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Early competition between native and non-native species can greatly influence ecosystem integrity through its effect on species regeneration, which can be further modulated by environmental context. Bromus tectorum (cheatgrass, winter annual grass) has recently invaded the temperate grasslands of Patagonia Argentina ecosystems mainly used for extensive livestock raising. We evaluated the relative impact of competition from B. tectorum on two native species with different life-forms, from the seedling stage: Vulpia australis, the only winter annual grass in the community, and Bromus setifolius, a perennial grass highly palatable to livestock. The effect of asymmetric competition between B. tectorum (seedling or adult individuals) on B. setifolius was also assessed. A greenhouse experiment was conducted to simulate interspecific competition (two species per pot), and control (one species per pot) treatments. We regulated the recruitment timing of all studied species to represent realistic competition dynamics in the field. Bromus tectorum had a greater negative impact on the growth of both native species relative to the effect produced by a co-occurring native, even when that native was ecologically equivalent to the invader. Also, the impact of B. tectorum on B. setifolius depended on the invader’s developmental stage, with bigger individuals having the largest impact. In contrast, native species hardly affected B. tectorum development. Our findings indicate that native grasses may not hinder the spread of B. tectorum through competition. Moreover, B. tectorum could have a negative impact at the community level through its effect on the recruitment of native species, probably exacerbating degradation in overgrazed areas.

1- Plant damage by invertebrate herbivores and pathogens influences the dynamics of grassland ecosystems, but anthropogenic changes in nitrogen and phosphorus availability can modify these relationships. 2- Using a globally distributed experiment, we describe leaf damage on 153 plant taxa from 27 grasslands worldwide, under ambient conditions and with experimentally elevated nitrogen and phosphorus. 3- Invertebrate damage significantly increased with nitrogen addition, especially in grasses and non-leguminous forbs. Pathogen damage increased with nitrogen in grasses and legumes but not forbs. Effects of phosphorus were generally weaker. Damage was higher in grasslands with more precipitation, but climatic conditions did not change effects of nutrients on leaf damage. On average, invertebrate damage was relatively higher on legumes and pathogen damage was relatively higher on grasses. Community-weighted mean damage reflected these functional group patterns, with no effects of N on community-weighted pathogen damage (due to opposing responses of grasses and forbs) but stronger effects of N on community-weighted invertebrate damage (due to consistent responses of grasses and forbs). 4- Synthesis. As human-induced inputs of nitrogen and phosphorus continue to increase, understanding their impacts on invertebrate and pathogen damage becomes increasingly important. Our results demonstrate that eutrophication frequently increases plant damage and that damage increases with precipitation across a wide array of grasslands. Invertebrate and pathogen damage in grasslands is likely to increase in the future, with potential consequences for plant, invertebrate and pathogen communities, as well as the transfer of energy and nutrients across trophic levels. EEA Santa Cruz Fil: Ebeling, Anne. University of Jena. Institute of Ecology and Evolution; Alemania Fil: Strauss, Alex T. University of Minnesota. Department of Ecology, Evolution, and Behavior; Estados Unidos Fil: Strauss, Alex T. University of Georgia. Odum School of Ecology; Estados Unidos Fil: Adler, Peter B. Utah State University. Department of Wildland Resources and the Ecology Center; Estados Unidos Fil: Arnillas, Carlos Alberto. University of Toronto —Scarborough. Department of Physical and Environmental Sciences; Canadá Fil: Barrio, Isabel C. Agricultural University of Iceland. Faculty of Environmental and Forest Sciences; Islandia Fil: Biederman, Lori A. Iowa State University. Department of Ecology, Evolution, and Organismal Biology; Estados Unidos Fil. Borer, Elizabeth T. University of Minnesota. Department of Ecology, Evolution, and Behavior; Estados Unidos Fil: Bugalho, Miguel N. University of Lisbon. Centre for Applied Ecology (CEABN-InBIO). School of Agriculture; Portugal. Fil: Caldeira, Maria C. University of Lisbon. Forest Research Centre. School of Agriculture; Portugal. Fil: Cadotte, Marc W. University of Toronto Scarborough. Department of Biological Sciences; Canadá Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina. Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Blumenthal, Dana M. USDA-ARS, Rangeland Resources & Systems Research Unit; Estados Unidos

