Biodiversity promotes ecosystem multifunctionality (EMF), yet it remains unclear how wetland types mediate the biodiversity–EMF relationship. This study investigated the differences in maintaining ecosystem functionality between lacustrine (lake) and riverine (river) wetlands in a semi-arid region. We examined how multiple soil environmental variables individually influence plant communities, soil enzyme activities, and microbial community composition and diversity, and we further explored how these factors drive EMF via interactions with microbial communities. Results showed that both individual ecosystem functions and EMF were significantly lower in lacustrine wetlands compared to riverine wetlands. Plant community attributes were the primary drivers of spatial heterogeneity in bacterial, fungal, and archaeal communities; conversely, soil enzyme activities were more strongly correlated with soil structure. Structural Equation Modeling (SEM) revealed distinct regulatory mechanisms: riverine wetlands were primarily subject to direct linkage between ecosystem multifunctionality and microbial diversity, whereas lacustrine wetlands exhibited a regulatory paradigm dominated by environmental filtering, where abiotic stressors (e.g., salinity and soil moisture) indirectly drove EMF by reshaping plant communities. These findings provide critical theoretical and technical insights for the conservation and restoration of wetland ecosystems.

The Ulansuhai Basin stands as the most crucial ecological and economic zone in northern China. Resource and environmental planning serves as a core strategy, aimed at mitigating the consumption of environmental resources induced by economic expansion within the Ulansuhai Basin and facilitating the synergistic development of the economy and the environment. In this paper, by taking the data of the economy, resource and water environment of the Ulansuhai Basin during the period from 2010 to 2022 as the research basis, a fuzzy multi-objective programming model for the resource–environment and socio-economic system was constructed. The results showed that within the planting industry, giving priority to the cultivation of sunflowers and corn will enable the model results to remain in an optimal state. In the field of animal husbandry, the quantity ratio of cows to pigs should be maintained at 1.5:1, and the quantity ratio of sheep to cows should be controlled at approximately 20:1; these ratio settings were conducive to ensuring the model remains in an optimal state. When the ratio of planting industry to animal husbandry was set at 13.16:1 (with the unit of “head” for livestock quantity and “hm²” for planting area), the model arrived at the optimal solution. This study, by virtue of its analysis of the coordination mechanism of economic development with environmental protection in typical watersheds, can provide meaningful policy references for realizing the synergistic enhancement of ecological quality and economic benefits in arid and semi-arid basins, fragile ecological carrying capacity, and the balance between agricultural production expansion and environmental pollution control in these regions.