青海贵南高寒草甸垂穗披碱草功能性状对长期放牧的响应OA

Plant traits can be altered by grazing,wherein phenotypic plasticity is related to grazing intensity.Three grazing intensity plots,including a no grazing control and light and heavy grazing groups,were selected at the Guinan County,Qinghai Province.The modular characteristics and the phenotypic plasticity index were calculated to explore the impacts of grazing intensity on the functional traits of Elymus nutans in alpine meadow.The results showed that:1)Compared with the no grazing group,grazing treatment significantly reduced crown width,nutrient branch height,reproductive branch height,tiller number,leaf number,leaf thickness,leaf shape index,and average leaf area of E.nutans(P<0.05).2)Grazing significantly reduced the stoichiometric characteristics such as leaf carbon content,carbon nitrogen ratio,carbon phosphorus ratio,and nitrogen phosphorus ratio(P<0.05).3)The total aboveground biomass of E.nutans and the nutrient and reproductive branch weights were significantly reduced after long-term grazing(P<0.05),and the proportion of nutrient branch weight decreased with increasing of grazing intensity.4)Leaf dry matter content was insensitive to grazing and was an inert trait,while reproductive branch weight and total aboveground biomass were the most sensitive traits.Therefore,grazing significantly altered the functional traits of E.nutans,and the plasticity of phenotypic traits was influenced by grazing intensity.E.nutans adopted a rapid resource-based adaptation strategy to grazing.Appropriately adjusting grazing intensity provides valuable insights for grassland health and sustainable use.