The impact of plant restoration on soil aggregates in karst mountainous areas of southwestern China

Soil aggregates are the basic structure of soil. To investigate the distribution characteristics of karst soil aggregates in southwest China and the response of their stability to long-term vegetation restoration, we took karst areas and their restored successional transects in Caohai Nature Reserve of Weining, Guizhou Province, as the research subject. The result showed that: (1) soil water stable macroaggregates (R 0.25 ), soil geometric mean diameter MWD, and mean weight diameter GMD were significantly reduced with vegetation restoration. (2) generalized linear mixed model (GLMM) and structural equation models revealed that vegetation type exhibited a highly significant effect on soil aggregates ( p < 0.001), including both karst soil and vegetation-restored soil, during a homogeneous garden experiment. Vegetation type is the core factor affecting the formation and stability of soil aggregates, while topographic characteristics have no significant effect on soil aggregates during vegetation restoration.