Long‐term restoration altered edaphic properties and soil microbial communities in forests: evidence from four plantations of southern China

Abstract

Afforestation has been an important approach to mitigate land deterioration and biodiversity reduction. There are increasing interests in understanding the responses of soil microbial communities under long‐term forest restoration, since they play a crucial role in the mediation of ecosystem functions while interacting with plants. Here we examined the effects of four forests (Acacia species [AM], Eucalyptus species [EE], mixed coniferous species [MC], mixed native broadleaf species [NS]) after 35‐year restoration (1986–2015) on soil environmental factors and soil microbial communities. Our results showed that afforestation significantly increased soil organic carbon (SOC) and total N (TN) while decreasing soil pH. Among the four forest types, there were significant differences for TN and TK (total K) but not for pH, sSOC, and TP (total P). Bacterial species richness and phylogenetic diversity in Acacia forest significantly declined more than those of other forests, but those of fungal communities were remarkably higher in the Acacia forest. Both the bacterial and fungal communities' structure of each forest were strongly related to soil TK and TP. Besides, TK and SOC were primary edaphic properties that respectively affected the distribution pattern of bacterial and fungal communities in four forests. Network structures in AM and MC compared with EE and NS were more complex and closely linked, hence more resistant to extrinsic interference. Our results demonstrate that afforestation altered soil properties and microbial communities during long‐term restoration, which may provide insight into ecological restoration practices and biodiversity maintenance.