Biodiversity can influence forest productivity, but this does not necessarily translate into higher provision of wood‐based Nature's contributions to people (NCP), as only a subset of the wood produced is used for each NCP. Biodiversity–NCP relationships therefore require further assessment. Using forest inventory and plant trait data, and local socio‐economic information from Mt Kilimanjaro, Tanzania, we examined how different biodiversity components affect the supply of wood‐based NCP namely; timber, charcoal and firewood, compared to standing tree above‐ground biomass. Confounding environmental variables such as climate and land‐use intensity (LUI) were also incorporated in a structural equation modeling framework. Tree biomass, timber, charcoal and firewood supply peaked at intermediate elevations and low LUI, particularly in lower montane, Ocotea and Podocarpus ‐dominated forests within protected areas. Supply dropped to zero at the highest and lowest elevations, where herbaceous vegetation and agricultural land covers dominate. The role of biodiversity components varied across NCP and all three NCP showed a different response than total aboveground biomass to biodiversity components. Timber supply was positively associated with tree taxonomic diversity, most likely because the species selected for logging are found in diverse forests but was unrelated to community‐weighted mean (CWM) tree height. In contrast, charcoal supply was influenced positively by both taxonomic diversity and CWM tree height. Firewood supply did not respond to either taxonomic diversity or CWM tree height. Our results suggest that relationships between biodiversity and NCP differ from those linking biodiversity to ecosystem functioning due to selective human use. This has implications for the transferability of biodiversity–ecosystem functioning research and the management of biodiversity and NCP.
Koggani et al. (Tue,) studied this question.