Biogeographical patterns in fungal communities from soils cultivated with sugarcane

AimDespite the important roles that microbial communities play world-wide, relatively little attention has been given to the processes that shape their distributions. Of those studies that have addressed this question, the vast majority has focused on temperate regions and relatively undisturbed environments. In particular, tropical agricultural environments have been rarely studied, and it is commonly assumed that agriculture reduces spatial variation in microbial communities, especially in soil. Here, we evaluated the diversity and abundance of fungal communities in soils used for the cultivation of the world's largest crop, sugarcane, in the world's largest producer, Brazil. LocationState of SAo Paulo, Brazil. MethodsOur study sampled across 23,022km(2) of the State of SAo Paulo, Brazil, in an area that is a major producer of sugarcane. The composition of the fungal communities was estimated via terminal restriction fragment length polymorphism (T-RFLP) analysis, and the fungal abundance was estimated by quantitative PCR (qPCR). ResultsWe observed that the variance in community composition explained by soil characteristics was 2.88%, and that explained by climate variables was 2.93%. In contrast, geographical distance explained 50.75% of the variance. Moreover, the distribution of fungal species abundance fits a neutral model that assumes only dispersal and drift better, rather than models that assume environmental filtering. Main conclusionsOur work demonstrates that fungal communities in soil can exhibit biogeographical patterns, even in agricultural soils, and that these patterns are likely to be due at least in part to dispersal limitation.