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Macrophytes assemblages in mountain lakes of Huerquehue National Park (39[degrees]S, Araucania Region, Chile)/Ensambles de macrofitas en lagos de montana del Parque Nacional Huerquehue (39[grados]S, Region de la Araucania, Chile.

The Chilean lakes of the north Patagonia are characterized by their oligotrophy, due to the native forest and chemical composition of the soil of their basin that avoid the nutrient entry from the land to the water, mainly in unpolluted mountain zones (Soto, 2002; Steinhart et al., 2002). Nevertheless, an oligotrophy to mesotrophy transition has been observed in some lakes located mainly between 38 to 41[degrees]S, due to the replacing of the native forest of their basin by agricultural zones, towns and industries (Soto, 2002). One of the biotic components that can be an indicator of trophic status is the assemblage of macrophytes (Hauenstein et al., 2002; Nagasaka, 2004; Li et al., 2009). We define macrophytes according to Ramirez & Stegmeier (1982). The macrophytes in Chilean inland waters have numerous endemic species (79.3%) and a low amount of introduced species (20.7%); there are endangered species that would need more studies about conservation topics (Hauenstein, 2006), specially if we consider that some Chilean lagoons close to coastal zones, and small stands of plants in the lakes have human intervention (Soto, 2002; Hauenstein et al., 2008), with the consequent alterations in macrophytes assemblages (Hauenstein et al., 2002; Ramirez & San Martin, 2006).

According to this point of view, the macropytes and riparian assemblages are not random, that means that the regulator factors are deterministic. The absence of regulator factors, this is random distribution in species co-occurrence, is the basis of null models; one of these models used presence and absence of species to determine the absence of deterministic factors as regulator of co-occurrence species (Gotelli, 2000; Tiho & Johens, 2007). These null models are more robust in comparison with deterministic models (Gotelli, 2000). The aim of the present study is applying a null model analysis based in a presence-absence species matrix for determining the absence regulator factors to explain species associations in macrophytes of lakes in Huerquehue National Park.

Between December 2005 to March 2006 we worked in four lakes of a mountainous zone with Nothofagus alpina, N. pumilio, N. dombeyi and Araucaria araucana forests: Tinquilco Lake, at the main access of Huerquehue National Park (39[degrees]10'00"S, 71[degrees]43'25"W; 763 m a.s.l); it receives many small streams from the mountains. One of these streams called Tinquilco, is the effluent of a network of at least three lakes located higher in the mountains, Verde (39[degrees]08'10"S, 71[degrees]42'33"W; 1254 m a.s.l), Toro (39[degrees]08'20"S, 71[degrees]42'33"W; 1245 m a.s.l) and Chico (39[degrees]08'21"S, 71[degrees]42'33"W; 1240 m a.s.l), which are connected to each other by small streams, these studied lakes are oligotrophic with chlorophyll concentrations of 1.6; 2.0; 1.5 and 1.9 [gL.sup.-1] respectively (De los Rios et al., 2007).

The riparian and macrophyte species were collected and identified, according to Matthei (1995), Espinoza (1996) and Hoffmann et al. (1997); the scientific names updated by means of Zuloaga et al. (2008) and in the following page web: (http://www. ipni.org/). The taxonomical classification and the phytogeographical origin, according to Marticorena & Quezada (1985), and the helophytes and hydrophytes taxa, according to the classification of Ramirez & Stegmeier (1982) and Ramirez & San Martin (2006). The degree of human intervention was determined on the basis, according to the proposal of Hauenstein et al. (1988) and the scale of assessment proposed by Gonzalez (2000), who used the phytogeographical origin (percentage relationship between native and the introduced species) to establish the degree of human disturbance of a specific area.

