Grazing intensity, duration, and grassland type determine the relationship between soil microbial diversity and ecosystem multifunctionality in Chinese grasslands: A meta-analysis

Grazing can alter soil microbial diversity and ecosystem multifunctionality (EMF) through feeding, trampling, and excreta deposition. However, it remains unclear how grazing intensity and grazing duration across Chinese grasslands affect the relationship between soil microbial diversity and EMF. Here, we conducted a meta-analysis to analyze the responses of soil microbial diversity and EMF to grazing disturbance using 54 publications with 62 sample sites from alpine grasslands and temperate grasslands in China. The results showed that EMF tended to decrease with increasing grazing duration and grazing intensity. Bacterial diversity was significantly and negatively correlated with EMF under moderate grazing, whereas fungal diversity was significantly and positively correlated with EMF under heavy grazing. Both fungal and bacterial diversity regulated the effects of grazing on EMF with grazing durations of up to 5 years. Furthermore, bacterial diversity was negatively correlated with EMF in typical steppe but positively in alpine grassland, and fungal diversity was positively correlated with EMF in typical steppe. Our results highlight the importance of microbial diversity in maintaining the multifunctionality of grassland ecosystem. We suggest that both grazing intensity, duration and grassland type should be seriously considered in the conservation of biodiversity and the sustainability of grassland ecosystem services and functions.