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A review on invasive plants in rangelands of Argentina/Una revision de las plantas invasoras en pastizales Argentinos/Uma revisao das plantas invasoras em pasticais Argentinos.

Scientific and societal awareness of the problems linked with the invasion of non-native plant species into the Argentine rangelands has increased lately due to their eventual economical and ecological harm on native ecosystems (Klich, 2005; Bezic, 2010). The recognition of the problems related to plant invasions into local rangelands has grown considerably because of the negative effects of some non-native species have became too evident to be ignored (Vigna and Lopez, 2008; Bezic, 2010). Another point is that the number of alien species introduced into novel locations appears to be growing (Cipriotti et al., 2010). This question is critical in a country where about two thirds of its 2.8 x [10.sup.6] [km.sup.2], extending from 22[degrees] to 55[degrees]S, are associated with arid and semi-arid rangeland ecosystems (Fernandez and Busso, 1999). Rangeland vegetation provides the forage for livestock production in a country whose major economical activities are the production of grains and meat (www.surdelsur.com/economia/ indexing/es. html).

As in many other parts of the world, anthropogenic perturbations are considered the main cause assisting plant invasions on the Argentine rangelands (Cipriotti et al., 2006, 2010). In the long term, these disturbances are associated with changes in 1) community structure, 2) soil resource availability, and 3) the creation of open areas accessible for to the establishment of non-native species (Vila, 1998; Castro Diezo et al., 2004). Disturbing factors have included timber extraction, uncontrolled fuel wood harvesting, plowing of non-arable lands and the development of a livestock grazing industry based on the overutilization of natural ecosystem vegetation (Fernandez and Busso, 1999). The massive addition of new, non-native herbivores with their own foraging behavior was critical in a region where large herbivores were very scarce from the end of the Pleistocene to the European colonization (Webb, 1978). Herbivory is considered as one of the main causes in disturbing arid and semi-arid ecosystems of the country (Fernandez and Busso, 1999). Major environmental impacts as a result of rangeland livestock mismanagement have included shifts in species composition, changes in community structure and soil erosion (Fernandez et al., 2009). Even further, Hierro et al. (2005, 2006) have shown that the effects of disturbances on the abundance, size and fecundity of exotic, invader weeds have been greater at the place of exotic weed introduction than at that of origin.

Most of the invasive plants in Argentina (39%) came exclusively from Europe (Table I). However, the precise information about their date and pathway of entry or location of release is known only for very few species. Despite the awareness that they often cause substantial ecological and economical problems, we are short of experimental information about the reasons of their success as colonizers, or their environmental and economic impacts on native ecosystems. Increased understanding of invasions, in turn, has the potential to provide unique insights into fundamental ecological theory, including that on 1) top-down vs bottom-up control of communities, 2) disturbances as drivers of invasions, and 3) the role of soil microbes in regulating plant populations and interactions among species. This information is critical for developing management practices that allow avoidance of establishment or reductions in abundance of invasive plant species.

Clements et al. (2004) indicated that the ecological theory on invader species is highly applicable to weeds that affect agricultural as well as rangeland ecosystems. A perennial plant species can be considered as invader if it proliferates effectively, and grows vigorously, within a wide environmental tolerance but it is also difficult to control (Bezic, 2010). In the whole world, various exotic species threaten the integrity of rangelands and agricultural systems [e.g., North America: Di Tomaso, 2000; Argentina: Zalba et al, 2008; other countries in Central America (e.g., Nicaragua: http://www.issg.org/database/species/search.asp?sts=sss&st=sss&f r=1&sn=&rn=Nicaragua&hci=-1&ei=1&lang=EN/species/search.asp?.Nicara- gua) and South America (e.g., Colombia: http://www.issg.org/database/species/ search.asp?sts=sss&st=sss&fr=1&sn=&rn =Colombia&hci=-1&ei=-1&lang=EN/species/search.asp?.Colombia); Europe (http:// www.europe-aliens.org/); Asia (http:// en.wikipedia.org/wiki/List_of_invasive_ species_in_Asia); Australia (http:// en.wikipedia.org/wiki/List_of_invasive_ species_in_Australia); and Africa (http:// en.wikipedia.org/wiki/List_ of_invasive_species_in_ Africa)]. The majority of invader species do not behave as dominant competitors in their native habitats but they have the capacity to competitively replace the existing communities in the new habitats (Callaway and Aschehoung, 2000). Plant invasions would be favored in habitats which are compatible with the requirements of the new species (Rejmanek et al, 2005) or where disturbances have occurred that allow proliferation of the invader species (Mashhadi and Radosevich, 2004).

The objectives of this work were to 1) identify and describe various characteristics of the most important non-native species that have become invasive and widespread in the major rangeland territories of Argentina; 2) summarize the biological information about some naturalized, non-native species with the potential of transforming natural plant communities; and 3) discuss strategies for plant invasion management and biodiversity conservation in rangeland ecosystems of the country.

Area Description and History

There are pronounced ecological differences in environmental factors within regions in Argentina which make them unique in several ways. These regions vary from the hot and high mountain deserts in the north to the cool sub-antartic districts in Patagonia (Figure 1). A detailed work on the climate, soils, vegetation and land use of the arid and semi-arid Argentine rangelands has been published (Fernandez and Busso, 1999).