Biotic and abiotic factors interact with dominant plants—the locally most frequent or with the largest coverage—and nondominant plants differently, partially because dominant plants modify the environment where nondominant plants grow. For instance, if dominant plants compete strongly, they will deplete most resources, forcing nondominant plants into a narrower niche space. Conversely, if dominant plants are constrained by the environment, they might not exhaust available resources but instead may ameliorate environmental stressors that usually limit nondominants. Hence, the nature of interactions among nondominant species could be modified by dominant species. Furthermore, these differences could translate into a disparity in the phylogenetic relatedness among dominants compared to the relatedness among nondominants. By estimating phylogenetic dispersion in 78 grasslands across five continents, we found that dominant species were clustered (e.g., co‐dominant grasses), suggesting dominant species are likely organized by environmental filtering, and that nondominant species were either randomly assembled or overdispersed. Traits showed similar trends for those sites (, We found a prevalent disparity between the dominant and nondominant species (measured as the standardized effect size of the mean nearest taxonomic distance), with the former more clustered than the latter, suggesting a disparity in the mechanisms organizing both groups. We also found several clades more likely to have nondominant species than dominant species, measured as the probability of finding a species of a given clade among the third less abundant species in the sites where that clade occurred. Unexpectedly, many nondominant clades have a large number of species, mainly were comprised of nonwoody species, and often appeared in the phylogeny. Together, these findings suggest dominance and nondominance are conserved and that their differences have ecological consequences.

Vultures and condors are among the most threatened avian species in the world due to the impacts of human activities. Negative perceptions can contribute to these threats as some vulture species have been historical ly blamed for killing livestock. This perception of confli ct has increased in recent years, associated with a viral spread of partial and biased information through social media and despite limited empirical support for these assertions. Here, we highlight that magnifying infrequent events of livestock being injured by vultures through publically shared videos or biased news items negatively impact efforts to conserve threatened populations of avian scavengers. We encourage environmental agencies, researchers, and practitioners to evaluate the reliability, frequency, and context of reports of vulture preda tion, weighing those results against the diverse and valuable contributions of vultures to environmental health and human well-being. We also encoura ge the development of awareness campaigns and improved livestock management practices, including commonly available nonlethal deterrence strategies, if needed. These actions are urgently required to allow the development of a more effective conservation strategy for vultures worldwide.

Rubbish dumps can become an important environmental source of plastic. Several species feed on organic waste from these sites, but at the same time are exposed to non-organic materials. Species that can gather food in these sites might at the same time disperse waste consumed, but this has rarely been evaluated. We compare the occurrence of plastic debris in regurgitated pellets of three sympatric vultures from northwest Patagonia, Andean condors (Vultur gryphus), black vultures (Coragyps atratus) and turkey vultures (Cathartes aura), foraging in different degrees of humanized sites. We also evaluate the influence of rubbish dumps in the presence of plastic debris in pellets of the studied species and their potential role in spreading plastic to the environment. Most synthetic material present in pellets was plastic. Pellets of Andean condors, which avoid disturbed anthropic sites in this area, showed almost no plastic debris compared with the other sympatric vulture species, suggesting an influence of the foraging habits on plastic ingestion. For black and turkey vultures, we found that rubbish dumps may be an important source of plastic. The occurrence of plastic debris in pellets of black vultures sampled in 2010 and 2020 increased, probably associated with the increase in urbanization and waste production in the study area. Avian scavengers were exposed to and are able to transport plastic to distant communal roosts generating "plastic islands". It is necessary to reduce plastic generation and better waste management practices to avoid species and environments to be affected by this pollutant.