The comparison of the data set gathered is useful to test the hypothesis that species reported are non-randomly associated. For this, we use the "C score" index (Tiho & Johens, 2007), which determines the presence-absence co-occurrence based on presence absence matrices for zooplankton species in the sample. According to Gotelli (2000) and Tiho & Johens (2007) the presence/absence matrix was analysed as follows: (a) fixed-fixed: in this algorithm, the row and the column sums of the original matrix are preserved. Thus, each random community contains the same amount of species as the original community (fixed column), and each specie occurs with the same frequency as in the original community (fixed row). In this case, it is not prone to type I errors (falsely rejecting the null hypothesis) and it has a good power for detecting the non-randomness (Gotelli, 2000; Tiho & Johens, 2007). (b) Fixed-equiprobable: in this simulation, only the row sums are fixed, whereas the columns are treated as equiprobable. This null model treats all the samples (columns) as equally suitable for all species (Tiho & Johens, 2007; Gotelli, 2000). (c) Fixed-proportional: in this algorithm, the total of species occurrence is maintained as in the original community, and the probability that a specie occurs in a sample (= column) is proportional to the total column for that sample (Gotelli, 2000; Tiho & Johens, 2007). The data were analysed with the Ecosim program version 7.0 (Gotelli & Entsminger, 2009). Finally, it was applied a Jaccard index for determining the similarities between the studied sites (Gotelli & Graves, 1996), this analysis was applied using the software Biodiversity Pro. 2.0.

The results of the floristic analysis revealed the presence of 75 species (74 vascular plants and one non vascular plant) and, in decreasing order, the lakes with more species were Tinquilco, Toro, Chico and Verde with 54; 28; 22 and 21 species respectively. Table 1 shows the complete and current catalogue. The more represented species are Magnoliopsida with 58% and Liliopsida with 37%. The total flora includes 5 classes, 32 families and 50 genus, with a different distribution between the lakes: four classes, 27 families and 45 genus were found in Tinquilco Lake, in Toro Lake, four classes, 22 families and 56 genus, in Chico Lake, three classes, 16 families and 19 genus, and finally in Verde Lake, three classes, 14 families and 18 genus (Table 1).

In the Great Lakes of the region of the Andean precordillera so-called "Araucanians", whose waters are oligotrophic and the lakes have a much larger surface area in study (Campos, 1984; Soto & Campos, 1995), there has been a greater variability in the richness of flora. While the lakes Llanquihue and Cayutue presented a richness of species similar to the lakes of this study, 40 and 37 respectively (Hauenstein et al., 1991, 1992), the lakes Villarrica, Caburgua and Calafquen are richer in diversity of species, registering 65, 64 and 69 species respectively (Hauenstein et al., 1996, 1998), of which the only one that presents characteristics of mesotrophy condition is Villarrica Lake, with values of 87 ug [L.sup.-1] de N[O.sub.3] y de 20.4 ug [L.sup.-1] of total phosphorus (Soto & Campos, 1995). The low amount of species of the four lakes surveyed confirms the oligotrophic character of their waters.

The phytogeographical origin shows that in the four lakes surveyed the native species are dominant (Table 1, Fig. 1). The relatively low percentage of non-native species indicates a certain anthropized degree on their banks (Hauenstein et al., 1988), which would below, according to the scale of Gonzalez (2000), to the category of "low human disturbance" for the three lakes of higher altitude (Verde, Toro and Chico), since it does not exceed 20% of allochthonous species (14.3, 17.9, 18.2% respectively); instead the Tinquilco Lake has a percentage of allochthonous (32%), that has classified it in the category of "high human disturbance".

[FIGURE 1 OMITTED]

The results of null model analysis revealed the existence of regulator factors in species assemblages for Fixed-Fixed simulation (P < 0.005), whereas these results do not correspond to the Fixed-Proportional (P < 0.899) and Fixed-Equiprobable simulations (P < 0.999). A possible cause would be the presence of many repeated species (Table 2). In according to Bray-Curtis index, the most similar sites were lakes Verde and Chico with 45.5% of floristic similitude, Toro Lake has a floristic similitude of 41%, and finally Tinquilco Lake with only 29% (Fig. 2). This difference between Tinquilco Lake and other lakes studied, it is probably due to its lower altitude and the increasing presence of the human population in its banks, which is expressed in an increase of non-native species and in a greater contribution of nutrients (N and P) in its waters; on the other hand, the Verde, Chico and Toro lakes are pristine and surrounded by native forests (Steinhart et al., 2002; De los Rios et al., 2007).