The first introduction of exotic plant species into Argentina occurred during the colonization of South America by the Spanish (http://www.banrepcultural.org/blaavirtual/historia/puti/ puti1.htm; Guadagnin et al, 2009; Fonseca et al. (in press)). They brought these plant species mainly for food purposes. However, long distances and slow or dangerous ground transportation led to little movement inside the country in that period, thus avoiding seed dispersal. A second phase of human-mediated transport, which is still ongoing, occurred during the late 19th and early 20th centuries (http://www.enjoy-patagonia.org/relatedarticles/cientific-oxotic-species.php; Guadagnin et al., 2009; Fonseca et al. (in press)). This was associated with the heavy immigration of European people, and the land occupation and settlement of the colonizing ranchers in the interior of the country. The movement of men and their materials has resulted in a flood of alien species into new regions, both by accidental as well as by deliberate introduction of species considered of interest to humans.

Creation of a Plant Invasion Database in Argentina

Strategies to deal with plant invasions in the country were determined in the first National Meeting about Biological Invasion and Biodiversity

Conservation, during July 1998, in Bahia Blanca, Argentina. At the beginning of 2002, Argentina developed a survey system to save and organize information about biological invasions through a project of the Inter-American Biodiversity Information Network (IABIN). Researchers, managers of protected areas, the government and other people contribute to generate a database (Invasive Plant Database, 2009). This database allowed tabulation and access to updated information of invasive plants and provides vital information about the biology, management, propagation and other characteristics of the species included in it.

National regulations include the Biological Diversity Law (http:// www2.medioambiente.gov.ar/sian/pan/ Leyes-decretos/Ley24375.htm). It avoids introduction and fosters inspection of any potential invasive species. In addition, it contains guidelines for 1) eliminating plants that could limit biodiversity, and 2) preserving the renewable natural resources. Recently, the Government established the Secretary of Environment and Sustainable Development to achieve and protect biodiversity. Argentina federal authorities, together with those of all states in the country, regulate the introduction of alien species.

The current Invasive Plant Database of Argentina comprises 219 invasive plant species (Invasive Plant Database, 2009; http://inbiar.org.ar/? p= NTkwc3A4ZTQyPWAhJUJZE0NRAFVXBxUaHEolb21ofj9m). In addition, a list of 100 aggressive invasive species has been reported by Delucchi (2009). Only 51 of these plant species will be considered in this work as exotic invaders which have become naturalized and expanded into the extensive rangeland territories of the country. Their names, origin, growth habit, way of reproduction, dispersal and details of the phytogeographical territories (Figure 1) are presented in Table I. These species are distributed in 14 families. The families that showed the greatest number of species were: Asteraceae (18 species), Fabaceae (6) and Poaceae (6). There were a 76.5, 15.7 and 7.8% of herbaceous, shrubby and tree species, respectively. More than 54% of the species were perennials, and 37.2% were annuals. A little over 39% of the species came exclusively from Europe while 60.8% had various origins (Table I).

Major Naturalized, Non-Native Plant Species in Argentine Rangelands

Many exotic non-native plant species have become rangeland weeds in various provinces of Argentina (Table I). Even more, some of them have been declared national plagues. The seven most abundant plant species with these characteristics in rangelands of Argentina (Burkart, 1957; Cipprioti et al., 2006, 2007; Vigna and Lopez, 2008) are indicated below.

Acroptilon repens (L.) DC. (= Rhaponticum repens (L.) Hidalgo= Centaurea repens), of the Asteraceae family, is a perennial invasive weed in rangelands and irrigation agricultural sites (Table I; Ibarra and La Porte, 1944; Lopez-Alvarado et al., 2011). Bezic et al. (2008) and Bezic (2010) emphasized the importance of achieving a scientific basis and criteria to develop a weed management program for controlling the A. repens invasion in the Lower Valley of Rio Negro and arid rangelands of southwestern Buenos Aires Province. Dispersal of A. repens aggregated in patches can be constrained when competition from range, native perennial grasses is high (Bezic, 2010). Plants of this species, for example, produce allelopathic compounds that have excluded various native species in other regions (Fletcher and Renney, 1963; Jakupovic et al., 1986). The work of Jakupovic et al. (1986) focused on the perspective of biological invasions, and on the prevailing theory that habitat and plant attributes would be the major determinants of the invasion process. A. repens is a broadleaf herbaceous species that reproduces from seed and gemmiferous root sprouting. Its gemmiferous roots can grow deep, although most of them grow shallow and produce new shoots during spring (Fryer and Makepeace, 1977; Bezic et al., 2005). These erect, branched shoots can be 30-90cm tall (Whitson, 1987; Panter, 1991). Vertical roots of A. repens can reach from 1.8-2.4 to 7m during the first or second year of establishment, respectively (Whitson, 1987; Dall and Zimdahl, 1988). Patches of shallower roots (30cm depth) can give rise to ramets at a density of 65 to 300/[m.sup.2] (Bezic et al., 2005). Lineal growth of this species can reach 6m annually in the absence of factors that promote dispersal of its vegetative, belowground structures (Watson, 1980). It means that 20 years would be necessary for obtaining a complete 1ha colonization with plants of A. repens. Despite the vegetative (root) propagation of A. repens, it can be controlled effectively if an intensive tillage is applied adequately (Fryer and Makeplace, 1977). Also, the timing of active growth and the stage of the belowground reserves can determine the best time for grazing and the applications of systemic herbicides (Bezic, 2010). On undisturbed sites and in the absence of competition, gemmiferous roots of A. repens can have a radial increment of 12 [m.sup.2] within the patch in a two-year-period (Watson, 1980). Weed sprouting responds to thermal time above 10oC, and occurs in one inundating event where the weed density (100 to 300 ramets/[m.sup.2]) remains constant until the end of the season; however, there are small simultaneous recruitment and mortality events that occur during the entire growing season (Bezic, 2010). This author also suggested that the high competitive capacity of A. repens might be the result that two thirds of its clonal population biomass corresponded to underground components, which in turn represent the bud bank.

