Soil bacterial community varies but fungal community stabilizes along five vertical climate zones

Abstract

Studying the variations in soil microbial community diversity and structure along a climate gradient can help to understand the impact of climate change on ecosystem functions regulated by soil microbes. Herein we aimed to reveal and compare the distribution patterns of soil bacterial and fungal communities along different vertical climate zones. Five climate zones from subtropical to cold temperate, with altitudes ranging from 1600 m to 3200 m corresponding to different forest types, were selected across the eastern slope of Mount Gongga. The structure and diversity patterns, co-occurrence network of soil microbial communities along the climate gradient and influential factors were studied. The bacterial Shannon and Simpson indices were higher in subtropical and cold temperate zones than in warm and mid-temperate zones, whereas fungal community diversity changed only slightly. Nonmetric multidimensional scaling (NMDS) indicated apparent differences in both bacterial and fungal community composition across the climate zones. The microbial co-occurrence network was more closely connected for fungal than for bacterial communities. Variation partition analysis (VPA) demonstrated that climate, vegetation and soil properties caused variations in bacterial community diversity, while spatial factors were the main factors affecting fungal diversity. These results indicate that climate zonation is more apparent for bacterial than fungal communities, and bacterial communities are more vulnerable to environmental change than fungal communities. The results also indicate that future climate change may affect ecosystem functions by altering microbial community composition structure and diversity.