The results about littoral macrophytes are similar to the descriptions of mountain lakes; where the macrophytes are present contributing a high oxygen concentration (Nagasaka, 2004; Li et al., 2009). The high amount of species in Tinquilco Lake would be probably related to the transition from oligotrophy to mesotrophy observed in this lake (De los Rios et al., 2007), these patterns are similar to other lakes of the same category, with changes in trophic status, where ultraoligotrophic lakes have a low amount of species and abundance (Nagasaka, 2004; Li et al., 2009).

Similar results of low amount of macrophytes species associated to diversity were observed for coastal wetlands in the Araucania region with different trophic status due to human intervention (Hauenstein et al., 2002; Pena-Cortes et al., 2006). By his part, Ramirez & San Martin (2006) signal that the aquatic flora is scarce in water bodies oligotrophic and that this tends to situate in slots well delimited in the littoral zone, process known as zoning, which depends of habit of the species (submerged, floating, emergent).

[FIGURE 2 OMITTED]

These results are the first observations for pristine mountain lakes of the north Patagonia, because this condition generates a different regulator mechanism in comparison to lakes of the north hemisphere (Soto, 2002; Steinhart et al., 2002).

DOI: 10.3856/vol39-issue3-fulltext-19

ACKNOWLEDGEMENTS

The present paper was funding by the projects DGIPUCT 2005-04-11 and 2009-3-6, and it was recognized the logistic support of staff of Huerquehue National Park CONAF-Chile (Forestry National Corporation, Chile).

REFERENCES

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De los Rios, P., E. Hauenstein, P. Acevedo & X. Jaque. 2007. Littoral crustaceans in mountain lakes of Huerquehue National Park (38[degrees]S, Araucania Region, Chile). Crustaceana, 80: 401-410.

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Gotelli, N.J. & G.R. Graves. 1996. Null models in ecology. Smithsonian Institution Press, Washington DC., 357 pp.

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Munoz-Pedreros. 2002. Clasificacion y caracterizacion de la flora y vegetacion de los humedales de la costa de Tolten (IX Region, Chile). Gayana Bot., 59: 87-100.

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Hauenstein, E., F. Pena-Cortes, C. Bertran, J. Tapia & R. Schlatter. 2008. Comparacion floristica y estado trofico basado en plantas indicadoras de lagunas costeras de la region de La Araucania, Chile. Ecol. Austr., 18: 45-53.

Hauenstein, E., C. Ramirez, M. Gonzalez, L. Leiva & C. San Martin. 1996. Flora hidrofila del lago Villarrica (IX Region, Chile) y su importancia como elemento indicador de contaminacion. Medio Ambiente, 13(1): 88-96.

Hoffmann, A., M. Kalin, F. Liberona, M. Munoz & J. Watson. 1997. Plantas altoandinas en la flora silvestre de Chile. Edicion Fundacion Claudio Gay, Santiago, 281 pp.

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Nagasaka, M. 2004. Changes in biomass and spatial distribution of Elodea nuttallii (Planch.) St. John, an invasive submerged plant, in oligomesotrophic Lake Kizaki from 1999 to 2002. Limnology, 5: 129-139.

Pena-Cortes, F., P. Gutierrez, G. Rebolledo, M. Escalona, E. Hauenstein, C. Bertran, R. Schlatter & J. Tapia. 2006. Determinacion del nivel de antropizacion de humedales como criterio para la planificacion ecologica de la cuenca del lago Budi, IX Region de la Araucania, Chile. Rev. Geogr. Norte Grande, 36: 7591.