Changes in the bud bank represent the most appropriate criterion to measure the level of control. The aboveground biomass of A. repens has a high phenotypic plasticity to shade, and a high degree of tolerance to low irradiance (Bezic, 2010). A significant effect on aboveground biomass accumulation, without changes in belowground accumulation, was achieved only with shading levels >80% (Bezic, 2010). Glyphosate applied in doses ranging from 1.92 to 3.84kg ai/ha provided a belowground biomass control >95% after two years of treatment (Bezic, 2010). However, tillage (typical of intensive agricultural systems) enables partitioning of sprouting roots, and might explain the high weed densities found in agricultural sites (Bezic, 2010). Also, A. repens can produce allelo-chemicals that might exclude native species in the rangelands of Argentina (Gajardo et al., 2004).

Centaurea solstitialis L. (Yellow starthistle) also belongs to the Asteraceae family (Table I). It is an invasive winter annual, native of Western Europe and Eastern Asia. It is considered an important weed in temperate areas of cereal crops in the Argentina (Montoya, 2010); besides, it is also a widespread naturalized representative of the flora in rangelands (Cabrera and Zardini, 1978; Lamberto et al., 1997; Hierro et al., 2011). Perhaps the most accepted truism in invasion biology is that disturbance promotes invasion of exotic plant species. Reports of Hierro et al. (2006) in the native (Eurasia) and nonnative (California and central Argentina) ranges of C. solstitialis, as one of the most invasive exotic ruderals in these regions, support this perspective. However, they show that disturbances have much stronger effects on C. solstitialis abundance and performance abroad than at home. Their results question the assumption that disturbance per se is sufficient to explain the remarkable success of invasive plant species under disturbed conditions in their non-native range. However, they were limited in replication and geographical scope. Hierro et al. (2006) indicated that the powerful effects of disturbance must act in concert with the release

from other controlling factors, enabling some species to attain community dominance only where they occur as exotics.

The exact moment of its introduction into Argentina it is not known. Parodi (1926) cited its presence as the consequence of multiple introductions, favored by contaminated alfalfa seeds as a vehicle. Once established, the species can survive at higher population densities year after year, affecting the development and germination of other species (Callaway et al., 2003). Seed production, germination and dispersal are mayor determinants of its invasive potential (Barthell et al., 2001). Dimorphism of achenes is a reproductive characteristic; they are clear, with a small pappus in the center of the capitulum, dark and without pappus in the periphery (Lamberto et al., 1997). Both types of achenes show the potential to germinate in a wide temperature range (6-30[degrees]C); however, the highest germination values occurred at 14[degrees]C with 86% germination for the achenes with pappus, and 46% for those without it (Escandon et al., 2005). Regardless of the differences in germination at the cited temperatures, a few established plants can ensure species perpetuation in places where it has become naturalized. C. soltitialis can be considered an undesirable species under many circumstances; however, it can be beneficial to the honey industry in the SE of La Pampa and SW of Buenos Aires Provinces (Monge, 1992; Valle et al., 2001). Honey derived from C. solstitialis in Argentina and other parts of the world, is appreciated for its quality (Cheng et al., 1993; Somerville, 2000).

Elaeagnus angustifolia L. (Russian olive, Narrow-leaved oleaster), of the Elaeagnaceae family, is a deciduous tree introduced as ornamental into the Middle Valley of the Rio Negro (39[degrees]30'S, 65[degrees]30'W; Table I). Today, this species has become naturalized in extensive regions along river margins, threatening the biodiversity in areas previously occupied by rheophytic vegetation. As a result, it is also threatening the livestock industry that uses natural grassland as the main food source for animals. When the first small plant patches appeared in the 1970s, E. angustifolia was either ignored or not judged as an invasive damaging species. A detailed study of its ecology, including the invasive potential, was performed by Klich (2005). The rates of invasion and naturalization have been assigned to the combination of several ecological strategies (Klich, 2005): 1) the huge capacity for sexual reproduction, which secures the existence of a persistent seed bank (recently collected seeds showed 75% germination); 2) vegetative expansion that takes place from a gemmiferous, plagiotropic root system (physical fragmentation of the roots is translated into the release of bud dormancy, and new shoots appear over the soil surface); 3) its adaptive capacity is noticeable for achieving several allometric forms, a result of environmental heterogeneity; and 4) a variable root growth architecture that responds to different soil physical situations. When combined, these ecological strategies make this species a successful thriving invader, which will definitively expand.

