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Estevez R.A.,University of Melbourne | Estevez R.A.,University of Santiago de Chile | Anderson C.B.,National University of Tierra del Fuego | Anderson C.B.,CONICET | And 2 more authors.
Conservation Biology | Year: 2015

Decision makers and researchers recognize the need to effectively confront the social dimensions and conflicts inherent to invasive species research and management. Yet, despite numerous contentious situations that have arisen, no systematic evaluation of the literature has examined the commonalities in the patterns and types of these emergent social issues. Using social and ecological keywords, we reviewed trends in the social dimensions of invasive species research and management and the sources and potential solutions to problems and conflicts that arise around invasive species. We integrated components of cognitive hierarchy theory and risk perceptions theory to provide a conceptual framework to identify, distinguish, and provide understanding of the driving factors underlying disputes associated with invasive species. In the ISI Web of Science database, we found 15,915 peer-reviewed publications on biological invasions, 124 of which included social dimensions of this phenomenon. Of these 124, 28 studies described specific contentious situations. Social approaches to biological invasions have emerged largely in the last decade and have focused on both environmental social sciences and resource management. Despite being distributed in a range of journals, these 124 articles were concentrated mostly in ecology and conservation-oriented outlets. We found that conflicts surrounding invasive species arose based largely on differences in value systems and to a lesser extent stakeholder and decision maker's risk perceptions. To confront or avoid such situations, we suggest integrating the plurality of environmental values into invasive species research and management via structured decision making techniques, which enhance effective risk communication that promotes trust and confidence between stakeholders and decision makers. © 2015, Society for Conservation Biology. Source

Valenzuela A.E.J.,Southern Patagonia Coordination Office | Anderson C.B.,National University of Tierra del Fuego | Anderson C.B.,OSARA Omora Sub Antarctic Research Alliance | Anderson C.B.,CONICET | And 2 more authors.
Acta Oecologica | Year: 2013

Understanding processes and impacts of biological invasions is fundamental for ecology and management. Recent reviews summarized the mechanisms by which invasive species alter entire ecosystems, but quantitative assessments of these mechanisms are lacking for actual assemblages to determine their relative importance, frequency and patterns. We updated information on introduced vertebrates in the Tierra del Fuego Archipelago (TDF) via an exhaustive literature review and new data to evaluate ecosystem impact mechanisms and provide management recommendations. To date, 24 exotic vertebrates have naturalized in TDF, outnumbering natives nearly 2:1, with the North American beaver (Castor canadensis) and muskrat (Ondatra zibethica) being the most widely distributed species and also impacting the ecosystem through the greatest number of mechanisms. Introduced vertebrates occupied most parts of the archipelago with human-inhabited islands having greater taxa richness. All exotics potentially altered ecosystems by one or more mechanisms: 100% food webs, 92% invasional meltdown, 42% habitat modification, 38% disease or parasite transmission, 21% soil property and disturbance regime changes. Impact to habitat structure was the main clustering criterion for this assemblage. Within the species that physically alter habitats, we found two sub-groups: 1) large herbivores and 2) "others" including beavers and muskrats. Species that did not alter habitat were divided further into those with predatory trophic effects (carnivorous mammals and trout, sub-group 4) and the rest with assorted impacts (sub-group 3). By establishing high quality information on archipelago-wide assemblage, distribution, impacts and mechanisms for exotic vertebrates, we recommend, based on ecological criteria, prioritizing the management of sub-group 2. A secondary priority might be given to the carnivores in sub-group 4, while species in sub-groups 1 and 3 are less urgent. As the first systematic survey of introduced fauna on an archipelago-scale, we identified knowledge gaps, such as population abundance and dynamics for specific species, which are needed to orient future work, but the notable progress made to date is highlighted. © 2013 Elsevier Masson SAS. Source

Dell'Osa A.H.,National University of Tierra del Fuego
IFMBE Proceedings | Year: 2016

Electrical Impedance Tomography (EIT) techniques elaborate two dimensions images from average spatial distribution of resistivity within a three-dimensional structure. In the fracture and healing process of long bones, the limb has changes of bioimpedance values. This paper review varius works in bone electrical impedance and tomographic reconstruction, and proposes potential improvements for clinical applications of the current technology to apply in first emergency attention in difficult access areas (p.e.: mountains areas). © Springer Science+Business Media Singapore 2016. Source

Colautti D.,CONICET | Baigun C.,CONICET | Llompart F.,CONICET | Llompart F.,National University of Tierra del Fuego | And 5 more authors.
Hydrobiologia | Year: 2015

Pampean lakes are characterised by the alternation of flood and drought periods, but little is known about its effects on fish assemblage in an extended temporal scale. This study analyses the temporal variability of the fish assemblage in Chascomús Lake, and discusses the role of temperature and precipitation as potential drivers of fish composition shifts. Data acquisition was based on experimental fishing performed from 1999 to 2013 and from historical fishing records. Two alternative fish assemblage configurations were identified by cluster analysis. Odontesthes bonariensis, Parapimelodus valenciennis and Cyphocharax voga were the dominant species, which accounted for 70–80% of the relative abundance. The species O. bonariensis showed temporal fluctuations in its representativeness, changing from dominant to almost absent, whereas C. voga and P. valenciennis changed their abundance following a similar pattern along time. When historical data were considered, Platanichthys platana appeared as the fourth most relevant species. Precipitation, critical temperatures and fish mortalities were identified as the main drivers of species abundance shifts. This study highlights the importance of long-term assessments to understand the influence of climatic factors and the need to maintain or restore natural ecological processes as the basis to support dynamic sustainable fisheries in Pampean shallow lakes. © 2014, Springer International Publishing Switzerland. Source

Henn J.J.,CONICET | Henn J.J.,University of Wisconsin - Madison | Anderson C.B.,CONICET | Anderson C.B.,National University of Tierra del Fuego | Martinez Pastur G.,CONICET
Biological Invasions | Year: 2016

Understanding the amount of impact and distribution of invasive species is important for both basic ecological research and making management decisions. Because of their extensive impacts in southern Patagonia, invasive North American beavers (Castor canadensis) are considered both a scientific and conservation priority. However, little is known about the landscape-scale effects of these exotic ecosystem engineers. Using satellite imagery, we estimated the impact of beavers in the Argentine portion of Tierra del Fuego Island and determined the habitat factors (vegetation cover, forest type, stream presence and topography) related to their presence using both non-parametric statistical and information-theoretic approaches. Results indicated that more than 31,000 ha (1.6 % of the study area) were impacted by beavers and that the presence, but not the amount, of beaver impacts were spatially clustered. Impacts were greater in the Mountain ecoregion (2.8 % of the ecoregion) and lower in the Steppe (0.1 %). The best model for predicting beaver presence included variables related to water availability (presence of peatlands and streams), forage availability (forest type cover), and topography (slope and elevation). These findings support previous assertions that this invasion is the largest alteration to the sub-Antarctic forests in the Holocene. They also serve as a foundation for the development of maps based on habitat- and landscape-scale conditions to assist with the orientation of control, eradication, and restoration efforts currently being planned. © 2016 Springer International Publishing Switzerland Source

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