Ramirez, C. & C. San Martin. 2006. Diversidad de macrofitos chilenos. In: I. Vila, A. Veloso, R. Schlatter & C. Ramirez (eds.). Macrofitos y vertebrados de los sistemas limnicos de Chile. Editorial. Universitaria, Santiago, pp. 21-72.

Ramirez, C. & E. Stegmeier. 1982. Formas de vida en hidrofitos chilenos. Medio Ambiente, 6(1): 43-54.

Soto, D. 2002. Oligotrophic patterns in southern Chile lakes: the relevance of nutrients and mixing depth. Rev. Chil. Hist. Nat., 75: 377-393.

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Steinhart, G.S., G.E. Likens & D. Soto. 2002. Physiological indicators of nutrient deficiency in phytoplankton of southern Chilean lakes. Hydrobiologia, 489: 21-27.

Tiho, S. & J. Johens. 2007. Co-occurrence of earthworms in urban surroundings: a null models of community structure. Eur. J. Soil. Biol., 43: 84-90.

Zuloaga, F., O. Morrone & M. Belgrano. 2008. Catalogo de las plantas vasculares del Cono Sur (Argentina, Sur de Brasil, Chile, Paraguay). URL: http://www. darwin.edu.ar/Proyectos/FloraArgentina/Especies.asp

Received: 11 June 2010; Accepted: 17 August 2011

Enrique Hauenstein (1), Fabiola Barriga (1), Patricio de los Rios-Escalante (1)

(1) Escuela de Ciencias Ambientales, Facultad de Recursos Naturales Universidad Catolica de Temuco, Temuco, Chile

Corresponding author: Enrique Hauenstein (ehauen@uct.cl)
Table 1. Catalogue of macrophytes in four lakes of the Huerquehue
National Park. X: presence, empty space: absence; N: native,
I: introduced.

Tabla 1. Catalogo de macrofitas en cuatro lagos del Parque Nacional
Huerquehue. X: presencia, espacio en blanco: ausencia;
N: nativa, I: introducida.

