Effect of moss removal on soil multifunctionality during vegetation restoration in subtropical ecosystems

Mosses are multifunctional communities that are increasingly recognized as potential and sustainable resources to restore degraded ecosystems. However, available information is limited on the influence of mosses on soil multifunctionality during vegetation restoration in subtropical ecosystems. We investigated the effects of mosses on soil multifunctionality and four single functions in three vegetation restoration approaches (monoculture plantations, monoculture forage grasses and intercropping of trees and forage grasses) by conducting a moss removal and retention experiment. Moss removal decreased soil multifunctionality and the single functions of nutrient provisioning, water retention and plant-microbe symbiosis, particularly in monoculture plantations, in the 0-5 cm soil layer. Moss removal decreased the phospholipid fatty acid abundance of soil microbes (e.g., bacteria, Gram-negative bacteria and general fungi) in the 2-5 cm soil layer but had nonsignificant effects on the nematode community. Random forest analysis showed that moss properties were more important factors than the soil physicochemical, microbial and nematode properties linked to soil multifunctionality. Moss properties (diversity, thickness, biomass, carbon and nitrogen concentrations, carbon to nitrogen ratio, biological nitrogen fixation rate and saturated water absorption content) were positively associated with soil multifunctionality, nutrient provisioning, water retention and plant-microbe symbiosis. These findings highlight the importance of preserving mosses to maintain soil multifunctionality during vegetation restoration in degraded subtropical ecosystems, especially in monoculture plantations.