Modelling land cover changes in the tropical dry forest surrounding the Chamela-Cuixmala biosphere reserve, Mexico

摘要

Land-use change is one of the main threats to biodiversity conservation in tropical landscapes and natural protected areas are particularly threatened because of the transformation occurring at their neighbouring environments. We analysed the 'land-cover' change (LCC) occurring in the areas surrounding the Chamela-Cuixmala Biosphere Reserve (CCBR) in the Pacific coast of Jalisco, Mexico, during the last 40 years (split in two periods, 1970-1993/94 and 1993/94-2011/12). Supervised classifications were generated by applying a multi-temporal approach on Landsat Thematic Mapper (1993/94) and Satellite Pour l'Observation de la Terre SPOT (2011/12) imagery. The base line (t(0)) consisted of an historical 1:50,000 scale map of land-use/land-cover (LULC) made in 1970. In addition to LCC predictions for the next four decades, this study generated a variety of indicators identifying the location and intensity of LCC occurring in the CCBR's surrounding landscapes. The main vegetation formations, tropical dry forest (TDF), and semi-deciduous tropical forest (SDTF), decreased in area 25% and 50%, respectively, during the 1970-1993/94 period. However, annual rates of change (ARC) showed a deacceleration in the reduction of main vegetation formations, for the period 1993/94-2011/12. This study generated indicators identifying the location and intensity of 'land-cover' changes occurring in the CCBR's surrounding landscapes. Potential transition models made evident the CCBR's key role as a reservoir of the region's biodiversity associated to main vegetation types such as the tropical deciduous forest and the semi-deciduous forest.