Changes in soil microbial communities during litter decomposition

Abstract

Litter decomposition is an important ecosystem function, and is an indispensable process for carbon and nutrient cycling. Litter decomposition is influenced by many factors, especially soil microbial communities, which are subject to their corresponding plant communities. It is necessary to study changes in soil microbial communities during litter decomposition and how these changes respond to plant diversity in corresponding forest communities to understand the mechanisms of decomposition. In the present study, we investigated these changes and responses using a litter bag method. Our results showed: (1) After 183 days of litter bag placement, microbial diversity decreased, and there was a negative correlation between plant species diversity and microbial diversity; (2) Soil microbial communities varied before and after the placement of plant litter bags. In particular the PLFAs of fungi and bacteria after the placement of litter bags were much higher than those before the placement of litter bags; (3) Topography was the most important factor correlated with the soil microbial community, and explained 29.55% of the variation of microbial communities. In contrast, litter quality and plant diversity explained 15.39% and 8.45%, respectively, and the interaction of the three factors explained 2.97% of the variation of the microbial communities. In conclusion, we find plant diversity plays a less important role than topography in determining soil microbial diversity, and litter quality influences soil microbial communities during litter decomposition.