Effects of Vegetable Cover on the Regeneration Process in Degraded Dry Forest in Brazil

Abstract

The Brazilian Caatinga is among the most diverse dry forests in the world, yet half of its original coverage has been degraded. Natural regeneration is influenced by climatic and edaphic conditions, as well as the existing adult stratum. Despite its significance, this process remains poorly understood in the Caatinga. Thus, our study aimed to analyze how anthropogenic disturbance, vegetation cover, and soil properties affect the regenerating stratum under different levels of Caatinga vegetation cover. The research was conducted in the driest region of Brazil. The selected sites represent low (Area I) and high (Area II) normalized difference vegetation index. Six vegetable plots (50 × 20 m each) were delimited to study adult stratum, and four vegetable plots (10 × 10 m each) to regeneration stratum. Topsoil was sampled in all vegetable plots. Our results reveal interactions between soil characteristics and the adult and regenerating strata. Area II exhibited higher diversity and a greater number of exclusive species, while Area I was dominated by species more resistant to limiting conditions, such as Aspidosperma pyrifolium Mart. & Zucc. The C and N content in the soil showed a positive and significant correlation with the diversity of the regenerating stratum. The data suggest that the area with less vegetation cover, richness, and diversity shows signs of desertification.