Changing vegetation and landscape patterns in semi-arid Spain

摘要

Detecting hierarchical vegetation patterns of landscape change at different scales is necessary to know how complex the landscape system is. Here we focus our research on dynamics at meso and micro scales in the Ventos-Agost catchment (Alicante, South East Spain) between 1946 and 1999. At meso scale, the observed dynamics indicate two main human-induced trends in the landscape, caused by land management: pine afforestation and land abandonment. As a consequence, an increment in the Shannon index at landscape level is directly related to the increase in uses and heterogeneity, indicating that the whole study area has experienced fragmentation over the 53-year study period. Some quantitative traits of vegetation dynamics at micro scale show a quick growth during the first decade of land abandonment. Despite the species composition turnover, there are no significant differences in these vegetation characteristics throughout the succession during the subsequent 10-50 year period, indicating both cover and species diversity stabilisation in old-fields.