnas, O
Valadouro, Lugo, 617/4815; 32: Rego de Vilarino, between A Ribeira
and Xermade, Xermade, Lugo, 597/4800; 33: Rego da Fraga de Freire,
upstream from Vilapedre, Vilalba, Lugo, 609/4807; 34: Arroyo de La
Acebedal, Illano, Asturias, 669/4803; 35: Rego do Campo do Seixo,
between Vilalverde and Besterrexulfe, Ourol, Lugo, 610/4818; 36: A
Fra- gavella, Rego do Cal, Abadin, Lugo, 624/4811; 37: Rio do
Pedrido, upstream from Ponte Xestido, Abadin, Lugo, 621/4809; 38:
Rio Frai Bermuz, between A Ponte da Laxe and A Maceira, Monfero, A
Coruna, 585/4799; 39: Rio Trimaz, in front of Tardaz, Vilalba,
Lugo, 601/4797; 40: Rego do Solloso, near Ambosores, As Pontes, A
Coruna, 600/4823.

Table 7

Synthetic table showing the floristic composition of the ash,
hazel-willow and birch-dominated riparian forests described in the
NW Iberian peninsula (only companions in at least 4 synthetic releves
were included)

Number of releves             60     20     21     40
Mean number of taxa           38     40     34     34
Releve number                 1      2      3      4

Differential taxa

Lonicera periclymenum         V      IV     V      IV
Dryopteris afffinis s.l.      V      IV     IV     IV
Teucrium scorodonia           II     II    III     V
Crepis lampsanoides           II     IV     I      I
Stellaria holostea            II     II     II    III
Viola riviniana              III     I     III     II
Frangula alnus                I      II     II    III
Primula acaulis              III     II     II     I
Crataegus monogyna            II     I      II     I
Oxalis acetosella             V      IV     V      II
Dryopteris dilatata           IV    III     IV    III
Holcus mollis                 IV    III     V      V
Polypodium vulgare           III     IV    III    III
Sorbus aucuparia              I     III     II     I
Vaccinium myrtillus           II     II     IV    III
Ilex aquifolium              III     II    III     II
Ranunculus tuberosus          II     I      I      I
Carex remota                  II     I      II     I
Acer pseudoplatanus           IV     V      I      I
Sambucus nigra                II     I      I      I
Aquilegia vulgaris            II     II     II     I
Euphorbia amygdaloides        II     II     I      I
Solidago virgaurea            I      I      I      I
Castanea sativa              III     I      I      II
Hedera hibernica              V      .      V      V
Deschampsia cespitosa         I      .      I      V
Quercus robur                III     .      IV     V
Chaerophyllum hirsutum        II     V      I      .
Polygonatum verticillatum     I      I      II     .
Valeriana pyrenaica          III     V      II     +
Polystichum setiferum        III     V      I      .
Festuca gigantea              II     IV     I      .
Scrophularia alpestris        II    III     I      .
Angelica sylvestris           II     I      I      +
Carex sylvatica               I      I      I      .
Ajuga reptans                 IV     +     III    III
Dryopteris aemula             I      .     III     II
Pyrus cordata                 I      +      II     II
Valeriana montana             I      I      +      .
Ulmus glabra                 III    III     .      .
Melica uniflora               I      II     .      .
Poa nemoralis                 .      I      .      .
Cardamine impatiens           II     I      .      .
Milium effusum                I      II     +      .
Veronica montana              I      I      +      .
Helleborus occidentalis       I      I      .      .
Phyllitis scolopendrium       I      I      .      .
Ruscus aculeatus              II     +      II     +
Laurus nobilis                II     .      I      +
Carex pendula                 II     .      I      .
Woodwardia radicans           II     .      I      .
Hymenophyllum tunbrigense     I      .      I      +
Alnus glutinosa               I      .      .      1
Tamus communis                .      +      +      .
Daphne laureola               .      I      .      .
Arbutus unedo                 I      .      +      +
Asplenium onopteris           I      +      .      .
Culcita macrocarpa            I      .      +      .
Rubia peregrina               I      .      .      .
Hedera helix                  .      IV     .      .
Festuca rubra                 .      II     .      .
Epilobium parviflorum         .      II     .      .
Galium odoratum               .      I      .      .
Astrantia major               .      I      .      .
Polystichum aculeatum         .      I      .      .
Agrostis x fouilladei         .      .      .      .
Aquilegia dichroa             .      .      .      .
Calamagrostis arundinacea     .      .      .      .
Allium scorzonerifolium       .      .      .      .
Anemone albida                .      .      .      .
Epilobium obscurum            .      .      .      .
Galium broterianum            .      .      .      .
Hieracium vulgatum            .      .      .      .
Paradisea lusitanica          .      .      .      .
Quercus pyrenaica             .      +      .      .
Silene vulgaris               +      +      .      .

