Response of soil nutrients and enzyme activities to altitude in the grassland in the central Qilian Mountains
[Objective]The aim of the study is to investigate the characteristics changes of soil nutrients and en-zyme activities in surface layer soil of grassland at different altitudes.[Method]In this research,the natural grassland in the middle of Qilian Mountains was used as the research object,and characteristics changes of soil nutrient content,ecological stoichiometry ratio and enzyme activity at different altitudes (2995 m,3170 m,3403 m,3620 m,3817 m and 4068 m) were analyzed.[Result]The research showed that altitude had significant effects on the nutrient and en-zyme activities of the grassland surface soil. With the increase of altitude,soil pH and Cu content showed an increas-ing trend,while soil organic carbon,total N,total P,N/P ratio,urease activity,alkaline phosphatase activity,peroxi-dase activity,Zn content and Mg content first increased and then decreased.Soil C/N ratio,C/P ratio and Fe content decreased first and then increased.However,the minimum and maximum values of each index occurred in different al-titude gradients. Meanwhile,the N/P ratios in different altitude were 3.58～5.86,and were all less than 10,which meant that grassland productivity was limited by nitrogen. Based on RDA analysis it could be found that soil organic carbon and total phosphorus were the key nutrient factors affecting soil enzyme activity.[Conclusion]The soil nutri-ents and enzyme activities in the surface layer of grassland showed regular distribution with altitude,and the productiv-ity was mainly limited by nitrogen.It is suggested that reasonable management measures should be formulated accord-ing to altitude differences to promote the healthy development of grassland ecology.
万方数据
维普
