Mamíferos puneños y altoandinos

Los mamíferos de la Puna argentina se encuentran representados por 54 especies, 33 géneros per tenecientes a 15 familias y 6 órdenes. Rodentia y Carnivora son los órdenes más ricos en especies comprendiendo el 69 y 15%, respectivamente, seguidos de Chiroptera con el 9%. En orden de importancia sigue Artiodactyla con una sola familia y dos especies. Cingulata y Marsupialia se ubican al final con una familia y una especie cada una. Considerando la totalidad de las especies de mamíferos de la Puna y las cinco áreas protegidas nacionales presentes en esta ecorregión se calculó una representatividad general del 65%, es decir 35 de las 54 especies de mamíferos se encuentran registradas en las áreas protegidas nacionales de Argentina. Chiroptera y Rodentia fueron los órdenes presentes en la Puna que tuvieron especies no registradas dentro del sistema nacional de áreas protegidas, alcanzando representatividades del 80 y 51%, respectivamente. Las principales amenazas para los mamíferos en estos ambientes se relacionan con actividades humanas, e incluyen: la cacería, la contaminación y desecación de las fuentes de agua, la introducción de especies exóticas, la degradación del hábitat, la contaminación causada por el turismo y/o las competencias deportivas y la disminución de la cobertura vegetal. Son pocos y muy específicos los esfuerzos científicos y gubernamentales por generar conocimiento sobre los mamíferos puneños, siendo sumamente difícil implementar políticas de uso comercial, manejo y/o conservación. En general, se sabe muy poco sobre los roedores y quirópteros, siendo este desconocimiento una de las amenazas más críticas en algunas circunstancias. Esto ha hecho sumamente difícil interpretar los impactos que una actividad determinada puede causar sobre sus poblaciones.“Puna and High-Andes Mammals”. Mammals at the Puna of Argentine are represented by 54 species, 33 genera belonging to 15 families and 6 orders. Rodentia and Carnivora are the richest orders (69 and 15%, respectively) followed by Chiroptera (9%). Artiodactyla includes one family and two species; Cingulata and Marsupialia are last with one species each. Considering all mammalian species of the Puna and High Andes and the four protected areas of national jurisdiction, a general representation of 61% is calculated: 33 of the 54 mammal species of these ecoregions are recorded in national protected areas of Argentina. Chiroptera and Rodentia orders have species not recorded in the national system of protected areas, reaching a representativeness of 80 and 46% respectively. The main threats to mammals in these environments due to interaction with human activities include: pollution and loss of water sources, hunting and introduction of exotic species, habitat degradation, pollution caused by tourism and/or sporting activities and decreased vegetation cover. Scientific and government efforts are scarce and very specific to generate knowledge about Puna mammals, which results in extremely difficult implementation of policies for commercial use, management and/or conservation. Very little is known about rodents and bats, and this ignorance is one of the most critical threats in some circumstances, since it is not possible to interpret the impacts of any activity to their populations.Fil: Perovic, Pablo Gastón. Administración Nacional de Parques Nacionales; ArgentinaFil: Trucco Aleman, Carlos Eduardo. Universidad Nacional de Salta; ArgentinaFil: Tellaeche, Cintia Gisele. Universidad Nacional de Jujuy; ArgentinaFil: Bracamonte, Julio Cesar. Universidad Nacional de Jujuy; ArgentinaFil: Cuello, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Novillo, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Lizárraga, Leónidas. Administración Nacional de Parques Nacionales; Argentin

Woody vegetation of an abandoned road in the semiarid Chaco forest in relation to the surrounding vegetation matrix and grazing

En un camino abandonado del bosque chaqueño semiárido (Parque Nacional Copo, Argentina), comparamos la comunidad de plantas leñosas en dos sectores: uno de bosque secundario con presencia de ganado vacuno (“Vacas-Bs”), y otro de bosque primario sin presencia de ganado vacuno (“Sin Vacas-Bp”). Para esto, medimos atributos de la vegetación leñosa en parcelas dispuestas al azar en cada sector. La riqueza de especies, la densidad de plantas adultas y el área basal fueron similares en los dos sectores. En las parcelas del sector “Vacas-Bs”, Capparis retusa representó el 34% del área basal total, disminuyendo la equitatividad del ensamble de este sector. El número de ramas por individuo y la densidad de ramas fueron similares en ambos sectores. Achatocarpus praecox, Prosopis sp. y Ximenia americana estuvieron presentes sólo en las parcelas del sector “Vacas-Bs”, mientras que Senna aphylla fue encontrada sólo en las parcelas del sector “Sin Vacas-Bp”, aunque estas diferencias podrían deberse a la variación intrínseca. En el tiempo considerado, no encontramos evidencias marcadas de que la comunidad de plantas leñosas difiera entre sectores con distinta historia de pastoreo y vegetación circundante.In an abandoned road in of the semiarid Chaco forest (Copo National Park, Argentina), we compared the community of woody plant species in two areas: one with livestock, surrounded by secondary forest, and another without livestock, surrounded by primary forest. We measured characteristics of the woody vegetation in nine plots (2 x 100 m) selected randomly in the area with livestock and in six plots in the area without livestock. Considering the same number of samples, species richness was similar in both areas. No significant differences were found in species richness per plot, adult plants density and basal area between the two areas. In the plots with livestock, 34% of the total basal area corresponded to Capparis retusa, decreasing the assembly eveness in this area. The number of branches per individual and the branch density were similar in both areas. Achatocarpus praecox, Prosopis sp. and Ximenia americana were present only in plots with livestock, while Senna aphilla was found only in the plots without livestock, however these differences could be the result of intrinsic variations. The density and basal area per species were not different between areas. In the considered period of time, we did not find evidence of differences in the community of woody plant species related to the different grazing history and the surrounded vegetation matrix.Fil: Tálamo, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Trucco Aleman, Carlos Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. Ministerio de Ambiente y Desarrollo Sustentable de la Provincia de Salta; ArgentinaFil: Caziani, Sandra Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentin

