Subtropical Dry Forests: The Main Forest Ecoregion of Argentina

The Chaco is a sparsely populated, wooded grassland natural region of the Río de la Plata basin, where four physiognomic regions can be identified: Humid Chaco, Semi-arid Chaco, Arid Chaco, and Chaco Serrano. In this introduction to the section of subtropical dry forests, the most relevant tree genera and species are presented. A severe degradation and deforestation process characterize this region in the current century. The main productive systems are described, together with their effects on environmental, economic, and social aspects: extraction of firewood, production of charcoal, and extensive livestock. The recent advance of the agricultural frontier threatens the native communities living within and from the forest in an ancient equilibrium: changes in land use, technological advances of agriculture, increase of logging in the natural forest are occurring. A new tree-centered production paradigm is needed. “Quebracho” species represent a historical paradigm of overexploitation but a promise of possible sustainable management. Key species for the reconversion of the productive systems in the Chaco (not treated in the following chapters) are presented, taking into account their potential for breeding and relevance for restoration, within the environmental, economic, and social context of the region.Instituto de Fisiología y Recursos Genéticos VegetalesFil: Verga, Anibal. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Rioja. Agencia De Extensión Rural La Rioja; ArgentinaFil: Lopez Lauenstein, Diego. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Fisiología y Recursos Genéticos Vegetales; ArgentinaFil: Lopez Lauenstein, Diego. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Estudios Agropecuarios (UDEA); Argentin

Structure and diversity of Arbuscular Mycorrhizal fungal communities across spatial and environmental gradients in the Chaco forest of South America

The Chaco forest is one of the most diverse ecosystems in South America andharbors different vegetation units with high levels of biodiversity. However, theinformation about how belowground communities are spatially structured acrossvegetation units in the Chaco forest is scarce. We aimed to analyze the variation oftaxonomic and phylogenetic diversity and structure of the arbuscular mycorrhizal fungalcommunities across different vegetation units of the Chaco forest. Arbuscularmycorrhizal fungi (AMF) richness showed significant differences between vegetationunits. The AMF community composition was being significantly structured bygeographic variables (i.e. wider scale), environmental variables (i.e. altitude,temperature and precipitation) and edaphic (i.e. pH and Nitrogen). In addition, the AMFcommunities in Chaco forest might be phylogenetically clustered compared to local(Córdoba Province), regional (South America) and global species pool. In general, avariation of AMF communities in the Chaco forest might be determined by the spatialconfiguration and environmental conditions.Fil: Grilli, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Marro, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Risio Allione, Lucia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentin

Surface activity, sex ratio and diversity of scorpions in two different habitats in an Arid Chaco reserve, Argentina

Scorpions are one of the most important taxa of predators in terms of density, biomass, and diversity in various areas of the world. In this study, we compared population- and community-level data between a mature and a secondary forest in the Chancaní Reserve (Córdoba, Argentina). Scorpions were collected using pitfall traps (54 nights per site), and their nocturnal activity was observed by means of UV light (26 nights per site) over 7 months. Seven species of scorpions (1964 individuals) were observed in the study area (Bothriuridae and Buthidae). Brachistosternus ferrugineus composed >74 % of all individuals and was numerically dominant in most months. It was the most common species sampled with UV light method in all months (85.73 % in mature and 81.80 % in secondary forest). Timogenes elegans was the most common species sampled with the pitfall traps method in secondary forest (48.58 %). General sex ratio (males:females) for B. ferrugineus was 1:1.24 and for T. elegans was 1:0.53. The Shannon index was not significantly different between sites. Species richness was similar, and the Jaccard index was Cs = 0.86, indicating that both sites share 86 % of the species. Tityus confluens was the only species not shared between sites. Our results indicate that species composition in regenerating forest resembles that of primary forest after c. 15 years, but the relative abundances of these species differ.Fil: Nime, Mónica Fernanda. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; ArgentinaFil: Casanoves, Fernando. Consejo Nacional de Investigaciones Cienti­ficas y Tecnicas. Centro Cientifico Tecnologico San Juan. Instituto de Ciencias Astronomicas de la Tierra y del Espacio; ArgentinaFil: Mattoni, Camilo Ivan. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Instituto de Diversidad y Ecologia Animal; Argentin