Paleolimnological records of the Central Southern Pampa plain

Abstract

In the last few centuries, human activity has itself become a kind of geological force, and since 1950, Earth’s evolution is apparently driven by human rather than natural forces. The rates of environmental change increased abruptly as a consequence of the mid-20th century economic growth. The energy use and the emerging technologies exerted unprecedented pressures on the environment, altering their natural rhythms, what has now become known as the “Great Acceleration”. Urbanization contributed to habitat fragmentation and loss, whereas agricultural mechanization led to farmland expansion. However, the interactions between these impacts have spatial and temporal implications, propagating across different settings and contexts. Few studies have assessed the consequences of the Great Acceleration on the Pampa plain, and the identification of the main forcings behind the last centuries´ changes is still poorly understood. The main objective of this chapter is to compile publications concerning the paleoenvironmental history of the shallow lakes of the Central Southern Pampas and do a comprehensive analysis of the last 600 years. This time frame includes the period prior to the European arrival, the conversion of the natural landscape to land-use for agriculture during the first half of the 19th century, the agricultural expansion between 1850-1890, and the urbanization and the strong growth of agricultural production during the mid-20th century. All these socio-economic transformations occurred under specific paleoclimatic scenarios, including a significant precipitation jump in the 1970s, resultingin major environmental degradation. By considering simultaneously socio-economic and natural forcings, we can fill the gap in our understanding of what causes the shallow lakeenvironmental evolution in one of the world´s prime agricultural regions and discriminate natural from historical and inherited factors.