Woody encroachment reshapes vegetation structure, diversity, and carbon stocks in a Cerrado wetland

Woody encroachment has reshaped open ecosystems worldwide by altering vegetation structure and composition, often reducing plant richness and diversity. In wetlands, this process can disrupt plant-soil–water interactions that sustain spatial heterogeneity and ecosystem services. However, links between woody encroachment, biomass accumulation, and carbon stocks remain poorly understood in Cerrado wetlands. We assessed how woody encroachment affects plant community and ecosystem properties in Cerrado palm swamps ( veredas ), focusing on changes in species richness, diversity, and composition, and their relationships with aboveground biomass, carbon stocks, and soil attributes. We sampled plant incidence, cover, biomass, and soil properties in encroached and non-encroached veredas in the Brazilian Cerrado. Species richness and diversity were compared between conditions, and differences in biomass and carbon stocks were evaluated. A generalized linear model assessed the effects of woody biomass on species richness, and multivariate analyses examined patterns of species composition in relation to soil attributes. Woody encroachment caused a marked decline in plant diversity, including a 45% reduction in herbaceous-shrub species richness (from 115 to 63), and promoted vegetation homogenization. Aboveground woody biomass and carbon stocks were more than 300 times higher under woody encroachment, showing a strong negative relationship with species richness. Non-woody biomass did not differ between veredas , but showed higher water content in non-encroached conditions. Encroachment also led to lower soil pH, phosphorus, potassium, and cation saturation. Woody encroachment profoundly alters vegetation structure, compositional heterogeneity, and soil properties in veredas , promoting woody dominance at the expense of herbaceous diversity, and potentially compromising wetland functioning.