Single-Species Artificial Grasslands Decrease Soil Multifunctionality in a Temperate Steppe on the Qinghai–Tibet Plateau

Abstract

Artificial grasslands have been regarded as an effective method to improve grass production and quality, especially on the Qinghai–Tibet Plateau. Soil ecosystem multifunctionality (EMF) plays an important role in sustainable regional development. However, few studies have investigated the impacts of artificial grasslands on soil EMF. Here, we constructed single-species artificial grasslands in a natural temperate steppe and investigated soil microbial communities, abiotic factors (soil moisture and pH), and functions related to biogeochemical cycles to explore (1) how the transformation from temperate steppe to artificial grasslands affected soil EMF and (2) the roles of species and phylogenetic microbial diversities, microbial community composition, and abiotic factors in driving differences in soil EMF. Our results showed that artificial grasslands decreased soil EMF regardless of planting species; that the bacterial and fungal community composition contributed more to soil EMF prediction than species and phylogenetic diversities; and that microbial phylogenetic diversities were negatively associated with soil EMF. Soil pH played an important role in the effects of artificial grasslands on soil EMF—artificial grasslands increased soil pH, which was negatively associated with soil EMF. Overall, the benefits of establishing artificial grasslands, for example, higher grass production and quality, might be at the expense of soil EMF. Further studies should explore mixed-species artificial grasslands.