Previous studies of Chilean mediterranean-type ecosystems have suggested a major role for predation, and plant-animal interactions in structuring small mammal assemblages, and in community level interactions. However, few long-term or carefully replicated field experiments have been conducted in temperate Neotropics, and such studies are needed to assess the generality of patterns elucidated largely from Northern Hemispheric communities. This research will investigate the specific effects of major predator groups on small mammals, and the evidence for significant plant-small mammal interactions in a semi-arid mediterranean community in a Chilean national park which has received considerable previous effort on small mammal population dynamics, resource partitioning patterns, predator diets, and floristic associations. Replicated fenced and/or net- covered exclosures permeable to small mammals, and small mammal- proof exclosures will be used to assess predation impace, and consumer effects, respectively, In addition to moitoring of direct effects, the evidence for changes in small mammal foraging patterns and habitat utilization will be assessed. Detectable responses to predator, and small mammal exclusion are expected to be rapid, and the proposed work will be among the first such large scale studies of these processes in temperate Neotropical small mammals.
