Effects of macroclimate and resource on the diversity of tropical wood-inhabiting fungi

Wood-inhabiting fungi are one of the most important groups of organisms as they contribute substantially to carbon and nutrient cycles by decomposing dead wood. Current knowledge of their occurrence, distribution, and drivers of their diversity derives almost exclusively from temperate and boreal forest ecosystems. We sampled wood-inhabiting fungi across Benin, a tropical country in West Africa with a strong north–south seasonality gradient consisting of three macroclimatic zones. We aimed at determining whether macroclimate or the resource (size or amount of dead wood, number of host tree species, and stage of wood decomposition) is more important for their diversity. Variation partitioning revealed a stronger partial effect of resource on fungal species richness and a strong effect of macroclimate on the community composition. A more detailed linear mixed-effects model revealed a significantly positive effect of host richness, amount of dead wood, and macroclimate on fungal species richness and a significantly positive effect of macroclimate and stage of wood decomposition on the community composition. These findings are consistent with patterns found in temperate and boreal ecosystems, which indicates the existence of general pattern of the diversity of wood-inhabiting fungi. Based on these results, we recommend that existing knowledge should be exploited for the conservation of wood-inhabiting fungi in tropical Africa. Thus, to protect tropical wood-inhabiting fungal diversity, we recommend that any size of dead-wood objects of diverse tree species be enriched in all tropical macroclimatic zones.