Contrasting diversity and community composition of leaf- and root-associated bacterial communities from 13 tree species in a subtropical forest

Abstract

Deciphering the local diversity and community composition of plant-associated microorganisms is crucial to predict the ecological functioning in forest ecosystems. The differences in microbial diversity and community composition between tree’s aboveground and belowground compartments remain largely unknown. Here we examined the bacterial communities in the leaf surface and root-associated (root and rhizospheric soil) habitats of 13 tree species. The bacterial richness substantially differed across the three habitats, with the highest value observed in soil compartment. The variations of α-diversity (richness and diversity indices) amongst the 13 tree species were more obvious in leaf and soil habitats than in their corresponding roots. The community compositions were different across habitats and were significantly more divergent in leaf- than in root-associated habitats. Leaf nutrients and soil pH and NH4+-N were main factors influencing leaf- and root-related community compositions, respectively. This study highlights the contrasting diversity and community composition between leaf- and root-inhabiting bacteria. Our findings would improve understanding of the effect of compartments and tree identity on microbial diversity in the subtropical forest.