Medicago minima (L.) Grufberg. This species, which belongs to the Leguminosae family (Table I), is a naturalized exotic annual that deserves major attention. It is native from Europe, and has become naturalized and widely distributed in extensive semi-arid temperate rangelands of Argentina dedicated to livestock production (Cabrera and Zardini, 1978; Cano, 1988; Lamberto et al., 1997; Daddario, 2012). Hauman (1925) quotes its presence in 1925. Several biological and ecological studies have been conducted on M. minima in populations coming from the Caldenal (38[degrees]45'S, 63[degrees]45'W; Figure 1); these studies are related to the morphology and phenology, seed dormancy, germination, seedling establishment and survival, responses to water stress and forage production (Fresnillo et al., 1991, 1992, 1995a, b, c; Fresnillo Fedorenko, 2001; Pelaez et al., 1995). Its persistence in the local flora is ensured by its capacity to 1) colonize open, overgrazed areas, 2) grow in association with perennial grasses, and 3) tolerate severe drought periods (Fresnillo Fedorenko, 2001). In central Argentina, this species was recognized for making a significant contribution to cattle diet during late winter and spring in wet years (Fresnillo et al., 1992; Bontti et al., 1999).

Chondrilla juncea L. (Rush skeleton-weed), of the Asteraceae family, was introduced in the country in the 70s and declared a national plague in 1977 (Vigna and Lopez, 2008; Table I). It is an herbaceous perennial 0.30-0.90m tall with a gemmiferous taproot that can reach at least 2m in depth (Vigna and Lopez, 2008). Mechanical injury can produce new shoots from any part of the root system, ensuring its persistence in colonized areas. It overwinters as a rosette. Mature plants can produce more than 1000 flower heads with the potential to yield 25000 seeds with pappus, which allows them major wind dispersal (Vigna and Lopez, 2008). Rangeland invasions by C. juncea might affect cattle industry because it can outcompete native desirable forage species (Vigna and Lopez, 2008). These authors reported that the area invaded with this species can reach ~4 x [10.sup.6] ha. Current management of this invader species has involved control of small infestations and young plants with herbicides, and synchronized grazing times. A promissory, successful biological control agent in the infested area can be achieved with the gall mite Eriophyes chondrillae, released in 1989 (Vigna et al., 1993).

Dipsacus fullonum (L.) Honck. (Indian teasel), a Dipsacaceae, was introduced from Eurasia and naturalized in several localities of Argentina (Burkart, 1957; Lamberto et al., 1997; Daddario, 2012; Table I). It is a biennial species that reproduces only by seed. Plant growth habit is like a rosette in the first year. Despite the fact that seed dispersion is mostly around the parent plant, seeds are also dispersed via water, animals, humans and vehicles. Consequently, new patches of this species can be found far away from the original areas (Bentivegna, 2006).

Sorghum halepense (L.) Pers. (Johnson grass) is a perennial invasive alien species of the Poaceae family of worldwide distribution (Table I). It was introduced as a forage species from Central Africa and the Mediterranean region of Europe around 1910, and it was declared a national plague in 1930 (Leguizamon, 2006; De la Fuente and Suarez, 2008). It is a common crop and rangeland weed (Cabrera and Zardini, 1978; Lamberto et al., 1997). Invasion of Johnson grass occurs firstly by seeds germination. Thereafter, the most successful genotypes expand by an extensive and vigorous rhizomatous system at a given environment, making this species difficult to get rid off. It shows high fecundity, seed dormancy and a residual seed bank viable for many years (Leguizamon, 1986). A recent problem is the presence of biotypes resistant to Glyphosate, the chemical product most used as a low-cost herbicide for the control of this species (Vila-Aiub et al., 2007).

Weed Management Strategies and Biodiversity Conservation in Argentina's Rangeland Ecosystems

Awareness about the problems associated with plant invasions into rangeland areas has greatly increased during the last two decades, because the ecological or economical damage caused by some alien species on the native flora has been too significant to be overlooked (Cipriotti et al., 2006, 2007). This has led to a concern for fostering research focused on invaders management. Recognizing the invasion phase of a non-native particular species that is able to establish into a novel ecological habitat is the first step for risk assessment and management of species invasion. Once the non-native species suspected to be harmful invaders have been detected, or have already established incipient populations, there is the urgent need for early warming systems and a precise understanding of invasion vectors. The problem becomes much more difficult when attempting to implement management of well established invasive plant species. In general, they are geographically widespread and their integration with the invaded ecological system is highly successful. Ecological studies are first needed to gain proper understanding of the strategies that turn a species into a successful invader. Thereafter, it could be possible to implement policies for ecological management.