Prevention is regarded as a cost-effective management action to avoid unwanted impacts of non-native species. However, targeted prevention can be difficult if little is known about the traits of successfully invading non-native species or habitat characteristics that make native vegetation more resistant to invasion. Here, we surveyed mountain roads in seven regions worldwide, to investigate whether different species traits are beneficial during primary invasion (i.e. spread of non-native species along roadside dispersal corridors) and secondary invasion (i.e. percolation from roadsides into natural adjacent vegetation), and to determine if particular habitat characteristics increase biotic resistance to invasion. We found primary invasion up mountain roads tends to be by longer lived, non-ruderal species without seed dispersal traits. For secondary invasion, we demonstrate that both traits of the non-native species and attributes of the receiving natural vegetation contribute to the extent of invasion. Non-native species that invade natural adjacent vegetation tend to be shade and moisture tolerant. Furthermore, non-native species invasion was greater when the receiving vegetation was similarly rich in native species. Our results show how mountain roads define which non-native species are successful; first by favouring certain traits in mountain roadsides (the key dispersal pathway to the top), and secondly by requiring a different set of traits when species invade the natural adjacent vegetation. While patterns in species traits were observed at a global level, regional abiotic and biotic variables largely generated region-specific levels of response, suggesting that management should be regionally driven. Fil: McDougall, Keith. La Trobe University; Australia. Office of Environment and Heritage; Australia Fil: Lembrechts, Jonas. Universiteit Antwerp; Bélgica Fil: Rew, Lisa J.. State University of Montana; Estados Unidos Fil: Haider, Sylvia. Martin Luther University Halle-Wittenberg; Alemania. German Centre for Integrative Biodiversity Research; Alemania Fil: Cavieres, Lohengrin A.. Universidad de Concepción; Chile Fil: Kueffer, Christoph. Instituto de Ecología y Biodiversidad; Chile. Institute of Integrative Biology; Suiza Fil: Milbau, Ann. Research Institute for Nature and Forest; Bélgica Fil: Naylor, Bridgett J.. United States Department of Agriculture; Estados Unidos Fil: Nuñez, Martin Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Pauchard, Anibal. Universidad de Concepción; Chile. Instituto de Ecología y Biodiversidad; Chile Fil: Seipel, Tim. State University of Montana; Estados Unidos Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Wright, Genevieve T.. Office of Environment and Heritage; Australia Fil: Alexander, Jake M.. Universite de Lausanne; Suiza

It is widely known that disturbed areas favour plant species invasion. However, the presence and impacts of introduced plants at rubbish dumps and landfills are less clear. We conducted a literature review to evaluate current knowledge on introduced plants species at these sites to assess their potential role as invasion epicentres. Most of the studies we found (91%) were observational and only described plant species presence in multiple landscapes, including rubbish dumps or landfills. A minority of studies (< 20%) specifically focused on plant species at these sites but did not evaluate their potential as invasion epicentres. The 215 introduced plant species belonging to 57 families recorded at rubbish dumps or landfills underestimates true numbers given that most studies do not report the full list of species. Most species are invasive (> 95%) and included in the Global Invasive Species Database or the DAISIE list. One species, Arundo donax, is among the 100 worst invasive species in the world and eight more are listed among the 100 worst invasive species in Europe. Invasive species present at these sites may alter fire regimens, produce toxic and allergen effects, outcompete native species, act as agricultural pests, and lead to economic losses. Our results are a first step to include rubbish dumps and landfills in the agenda of ecologists and managers that study invasive species, especially since compost from these sites are now being used in agricultural practices, thus possibly spreading invasive species propagules to distant locations. Fil: Plaza, Pablo. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina

[Aims]: Seed dispersal by endozoochory is an important process in plant regeneration and the establishment of new populations. Seeds with dormancy may especially benefit after disperser gut passage. However, the ways in which gut passage affect the germination of plant species with physiological dormancy remain unclear. Here, we experimentally assessed the mutualistic interaction between the Austral parakeet (Enicognathus ferrugineus) as a disperser of calafate (Berberis microphylla), a thorny bush inhabiting the understory of the Austral temperate forests of South America with seeds that are characterized by deep physiological dormancy., [Methods]: Germination success and viability of calafate seeds obtained from faeces and from intact fruits were tested under four treatments: (i) digested seeds, (ii) digested seeds with faecal extract, (iii) intact seeds from fruit and (iv) intact seeds from fruit with pulp., [Important]: Findings About 65% of the Austral parakeet droppings contained calafate seeds. Viability of seeds did not differ between treatments. However, germination was significantly higher in digested seeds than in intact seeds from fruits, while no difference was found between faecal and pulp extracts. Neither faecal matter nor fruit pulp provided seeds with any ecological advantages derived from enhancing germinability, but did confer some disadvantage in germination time. Faecal matter is expected to be completely lacking around seeds after several months under snow before germinating in the following spring, given intense washing due to persistent rain and the spring thaw in the Patagonian Andes. The higher germinability along with faster germination of digested seeds supports the hypothesis of a legitimate mutualistic interaction between Austral parakeets and calafate. We hypothesized that the passage through the disperser digestive tract might break physiological dormancy as differences in germinability between ingested and non-ingested seeds. Our results highlight the relevant role of endozoochory in plant species with physiological dormancy living in highly seasonal environments., K.S. and S.A.L. were funded by the projects PICT 2015-2072 and PICT 2018-1623.

