Nitrogen and phosphorus uptake dynamics in anthropized and conserved Caatinga dry forests

• Published in: Journal of arid environments 2024-10, Vol.224, p.105242, Article 105242
• Main Authors: Araújo Silva, Elizabete Cristina, Leite, Jakson, Alves, Maria Claudjane Jerônimo Leite, dos Santos, Claudiana Moura, Daibes, Luís Felipe, Fernandes-Júnior, Paulo Ivan, Moura, Flávia de Barros Prado, Vieira Silva, José
• Format: Article
• Language: English
• Subjects: Foliar stoichiometry; Nutrient cycling; Semiarid; Tropical dryland
• ISSN: 0140-1963
• DOI: 10.1016/j.jaridenv.2024.105242

Understanding human impacts on drylands is crucial in a global scenario of forest degradation and biodiversity loss. This study analyzed foliar concentrations of nitrogen (N) and phosphorous (P) in the Brazilian seasonally dry tropical forests (Caatinga). Foliar patterns of N, P, and the N/P ratio were assessed both within and among botanical families. To do this, 10 plots were established in an anthropized area and 10 in a conserved area. Within each plot, leaves from all tree species and soil samples from four random points were collected. Stoichiometric analyses were performed on the leaves of 136 trees from 14 botanical families. Significant differences were observed in soil P concentrations, organic matter content, and cation exchange capacity, with the highest values found in the conserved area. Foliar N and P concentrations and N/P were also higher in the conserved area for the F+ (nitrogen-fixing Fabaceae), F- (non-nitrogen-fixing Fabaceae), and NF (non-Fabaceae) groups, indicating greater efficiency in nutrient retention and cycling. When comparing species found in both areas, Aspidosperma pyrifolium (NF), Bauhinia forficata (F-), and Mimosa ophthalmocentra (F+) showed significant differences in foliar N concentrations and foliar P (for A. pyrifolium and B. forficata only). Degradation of the Caatinga directly impacts nutrient cycling. •Foliar N and P concentrations, and N/P ratio, are higher in the conserved area.•Species richness in conserved area influences the higher soil nutrient production.•Anthropogenic impacts reduce Caatinga species richness and nutrient availability.•Fixing Fabaceae efficiently absorb foliar N and P in this semi-arid region.•Degradation of the Caatinga directly impacts nutrient cycling.