Plant invasions might have a negative impact on ecosystem biodiversity at a local scale. For example, Cipriotti et al. (2006, 2007) have reported that Hieracium pilosella L. (Asteraceae: Rauber et al., 2005) has invaded the southern Patagonian rangelands in Argentina. As a result, this species might form intraspecific patches that can occupy more than one hectare, replacing native flora. This perennial herb, introduced from Eurasia, was first recognized in Tierra del Fuego in 1993 (Livraghi et al., 1998), and thereafter it invaded the southern portion of continental Patagonia.

Policies calling for removal of exotic, alien, or introduced species appear to rest on the old notion that changes in the abundance of any species in the plant community mean a threat to the entire community. However, wildland communities receive continuous new arrivals, yet it does not necessarily result in a net loss of species. For example, Johnson and Mayeaux (1992) reported that plant species richness of the California annual grasslands is probably much higher today than it was prior to the arrival of the Europeans. Most communities do not consist of highly co-evolved species pairs, but exhibit some species replacement within groups (Westman, 1990). This does not deny mutualism and the existence of keystone or critical species (those playing a vital role in ecosystem functioning), but acknowledges that not all species play those roles. We do have to differentiate between the exotics to either worry or not about, based on their effects on ecosystem functioning and man welfare (e.g., the beneficial effects of the exotic, naturalized legume M. minima in rangelands of central Argentina). We have to be aware, however, that if invasive noxious species cross a threshold level, they can (and often do) dominate the site (see Pyke et al., 2002).

Hobbs and Humphries (1995) already recognized that focusing on the characteristics and control measures of individual invading species is inadequate as a management approach to tackle the problem associated with plant invasions to natural ecosystems. They suggested various strategies for the control of invader plant species: 1) many species have a lag phase following introduction before they spread explosively; as a result, plant invasions should be detected and treated early, before explosive spread occurs; 2) the focus should be placed on the invaded ecosystem and its management rather than on the invader; 3) more effective integrated control programs could be reached after identification of the causal factors enhancing ecosystem invasiveness; 4) management priorities for protection and control have to be reached after a value assessment of particular sites and their degree of disturbance; 5) changes in human activities in terms of plant introduction and use, land use, and timing of control measures are needed to appropriately tackle plant invasion problems; their thoughts should be taken into account if we simultaneously want to conserve ecosystem's biodiversity.

If sustainable development is to be achieved, we need to find ways for natural resources be both used and maintained. Finding balance points would be easier if the role that species play in ecosystem functioning is better understood. If functional groups, guilds, keystone or critical species, and exotics to be worried or not worried about are identified, the overly simplistic, species-only notions of biodiversity will be replaced, and we will gain a larger role in setting policies on use of rangelands.

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Received: 04/30/2012. Modified: 02/08/2013. Accepted: 02/15/2013.

Carlos A. Busso. Agronomical Engineer and M.Sc., Universidad Nacional del Sur (UNSur), Argentina. Ph.D. in Range Ecology, Utah State University, USA. Professor, UNSur, and Research Scientist, Centro de Recursos Naturales Renovables de la Zona Semiarida (CERZOS)-CONICET, Argentina. Address: Departamento de Agronomia, CERZOS, UNSur. Altos del Palihue, 8000--Bahia Blanca, Argentina. e-mail: cebusso@criba.edu.ar

Diego J. Bentivegna. Agronomical Engineer and M.Sc., UNSur; Argentina. Ph.D. in Plant Insect and Microbiology Science, University of Missouri, USA. Researcher, CONICET, Argentina. e-mail: dbentive@criba.edu.ar

Osvaldo A. Fernandez. Agronomical Engineer, UNSur, Argentina. M.Sc. in Plant Physiology, University of Toronto, Canada. Ph.D. in Range Ecology, Utah State University, USA. Professor, UNSur, Argentina. Researcher, CONICET, Argentina. e-mail: ofernan@criba.edu.ar

TABLE I

INVASIVE SPECIES IN RANGELANDS OF ARGENTINA

Family               Species              Origin       Growth

Apiaceae      Conium maculatum (L.)      Europe-         P
                                          Western
                                           Asia
                   Foeniculum             Europe         P
                 vulgare (Mill.)
                   Acroptilon          Europe-Asia       P
                 repens (L.) Dc.
                    Anthemis              Europe         A
                    cotula L.
                  Baccharis sp.       America Center     P
                     Carduus              Europe        A-B
                  acanthoides L.
                    Carthamus             Europe         A
                   lanatus L.
                    Centaurea          Europe- Asia     A-B
                solstitialis (L.)
                   Chondrilla          Europe- Asia      P
                   juncea (L)
                    Cichorium         Mediterranean      P
                    intybus L.
                     Cirsium              Europe         A
                     vulgare
                   (Savi) Ten.

Asteraceae        Crepis setosa           Europe         A
                   (Hallier f)
                     Cynara            Spain-North       P
                 cardunculus L.           Africa
               Hieracium pilosella     Europe-Asia       P
                  Leucanthemum         Europe- Asia      P
                  vulgare Lam.