Most ecosystems of the world are being increasingly invaded by a variety of alien species. However, little is known about the combined ecological impacts of multiple co-occurring invaders. We assessed the impact of a community of exotic mammals (five domestic and four wild) on forests of monkey puzzle (Araucaria araucana), a globally endangered tree restricted to ca 400 km2 on the slopes of the Andes in Chile and Argentina. Seeds of monkey puzzles provide food during winter to a small community of native mice and Austral parakeets (Enicognathus ferrugineus). We recorded the number of uneaten seeds and the number of young seedlings at the end of winter under 516 female monkey puzzle trees located across the species' distribution, and identified the signals of native and exotic species that visited the under-canopy of each tree. Moreover, we studied the diet and foraging behavior of Austral parakeets to explore the potential indirect effects of exotic mammals through the disruption of a key ecosystem service (seed dispersal) supposedly provided by parakeets. All but one tree were visited by at least one seed predator species. Austral parakeets and mice predated seeds from 85% and at least 45% of the trees, respectively, and both the number of remaining seeds and seedlings were significantly larger when only parakeets or mice predated seeds than when exotic mammals also visited the trees. At least 90% of trees were visited by one or more exotic species, and the number of seeds and seedlings dropped drastically when at least two and four exotic species visited the tree, respectively. Austral parakeets mostly foraged on monkey puzzle trees during the winter period and dispersed their seeds in most feeding instances once seeds fell to the ground. The proliferation of exotic mammals may reduce the populations of native seed-predators in the long-term as well as the regeneration of monkey puzzle forests, directly through a reduction of seed availability and seedling survival, and indirectly through the disruption of dispersal processes. Our results show how strategies based on protecting areas may assure the survival of individuals of this long-lived (up to 1300 yr) tree species. However, forest regeneration and the community of native seed-predators and related ecological processes further depend on the proper management of exotic mammal invasions. Fil: Tella, José L.. Consejo Superior de Investigaciones Científicas; España Fil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina

Sexual functions in gymnosperms are mostly performed by separate reproductive structures, which largely reduces sexual interference and sets the scene for morphological and functional sexual specialization. The evolutionary trajectories followed by traits related to the male and female functions are therefore expected to be uncoupled. Studies on the fossil record of the conifer family Araucariaceae revealed important morphological changes occurring in reproductive cones. Here, we explored the pattern of evolution of male and female cone sizes in Araucariaceae, with a special focus on Araucaria-the most variable and widespread genus in the family. We gathered data on male and female cone sizes from fossils and extant Araucariaceae species. Focusing on Araucaria, we analyzed whether cone sizes are phylogenetically structured. Furthermore, we compared the evolutionary trajectories of male and female cone sizes by evaluating the goodness of fit of different evolutionary models. Finally, we evaluated whether different selective regimes across the phylogeny could have shaped cone morphology. Size changes in Araucariaceae occurred in both male and female cones, with the largest cones appearing in extant Araucaria. In this genus, different evolutionary models best described cone size changes, with male cone evolution best described by a model not influenced by phylogeny and female cone evolution by a stabilizing selection model with two optima. This resulted in contrasting phylogenetic signals, with female cone size being more phylogenetically structured than male cone size. Changes in cone size in Araucariaceae occurred in both male and female cones. The largest male and female cones appeared in Araucaria through uncoupled evolutionary pathways, both involving a natural selection component as a driver of evolutionary change. A contrasting pattern of phylogenetic signal in male and female cone size reflected the uncoupled evolutionary trajectories followed by these sexual structures. Fil: Gleiser, Gabriela Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Hiraldo, Fernando. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; España Fil: Tella Escobedo, José Luis. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; España Fil: Aizen, Marcelo Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina

