高寒地区不同人工牧草种类对土壤酶活性及酶化学计量比的影响OA北大核心

[Objective]The aims of this study are to explore the characteristics of soil enzyme activity and its chemical stoichiometry in alpine meadows of the Qinghai-Tibet Plateau under different artificial grass species,and provide scientific basis for a deeper understanding of soil nutrient status and grassland ecosystem function in the alpine pastoral areas.[Methods]Soils in seven different artificial grass planting including Poa crymophila,Elymus submuticus,Elymus breviaristatus,Elymus nutans,Puccinellia tenuiflora,Elymus sibiricus,and Roegneria pauciflora,were chosen as research objects,and the adjacent natural temperate grassland was used as a control(CK).The enzyme activity and chemical stoichiometry related to soil carbon,nitrogen and phosphorus cycles were investigated.[Results](1)The soil enzyme activity in different pasture planting sites was significantly different,which was in the range of 3～496 nmol/(g·h),and the soil enzyme activities of the seven pasture species were significantly lower than that of the control at 13～506 nmol/(g·h).(2)No significant difference in soil carbon/nitrogen enzyme ratio(EC∶N)was observed among the different sites,and the carbon/phosphorus enzyme ratio(EC∶P)at 0.82 and nitrogen/phosphorus enzyme ratio(EN∶P)at 0.94 were the highest in the plot of Poa crymophila.The vector angles of soil enzyme activities for all seven grass types were greater than 45°,indicating that soil microorganisms in the pastoral areas were limited by phosphorus.(3)Soil enzyme activities and its chemical stoichiometry were mainly influenced by soil organic carbon,total nitrogen,soil moisture,microbial biomass carbon,and microbial biomass nitrogen,were also significantly related to MBC∶MBN,SOC∶TP and TN∶TP.[Conclusion]The cultivation of artificial pasture has changed the nutrient structure of soil and affected the secretion of soil enzymes.There are significant differences in soil enzyme activity and chemical stoichiometry among different pasture species planting sites.In the future,the composition and functional characteristics of soil microbial communities can be further revealed to elucidate the mechanisms of nutrient cycling and grassland ecosystem function in high-altitude alpine meadow soils of the Qinghai-Tibet Plateau.