Effect Of Warming And Increased Precipitation On Soil Enzyme Activity And Soil Microbial Community Composition

With the increasing global warming,there is no doubt that temperature and precipitation pattern has been changed.Stipa krylovii steppe of Inner Mongolia located in arid and semi-arid areas,it is sensitive to climate change.Studying the response of typical steppe to climate change in Inner Mongolia can help to determine the adaptation of grassland ecosystems in future.In this paper,we studied the Stipa krylovii steppe of Inner Mongolia,and we used open-top chambers to simulate warming and increased precipitation in the whole growing season of 2016.To explore the response mechanism of grassland microbial and soil enzyme activities to climate change,so as to provide basic data and theoretical basis for future climate change.The main conclusion as follow:(1)The warming treatment significantly increased soil temperature and reduced the soil moisture,contrary to increased precipitation treatment.Effect of warming,increased precipitation and interaction had no significant effect on soil pH,organic material,total nitrogen,ammonium nitrogen,total phosphorus,rapidly available phosphorus.T and TP treatments significantly increased nitric nitrogen.(2)The activity of catalase increased CT,T,P and TP treatment have increased,but did not reach the significant level of CK treatment.CT,P and TP treatment significantly increased urease activity,and T treatment no significant changes.CT,T,P and TP treatment of alkaline phosphatase activity decreased,and CT treatment decreased significantly.The activities of sucrose after CT,T,P and TP treatment had different degrees of fluctuation,but there was no significant difference with CK treatment.(3)The growth season and experimental treatment had some effect on the diversity of soil bacteria and fungal,but the effect was not significant.Community similarity analysis showed that warming,increased precipitation and interaction changed the structure of soil microbial community to a certain extent.(4)Soil enzyme activities were affected by soil physical and chemical indexes.The effects of different soil physical and chemical indexed on soil microbial diversity were different.The relationship between microbial diversity and enzyme activity is not regular.(5)The relationship between soil microbial diversity and soil temperature and moisture was not affected by warming,increased precipitation and interaction,and did not show the specificity.