Characteristics of Hyperico-Alnenion

Hypericum androsaemum         IV     II     IV     I
Senecio nemorensis            II     .      II    III

Characteristics of Populetalia albae and Salici-Populetea nigrae

Athyrium filix-femina         V      V      V      V
Salix atrocinerea             IV     IV     IV     V
Brachypodium sylvaticum       II     IV     +      I
Osmunda regalis               II     +      II     II
Ranunculus ficaria            I      I      .      +
Circaea lutetiana             I      .      .      .
Arum italicum                 I      .      .      .

Characteristics of Fagetalia

Euphorbia dulcis              IV     V      IV    III
Fraxinus excelsior            V      V      +      I
Mercurialis perennis         III    III     +      I
Lysimachia nemorum            I      +      I      I
Prunus avium                  I      II     .      .
Pulmonaria longifolia         I      .      +      I
Potentilla sterilis           I      +      +      .
Stachys sylvatica             +      +      .      .
Allium ursinum                +      +      .      .

Characteristics of Querco-Fagetea

Betula pubescens              II    III    III     V
Blechnum spicant              V     III     V      V
Corylus avellana              V      V      V      II
Saxifraga spathularis         V     III     V      IV
Luzula henriquesii            IV     IV    III     II
Anemone nemorosa              II     +      II     I
Hyacinthoides non-scripta     II     I      II     +
Euphorbia hyberna             I      +      I      .
Lathyrus linifolius           I      +      +      .
Avenella flexuosa             I      +      II    III
Fagus sylvatica               I      I      +      .
Dryopteris filix-mas          II     II     I      .
Hypericum pulchrum            .      I      +      +
Melittis melissophyllum       I      +      .      .
Physospermum cornubiense      +      +      .      I
Salix caprea                  I      II     .      .
Stachys officinalis           I      .      I      I
Sanicula europaea             I      +      I      .
Taxus baccata                 I      .      +      .

Companions

Omphalodes nitida             II     II    III     II
Heracleum sphondylium        III     I      +      I
Caltha palustris              I      .      I      I
Erica arborea                 I      I      II     IV
Carex laevigata               I      +     III    III
Pteridium aquilinum           I      I      I     III
Rubus sp.                     V      II     V      V
Viola palustris               II     +     III     IV
Dactylis glomerata            I     III     +     III
Ranunculus repens             I      II     +      II
Digitalis purpurea            I      +     III    III
Rumex acetosa                 II     II     II     I
Arrhenatherum bulbosum        I      I      I     III
Juncus effusus                I      II     I      I
Cirsium palustre              .      I      I      I
Carex reuteriana              I      .      +     III
Oenanthe crocata              II     .      +     III
Scrophularia auriculata       I      .      I      I
Adenostyles hybrida           II     II     II     I
Silene dioica                 II    III     I      I
Lastrea limbosperma           I      +      II     I
Centaurea nigra               I      II     .     III
Saxifraga lepismigena         I     III     .      I
Cardamine pratensis           II     +      IV     I
Anthoxanthum odoratum         I      II     I      +
Umbilicus rupestris           I      I      I      I
Myosotis sp.                  I      +      +      +
Cardamine hirsuta             +      +      +      +
Potentilla erecta             .      .      I      I
Lotus pedunculatus            .      II     .      +
Agrostis capillaris           I      .      II    III
Brachypodium rupestre         I      .      I     III

Number of releves             9      5      37
Mean number of taxa           32     18     30
Releve number                 5      6      7

