Actualités et séminaires

Glycerol dialkyl glycerol tetraethers are a class of lipid biomarkers that in recent decades have been show to act as paleoclimate indicators in lake sediment. New research and recent methodological advances have shown that the 5’ methyl branched tetraether index (MBT5’­­Me ) correlates well with temperature, however its use as a paleoclimate marker requires the development of calibration estimates for the areas under investigation.

Groundwater and surface water are a single complex and interacting system depending on geological, climatic, and hydrological factors, among others. In the context of global change, anthropic activities are an additional forcing in the groundwater-surface water interaction (GW-SW-I) systems, which may impact water quality, quantity, and ecosystems health. A commonly impacted variable in lakes is water level. Several lakes worldwide have shown water level decline trends and total desiccation in recent decades, particularly in arid regions.

The abundant precipitation of westerly origin controls the climate on the western side of the Andes Mountains with non-seasonal rainfall (i.e., year-round) from 55° to 42°S and seasonal rainfall pattern from 42°S to 30°S, associated with a seasonal drought at latitudes <42°S. As a result, the vegetation change (ca. 42°S) from Temperate and Valdivian Rain Forest to North Patagonian Evergreen Forest, a vegetation change characterized by a gradual decrease in diversity attributed to lower temperatures as well as changes in precipitation.