Short-term grazing diminished ecosystem multifunctionality of grassland in northern China

Grasslands play important roles in production as well as having ecological functions. Grazing affects grassland ecosystem multifunctionality (EMF). However, the underlying grazing processes that influence grassland ecosystems in the agro-pastoral ecotone of northern China remain unclear.

We conducted a three-year (2018–2020) in-situ experiment under four grazing intensities: no grazing, light grazing, moderate grazing, and heavy grazing. Plant community structure, productivity, and plant–soil–microbial stoichiometric characteristic indices were monitored throughout the study to compute nutrient storage. We then analyzed the effects of grazing intensity and the number of grazing years on EMF.

Short-term grazing during the growing season lowers multiple functional indicators and multifunctionality of grassland ecosystems. Moreover, the negative effects of grazing on grassland EMF were primarily related to grazing intensity. Moderate grazing had the least impact on EMF, whereas heavy grazing had the greatest impact. Grazing intensity substantially diminished aboveground multifunctionality, whereas the interannual impact of grazing years on belowground multifunctionality was modified by growing season precipitation. Short-term grazing mostly reduced nutrient storage by reducing dominant species (Leymus secalinus) biomass and litter biomass, thereby diminishing grassland EMF.

Short-term grazing during the growing season could reduce grassland EMF, further highlighting that grazing intensity indirectly controls grassland EMF by reducing dominant species biomass. When grazing production activities were conducted in the study region, moderate grazing could preserve critical ecological functions. Our study contributes to the sustainable use and ecological protection of agro-pastoral ecotone grasslands.