The global distribution of body size in animals and plants has been investigated by researchers for centuries. However, global patterns of traits in the fungal kingdom remain widely underexplored. In this study, we examined the relationship between the mean fruit body size of mushroom assemblages and latitude across the major biomes. We compiled a trait database of 5,263 species covering eight orders, 44 families and 347 genera in major terrestrial biomes (tropical, temperate, boreal) using literature data. We used generalised additive and linear mixed effect models while accounting for ancestral relationships, and fitted models of fruit body size versus latitude and major biomes.
Results/Conclusions
We determined that fruit body size correlated significantly with latitude, peaking at temperate ecosystems, and was consistent for fungi with different lifestyles (free-living saprotrophs and mutualists). Nonetheless, the fruit bodies of mutualists were, on average, larger and within genera exhibited a larger variability across latitude than was the case for saprotrophs. Our results suggest that the fruit body size of fungal species can be explained by lifestyle and biome-related effects but is decoupled from latitudinal fungal diversity patterns and primary productivity. We hypothesize that different mechanisms account for the observed latitudinal pattern, with mushroom size constrained by a biotic filter in tropical biomes and an abiotic filter in boreal biomes.