                   Matricaria            Europe-         A
                   recutita L.          North Asia
               Picris echioides L.    Mediterranean     A-P
                Silybum marianum      Mediterranean      A
                   L. Gaertn.
                  Sonchus asper           Europe         A
                    (L.) Hill
                    Taraxacum             Europe         P
                   officinale
                   (G. Webber)

Brassi-           Diplotaxis             Europe         P
 caceae        tenuifolia (L.) Dc.
                    Raphanus              Europe         A
                  sativus (L.)
                    Rapistrum         Mediterranean     A-B
                  rugosum (L.)

Caryophy-          Cerastium             Europe         A
 llaceae           glomeratum
                    (Thuill)
                Stellaria media          Europe         A
                 (L.) Cirillo

Dipsacaceae     Dipsacus fullonum      Europe-Asia       B
                   (L.) Honck.

Eleagnaceae         Elaeagnus              Asia          P
                   angustifolia
                     Cytisus             Europe-         P
                  scoparius (L.)       Mediterranean
                                          British
                                          islands
               Lupinus polyphyllus    North America      P
                     (Lindl.)

Fabaceae         Medicago minima          Europe         A
                  (L.) Grufberg
              Trifolium repens (L.)       Europe         P
                    Prosopis          North Mexico-      P
                 glandulosa Torr.        South USA
               Ulex europaeus (L.)        Europe        B-P

Oleaceae            Fraxinus          North America-     P
                  pennsylvanica           Eurasia
                    (Marshall)
               Ligustrum lucidum          Asia           P
                  (W. T. Aiton)
                    Ligustrum             China          P
                  sinense (Lour)

Pinaceae            Pinus sp.         North America      P

Plantagi-          Plantago           Europe-Asia        P
 naceae         lanceolata (L.)
              Plantago major (L.)     Europe-Asia        P

Poaceae        Avena barbata Pott        Eurasia         A
                Cynodon dactylon       Consmopolite      P
                    (L. Pers.)
               Lolium multiflorum     Mediterranean     A-P
                      (Lam.)
                Poa annua (L.)           Europe          A
                    Polypogon            Europe-         A
                                        Asia-Africa
                monspeliensis (L.)                       P
                  Desf.
               Sorghum halepense         Central
                    (L) Pers.            Africa-
                                         Europe

Primulaceae         Anagallis             Europe        A-B
                  arvensis (L.)
                   Centunculus            Europe         A
                  minimus (L.)

Rosaceae             Malus              Europe-          P
                domestica (Borkh)       West Asia
                   Pyracantha             China          P
                  angustifolia
                 (Franch) C.K.
                     Schnied              Europe         P
                Rubus ulmifolius
                    (Schott).

Tamaricaceae        Tamarix           Mediterranean      P
               ramosissima Ledeb.

Family               Species          Reproduct.     Main dispersal
                                                           way

Apiaceae      Conium maculatum (L.)      Seed          Water-Wind
                   Foeniculum            Seed         Water-Birds-
                 vulgare (Mill.)                         Animals
                   Acroptilon          Seed-Veg     Human activities
                 repens (L.) Dc.
                    Anthemis             Seed             Wind
                    cotula L.
                  Baccharis sp.        Seed-Veg           Wind
                     Carduus             Seed             Wind
                  acanthoides L.
                    Carthamus            Seed       Water-Adhesion-
                   lanatus L.                       Wind-Contaminant
                    Centaurea            Seed           of grain
                solstitialis (L.)                       and wool
                                                       Wind-Animal
                   Chondrilla          Seed-Veg           Wind
                   juncea (L)
                    Cichorium            Seed             Wind
                    intybus L.
                     Cirsium             Seed             Wind
                     vulgare
                   (Savi) Ten.

Asteraceae        Crepis setosa          Seed             Wind
                   (Hallier f)
                     Cynara              Seed             Wind
                 cardunculus L.
               Hieracium pilosella     Seed-Veg           Wind
                  Leucanthemum         Seed-Veg      Water-Animal-
                  vulgare Lam.                        Agricultural
                                                    products-Vehicles
                   Matricaria            Seed            Animal
                   recutita L.
               Picris echioides L.       Seed        Wind-Adhesion
                Silybum marianum         Seed             Wind
                   L. Gaertn.
                  Sonchus asper          Seed             Wind
                    (L.) Hill
                    Taraxacum            Seed             Wind
                   officinale
                   (G. Webber)

Brassi-            Diplotaxis            Seed        Water-Animals-
 caceae        tenuifolia (L.) Dc.                  Vehicles-Clothes
                   Raphanus              Seed         Wind-Water-
                  sativus (L.)                         Machinery
                    Rapistrum            Seed         Contaminated
                  rugosum (L.)                      commercial seeds

Caryophy-          Cerastium             Seed             Wind
 llaceae          glomeratum
                    (Thuill)
               Stellaria media           Seed        Foot traffic-
                 (L.) Cirillo                      Tools-Rain-Birds-
                                                        Machinery

Dipsacaceae     Dipsacus fullonum        Seed        Water-Animal-
                   (L.) Honck.                       Human-Vehicles

Eleagnaceae         Elaeagnus          Seed-Veg       Water-Animal
                   angustifolia
                     Cytisus             Seed             Self
                  scoparius (L.)