Differential taxa

Lonicera periclymenum         IV     +     III
Dryopteris afffinis s.l.      IV     .      IV
Teucrium scorodonia          III     +      I
Crepis lampsanoides           IV     +     III
Stellaria holostea            II     .      I
Viola riviniana               II     .     III
Frangula alnus                II     .      I
Primula acaulis               II     +      I
Crataegus monogyna            II     .      I
Oxalis acetosella             .      V      II
Dryopteris dilatata           .      II     I
Holcus mollis                 II     .      +
Polypodium vulgare            II     .      .
Sorbus aucuparia              .      V      .
Vaccinium myrtillus           .      V      +
Ilex aquifolium               .      II     .
Ranunculus tuberosus          .     III     .
Carex remota                  .      .      IV
Acer pseudoplatanus           +      .     III
Sambucus nigra                .      .      II
Aquilegia vulgaris            .      .      II
Euphorbia amygdaloides        .      .     III
Solidago virgaurea            .      .      I
Castanea sativa               +      .      .
Hedera hibernica             III     .     IV *
Deschampsia cespitosa         II     .      I
Quercus robur                 II     +      +
Chaerophyllum hirsutum        .      V      II
Polygonatum verticillatum     .     III     .
Valeriana pyrenaica           .      +     III
Polystichum setiferum         .      .      IV
Festuca gigantea              .      .      IV
Scrophularia alpestris        .      .      I
Angelica sylvestris           +      .     III
Carex sylvatica               .      .      I
Ajuga reptans                 .      .      I
Dryopteris aemula             .      .      .
Pyrus cordata                 +      .      .
Valeriana montana             .      .      .
Ulmus glabra                  .     III     I
Melica uniflora               .      .      I
Poa nemoralis                 .     III     IV
Cardamine impatiens           .      .      .
Milium effusum                .      .      .
Veronica montana              .      .      +
Helleborus occidentalis       .      .      .
Phyllitis scolopendrium       .      .      +
Ruscus aculeatus              .      .      +
Laurus nobilis                .      .      I
Carex pendula                 .      .      II
Woodwardia radicans           .      .      +
Hymenophyllum tunbrigense     .      .      .
Alnus glutinosa               .      .      V
Tamus communis                .      .      I
Daphne laureola               .      IV     .
Arbutus unedo                 .      .      .
Asplenium onopteris           .      .      .
Culcita macrocarpa            .      .      .
Rubia peregrina               .      .      .
Hedera helix                  .      .      .
Festuca rubra                 .      .      .
Epilobium parviflorum         .      .      .
Galium odoratum               .      .      .
Astrantia major               .      .      .
Polystichum aculeatum         .      .      .
Agrostis x fouilladei        III     .      .
Aquilegia dichroa            III     .      .
Calamagrostis arundinacea    III     .      .
Allium scorzonerifolium       II     .      .
Anemone albida                II     .      .
Epilobium obscurum            II     .      .
Galium broterianum            II     .      .
Hieracium vulgatum            II     .      .
Paradisea lusitanica          II     .      .
Quercus pyrenaica             II     .      .
Silene vulgaris               II     .      +

Characteristics of Hyperico-Alnenion

Hypericum androsaemum         .      .      IV
Senecio nemorensis            .      .     III

Characteristics of Populetalia albae and Salici-Populetea nigrae

Athyrium filix-femina         V      IV     V
Salix atrocinerea             V      IV     V
Brachypodium sylvaticum       II     .      V
Osmunda regalis               II     .      IV
Ranunculus ficaria            +      .      .
Circaea lutetiana             .      .     III
Arum italicum                 .      .      I

Characteristics of Fagetalia

Euphorbia dulcis              V      V     III
Fraxinus excelsior            .      .      V
Mercurialis perennis          .      .      +
Lysimachia nemorum            .      .      I
Prunus avium                  II     .      .
Pulmonaria longifolia         .      .      I
Potentilla sterilis           .      .      .
Stachys sylvatica             .      .      I
Allium ursinum                .      +      .

Characteristics of Querco-Fagetea

Betula pubescens              V      V      I
Blechnum spicant              IV     V      II
Corylus avellana              II    III    III
Saxifraga spathularis         II     IV     II
Luzula henriquesii            IV     V     III
Anemone nemorosa              +      .      I
Hyacinthoides non-scripta     .      +      .
Euphorbia hyberna             +      +      .
Lathyrus linifolius           IV     .      .
Avenella flexuosa             .      .      .
Fagus sylvatica               .      +      .
Dryopteris filix-mas          .      .      .
Hypericum pulchrum            .      .      .
Melittis melissophyllum       +      .      .
Physospermum cornubiense      .      .      .
Salix caprea                  .      +      .
Stachys officinalis           .      .      +
Sanicula europaea             .      .      .
Taxus baccata                 .      +      .