Background. Global change produces pervasive negative impacts on biodiversity worldwide. Land use change and biological invasions are two of the major drivers of global change that often coexist; however, the effects of their interaction on natural habitats have been little investigated. In particular, we aimed to analyse whether the invasion of an introduced grass (Bromus tectorum; cheatgrass) along roads verges and the disturbance level in the natural surrounding habitat interact to influence the degree of B. tectorum invasion in the latter habitats in north-western Patagonia. Methods. Along six different roads, totalling approximately 370 km, we set two 50 m × 2 m sampling plots every 5 km (73 plots in total). One plot was placed parallel to the road (on the roadside) and the other one perpendicular to it, towards the interior of the natural surrounding habitat. In each plot, we estimated the B. tectorum plant density in 1m2 subplots placed every 5 m. In the natural habitat, we registered the vegetation type (grassy steppe, shrub-steppe, shrubland, and wet-meadow) and the disturbance level (low, intermediate, and high). Disturbance level was visually categorized according to different signs of habitat degradation by anthropogenic use. Results. B. tectorum density showed an exponential decay from roadsides towards the interior of natural habitats. The degree of B. tectorum invasion inside natural habitats was positively related to B. tectorum density on roadsides only when the disturbance level was low. Shrub-steppes, grassy steppes and shrublands showed similar mean density of B. tectorum. Wet-meadows had the lowest densities of B. tectorum. Intermediate and highly disturbed environments presented higher B. tectorum density than those areas with low disturbance. Discussion. Our study highlights the importance of the interaction between road verges and disturbance levels on B. tectorum invasion in natural habitats surrounding roads of north-western Patagonia, particularly evidencing its significance in the invasion onset. The importance of invasion in road verges depends on disturbance level, with better conserved environments being more resistant to invasion at low levels of B. tectorum density along road verges, but more susceptible to road verges invasion at higher levels of disturbance. All the habitats except wet-meadows were invaded at a similar degree by B. tectorum, which reflects its adaptability to multiple habitat conditions. Overall, our work showed that synergies among global change drivers impact native environments favouring the invasion of B. tectorum. Fil: Speziale, Karina Lilian. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Di Virgilio, Agustina Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Lescano, María Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Pirk, Gabriela Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Franzese, Jorgelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina

Aim: We investigated patterns of species richness and community dissimilarity along elevation gradients using globally replicated, standardized surveys of vascular plants. We asked how these patterns of diversity are influenced by anthropogenic pressures (road construction and non-native species). Location: Global. Time period: 2008–2015. Major taxa studied: Vascular plants. Methods: Native and non-native vascular plant species were recorded in 943 plots along 25 elevation gradients, in nine mountain regions, on four continents. Sampling took place in plots along and away from roads. We analysed the effects of elevation and distance from road on species richness patterns and community dissimilarity (beta-diversity), and assessed how non-native species modified such elevational diversity patterns. Results: Globally, native and total species richness showed a unimodal relationship with elevation that peaked at lower-mid elevations, but these patterns were altered along roads and due to non-native species. Differences in elevational species richness patterns between regions disappeared along roadsides, and non-native species changed the patterns’ character in all study regions. Community dissimilarity was reduced along roadsides and through non-native species. We also found a significant elevational decay of beta-diversity, which however was not affected by roads or non-native species. Main conclusions: Idiosyncratic native species richness patterns in plots away from roads implicate region-specific mechanisms underlying these patterns. However, along roadsides a clearer elevational signal emerged and species richness mostly peaked at mid-elevations. We conclude that both roads and non-native species lead to a homogenization of species richness patterns and plant communities in mountains. Fil: Haider, Sylvia. Martin Luther University; Alemania. German Centre for Integrative Biodiversity Research; Alemania Fil: Kueffer, Christoph. Institute of Integrative Biology; Suiza. Stellenbosch University; Sudáfrica Fil: Bruelheide, Helge. Martin Luther University; Alemania. German Centre for Integrative Biodiversity Research; Alemania Fil: Seipel, Tim. State University of Montana; Estados Unidos Fil: Alexander, Jake M.. Universite de Lausanne; Suiza Fil: Rew, Lisa J.. Universite de Lausanne; Suiza Fil: Arévalo, José Ramón. Universidad de La Laguna; España Fil: Cavieres, Lohengrin A.. Universidad de Concepción; Chile Fil: McDougall, Keith L.. National Parks and Wildlife Service; Australia. La Trobe University; Australia Fil: Milbau, Ann. Research Institute for Nature and Forest; Bélgica Fil: Naylor, Bridgett J.. Forestry and Range Sciences Lab; Estados Unidos Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Pauchard, Aníbal. Universidad de Concepción; Chile

