Unveiling the impacts moso bamboo invasion on litter and soil properties: A meta-analysis

Moso bamboo invasion potentially alters litter, soil properties and soil microbial communities in forest ecosystems. However, the overall direction and magnitude of this alteration at a large spatial scale remain unclear. Here, we conducted a meta-analysis of 72 experimental studies on the impact of moso bamboo invasion on litter, soil physicochemical properties, and soil microbial communities. Overall, the moso bamboo invasion increased litter decomposition, soil pH, and NH₄⁺-N, while concurrently leading to a decrease in soil bulk density, soil electrical conductivity, soil TN: TP ratio, soil NO₃^--N, and available potassium. Moreover, we observed that the invasion significantly enhanced soil microbial biomass nitrogen, fungal ACE diversity index, fungal biomass, and bacterial Shannon diversity index, while decreasing the ratio of Gram-positive to Gram-negative bacteria and the biomass of Gram-positive bacteria. Furthermore, we identified the primary factors influencing specific soil properties and microbial community responses to moso bamboo invasion. Specifically, the response of NH₄⁺-N, NO₃^--N, soil bulk density, fungal diversity and pH were found to be primarily influenced by climatic factors (mean annual temperature, mean annual precipitation), topographic factors (aspect), and invasion stage, respectively. In addition, we further revealed a close relationship between soil physicochemical properties and microbial communities during moso bamboo invasion. Specifically, the response of soil microbial biomass nitrogen was positively correlated with the responses of soil organic nitrogen and total nitrogen content, Gram-positive bacteria biomass was positively correlated with soil total nitrogen but negatively correlated with soil pH. Meanwhile, soil bacterial diversity showed a significant positive correlation with soil pH but exhibited a negative correlation with soil SOC. Our study suggests that macro-climatic conditions, local microenvironment, and invasion stage co-regulate the important effects of moso bamboo invasion on litter, soil physicochemical properties, and microbial communities.