Companions

Omphalodes nitida             V      IV     II
Heracleum sphondylium         II     +      I
Caltha palustris              II     II     I
Erica arborea                 V      V      .
Carex laevigata               II     +      .
Pteridium aquilinum           +      II     .
Rubus sp.                     .      II     V
Viola palustris               II     .      I
Dactylis glomerata            +      .      II
Ranunculus repens             +      .      I
Digitalis purpurea           III     .      .
Rumex acetosa                III     .      .
Arrhenatherum bulbosum        II     .      .
Juncus effusus                II     .      .
Cirsium palustre             III     IV     .
Carex reuteriana              V      .      IV
Oenanthe crocata             III     .     III
Scrophularia auriculata       II     .     III
Adenostyles hybrida           .      IV     .
Silene dioica                 .      .     III
Lastrea limbosperma           .      .      I
Centaurea nigra               II     .      +
Saxifraga lepismigena         II     .      I
Cardamine pratensis           .      .      .
Anthoxanthum odoratum         .      .      .
Umbilicus rupestris           .      .      .
Myosotis sp.                  .      .      .
Cardamine hirsuta             .      .      .
Potentilla erecta             II     .      .
Lotus pedunculatus            II     +      .
Agrostis capillaris           II     .      .
Brachypodium rupestre         II     .      .

Other species: Characteristics of Populetalia albae and
Salici-Populetea nigrae: Stegnogrammapozoi +, Malus sylvestris and
Symphytum tuberosum I in 1; Prunuspadus + in 2; Malus sylvestris +
in 3; Fraxinus angustifolia + in 5. Characteristics of Fagetalia
sylvaticae: Conopodium majus and Saxifraga hirsuta I in 1;
Saxifraga hirsuta and Tilia platyphyllos + in 2;
Ornithogalumpyrenaicum + in 5. Characteristics of Querco-Fagetea:
Ceratocapnos claviculata and Sorbus aria +, Helle- borus foetidus,
Quercuspetraea and Quercus x rosacea I in 1; Hieracium murorum and
Melampyrumpratense +, Helleborus foetidus and Viola gr. sylvestris
I, Quercus petraea IV in 2; Ceratocapnos claviculata+ in 4; Lilium
martagon + in 5. Precedence of releves: 1:
Valerianopyrenaicae-Fraxinetum excelsioris, synthetic table from
tables 2, 3 and 4 of this paper; 2: Festuco giganteae-Fraxinetum
excelsioris, synthetic table from Diaz Gonzalez & Fernandez Prieto
(1994), Table 5, 13 rels. and Rodriguez Guitian & al. (2001), Table
6, 7 rels.; 3: Hyperico androsaemi-Coryletum avellanae, synthetic
table from table 5 of this paper; 4: Violo palustris-Betuletum
pubescentis, synthetic table from table 6 of this paper; 5: Carici
reuterianae-Betuletum celtibericae, synthetic table from Honrado &
al. (2002), Table 1, 9 rels.; 6: Luzulo henriquesii-Betuletum
celtibericae subass. salicetosum atrocinereae, synthetic table from
Izco & al. (1986), Table 3, rels. 8 to 12; 7:
Valerianopyrenaicae-Alnetum glutinosae, synthetic table from amigo
& al. (1987), Table 3, 37 rels.

Table 8

Conservation value of the riparian forests studied based on presence
of protected species of vascular plants and bryophytes. Protection
orders: DC 92/43/CEE: annexes of the Directive 92/43/EEC; CREAPA:
Catalogo Regional de Especies Amenazadas del Principado de Asturias;
CGEA: Catalogo Galego de Especies Ameazadas. IE: species of special
interest; EP: species in risk of extintion; VU: vulnerable species.
Forest types: V-F: Valerianopyrenaicae-Fraxinetum excelsioris, H-C
(Hyperico androsaemi-Coryletum avellanae),V-B: Violo
palustris-Betuletum pubescentis. Frecuency (% of presence in
releves): * low (<10 %); **: medium (10-25 %); ** : high (>25%).

                                          Protection
Taxa                        92/43/CEE    order CREAPA   CGEA

Culcita macrocarpa              II            IE         EP
Dryopteris aemula             - - -         - - -        VU
Hymenophyllum tunbrigense     - - -         - - -        VU
Ilex aquifolium               - - -           IE        - - -
Narcissus asturiensis           II          - - -        VU
Ruscus aculeatus                V           - - -       - - -
Sphagnum spp.                   V           - - -       - - -
Taxus baccata                 - - -           IE        - - -
Woodwardia radicans             II            IE         VU

                                  Forest type

Taxa                         V-F     H-C     V-B

Culcita macrocarpa            *       *     - - -
Dryopteris aemula             *      **      ***
Hymenophyllum tunbrigense    **      **       *
Ilex aquifolium              ***     ***     **
Narcissus asturiensis         *      ***     **
Ruscus aculeatus             ***     ***      *
Sphagnum spp.               - - -     *       *
Taxus baccata                 *       *     - - -
Woodwardia radicans          ***     **     - - -
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Author:Rodriguez Guitian, Manuel Antonio
Publication:Lazaroa
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Date:Jan 1, 2010
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