Pérdida y fragmentación del bosque nativo en la cuenca del río Aysén (Patagonia-Chile) durante el siglo XX

Abstract

This work estimates the loss and fragmentation of native forest in the watershed of the river Aysén during the 20th century, as a result of clearance fires induced by land settlers. In order to generate the reconstruction of the native forest cover, several documentary records and GIS ArcView 3.2 were used. Different indexes of landscape changes were applied (area, density and size of the fragment, core area, euclidean distance, shape and aggregation index, and edge length) to estimate the distribution of the native forest between 1900 and 1998, which indicate that the main replacement of the forest was by prairies. A loss of approximately 23% of native forest was registered, also an increase in the number of forest fragments (<100 ha), as a result of the settlement process. Howerer, the increasing number of fragments has a high connectivity, wich was corroborated using different landscape indexes