小泊湖高寒湿地土壤理化性质对氮沉降的短期响应.

[Objective] Alpine wetland ecological environment is fragile and sensitive to global change. The present paper aimed to explore the response mechanism of soil physical and chemical properties to nitrogen deposition in alpine wetland. [Method] Four levels of CK（0 g/m2）,N2（2 g/m2）,N5（5 g/m2） and N10（10 g/m2） nitrogen addition tests were set in Xiaopo Lake Wetland in Qinghai Lake basin as the research object. Simulated nitrogen deposition test was conducted from June to October 2019.Samples were taken in October 2019 to determine soil water content, pH, organic carbon, total carbon, total nitrogen and inorganic nitrogen, and analyze the influence of nitrogen deposition test on soil physical and chemical properties.[Result]（i）Nitrogen deposition reduced soil moisture content and increased soil pH, and the influence reached extremely significant level（P<0.01）.(ii)Nitrogen deposition made soil carbon nitrogen content change. Total carbon organic nitrogen and ammonia nitrogen decreased with the increase of nitrogen concentration, and the influence on total carbon content was significant(P<0.05).The effect of nitrate nitrogen in the two soil layers was different. In the 0-15 cm soil layer, it increased with the increase of nitrogen concentration, and reached a significant level under the treatment of N10（P<0.05）,decreased with the increase of nitrogen concentration in the 15-30 cm soil layer.(iii) Soil moisture content was the main factor affecting soil organic carbon and total nitrogen.Soil inorganic nitrogen was not closely related to other factors, but there was a very significant correlation between soil organic carbon and total nitrogen(P<0.01).[Conclusion]The present study provides reference for the change of soil environment and the protection and utilization of wetland under the global change. [ABSTRACT FROM AUTHOR]