Trayectorias de cambios en coberturas terrestres en una cuenca de los Andes colombianos: río Grande, 1986-2012.

Introduction. Land-cover-change trajectories are related to different dynamics in the use of land in specific regions, and reveal a close relationship between human and environmental systems that may affect the ecosystem's provision of goods and services. Objective. Quantify land-cover changes in Río Grande basin between 1986 and 2012, based on data from remote sensors, in order to identify several land cover trajectories. Materials and methods. Timeseries of classified Landsat images between 1986 and 2012 were used to identify land cover changes; transition matrices were constructed and the main trajectories were mapped. Results. In the Río Grande basin a variation in land cover, in both space and time, was observed, and in the last period (1997- 2012) the forest cover was expanded by the abandonment of lands previously dedicated to extensive agricultural uses. Conclusion. The long history of occupation of this region, with activities of land use associated with the predominant pasture coverage, does not seem to prevent the gradual processes of forest recovery. It is important to preserve the remnants of existing forests and to establish a balance between agricultural production and the presence of ecosystem functions, particularly those associated with the provision of water, because regions such as the middle-high mountains provide drinking water to large cities in the Andean region. [ABSTRACT FROM AUTHOR]