The Upper Paraná Atlantic Forest of Misiones, Argentina, represents the most southern and interior expression of the Atlantic Forest, one of the most threatened ecoregions of the world. The degradation and fragmentation processes this region has been subject to for so many years, constitutes an important ecological factor that affects the diversity, community structure and population parameters of many species, putting many of them at the verge of extinction.

The non-flying small mammals constitute one of the most diverse animal groups in the region. Even though, the diversity and composition of the small mammal assemblage of the Atlantic Forest of Misiones is still poorly known, mostly because the sampling effort has been irregular and not systematic. Even in those few locations where the small mammal communities are better known, most of the information comes from studies on raptor’s pellets and not on systematic field studies using live or dead trapping. Besides, the studies developed during the last few years have been focus principally on the collection of mammals for taxonomic and public health studies, but none of them have had as goal to study how the small mammal assemblage changes in the natural environment and how the anthropogenic disturbances affect them.

With this study I will describe the composition and structure of the small mammal assemblage and analyse the influence of one the land-uses actually most relevant for the regional economy, pine plantations.

This study will let me:

1) characterize the Atlantic Forest of Misiones small mammal assemblage, and generate base line information on the structure and diversity of this group,

2) understand how the native forest replacement affects the composition and diversity of the small mammal assemblage. This in turn will help to generate recommendations for the conservation of biodiversity in this human dominated landscape.