Disentangling the effects of shrubs and herbivores on tree regeneration in a dry Chaco forest (Argentina)

Successful persistence of dry forests depends on tree regeneration, which depends on a balance of complex biotic interactions. In particular, the relative importance and interactive effects of shrubs and herbivores on tree regeneration are unclear. In a manipulative study, we investigated if thornless shrubs have a direct net effect, an indirect positive effect mediated by livestock, and/or an indirect negative effect mediated by small vertebrates on tree regeneration of two key species of Chaco forest (Argentina). In a spatial association study, we also explored the existence of net positive interactions from thorny and thornless shrubs. The number of Schinopsis lorentzii seedlings was highest under artificial shade with native herbivores and livestock excluded. Even excluding livestock, no seedlings were found with natural conditions (native herbivores present with natural shade or direct sunlight) at the end of the experiment. Surprisingly, seedling recruitment was not enhanced under thornless shrubs, because there was a complementary positive effect of shade and interference. Moreover, thornless shrubs had neither positive nor negative effects on regeneration of S. lorentzii. Regeneration of Aspidosperma quebracho-blanco was minimal in all treatments. In agreement with the experiment, spatial distributions of saplings of both tree species were independent of thornless shrubs, but positively associated with thorny shrubs. Our results suggest that in general thornless shrubs may have a negligible effect and thorny shrubs a net positive effect on tree regeneration in dry forests. These findings provide a conceptual framework for testing the impact of biotic interactions on seedling recruitment in other dry forests.Fil: Tálamo, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Barchuk, Alicia Haydee. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Garibaldi, Lucas Alejandro. Universidad Nacional de Rio Negro. Sede Andina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Trucco Aleman, Carlos Eduardo. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cardozo, Silvana. Universidad Nacional de Salta. Facultad de Ciencias Naturales; ArgentinaFil: Mohr, Federico. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentin

Waterbird richness in altiplano wetlands of northwestern Argentina

We measured waterbird richness and abundance, and characterized wetland features (altitude, size, and presence of submergent vegetation) of 50 altiplano wetlands, during summer and winter, 1998. We estimated 36,700 individuals of 24 avian species during the summer census. James' Flamingo (Phoenicoparrus jamesi) and Andean Flamingo (P. andinus) were the most abundant species, followed by Horned Coot (Fulica cornuta), Chilean Flamingo (Phoenicopterus chilensis), and Crested Duck (Anas specularioides). These species comprised 78% of total individuals. In winter, we counted 7,421 individuals of 16 species, and the three flamingo species were the most abundant. In summer, we found Chilean and Andean Flamingos primarily in intermediate-altitude wetlands (3,500-4,000 m a.s.1.), whereas James' Flamingos and other waterbirds were above 4,000 m. In winter, the three flamingo species moved to lower-altitude wetlands (below 3,500 m). Waterbird abundance was positively correlated with wetland size in wetlands with aquatic vegetation, with waterbird richness in wetlands without macrophytes. During summer, total abundance and richness were significantly higher in wetlands with macrophytes, where Chilean Flamingo and ten other waterbird species (e.g., ducks, grebes, gulls, and coots) were more common. James' Flamingo was the only species more abundant in hypersaline wetlands. In summer, four wetlands (Grande, La Alumbrera, Vilama, and Pozuelos) contained 68% of the total individuals, with more than 3,000 waterbirds each. In winter, wetlands Pozuelos and Guayatayoc included 50% of waterbirds counted, with more than 5,000 birds each. Thirty four percent of the wetlands surveyed are within protected areas, but only in Laguna de los Pozuelos Natural Monument is it actually implemented. In 42% of the wetlands we detected land uses that could represent threats to these environments. Here we propose some criteria to detect and prioritize relevant sites for conservation of altiplano waterbirds: a) large aggregations of individuals, either seasonal or permanent, b) vulnerable and/or endemic species and presence of nesting sites, c) ecological uniqueness, d) proximity to other complementary wetlands, e) high heterogeneity between and within sites. The complementary use of these environments by waterbirds, both seasonally and spatially, suggests considering conservation action from a landscape perspective.Fil: Caziani, Sandra Monica. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Derlindati, Enrique Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Tálamo, Andrés. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Sureda, Ana L.. Universidad Nacional de Salta; ArgentinaFil: Trucco Aleman, Carlos Eduardo. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Nicolossi, Guillermo. Administración de Parques Nacionales; Argentin