Effects of Grazing on Carbon,Nitrogen,and Their Stable Isotopes in Soils of Different Grassland Types
To investigate the response of carbon and nitrogen to heavy grazing in different types of grassland ecosystem,this research focused on three different grassland types,plain hilly steppe,plain hilly desert steppe,and sandy desert steppe.Soil organic carbon,soil total nitrogen,soil carbon and nitrogen stable isotopes,soil temperature,and soil moisture were measured under no grazing fence and heavy graz-ing conditions.Results revealed that(1)Soil organic carbon and soil total nitrogen were significantly reduced(P＜0.05)under heavy grazing for three grassland types.There is a trend of decreasing for soil carbon and nitrogen stable isotopes under heavy grazing.(2)Correlation of soil carbon stable isotope with soil moisture was significantly negative(P＜0.01),whereas soil organic carbon and soil total nitrogen were positively correlated with soil moisture(P＜0.01).Heavy grazing had different effect levels for differ-ent grassland types on carbon and nitrogen nutrition.Plain hilly steppe was affected the most by heavy graz-ing in three grassland types,which inhibited accumulation of soil organic carbon and soil total nitrogen.
GrazingGrassland typeSoil carbon and nitrogen stable isotopesSoil organic carbonSoil total nitrogen
万方数据
维普
