Late Holocene vegetation and environments from semiarid Pampas (Central Western Argentina): Hydro-climate variability from an integrative approach

ISABEL VILANOVA; ALFONSINA TRIPALDI; KARSTEN SCHITTEK; STEVE FORMAN; EDUARDO L. PIOVANO; ESTEBAN JOBBAGY

Karratha

Conferencia; Southern Deserts 5: Desertscapes: Adapting to Arid Landscapes?Developing new narratives of environmental change and human-environmental relationships within the great deserts of the southern hemisphere; 2018

The University of Western Australia

In light of the widespread evidence for global warming and climate change, reconstructing Late Quaternary environments and inferring climatic variability, particularly during the Holocene, occupy a central role in the effort to predict future responses of ecosystems and modeling upcoming scenarios. In the recent past, arid and semiarid regions of southern South America have experimented extreme droughts at the beginning of the 20th century (e.g. 1930s) as well as intensification of precipitation since 1970s; in both cases triggering dramatic environmental changes and concomitant economic consequences. This region has become increasingly important for agricultural and farming activities as a fundamental use of the land; which combined with shifts in the hydrological regime have caused landscape transformations. However, our knowledge of Holocene paleoenvironments, vegetation and moisture availability in this region is still limited and high-resolution records are needed for clearly establishing trends and timing of wet and dry phases, particularly for the last millennia, and to understand landscape response patterns to variations in the atmospheric circulation within South American context. Shallow lakes formed in blowoutdunes in the semiarid region (33º-34ºS; 65º2?W) are a key source for reconstructing Late Quaternary environmental and paleoclimatic evolution because the provide geomorphologic evidences, sedimentary archives, and proxy-indicators (pollen and non pollen palynomorphs, charcoal, C and N stable isotopes, among others) for deciphering the present landscape dynamics and the environmental changes over time. First results from 3 lakes show multi-decadal to centennial environmental and vegetation changes, as well as complex hydroecological variations involving great temporal variability in water availability as a result of variation in climate and weather at multiple scales and vegetation-soil water feedbacks. We expect the results of this investigation will provide robust information than can be useful for a sustainable management of grasslands, woodlands and lakes from this region. NOTA: Leandro D. Rojo (Universidad de Cuyo), Guillermo Heider y Jorge Chiesa (Universidad de San Luis) son otros autores que no pude incorporar en el SIGEVA