A regional study of Holocene climate change and human occupation in Peruvian Amazonia

Most palaeoecological research has focused on glacial– interglacial oscillations as the major climatic changes in Amazonia during the Quaternary (Haffer, 1969; Colinvaux et al., 2000; Pennington et al., 2000). Nevertheless accumulating data point to the importance of Holocene cycles of drought as a potent force shaping lowland communities. Servant et al. (1981) predicted the presence of a midHolocene arid phase in Amazonia based on geomorphological evidence from Bolivia. This prediction has been borne out by subsequent palynological evidence of drought in such environmentally sensitive locations as the Bolivian savanna/ forest ecotone (Mayle et al., 2000), the Carajas Plateau, Brazil (Absy et al., 1991) and the Colombian Llanos (Behling, 1998; Behling & Hooghiemstra, 1999). However, the timing of these events differs between localities, and it should be noted that no evidence of an equally strong mid-Holocene drying is evident in central Amazonia (Bush et al., 2000; De Toledo, 2004). While many sites within Amazonia reveal pronounced Holocene climate change, the probability of those changes strongly influencing vegetation structure is enhanced in the ecotonal areas between savanna and forest biomes. The origin of these climatic changes has variously been ascribed to orbital variation (Rowe et al., 2002), El Niño/Southern Oscillation Department of Biological Sciences, Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901, USA and Department of Biology, Wake Forest University, Box 7325, Reynolda Stn, Winston Salem, NC 27901, USA