Background The Otindag Sandy Land, a critical ecological zone in northern China, faces severe desertification and land degradation. The construction of power transmission and transformation projects lead to soil erosion, vegetation destruction, and habitat loss for animals and plants, severely limiting the ability of ecosystem service function. While vegetation restoration in disturbed tower foundation areas has been implemented, the ecological multifunctionality of these restored zones compared to undisturbed natural grasslands remains unclear. In this study, to explore the impact of power transmission projects on the functionality of ecosystems, we established the restoration grassland and natural grassland plots along the L229 tower base in Duolun county, Inner Mongolia.

Methods The compositions of community species were investigated in the field. The characteristics of plant leaves, aboveground and underground biomass of the community, as well as soil properties were measured in the laboratory. The species diversity and functional diversity indices of the grassland were calculated, their responses to the implementation of power transmission projects were analyzed, and the relationship between community diversity and ecosystem multifunctionality were investigated.

Results The power transmission project had no significant effect on the community species diversity index, but significantly reduced the community functional diversity index. The implementation of projects mainly reduced ecosystem multifunctionality by significantly reducing soil nutrient cycling function and ecosystem quality. Species diversity and functional diversity were key factors explaining the decline in ecosystem multifunctionality, and the decrease in functional evenness index in particular had a more significant impact on multifunctionality.

Conclusions The findings showed that the power transmission and transformation project in eastern Mongolia affected the soil nutrient condition, thus reducing the versatility of grassland ecosystem, providing a theoretical basis for ecological restoration measures in sandy grasslands.