Composición y estructura vegetal de fragmentos de bosque seco tropical en paisajes de ganadería extensiva bajo manejo silvopastoril y convencional en Córdoba, Colombia

Extensive farming for livestock has significantly affected the biodiversity and conservation of the dry tropical forest (DTF), today considered the most threatened ecosystem in the tropical lowlands. We analyzed the floristic composition, richness and structure of DTF fragmentsassociated with extensive livestock systems in four localities of the department of Córdoba, Colombia. Samples were taken in four plots of 0.1 ha/fragment according to the Gentry methodology, modified to include all individuals with a DAP = 1 cm. The index of value of importance by species (IVI), the value index of importance by families (IVIF), and the rate of change of species were determined. We identified 252 plant taxa from 137 genera and 55 families. Fabaceae (S= 45) and Rubiaceae (S= 19) had the highest richness. The richness was significantly higher in fragments of DTF associated with the silvopastoril system (SSP), compared with fragments under conventional system (SC). The rate of species turnover between SSP and SC was 84.5 %, with a taxon overlap of 30.8 %. In the SSP, the families Fabaceae (57.6) and Malvaceae (46.5) had the highest IVIF; the species with the highest IVI were Bactris major (40.8) and Guazuma ulmifolia (29.4). The families Fabaceae (42.9) and Arecaceae (23.8) had the highest IVIF in SC fragments; the species with the highest IVI were Cavanillesia platanifolia (31.8) and Ceiba pentandra (28). These results contribute to understand ecological processes and the importance of the SSP of extensive cattle ranching as a strategy for the conservation of DTF biodiversity.