Climate and Wildfire Regimes Shape Tree Community Composition and Carbon Storage Across Elevation Gradients in Miombo Woodlands

ABSTRACT

Understanding how climate and wildfire regimes influence biodiversity and carbon (C) storage is critical for predicting the resilience of tropical woodlands under climate change. We investigated the effects of precipitation, temperature, and wildfires on stand structure, tree species richness, floristic composition, and C stocks along a 0–1500‐m elevational gradient in miombo woodlands of Chimanimani National Park, Mozambique. Seventy‐two plots were established across the gradient, and structural equation modeling was used to quantify the effects of climate, fire, and biodiversity on woodland structure and C storage. Precipitation increased with elevation and was the principal climatic driver of basal area and above‐ and below‐ground C stocks, whereas temperature had the strongest effect on species richness (SR). Fire intensity reduced basal area and live tree and litter C stocks, while fire frequency increased stem density but decreased SR. SR exerted strong positive direct effects on stand structure and tree C stocks. Floristic composition differed markedly among elevation zones, with species turnover accounting for most of the observed β‐diversity. Brachystegia microphylla and Julbernardia globiflora exhibited broad climatic tolerances and consistently contributed the largest proportion of tree C across the gradient, underscoring their importance for conservation and restoration. These findings indicate that continued warming, declining precipitation, and intensified wildfires are likely to reduce biodiversity, alter species composition, simplify woodland structure, and diminish C sequestration capacity. Conservation strategies should integrate biodiversity protection with climate‐ and fire‐adapted management to enhance the long‐term resilience and C storage of miombo ecosystems.