               Lupinus polyphyllus       Seed        Vehicles-Human
                     (Lindl.)                        activities-Soil
                                                        transport

Fabaceae         Medicago minima         Seed            Animal
                  (L.) Grufberg
              Trifolium repens (L.)      Seed            Animal
                    Prosopis             Seed            Animal
                 glandulosa Torr.
               Ulex europaeus (L.)     Seed-Veg      Ejection from
                                                    pod contaminated
                                                          soil
Oleaceae           Fraxinus             Seed          Wind-Water
                  pennsylvanica
                    (Marshall)
                Ligustrum lucidum        Seed            Birds
                  (W. T. Aiton)
                    Ligustrum            Seed            Birds
                  sinense (Lour)
Pinaceae            Pinus sp.            Seed             Wind

Plantagi-           Plantago             Seed         Animal-Human
 naceae          lanceolata (L.)
               Plantago major (L.)       Seed        Animal-Birds-
                                                      Contaminant
                                                        of seeds

Poaceae        Avena barbata Pott        Seed            Human
                Cynodon dactylon       Seed-Veg      Water-Tillage
                    (L. Pers.)
               Lolium multiflorum        Seed      Irrigation Water-
                      (Lam.)                         Animal-Tillage
                 Poa annua (L.)          Seed        Animal-Human-
                                                       Machi-nery
                    Polypogon            Seed            Animal
                monspeliensis (L.)     Seed-Veg    Water-contaminated
                  Desf. Sorghum                     grain- Machinery
                    halepense
                    (L) Pers.

Primulaceae         Anagallis            Seed        Water-Animal-
                  arvensis (L.)                         Vehicles
                   Centunculus           Seed            Water-
                  minimus (L.)                     Contaminated soil

Rosaceae              Malus            Seed-Veg          Animal
                domestica (Borkh)
                   Pyracantha            Seed            Birds
                  angustifolia
                 (Franch) C.K.
                     Schnied             Seed            Animal
                Rubus ulmifolius
                    (Schott).

Tamaricaceae         Tamarix             Seed            Water
               ramosissima Ledeb.

Family               Species           Location        Ref.

Apiaceae      Conium maculatum (L.)       P-M          1, 2

                   Foeniculum           P-M-WC          3
                 vulgare (Mill.)

Asteraceae         Acroptilon              P           4, 5
                 repens (L.) Dc.
                    Anthemis              AC            6
                    cotula L.
                  Baccharis sp.       P-C-M-P-WC        7
                     Carduus            M-WC-PU         8
                  acanthoides L.
                    Carthamus            P-M-C          A
                   lanatus L.
                    Centaurea          P-C-M-WC       9, 10
                solstitialis (L.)

                   Chondrilla             C-M           11
                   juncea (L)
                    Cichorium            P-M-C         1, 8
                    intybus L.
                     Cirsium              AC           1, 8
                     vulgare
                   (Savi) Ten.
                  Crepis setosa           P-C           B
                   (Hallier f)
                     Cynara               M-C           12
                 cardunculus L.
               Hieracium pilosella         P            13
                  Leucanthemum           P-C-M          C
                  vulgare Lam.

                   Matricaria             M-P           D
                   recutita L.
               Picris echioides L.        P-M           14
                Silybum marianum       P-M-C-PU        1, 8
                   L. Gaertn.
                  Sonchus asper           AC            1
                    (L.) Hill
                    Taraxacum             AC           1,8
                   officinale
                   (G. Webber)

Brassi-            Diplotaxis          P-M-C-WC     E; 15, 16
 caceae         tenuifolia (L.) Dc.
                    Raphanus              AC            8
                  sativus (L.)
                    Rapistrum             AC            F
                  rugosum (L.)

Caryophy-          Cerastium            P-M-C           G
 llaceae          glomeratum
                    (Thuill)
                Stellaria media          AC             H
                 (L.) Cirillo

Dipsacaceae     Dipsacus fullonum        P-M-C          17
                   (L.) Honck.

Eleagnaceae         Elaeagnus              M            18
                   angustifolia

Fabaceae            Cytisus               P             19
                  scoparius (L.)

               Lupinus polyphyllus         P            20
                     (Lindl.)

                 Medicago minima       M-C-WC-P       21, 16
                  (L.) Grufberg
              Trifolium repens (L.)       AC            I
                    Prosopis              WC            22
                 glandulosa Torr.
               Ulex europaeus (L.)        AC            23

Oleaceae            Fraxinus              M-C           24
                  pennsylvanica
                    (Marshall)
                Ligustrum lucidum      M-C-WC-P         25
                  (W. T. Aiton)
                    Ligustrum            M-WC         26, 27
                  sinense (Lour)

Pinaceae            Pinus sp.            P-M-C          28
                    Plantago             P-M-C          29
                 lanceolata (L.)