Species                        Family             Origin

                                                           Verde

CHAROPHYCEAE
Nitella sp.                    Characeae            N
SPHENOPSIDA
Equisetum bogotense            Equisetaceae         N
  Kunth
FILICOPSIDA
Blechnum penna-marina          Blechnaceae          N
  (Poir.) Kuhn
Isoetes savatieri Franch.      Isoetaceae           N        X
MAGNOLIOPSIDA
Acaena ovalifolia              Rosaceae             N        X
  Ruiz & Pav.
Anagallis alternifolia Cav.    Primulaceae          N        X
Anagallis arvensis L.          Primulaceae          I
Azara lanceolata Hook. f.      Flacourtiaceae       N
Baccharis sp.                  Asteraceae           N
Berberis sp.                   Berberidaceae        N
Callitriche palustris L.       Callitrichaceae      I
Callitriche terrestris DC.     Callitrichaceae      N        X
Drimys andina (Reiche) R.A.    Winteraceae          N
  Rodr. & Quezada
Drimys winteri J.R. Forst.     Winteraceae          N
  & G. Forst.
Escallonia virgata Pers.       Escalloniaceae       N        X
Galium aparine L.              Rubiaceae            I        X
Geum magellanicum Lechler      Rosaceae             N
  ex Sheutz
Gratiola peruviana L.          Scrophulariaceae     N
Gunnera magellanica Lam.       Gunneraceae          N        X
Hydrocotyle chamaemorus        Apiaceae             N        X
  Cham. & Schltdl.
Hydrocotyle                    Apiaceae             N
  ranunculoides L.f.
Hypochaeris radicata L.        Asteraceae           I
Lotus pedunculatus Cav.        Fabaceae             I        X
Mentha aquatica L.             Lamiaceae            I
Myosotis scorpioides L.        Boraginaceae         I
Myrceugenia exsucca O. Berg    Myrtaceae            N
Myriophyllum aquaticum         Haloragaceae         N        X
  (Vell.) Verdc.
Nasturtium officinale R.Br.    Brassicaceae         I
Nothofagus pumilio             Fagaceae             N
  (Poepp. & Endl.) Krasser
Oldenlandia salzmannii         Rubiaceae            N
  (DC.) Benth. & Hook. f.
Osmorhiza chilensis            Apiaceae             N
  Hook. & Arn.
Perezia pedicularifolia        Asteraceae           N
  Less.
Plantago lanceolata L.         Plantaginaceae       I
Plantago major L.              Plantaginaceae       I        X
Polygonum hydropiperoides      Polygonaceae         I
  Michx.
Potentilla anserina L.         Rosaceae             I
Prunella vulgaris L.           Lamiaceae            I
Ranunculus bonariensis Poir.   Ranunculaceae        N
Ranunculus sp.                 Ranunculaceae        I
Rubus constrictus Lefevre      Rosaceae             I
  & P. J. Mull.
Rumex conglomeratus Murr.      Polygonaceae         N
Rumex crispus L.               Polygonaceae         I
Senecio fistulosus             Asteraceae           N        X
  Poepp. ex Less.
Taraxacum officinale           Asteraceae           I
  Weber ex F.H. Wigg.
Trifolium pratense L.          Fabaceae             I
Trifolium repens L.            Fabaceae             I
LILIOPSIDA
Agrostis capillaris L.         Poaceae              I
Bromus sp.                     Poaceae              N
Carex decidua Boott            Cyperaceae           N        X
Carex distenta Kunze           Cyperaceae           N
  ex Kunth
Carex inconspicua Steud.       Cyperaceae           N        X
Carex macloviana d'Urv.        Cyperaceae           N
Carex sp.                      Cyperaceae           N
Chusquea montana Phil.         Poaceae              N
  f. montana
Cortaderia pilosa              Poaceae              N        X
  (d'Urv.) Hackel
Dactylis glomerata L.          Poaceae              I
Eleocharis acicularis          Cyperaceae           N        X
  (L.) Roem. & Schult.
Eleocharis pachycarpa          Cyperaceae           N
  C.B. Clarke
Eleocharis palustris           Cyperaceae           N        X
  (L.) Roem. & Schult.
Holcus lanatus L.              Poaceae              I
Juncus imbricatus Laharpe      Juncaceae            N
Juncus pallescens Lam.         Juncaceae            N
Juncus procerus E. Mey.        Juncaceae            N
Juncus cyperoides Laharpe      Juncaceae            N
Nothoscordum striatellum       Alliaceae            N
  (Lindl.) Kunth
Paspalum dasypleurum Desv.     Poaceae              N
Poa sp.                        Poaceae              N
Polypogon australis Brongn.    Poaceae              N
Potamogetum linguatus Hagstr.  Potamogetonaceae     N
Rostraria cristata             Poaceae              I
  (L.) Tzvelev
Scirpus californicus           Cyperaceae           N        X
  (C.A.Mey.) Steud. var.
  tatora (Kunth) Barros
Scirpus inundatus (R.Br.)      Cyperaceae           N        X
  Spreng.
Sisyrinchium pearcei Phil.     Iridaceae            N
Trisetum sp.                   Poaceae              N        X

