Small mammal communities in rainforest fragments in Central Southern Chile Original Research Article

The Valdivian temperate rainforest of southern Chile and adjacent Argentina supports a diverse and unique biota, with a high percentage of endemic species. Progressive exploitation of these forests, especially in the Central Depression of southern Chile, has resulted in a complex and increasingly fragmented environment composed of isolated forest remnants in a landscape dominated by grazing and crop cultivation. To assess the consequences of this fragmentation, fourteen remnants were surveyed for small mammals during the winters of 1985 and 1986, and four of these were sampled in both years. Neither numbers of species (S), relative population sizes (nR), or species diversity (H′) were significantly related either to trapping effort or remnant area or perimeter, and only nR was significantly predicted by the area/perimeter ratio. Three native rodent species were found on all remnants in both years, and three additional native and one introduced rodent, and two marsupials, were found in lesser numbers and in fewer remnants.