Tree legume plantation strategy for bauxite-mined land recovery: 14-year aboveground carbon stock of Anadenanthera peregrina

Abstract

Identifying suitable mined-land recovery strategies and native tree species capable of attaining high aboveground carbon stocks is important for climate change mitigation and meeting global restoration goals. Understanding how carbon stocks are distributed within stands can improve the design and evaluation of recovery interventions in tropical landscapes. This study assessed aboveground carbon stock and distribution in monospecific plantations of Anadenanthera peregrina, 14 years after establishment on bauxite-mined land in southeastern Brazil. Six 18 × 20 m plots, one per plantation, were surveyed. Biomass was estimated using a pantropical allometric equation and converted to carbon using a factor of 0.47. Stems were grouped into diameter and height classes, and inequality in carbon distribution was assessed using Lorenz curves and the Gini index. Associations between carbon stock and edaphic gradients summarized by principal component analysis were explored. Mean aboveground carbon stock was 139.3 ± 32.5 Mg C ha?¹. The 20–30 cm diameter classes contained 53.8% of carbon and 24.1% of stems, whereas the 15–25 m height classes contained 71.8% of carbon and 35.9% of stems. The Gini index was 0.577, indicating uneven carbon distribution among stems. The first two principal components explained 84.4% of edaphic variation, but neither was significantly associated with carbon stock. These findings highlight the potential of A. peregrina plantations as a carbon-focused strategy for recovering bauxite-mined lands.