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.

中文翻译：

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蔬菜覆盖对巴西退化干旱林更新过程的影响


巴西卡廷加 （Caatinga） 是世界上种类最丰富的干旱森林之一，但其原始覆盖率的一半已经退化。自然再生受气候和毛发条件以及现有成虫层的影响。尽管它很重要，但这一过程在卡廷加仍然知之甚少。因此，本研究旨在分析人为干扰、植被覆盖和土壤特性如何影响不同级别的 Caatinga 植被覆盖下的再生层。该研究是在巴西最干燥的地区进行的。所选地点表示低 （Area I） 和高 （Area II） 归一化差值植被指数。划定 6 个菜地（每个 50 × 20 m）用于研究成年地层，4 个菜地（每个 10 × 10 m）用于再生地层。在所有菜地中对表土进行取样。我们的结果揭示了土壤特征与成年和再生地层之间的相互作用。区域II表现出更高的多样性和更多的独家物种，而区域I则由对限制条件更具抵抗力的物种主导，如Aspidosperma pyrifolium Mart. & Zucc。土壤中 C 和 N 含量与更新层的多样性呈正相关且显著。数据表明，植被覆盖率、丰富度和多样性较少的区域显示出荒漠化的迹象。