The exponential growth of the human population often causes the overexploitation of resources and disruption of ecological interactions. Here, we propose that the antagonist effect of humans on exploited species might be alleviated with the advent of a second predator species. We focused on the complex interactions between an endangered conifer (Araucaria araucana) and two seed exploiters: the Austral parakeet (Enicognathus ferrugineus) and human seed collectors. We tested the importance of partial seed consumption by parakeets as an escape from human seed harvesting. Although parakeets frequently ate whole seeds, a substantial proportion of the seeds found under trees were only partially eaten and avoided by human seed collectors. These seeds germinated at a similar proportion but faster than intact seeds under laboratory conditions. Our results revealed an overlooked mutualism between parakeets and an endangered tree. Incomplete seed eating by parakeets, plus selection against these eaten seeds by humans, may enhance regeneration possibilities for this conifer species subject to human seed collection, turning the scale of the antagonism–mutualism continuum to the mutualistic side. In this context, parakeets might be providing an important service in those forests subject to human harvesting by allowing a fraction of seeds to escape human predation

Despite the fact that parrots (Psitacifformes) are generalist apex frugivores, they have largely been considered plant antagonists and thus neglected as seed dispersers of their food plants. Internal dispersal was investigated by searching for seeds in faeces opportunistically collected at communal roosts, foraging sites and nests of eleven parrot species in different habitats and biomes in the Neotropics. Multiple intact seeds of seven plant species of five families were found in a variable proportion of faeces from four parrot species. The mean number of seeds of each plant species per dropping ranged between one and about sixty, with a maximum of almost five hundred seeds from the cacti Pilosocereus pachycladus in a single dropping of Lear's Macaw (Anodorhynchus leari). All seeds retrieved were small (

Understanding the factors underlying species coexistence is a major focus in community ecology. When dealing with competition between native and exotic species, the competitive exclusion of the ‘weaker’ species can have consequences for biodiversity conservation. We examined interspecific interactions during foraging between black vultures Coragyps atratus and Andean condors Vultur gryphus in Southern Argentina. Previous studies suggest facilitatory interactions between them. However, in most parts of their distribution ranges, these species did not coexist until recently, when black vultures expanded their geographic range following human development. Thus, facilitatory processes or segregation patterns could not be fine-tuned enough to allow their coexistence. Our hypothesis is that black vultures and Andean condors compete for food resources, and that this competitive scenario can change depending on local species abundances and habitat humanization. We experimentally placed sheep carcasses in two habitats differing in degrees of humanization to study the foraging patterns in these species. Both species exploited carcasses with similar temporal patterns. However, the first to arrive and the dominant species were different in both habitats, according to their abundances. Although black vultures do not completely prevent the arrival of Andean condors to carcasses, they represent serious obstacles for feeding. Thus, while dominance hierarchy at carcasses could be related to body size, carcass consumption was determined by species abundance. Our results support the hypothesis that the expansion of a ‘winning’ species may trigger interspecific competition with other ‘loser’ species, with negative responses towards human activities when they became abundant. Although the results are not conclusive, invasion and extinction processes could be occurring and they can have serious consequences for the diversity (i.e. richness and evenness) of the New World scavenger guilds.

Aim To evaluate the relative importance of climate, productivity, environmental heterogeneity, biotic associations and habitat use by cattle to account for the species richness of trees, shrubs and herbs across the Subantarctic–Patagonian transition. Location An area of c. 150 × 150 km, within the transition zone between the Subantarctic and Patagonian subregions on the eastern slope of the Andes (c. 39–42° S, 70–72° W). Methods All vascular plants found at each one of 50 (10 × 10 m) sampling plots were counted to estimate the local tree, shrub and herb species richness. Path analysis was used to evaluate the relationship between the richness of the three life-forms and plant cover, dried litter biomass, mean annual temperature, annual precipitation, daily temperature range, substrate heterogeneity and number of faecal pats. Principal coordinates of neighbour matrices was used to model the spatial autocorrelation of the data. Results Total plant species richness showed a unimodal pattern of spatial variation across the transition. Richness responded positively to indirect effects of precipitation mediated through plant cover, but there was a negative overall effect of precipitation on richness towards the west of the transition, most strongly for trees. An increase in substrate heterogeneity promoted a local increase in herb and shrub richness; the richness of trees increased in sites with steeper slopes. Canopy closure had a direct negative impact on herb richness; it also increased the local accumulation of litter, which negatively affected shrub and herb richness. The impact of habitat use by cattle negatively affected herb richness in areas to the east of the biogeographical transition. Main conclusions We suggest that the importance of indirect climatic effects mediated by vegetation cover can account for species richness patterns across this transition, most strongly for woody species, which supports the productivity hypothesis. The southern temperate forests towards the west may represent a deviation from the predictions of the water–energy dynamics hypothesis. Dissimilar spatial patterns of variation in the richness of woody and herbaceous species, and their different responses to climatic and heterogeneity variables across the transition, suggest that plant life-form influences the plant species richness–environment relationships.

