Small mammal communities in rainforest fragments in Central Southern Chile

The Valdivian temperate rainforest of southern Chile and adjacent Argentina supports a diverse and unique biota, with a high percentage of endemic spe cies. Progressive exploitation of these forests, especially in the Central Depression of southern Chile, has resulted in a complex and increasingly fr agmented environment composed of isolated forest remnants in a landscape do minated by grazing and crop cultivation. To assess the consequences of this fragmentation, fourteen remnants were surveyed for small mammals during th e winters of 1985 and 1986, and four of these were sampled in both years. N either numbers of species (S), relative population sizes (n(R)), or species diversity (H') were significantly related either to trapping effort or rem nant area or perimeter, and only n(R) was significantly predicted by the ar ea/perimeter ratio. Three native rodent species were found on all remnants in both years, and three additional native and one introduced rodent, and t wo marsupials, were found in lesser numbers and in Fewer remnants. (C) 2000 Elsevier Science Ltd. All rights reserved.