Change Characteristics Of Soil Enzyme Activity In Different Plant Communities Of Ebinur Lake Wetland

The Ebinur Lake is facing three major problems:drought,high salt and strong wind,resulting in different degrees of degeneration of wetland plant diversity and soil quality.Its ecological environment is directly related to the sustainable development of regional environment and the construction of green ecological corridor.The soil enzyme has a good indication function to the change of soil fertility and plant community,and its change can be used as a biological indicator for predicting and evaluating the soil quality change of lake wetland in arid area.In this paper,the typical plant communities?Haloxylon ammodendron-Tamarix chinensis,Haloxylon ammodendron,Populus euphratica,Phragmites communis?in the 160km around the lake for one week were selected as the research object,Set sample plots under typical plant communities in May,8 and November 2015²016,and other environmental factors were recorded at the same time.The change of soil enzyme activity under different plant communities was studied,and the factors affecting the changes of soil enzyme activity in different plant communities of Ebinur Lake wetland were analyzed,It is expected to provide basic data and basis for the changes in soil enzyme activity and the indicator of soil fertility changes in arid lakes and wetlands.The main conclusions are as follows:?1?In May and August,Haloxylon ammodendron-Tamarix chinensis,Haloxylon ammodendron,Populus euphratica,Phragmites communis community soil catalase,phosphatase and urease activity were increased with soil depth decreased,and the change of enzyme activity is more complex in November.Four typical plant communities of soil enzyme activity has obvious seasonal change,The peak of soil enzyme activity of Haloxylon ammodendron-Tamarix chinensis,Haloxylon ammodendron,Populus euphratica communities appeared in May,and the Phragmites communis community appeared in August,respectively,the minimum values of soil enzyme activities of the four plant communities all appeared in November,The soil enzyme activity of different plant communities showed Phragmites communis>Haloxylon ammodendron>Populus euphratica>Haloxylon ammodendron-Tamarix chinensis,Soil catalase and urease can be used as indicators of soil environmental change.?2?The soil organic matter,total phosphorus,total nitrogen,ammonium nitrogen,nitrate nitrogen,pH,salt and soil temperature of the 4 plant communities have obvious seasonal changes,showing the law of August>May>November,while the water content is in the opposite direction,Soil organic matter and total phosphorus are in a very lack-absent state.Total nitrogen is in grades 4 and 5,and the pH is alkaline,The soil is moderately and heavily salinized,and the overall wetland soil quality is poor.The soil organic matter of Haloxylon ammodendron-Tamarix chinensis,Haloxylon ammodendron,Populus euphratica,Phragmites communis community in the range of 8.9¹0.8,13.1¹5.7,9.8¹2.1,16.3²1.5 g·kg^-1,total nitrogen content in the range of 0.4⁰.5?0.5⁰.6?0.4⁰6?0.5⁰.7 g·kg^-1,total phosphorus in the range of 0.6⁰.7?0.7⁰.9?0.6⁰.7?0.8⁰.9 g·kg^-1,Ammonium nitrogen in the range of 2.8¹4.5 mg·kg^-1,nitrate nitrogen in the range of 14.5⁴9.6 mg·kg^-1,soil temperature in the range of 0.5²7.8?0.2²7.1?0.6²9?0.4³2.8?will be beneficial to the increase of enzyme activity;The pH value was 8.1⁸.4,8⁸.1,8.1⁸.2 and 7.8⁷.9 respectively,which was not conducive to the increase of soil enzyme activity.The salt increased from 7.4¹0.6g·kg^-11 to 15.8¹6.9 g·kg^-1and17.3²7.7 g·kg^-1,and the activity of enzyme decreased gradually.?3?In different months,soil enzyme activities in plant communities were significantly positively correlated with organic matter,total phosphorus,total nitrogen and enzyme activity,The activity of enzyme is positively correlated with ammonium nitrogen and nitrate nitrogen;The relationship between enzyme activity and water content is more complex;In August,Haloxylon ammodendron-Tamarix chinensis,Haloxylon ammodendron,Populus euphratica soil temperature and enzyme activity showed a significant negative correlation,it was a positively correlated with enzyme activity in May and November,There is a positive correlation between soil temperature and enzyme activity in different months of reed community;Soil salt,pH and enzyme activity showed a negative correlation under different plant communities,Through quantitative analysis,we know that soil organic matter,total nitrogen,salinity,soil temperature and water content are the main factors affecting enzyme activity.?4?By comparing the characteristics and influencing factors of soil enzyme activities,it is found that the soil enzyme activity under different plant communities in the wetland of Ebinur Lake was lower than that of freshwater lakes and swamps,which reflected that the soil fertility was obviously lower than that of the latter,But in arid area,soil catalase and urease can still serve as indicative indicators of soil environmental change;And its activity is mainly affected by salinity,nutrients and water and heat factors...