Temporal and Spatial Variation Characteristics of Grassland Soil Nutrients in Different Disturbed Habitats of East Qilian Mountains
LI Haiyun;YAO Tuo;ZHANG Jiangui;GAO Yamin;YANG Xiaomei;LI Qi;FENG Ying;LI Channing;Key Laboratory of Grassland Ecosystem,Ministry of Education,Pratacultural College,Gansu Agricultural University;
In order to explore the temporal and spatial variation characteristics of soil nutrients and their ecological stoichiometry in different disturbed alpine grasslands in East Qilian Mountains.The soil nutrient content and its ecometrics characteristics of different disturbed alpine grasslands in Eastern Qilian Mountains in August 2017 were studied.Compared with the same sites in 2003 and 2011,the same research methods were used to compare the soil physical and chemical properties in this area.Results showed that:(1)Soil pH value,electroconductibility,water content,soil total amount and available nutrient all decreased with the depth of soil and varied with different soil layers in the same disturbed habitat.(2)The soil C/N ranged from 7.64 to 18.21 in different disturbed habitats,which was basically close to the average value(10~12)of land soils in China.The soil C/P and N/P that ranged from 109.16 to 144.79 and 7.52 to 15.65 respectively,was much higher than the average C/P of 52.7 and N/P of 3.9 in China.(3)The principal component analysis showed that the physical and chemical properties of soil(pH,electrical conductivity,water content,total phosphorus,total potassium,available phosphorus,organic matter,organic carbon and available nitrogen)and ecological stoichiometry ratio(C/N,C/P and N/P)in the soil could sensitively reflected the different disturbance on grassland soil quality.The comprehensive evaluation of soil quality showed that the difference of grassland soil quality under different disturbed habitat vary greatly,the perennial grassland soil quality is higher,and the grass quality outside the fence is the worst.At 0-20 cm and 20-40 cm soil layer,soil quality ranged as perennial cultivated grasslandinside the fence grassland Annual cultivated grassland outside the fence grassland.(4)Compared with 2003 and 2011,the pH value and water content of four different disturbed alpine grasslands showed an overall upward trend,while the content of soil organic matter,total nitrogen and total phosphorus showed a significant downward trend.In summary,grazing disturbance and artificial planting had a great impact on the soil nutrient content of four disturbed grasslands in the eastern Qilian Mountains.Therefore,adequate attention should be paid to the utilization and conservation of the grassland in this area,and the grasslands should be rationally utilized and scientifically managed.
【CateGory Index】： S812.2
【CateGory Index】： S812.2