Land use patterns change N and P cycling bacterial diversity in an acidic karst soil

Karst soils are characterized by their deficient nutrients, complex pore structure, and high leaching potential. Improper use of karst soils leads to soil erosion, organic matter loss and nutrient imbalance, ultimately resulting in soil degradation. In this study, we investigated how bacterial communities and functional groups (N and P cycling bacteria) responded to different land use patterns in a karst shrubland by analyzing field fresh soil for physicochemical properties and using shotgun metagenomics for bacterial and functional diversity. The results indicated that all land management practices reduce bacterial diversity and alter N and P cycling bacterial communities when compared with Unused land. By using partial least squares path modelling, we found that land use affects bacterial diversity by altering N and P cycling bacterial communities. These results indicate that N and P cycling in karst soil can be significantly affected by land use patterns, which may deteriorate functional diversity and stability. Therefore, appropriate land management approaches and land managements are suggested to prevent and mitigate soil degradation in karst soils when changing to more intensive land use.