Beyond carbon accounting: integrating stand structure and community composition for understanding aboveground carbon storage in Sudanian savanna-woodlands

<title>Abstract</title> <p>Dryland ecosystems contribute to global climate regulation, but the ecological basis of Sudanian savanna-woodland carbon storage remains poorly documented. This study examined how stand structure and community composition contribute to aboveground carbon storage in Manda National Park, a protected savanna-woodland in southern Chad. Data were collected from seven transects (1.2 km × 20 m; 16.8 ha, 1.4% sampling intensity) during November–December 2016. All woody individuals with a stem circumference ≥ 2 cm were inventoried (5,968 individuals; 44 species, 38 genera, 18 families). Aboveground carbon was estimated using Chave et al. (2005) allometric equations; models relating carbon to taxonomic identity and structure were compared via AIC/BIC-based selection. The diameter distribution followed a reverse J-shaped pattern typical of continuous regeneration. Structural attributes explained most of the variation in carbon storage (R² = 0.998), while taxonomic models explained much less (R² = 0.018), reflecting its dependence on diameter. Family and genus had significant but limited effects (η² = 0.008–0.020), indicating that composition adds information beyond carbon accounting. These results support the ecological and economic value of carbon storage in Sudanian savanna-woodlands and the case for biodiversity-inclusive carbon assessment frameworks relevant to ecosystem resilience, nature-based climate solutions, and equitable integration into carbon markets.</p>