Effect of Grazing Types on Community-Weighted Mean Functional Traits and Ecosystem Functions on Inner Mongolian Steppe, China

Abstract

The relationships between community-weighted mean (CWM) functional traits and ecosystem functions have been extensively studied. However, how CWM traits and ecosystem functions respond to grazing types and whether the relationships between CWM traits and ecosystem functions mediate the response of ecosystem functions to grazing types remains controversial. In the present study, we set up a seven-year grazing experiment with four grazing types: no grazing (NG), cattle grazing (CG), sheep grazing (SG), and mixed grazing by sheep and cattle (MG) on Inner Mongolia grassland. Nine functional traits of dominant species and five ecosystem functions under different grazing types were determined, and the relationships between CWM traits and ecosystem functions were analyzed. The results showed that the CWM height decreased after grazing, while the CWM nitrogen and phosphorus contents increased after CG. SG caused a greater decrease in aboveground biomass (AGB) and a greater increase in the net ecosystem CO2 exchange (NEE) of grassland ecosystems than did CG. This result may be partially because the CWM nutrient content and NEE were more negatively related after CG; and the increase in the CWM nitrogen and phosphorus contents suppressed NEE after CG. Therefore, to protect the sustainability of grassland ecosystem functions, SG should be reduced. Additionally, our work emphasizes that the relationships between plant functional traits and ecosystem functions may mediate the response of ecosystem functions to grazing types.

Contrasting patterns of community-weighted mean traits and functional diversity in driving grassland productivity changes under N and P addition

“…Since grassland productivity is a prominent indicator of vigorous grassland ecosystems and grassland restoration( Schaub et al., 2020 ; Yang et al., 2022a ), evaluating the impact of nutrient-induced variations in community functional structure can inform us of grassland ecosystem functioning. CWM traits and functional diversity have primarily been used to unravel the relationship between functional traits and grassland ecosystem functioning ( Wang et al., 2020 ). We found that CWM traits and functional diversity play a pivotal contrasting role in explaining variations in grassland productivity under nutrient addition ( Figure 9 ).…”

Trade-off Strategy of Three Dominant Species in Grazing Exclusion of Desert Steppe,china

“…In addition to natural environmental lter, man-made environment also affects leaf traits such as grazing and grazing exclusion (An and Guoqi 2015;Li et al 2015). In the study of the effect of grazing on leaf traits, it was found that the leaf area and speci c leaf area decreased, and the leaf dry matter content increased under heavy grazing (Wang et al 2016;Wang et al 2020). Meanwhile,we found that different species have different change strategies in different grazing intensity (Bullock et al 2001;Wei et al 2009).…”