Afforestation increases microbial diversity in low-carbon soils

Afforestation has an important role in biodiversity conservation and ecosystem function improvement. A meta-analysis was carried out in China, which has the largest plantation area globally, to quantify the effects of plantings on soil microbial diversity. The results showed that the overall effect of afforestation on soil microbial diversity was positive across the country. Random forest algorithm suggested that soil carbon was the most important factor regulating microbial diversity and the positive response was only found with new plantings on low-carbon bare lands but not on high-carbon farmlands and grasslands. In addition, afforestation with broadleaved species increased microbial diversity, whereas planting with conifers had no effect on microbial diversity. This study clarified the effects of plantings on soil microbial diversity, which has an important implication for establishing appropriate policies and practices to improve the multiple functionalities (e.g., biodiversity conservation and climate change mitigation) during plantation establishment.