South American lake paleo-records across the Pampean Region

Abstract

Although paleolimnological studies in the Argentinean and Uruguayan Pampas are relatively incipient, they have already provided critical information on the regional response of aquatic systems to climate variability. The combined results of these research initiatives highlight the key role Figure 2: Conceptual paleolimnological model displaying the relationship between trophic development of Uruguayan lakes (purple line), climate change in the region (black line) and Holocene sea-level curves (colored lines) observed in Uruguayan lakes. Temperature and humidity curves were reconstructed from opal phytolith data (Bracco et al., 2005; Inda et al., 2006; del Puerto et al., 2006; 2008; 2009). Sea level curves reconstructed from stratigraphical and topographical data. 117 PAGES news ? Vol 17 ? No 3 ? October 2009 Science Highlights: Paleolimnology of the subtropical region of South America (i.e., the transition between the tropics and the extra tropics) in deciphering the forcing factors of past changes in atmospheric circulation. Both Argentinean and Uruguayan Holocene paleolimnological records indicate similar paleoclimatic trends, i.e. dominant dry conditions were observed during cold phases, whereas wet conditions prevailed during warm climatic phases. To our knowledge, this is the first attempt to integrate paleoclimatic data for the whole Pampean region. In addition, our results underscore the need to reinforce paleoclimate research at mid-latitudes in South America, in an attempt to fully appreciate natural climate variability beyond the instrumental record, as well as to design new strategies for the sustainable development of ecosystems and natural resources.