Plantagi-      Plantago major (L.)       P-M-C        29, 30
 naceae

Poaceae        Avena barbata Pott        P-C-M          J
                Cynodon dactylon         P-M-C          31
                    (L. Pers.)
               Lolium multiflorum         AC            32
                      (Lam.)
                 Poa annua (L.)           AC            1

                    Polypogon             AC            33

                monspeliensis (L.)     P-M-WC-PU    16, 21, 34
                  Desf. Sorghum
                    halepense
                    (L) Pers.

Primulaceae        Anagallis          P-M-WC-PU         35
                  arvensis (L.)
                   Centunculus        P-M-C-WC-PU       K
                  minimus (L.)

Rosaceae             Malus               P-M            36
                domestica (Borkh)
                   Pyracantha            WC-PU          26
                  angustifolia
                 (Franch) C.K.
                     Schnied            P-WC-PU         37
                Rubus ulmifolius
                    (Schott).
Tanaricaceae        Tamarix              P-M-C          38
               ramosissima Ledeb.

Growth= A: Annual, B: Biennial, P: Perennial; Veg: Vegetative;
Location (see Figure 1)= P: Patagonia: C:Caldenal; M: Monte;
WC: Western Chaco; PU: Puna; AC: All Country. References= 1:
Holm et al., 1977; 2: Woodard, 2008; 3: Erskine and Rejmanek,
2005; 4: Bezic, 2010; 5: Fryer and Makepeace, 1977; 6: Kay,
1958; 7: Giuliano, 2001; 8: Whitson et al., 1992; 9: Zouhar,
2002; 10: Young et al., 2005; 11: Vigna and Lopez, 2008; 12:
White and Holt, 2005; 13: Winkler and Stocklin, 2002; 14:
Sorensen, 1985; 15: Marzocca, 1957; 16: Lamberto et al., 1997;
17: Bentivegna, 2006; 18: Klich, 2005; 19: Paynter et al.,
1998; 20: Fremstad, 2010; 21: Cabrera and Zardini, 1978; 22:
Villagra et al., 2010; 23: Moss, 1959; 24: Zalba and Villamil,
2002; 25: Aragon and Groom, 2003; 26: Tecco et al., 2006; 27:
Pokswinski, 2008; 28: Sarasola et al., 2006; 29: Fernandez et
al., 2007; 30: Panter and Dolman, 2012; 31: Guglielmini and
Satorre, 2004; 32: Gundel et al., 2006; 33: Ridley, 1930; 34:
Leguizamon, 2006; 35: Requesens and Scaramuzzino, 1999; 36:
Paruelo et al., 2010; 37: Montaldo, 2000; 38: Dewine and
Cooper, 2008. A: http://florbase.dec.wa.gov.au/browse/profile/
7911. FloraBase. The Western Australia Flora.(Cons. 02/05/2013);
B: http://www2.dmu.dk/1_Om_DMU/2_Tvaerfunk/3_fdc_bio/projekter/
redlist/gpdata.asp?ID=67&mode=NA. Fagdatacenter for Biodiversitet
og Terrestrisk Natur. (Cons. 02/08/2013);
C:http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/
invasive_ox_eye_daisy. Victorian Resources Online.
Invasiveness Assessment. Ox-eye daisy (Leucanthermum vulgare)
in Victoria (Nox). (Cons. 02/05/2013);
D:http://www.gardenorganic.org.uk/organicweeds/weed_information/
weed.php?id=51. Organic Weed Management. Scented mayweed.
(Cons. 02/05/2013); E: http://vro.dpi.vic.gov.au/dpi/vro/
vrosite.nsf/pages/invasive_sand_rocket. Victorial Resources
Online. Invasiveness Assessment--Sand rocket (Diplotaxis
tenuifolia) in Victoria (Nox.). (Cons. 02/05/2013); F:
http://www.conabio.gob.mx/malezasdemexico/brassicaceae/
rapistrum-rugosum/fichas/ficha.htm#5. Biologia y Ecologia.
Brassicaceae= Crusiferae. Rapistrum rugosum (L.) All.
Rapistro rugoso (sugerido). (Cons. 02/05/2013);
G: http://www.gardenorganic.org.uk/organicweeds/weed_information/
weed.php?id=134. Organic Weed Management. Sticky mouse-ear.
(Cons. 02/05/2013); H: http://www.freshfromflorida.com/pi/
weed_of_the_month/1109_Stellaria_media.html. Botany. Weed
of the month. (Cons. 02/05/2013);
I:http://florabonaerense.blogspot_com.ar/2012/04/
trebol_blanco_trifolium.repens.html. (Cons. 02/05/2013);
J: www.albufera.com/parque/content/avena-barbata-pott-
ex-link-schrader-avena-erizada-cugula. Parc Natural d
L'Albufera. Avena barbata Pott. Ex Link in Schrader (avena
erizada, cugula). (Cons. 02/05/2013);
K http://www.floraargentina.edu.ar/detalleespecie.asp?forma
=&variedad=&subespecie=&especie=min imus&espcod=1644&genero=
centunculus& autor=6&deDonde=4. (Cons. 02/05/2013).
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Title Annotation:articulo en ingles
Author:Busso, Carlos A.; Bentivegna, Diego J.; Fernandez, Osvaldo A.
Publication:Interciencia
Date:Feb 1, 2013
Words:8633
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