Artificial vegetation restoration patterns regulated soil multifunctionality via co-occurrence network complexity of multitrophic organism in degraded karst region

Significant advancements have been achieved in recent years in the restoration of degraded vegetation in the karst regions of Southwest China. However, the effects of this restoration on soil multifunctionality (SMF) and soil multi-trophic organism remained largely unexplored. This study investigated SMF of three typical artificial vegetation restoration patterns (grass, forest, and forest-grass) in the Southwest karst region. High-throughput sequencing, morphological identification, and co-occurrence network analysis were utilized to examine the characteristics of multi-trophic organism communities in karst soil. Vegetation restoration patterns significantly affected single soil functions, SMF, and the biodiversity of soil multi-trophic organism. All co-occurrence networks of soil organism were predominantly positive relationships, with network in forest-grass pattern exhibiting greater complexity than that of forest and grass patterns. The topological parameters of the co-occurrence network showed a significant correlation with soil functions, while soil multi-trophic organism diversity did not. Structural equation models revealed that the restoration pattern, soil pH, soil moisture, soil multi-trophic organism diversity, and co-occurrence network complexity collectively explained 64 % of the SMF variation. The restoration pattern not only directly influenced SMF (p < 0.01) but also indirectly affected SMF by altering soil pH and the complexity of the co-occurrence network. These insights provide a better comprehension of the mechanisms underlying vegetation restoration effects on soil functions in karst regions, specifically from the perspective of soil multi-trophic organism.