VEGETATION COVER AND REGENERATION AS PREDICTORS OF DESERTIFICATION PROCESS IN DRY FOREST IN BRAZIL

The Brazilian Caatinga is one of the most diverse dry forests on the planet. Half of its original coverage is degraded, and it is currently identified as one of the main areas undergoing desertification. Natural regeneration depends on climatic and edaphic conditions, as well as the adult stratum present in an area. Despite its importance, this process is little known in the Caatinga. Thus, we aimed to analyze how the anthropic disturbance, vegetation cover, and soil properties influence regenerating stratum under different Caatinga vegetation cover levels. Our study was executed in the driest region of Brazil. We classified our studied areas as Area I (less vegetation cover) and Area II (greater coverage). Six plots of 50 x 20 m were delimited for sampling the adult and regenerating stratum, and the soil in each area. Our results show interactions between soil characteristics and adult and regenerating stratum. Area II showed greater diversity and a greater number of exclusive species; in contrast, a dominance of species more resistant to limiting conditions was observed in Area I, such as Aspidosperma pyrifolium Mart. & Zucc. The C and N contents in the soil indicated a positive and significant correlation with the diversity of the regenerating stratum. The data revealed that the area with less vegetation cover, richness, and diversity presented indications of desertification.