Ecosystems of the Atacama Desert and adjacent Andean area in northern Chile

In this paper we synthesize the information obtained from a research projec t within the Programa Sectorial Biomas y Climas Terrestres y Marines en el Norte de Chile carried out during two years in the Atacama Desert and adjac ent Andean area (Latitude 21 degrees-26 degrees S). We start by providing a climatic context for the study area emphasizing the high variability obser ved in rainfall and temperature at different spatial and temporal scales. O f great importance is the altitudinal variability in both variables. We con tinue by characterizing the Lomas, Riparian and Puna ecosystems within the area, in terms of their location, dominant abiotic conditions, component sp ecies and representative food webs. in the context of the observed variabil ity in abiotic conditions within the area, we characterize the physiologica l strategies of two rodent species that enable them to survive in a fluctua ting, unpredictable, and harsh environment. In the same context we synthesi ze the available information on patterns in ecosystem structure, mainly in relation to species diversity and abundance of rodents, birds, insects, and plants. Finally, we characterize the human-environment interaction in the area based on archeological, palynological, and anthropological data. These data allowed us to distinguish several episodes of interaction. As a detai led study case we present the history of human-environment interactions for the locality of Beter.