Análisis de cambios en la cobertura arbolada en nueve comunidades del Norte del Estado de Oaxaca y su relación con la acción colectiva para la conservación del bosque, el manejo y uso del suelo

Abstract

We analyzed the dynamics of change in coverage with trees in eleven Chinantec´s communities located north of the state of Oaxaca, during a 20 years period (1990-2010). Five communities were designated as "organized" and the remaining were called as "nonorganized", according with the forest conservation initiatives that communities have undertaken. LandSat satellite images of three dates (1990, 2000 and 2010) were used, with geographic information systems (GIS) a supervised classification was performed. After this process, maps of tree coverage/non-forested condition were generated. Pairs of maps were crossing between (1990-2000 and 2000-2010). Thus, maps of change processes (deforestation and recovery) and permanence (woody cover and no-trees condition) were obtained. Also, annual rates of changes were estimated. It was found that the coverage with trees was different among communities over the two periods analyzed; in general, there was a greater loss of coverage with trees between 1990-2000, comparing with the next decade. All communities, showed deforestation and recovery at different levels; “organized” communities were significantly different from “non-organized” communities in their coverage of trees and in their rates of change. "Organized" communities in 2010, showed coverage with trees in almost 95% of their territories and areas deforested between 2000- 2010 were centered around human settlements. In contrast, “non-organized” communities have an average of 85% coverage, 10% of area from a decade is a non-forested condition, and only in some cases, areas deforested between 2000-2010, were centered surrounded human settlements.