Forest eco-function restoration and its positive effects on biodiversity improvement in China's ecological conservation programs

Given that human activities have increasingly jeopardized the functionality and stability of forest ecosystems, China has implemented numerous national ecological conservation programs. Although there are many independent studies on changes in ecosystem functions or biodiversity during forest restoration processes, few have synthesized results across different restoration cases in China. Therefore, basing on 184 forest restoration studies, a review and meta-analysis was conducted to assess how ecosystem functions and biodiversity change throughout the restoration process and to evaluate their impacts. The results showed that (1) forest restoration enhanced ecosystem functions and biodiversity, with plant diversity initially declining before increasing, while microbial diversity steadily improved; (2) total phosphorus (TP) and available phosphorus (AP) were the key factors influencing biodiversity through ecosystem processes, and artificial addition of insufficient nutrient elements according to local conditions may improve biodiversity in areas undergoing forest restoration; (3) the implementation of large national ecological conservation programs was linked to biodiversity improvement observed in western China in recent years. Basing on the local restoration cases, the results can provide guides and references for the nationwide ecological conservation programs and policy decisions, which will be conducive to biodiversity protection and improvement in forest restoration process.