People down, forest up?. Forest expansion in a mountainous ecosystem of Northwestern Argentina

PAOLINI, L; GRAU, HR

bohn, Alemania

Conferencia; 6th Open Meeting of the Human Dimensions of Global Environmental Change Research Community; 2005

University of Bohn

Forest lost has been one of the major issues addressed during the last decades in land cover change studies of subtropical mountain forest. In the mountainous ecosystems of Northwestern Argentina (Yungas), climate change and human migration (at regional scale) could be driving a reverse process in forest cover change, causing a forest expansion during the last decades. Instrumental and tree-ring records from this region indicate that rainfall has increased during the second half of the twentieth century, while demographic records shows that the proportion of the population living in rural areas has decreased during the last 40 years, and that the population whose livelihood depend directly depends on agriculture, hunting, fishing or forestry has declined since 1980. We used remotely sensed data to asses the forests cover change in the subtropical mountain forest of northwestern Argentina (more than 2 million hectares) during the last 15 years, and to examine the relationship with climate change and rural-urban migration. We used two Landsat TM satellite image-mosaics (year 1986 and year 2001) to asses land cover change between 1300 and 3100 m.a.s.l., along all the Yungas extent. The results show that although there are local differences, the overall trend is of forest expansion into non-forested areas both in the upper and lower montane forest, since 1986, possibly favored by precipitation increase and rural-urban migration.