Changes in SOC, pH, and Ca associated with microorganism mediated SOC mineralization and temperature sensitivity following vegetation restoration in karst regions
摘要
Soil organic carbon (SOC) mineralization as a major C loss process, determines soil C accumulation following vegetation restoration in degraded land. However, SOC mineralization and underlying microbial mechanisms are still unclear during vegetation restoration in karst desertification areas, where the soil is characterized by high pH and calcium (Ca) content. This lack of clarity hinders the selection of optimal restoration strategies for adapting to karst conditions.
MethodsFour vegetation restoration strategies, which have undergone 12 years of recovery, were selected: natural shrubland (NS), Cornus Wilsoniana Wanaer (CWW), Eriobotrya japonica (EJ), and Cyclobalanopsis glauca (CG). SOC mineralization and its temperature sensitivity (Q10), soil properties, and microbial communities were measured.
ResultsSOC mineralization was highest in NS, which decreased by 24.75%, 18.76%, and 33.66%, respectively, in CWW, EJ, and CG. SOC content and pH associated with fungal community structure positively influenced SOC mineralization, with SOC content having the most direct effect. Q10 was highest in CG compared to the other three strategies. Ca and pH associated with Actinobacteria negatively impacted Q10, while the fungal community structure (particularly Basidiomycota) and bacterial Chao1 had positive effects. Furthermore Ca was the most direct influencing factor.
ConclusionsVegetation restoration types exhibited different effects on SOC mineralization and Q10 in karst areas. Changes in soil SOC content, pH, and Ca associated with microorganisms mediated SOC mineralization and Q10, with fungi and dominant microbial phyla playing significant roles. This highlights the importance of maintaining soil Ca and pH during vegetation restoration in karst regions.