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

Revista de Geoografía Norte Grande 09/2011; 49(49):125-138. DOI: 10.4067/S0718-34022011000200008


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.

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    • "The cattle industry has promoted the expansion of grassland in the lower and middle valley zones to the detriment of forests that have been limited to the upper slope positions. The environmental consequences of these forest fragmentation and land use changes in the region have been intensive soil erosion and loss of native species associated with original ecosystems (Ortega and Brüning 2004; Bizama et al. 2011). "
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