Human disturbance can be a severe problem for some animal species. Behavioural ecology theory predicts that sensitivity to mortality risks, and thereby to disturbance, will be related to life-history characteristics. Long-lived species with low reproductive rates are expected to have a high cost of predation and therefore avoid risks strongly. In this paper we quantify the effect of roads on the Andean condor (Vultur gryphus) using behavioural indicators. We used a pair wise design, offering condors standardized food patches near and far from roads simultaneously The patches consisted of dead adult shee We recorded. p. condors' behaviour when visiting each patch. This study establishes the versatility of behavioural indicators and their usefulness to study conservation problems. We found that, although near and far patches were discovered after similar times and there were similar numbers of condors in the vicinity of near and far patches, the use of patches differed strongly. In the patches far from roads many more condors came to feed, the average time spent per individual was longer, the proportion of time spent vigilant was lower, and the amount of food left uneaten on the carcasses was lower. These results strongly suggest that Andean condors clearly avoid roads, and behave in a way predicted from theory if they trade off safety for energy. This study shows that roads have stronger influence on the habitat use of Andean condors, than previously thought, and may be a significant problem for the species in populated areas. (C) 2008 Elsevier Ltd. All rights reserved.

Bromus tectorum (cheatgrass) is an aggressive invasive species posing threats to native ecosystems including increase in fire frequency, alteration of water and nutrient cycles and exclusion of native species. As such, it is important to monitor this species worldwide. However, outside the United States, it has been poorly studied. We studied this species at two scales: (i) at a local scale, evaluating the species presence and its determinants, along the ecotonal area between the steppe and the forest within north-western Patagonia, to reveal whether B. tectorum is actually invading natural ecosystems in areas comparable with those invaded in USA, and (ii) at a regional scale, through a search of literature and herbaria databases on B. tectorum in South America, to determine the current known distribution of the species in this subcontinent. Results indicate that it is already invading north-western Patagonia in Argentina, mainly in the semi-arid part of the region, and that precipitation influences the invasion process. We found that for South America, B. tectorum has been only documented in southern Argentina and Chile. Given the similarities to other invaded regions, the possibility of invasion for Patagonia has been predicted but not prevented. It is important to study changes in the invasion level where it is already established, and to encourage managers with prevention and control strategies. Combining this information with lessons from places with extensive periods of invasion could help to initiate management of the species in areas where the invasion process is beginning and before the species spreads widely. Fil: Speziale, Karina Lilian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina Fil: Ezcurra, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Patagonia Norte. Instituto de Investigación En Biodiversidad y Medioambiente; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio de Ecotono; Argentina

Reintroduction or reinforcement (RorR) of wild populations is a common conservation strategy. Many conservation projects involve the release of individuals of poorly studied species. This may lead to inefficient results or negative impacts on the conservation efforts. Here, we provide new insights into the conservation implications and potential consequences of a skew in the sex ratio of released birds and of the number of birds supplemented for the demography of a long-lived dimorphic bird species, the Andean condor ( Vultur gryphus ). We demonstrate that a RorR conservation program may be less effective in conserving a species if the sex ratios of the releases and the recipient populations are not considered. We also show that releases can reduce population declines but only if carried out over long periods (i.e., several decades). This can mean high costs for release programs and the added challenge of maintaining programs over time. If RorR programs are to be implemented, bearing in mind the importance of properly assessing their effectiveness, we urge conservation researchers and managers to consider the implications of sex ratio biases for wild populations, and particularly for dimorphic species with sexually despotic behaviour.