Species                               Lake

                               Toro   Chico   Tinquilco

CHAROPHYCEAE
Nitella sp.                     X
SPHENOPSIDA
Equisetum bogotense                               X
  Kunth
FILICOPSIDA
Blechnum penna-marina           X       X         X
  (Poir.) Kuhn
Isoetes savatieri Franch.       X       X         X
MAGNOLIOPSIDA
Acaena ovalifolia               X       X
  Ruiz & Pav.
Anagallis alternifolia Cav.                       X
Anagallis arvensis L.                             X
Azara lanceolata Hook. f.       X
Baccharis sp.                                     X
Berberis sp.                    X
Callitriche palustris L.        X       X
Callitriche terrestris DC.      X
Drimys andina (Reiche) R.A.     X
  Rodr. & Quezada
Drimys winteri J.R. Forst.                        X
  & G. Forst.
Escallonia virgata Pers.        X       X         X
Galium aparine L.                       X         X
Geum magellanicum Lechler       X
  ex Sheutz
Gratiola peruviana L.                             X
Gunnera magellanica Lam.        X       X
Hydrocotyle chamaemorus                 X         X
  Cham. & Schltdl.
Hydrocotyle                     X                 X
  ranunculoides L.f.
Hypochaeris radicata L.                           X
Lotus pedunculatus Cav.         X                 X
Mentha aquatica L.                                X
Myosotis scorpioides L.                           X
Myrceugenia exsucca O. Berg     X                 X
Myriophyllum aquaticum          X       X         X
  (Vell.) Verdc.
Nasturtium officinale R.Br.             X
Nothofagus pumilio              X       X
  (Poepp. & Endl.) Krasser
Oldenlandia salzmannii                            X
  (DC.) Benth. & Hook. f.
Osmorhiza chilensis                               X
  Hook. & Arn.
Perezia pedicularifolia                 X
  Less.
Plantago lanceolata L.                            X
Plantago major L.
Polygonum hydropiperoides                         X
  Michx.
Potentilla anserina L.                            X
Prunella vulgaris L.            X                 X
Ranunculus bonariensis Poir.            X
Ranunculus sp.                  X                 X
Rubus constrictus Lefevre                         X
  & P. J. Mull.
Rumex conglomeratus Murr.                         X
Rumex crispus L.                                  X
Senecio fistulosus                      X
  Poepp. ex Less.
Taraxacum officinale                              X
  Weber ex F.H. Wigg.
Trifolium pratense L.                             X
Trifolium repens L.                               X
LILIOPSIDA
Agrostis capillaris L.          X       X         X
Bromus sp.                      X
Carex decidua Boott             X       X
Carex distenta Kunze            X                 X
  ex Kunth
Carex inconspicua Steud.                X         X
Carex macloviana d'Urv.         X                 X
Carex sp.                               X
Chusquea montana Phil.          X
  f. montana
Cortaderia pilosa
  (d'Urv.) Hackel
Dactylis glomerata L.                             X
Eleocharis acicularis                             X
  (L.) Roem. & Schult.
Eleocharis pachycarpa                             X
  C.B. Clarke
Eleocharis palustris            X                 X
  (L.) Roem. & Schult.
Holcus lanatus L.                                 X
Juncus imbricatus Laharpe                         X
Juncus pallescens Lam.                            X
Juncus procerus E. Mey.                           X
Juncus cyperoides Laharpe                         X
Nothoscordum striatellum                          X
  (Lindl.) Kunth
Paspalum dasypleurum Desv.                        X
Poa sp.                                           X
Polypogon australis Brongn.                       X
Potamogetum linguatus Hagstr.           X         X
Rostraria cristata                                X
  (L.) Tzvelev
Scirpus californicus            X       X         X
  (C.A.Mey.) Steud. var.
  tatora (Kunth) Barros
Scirpus inundatus (R.Br.)               X         X
  Spreng.
Sisyrinchium pearcei Phil.                        X
Trisetum sp.

Table 2. Results of the null model analysis for studied sites.
P < 0.05 denote presence of non random (or regulator) factors
as regulator of the species association.

Tabla 2. Resultados del analisis de modelo nulo para los sitios
estudiados, valores de P < 0,05 denotan la presencia de factores
no aleatorios (o reguladores) de la asociacion de especies.

                     Observed   Mean    Standard     P
                      index     index    effect
                                          size

Fixed-Fixed           0.597     0.544     3.533    0.005
Fxed-Proportional     0.597     0.655    -1.320    0.899
Fixed-Equiprobable    0.597     0.735    -8.715    0.999
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Title Annotation:texto en ingles
Author:Hauenstein, Enrique; Barriga, Fabiola; de los Rios-Escalante, Patricio
Publication:Latin American Journal of Aquatic Research
Date:Nov 1, 2011
Words:3396
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