Responses of Tillering Stipa breviflora Traits to a Long-Term Grazing Gradient

Abstract

The Stipa breviflora desert steppe is an important component of the Eurasian steppe, and its ecosystem functions are directly affected by changes in the individual functional traits of S. breviflora . Based on 14 years of data from the grazing experiment in S. breviflora desert steppe, we investigated changes in the individual tillering traits of S. breviflora in response to four levels (none, light, moderate, heavy) of long-term grazing. The results showed that: ( i ) long-term grazing resulted in a greater decrease in species richness and increased biomass contribution of S. breviflora in the communities; ( ii ) long-term grazing resulted in significant differences in aboveground/belowground plant tillering functional traits and their relationships under different grazing intensities; ( iii ) the leaf biomass of S. breviflora tillering individuals was strongly dependent on leaf number, while the change in root biomass was strongly dependent on the total root length, specific root length, root furcation number, and root crossing number. The response of S. breviflora biomass to grazing intensity and its relation to tillering individual traits revealed that long-term grazing leads to vast tillering in S. breviflora tussock and significant changes in S. breviflora tillering traits, which will have a profound influence on the function of the desert grassland ecosystem.