Soil functional microbes can modify the plant functional diversity mainly through changing the plant functional traits of evergreen species in karst forests

Abstract

Aims

The dynamic interactions between plants and soil serve as the underlying mechanisms that drive various ecological processes linked to the biodiversity maintenance. Previous studies suggested soil microbes played an important role in linking the soil and plants. However, how and to what extent the soil functional microbes influence the plant functional community structure is still unclear, especially in sensitive karst forests.

Methods

We established a series of forest dynamic plots (FDPs) along the natural regeneration in the Maolan National Nature Reserve, a typical karst forest ecosystem, to explore the roles of soil microbial functional genes on the plant functional diversity (FD).

Results

Comparison analysis found significant changes in the relative abundance of soil microbial functional genes involved in nitrogen cycling (N-cycling), soil physicochemical properties, and the community-weighted variance (CWV) of plant functional traits as well as FD. In addition, variations in soil physicochemical properties mediated by soil microbial functional genes involved in N-cycling were closely related to changes in plant FD. Furthermore, evergreen species rather than deciduous ones were found to play the dominant role in determining the plant functional community structure.

Conclusions

This study highlighted the critical role of microbial communities in stabilizing ecosystem functioning and the disproportionate contribution of species with different life forms along the natural regeneration in karst evergreen-deciduous mixed forests.