色季拉山高寒草甸区大气氮沉降年内动态变化

Intra-annual Dynamics of Atmospheric Nitrogen Deposition in the Alpine Meadows of the Sejila Mountain

本研究以色季拉山高寒草甸区为研究对象,在2021-2022年期间连续采集大气氮干湿沉降样品,分析监测数据,研究色季拉山高寒草甸区大气氮沉降的年内动态变化特。结果表明:色季拉山高寒草甸降水量表现为夏季>春季>秋季>冬季的季节变化规律。NH_(4)^(+)-N的浓度季节变化规律表现为春季>冬季>夏季>秋季,NO_(3)^(-)-N的浓度季节变化表现为冬季>春季>秋季>夏季的变化趋势,无机氮沉降主要与降雨量和温度有关。在2021-2022年期间,研究区的大气氮湿沉降中的NH_(4)^(+)-N、NO_(3)^(-)-N和TN沉降通量均呈现出夏季>春季>秋季>冬季的特点,无机氮沉降表现为春、夏季高,秋、冬季低,DON沉降通量没有表现出很大的季节差异性,DON的沉降通量占总沉降通量的55.2%~82.85%之间,无机氮的占比在17.2%~44.85%之间。色季拉山高寒草甸区的大气氮干沉降中,NH_(3)沉降通量在季节分配上表现为夏季>秋季>春季>冬季的特点,NO_(2)表现为夏季>春季>冬季>秋季的特点。此外,干沉降以NH_(3)的沉降为主,春、秋和冬季中占了总干沉降通量96%以上。在2021-2022年期间,研究区的大气氮沉降以湿沉降为主。总干沉降通量为0.96 kg N ha^(-1),总湿沉降通量24.68 kg N ha^(-1),湿沉降通量远远高于干沉降通量.

This study focuses on the alpine meadow region of Sejila Mountain and examines the seasonal dynamics of atmospheric nitrogen deposition during the period from 2021 to 2022.Continuous collection of atmospheric nitrogen deposition samples is conducted,and the monitoring data are analyzed.The results indicate that the precipitation in the Sejila Mountain alpine meadow exhibits a seasonal pattern with the highest in summer,followed by spring,autumn,and winter.The concentration of NH_(4)^(+)-N shows a seasonal pattern of spring > winter >summer > autumn,while the concentration of NO_(3)^(-)-N exhibits a trend of winter > spring >autumn > summer.Inorganic nitrogen deposition is primarily influenced by rainfall and temperature.During the period from 2021 to 2022,the fluxes of NH_(4)^(+)-N,NO_(3)^(-)-N,and TN in atmospheric wet deposition in the study area showed a pattern of summer > spring > autumn >winter,indicating higher levels during spring and summer and lower levels during autumn and winter.The flux of dissolved organic nitrogen(DON) did not exhibit significant seasonal variation,accounting for 55.2% to 82.85% of the total deposition flux,while inorganic nitrogen ranged from 17.2% to 44.85%.In the atmospheric dry deposition of nitrogen in the Sejila Mountain alpine meadow,the flux of NH_(3) deposition exhibited a seasonal distribution of summer > autumn > spring > winter,while NO_(2) showed a pattern of summer > spring >winter > autumn.Furthermore,NH_(3) deposition dominated in dry deposition,accounting for over 96% of the total dry deposition flux during spring,autumn,and winter.In the period from 2021 to 2022,atmospheric nitrogen deposition in the study area was primarily in the form of wet deposition,with a total dry deposition flux of 0.96 kg N ha^(-1) and a total wet deposition flux of 24.68 kg N ha^(-1),indicating that wet deposition significantly outweighed dry deposition.