Cellulose dominantly affects soil fauna in the decomposition of forest litter: A meta-analysis

•Soil fauna contributes 30.9 ± 6.8% to forest litter decomposition rate.•The largest influence caused by soil fauna occurred in tropical wet forest.•Cellulose is vital to the effect of soil fauna on forest litter decomposition. Litter decomposition is widely acknowledged as a vital connection that links aboveground and belowground ecological processes, including the formation of soil organic matter and nutrient cycling in forest ecosystems. Soil fauna consumes significant quantities of litter and plays a critical role in the decomposition of soil organic matter. However, our understanding of the influences of soil fauna on the decomposition of forest litter remains elusive. Using a meta-analysis of 479 paired observations garnered from 49 studies, we found that, on average, soil fauna contributes 30.9 ± 6.8% (mean and standard error) to the forest litter decomposition rate. Moreover, the positive effects of soil fauna on litter decomposition increased with the cellulose concentration of the initial litter, and in warmer and moister climates. Our results suggest that the role of soil fauna in litter decomposition will even be more critical in view of ongoing global environmental change.