Corredores biológicos para la fauna de mamíferos en la provincia Carrasco (Departamento de Cochabamba, Bolivia): un estudio de caso

Abstract

BIOLOGICAL CORRIDORS FOR THE MAMMAL FAUNA IN THE PROVINCE OF CARRASCO (STATE OF COCHABAMBA, BOLIVIA): A CASE-STUDY Desde los anos 80, muchas familias andinas emigraron a la region Amazonica, buscando nuevas tierras sobre todo, mejores condiciones de vida. De la expansion de las areas agropecuarias y la presion demografica resulto una fragmentacion del espacio vital para los mamiferos. Rios y sus franjas de bosque pueden servir de corredores biologicos para los movimientos de la fauna entre las manchas de bosque que resultan de la fragmentacion. Este estudio enfoca en el rio Hondo, situado en la provincia Carrasco, donde se conserva una vegetacion (bosque poco intervenido y bosque secundario) casi a todo lo largo del rio. En este corredor se ha observado las huellas de diez especies de medianos y grandes mamiferos. Sin embargo, este corredor es tambien muy vulnerable. Un analisis multitemporal demostro que entre 1990-1998, habian cambios en la cobertura y el uso de la tierra en la zona y una gran reduccion de areas boscosas (aproximadamente menos un 20%). Se ha identificado un impacto negativo del aumento de campos de cultivo y de infraestructura (como la carretera Cochabamba-Santa Cruz) lo cual reduce de manera considerable el numero de indicios de animales (huellas y excrementos) presentes. Se incluyo una discusion sobre la importancia de corredores biologicos en la region. Palabras clave: corredor biologico, fragmentacion, colonizacion, mamiferos, indicios, Bolivia. ABSTRACT Since 1980's, a high number of Andean families in Bolivia have migrated to the Amazon basin in search for cultivable soil and better living conditions. One of the consequences of the expansion of the agricultural frontier and the demographic pressure has been the increased fragmentation of mammal habitats. However rivers and their riparian vegetation can function as biological corridors for fauna between forests that have been fragmented. This study is focused on the Hondo River in the Carrasco Province, which is characterized by an almost intact riparian vegetation (primary and secondary forest). In this corridor footprints of ten species of mid and large sized mammals were observed. However the corridor is very vulnerable to changes. A multi-temporal analysis showed that between 1990-1998 the vegetation cover and soil use has changed drastically resulting in a 20% reduction of the forest. A negative impact of the increase of agricultural areas and the improved infrastructure (such as the highway Cochabamba-Santa Cruz) on the number of animal signs (foot prints and excrements) was recorded. A discussion on the importance of river corridors in the area is also presented. Key words: Biological corridor habitat fragmentation, colonization mammals, animal signs, Bolivia.