[IN] Biological invasions are considered one of the major threats to the Earth's biota, and their prevention and control are widely recommended. A critical step is to gather information on the effects of introduced species on native species. In such analysis, it is important to consider both the negative effects and the fact that many nonnatives have become key components of existing ecosystems. The effects of nonnatives are particularly worrisome for raptors because raptors have high trophic positions and their ecological role can structure native communities. We here examine the effects of introduced species on raptors, as well as the interest in studying these effects, through a review of the published literature. The numbers of studies on raptors and introduced species as individual topics are rapidly increasing, but despite this we found few articles relating the two topics and fewer still with a clear aim of studying this relationship. Although the number of published reports we found was low, articles indicating negative effects outnumbered articles showing positive ones. Negative effects identified included decrease in native prey and direct or indirect poisoning via poisons aiming to protect productive introduced species from predators or to control introduced pests. Positive effects identified included extension of distributional range facilitated by introduced species or nonnative species as a food source. Very importantly, native raptors can become dependent on introduced species, and any proposed control of the nonnative/introduced species merits careful evaluation. In conclusion, the effects of nonnative species on this key group of top predators and scavengers have been poorly considered, but merit special attention and specific design in future studies, [ES] Las invasiones biológicas son una de las peores amenazas para la biodiversidad, y el control y la prevención de nuevas introducciones son ampliamente recomendados. Un paso fundamental en este proceso es la generación de conocimiento acerca del efecto de las especies introducidas sobre las especies nativas. En tal análisis, es importante considerar tanto los efectos negativos como el hecho de que algunas especies no nativas han llegado a convertirse en componentes clave de ecosistemas actuales. El efecto de las especies introducidas es especialmente preocupante para las rapaces debido a que, por su posición trófica y su rol ecológico, estas últimas pueden estructurar las comunidades nativas. Analizamos los impactos producidos por las especies introducidas sobre las rapaces y el interés en estudiarlos, mediante la revisión de la bibliografía publicada sobre el tema. Los estudios sobre rapaces y sobre especies introducidas como temas separados están aumentando rápidamente, pero a pesar de esto encontramos pocos artículos relacionando ambos temas y menos aún con un objetivo claro de estudiar dicha relación. Aunque el número de artículos encontrados fue bajo, los artículos que mostraban un efecto negativo han sido más numerosos que aquellos que indicaban un efecto positivo. Los efectos negativos identificados incluyeron la disminución de las presas nativas y el envenenamiento directo o indirecto producido por el veneno utilizado para la protección de especies introducidas económicamente productivas o para controlar especies introducidas consideradas pestes. Los impactos positivos identificados incluyeron la extensión del área de distribución facilitada por especies introducidas o las especies introducidas como fuente de alimento. Es importante notar que incluso las especies nativas pueden llegar a depender de las especies introducidas, y por lo tanto cualquier medida de control merece una cuidadosa evaluación. Concluyendo, las implicancias de las especies introducidas sobre este grupo clave de depredadores y carroñeros han sido poco consideradas pero merecen una atención especial y un diseño adecuado en estudios futuros.

Non-native species have reached South American ecosystems and may be threatening the exceptional biodiversity of this region. However, people often value and exploit introduced species not knowing that they are non-natives, nor understanding their impacts. In this paper we analyze the trend of scientific research on introduced species in South America and whether a socio-cultural explanation could underlie the results by comparing them with European, North American and Australasian countries. We also controlled for research effort, which could reflect economic inequalities, by analyzing the articles published on introduced species in relation to the total number of articles published on related disciplines. Research trends suggest that non-native species are not of major concern for South American countries, there being less research on this topic in countries with higher biodiversity. Compared to other colonized countries such as the USA, New Zealand and Australia, research on non-native species was lagging and less abundant in South America, even when controlling for research effort. Historical and recent socio-cultural particularities may explain the similar attitudes and research input seen in South American countries and their Spanish and Portuguese colonizers. A generational amnesia, where younger generations descendent from European colonizers are not aware of past biological conditions, could be exacerbating this lack of concern. South American policies seem to reflect the low level of interest in non-native species shown by their citizens. National policies are poorly developed and mainly deal with alien species threatening productive systems. Given the strong cultural component of this dilemma, integrated ways to reverse this situation are needed, including education, international research collaboration, and a common South American policy. © 2012 Springer Science+Business Media B.V.

Humans have spread species to nonnative environments for generations. In turn, these species can become invasive, threatening native species. There has been much discussion about the best way to control invasive species and protect native species ([ 1 ][1]). However, one point has been overlooked