Drivers and biodiversity indicators of Miombo degradation in the Lubumbashi charcoal production basin (Upper Katanga, DR Congo)

Abstract

Miombo woodlands of the Lubumbashi Charcoal Production Basin (LCPB) are crucial for biodiversity and ecosystem services, yet are threatened by anthropogenic pressures, including rising energy demand. This study analyzes key degradation drivers and biodiversity indicators across three recovery stages—advanced, intermediate, and early recovery—using plot-based surveys. The results identified wood harvesting for charcoal production as the main driver of Miombo woodland degradation, which increases with distance from settlements. In contrast, invasive species, bark stripping, and artisanal mining have comparatively minor effects. In terms of ecosystem condition, the early recovery stage showed low diversity (Shannon–Weiner index = 1.14). This ecosystem is dominated by Isoberlinia angolensis (IVI = 18.37; abundance = 22 individuals), Julbernardia paniculata (IVI = 11.17; 18 individuals), and Brachystegia wangermeeana (IVI = 8.53; 6 individuals), with weak structural attributes (51 trees/ha, mean DBH = 11.56 cm, mean height = 4.47 m). The intermediate recovery stage showed greater diversity (Shannon–Weiner index = 2.13), dominated by B. wangermeeana (IVI = 13.69; 83 individuals), B. spiciformis (IVI = 12.04; 56 individuals), and Albizia adianthifolia (IVI = 8.90; 48 individuals), with improved structure (285 trees/ha, DBH = 18.83 cm, height = 6.31 m). The advanced recovery stage exhibited the greater diversity (Shannon–Weiner index = 2.11), dominated by Marquesia macroura (IVI = 23.09; 88 individuals), Diplorhynchus condylocarpon (IVI = 11.27; 64 individuals), and J. globiflora (IVI = 9.10; 71 individuals), with the most developed structure (323 trees/ha, DBH = 24.20 cm, height = 9.64 m). The findings support policy reforms such as regulating destructive practices and expanding private protected areas to enhance forest management amid increasing anthropogenic pressures.