季节性温度升高对落干期消落带土壤氮矿化影响  

Effect of Seasonal Temperature Increasing on Nitrogen Mineralization in Soil of the Water Level Fluctuating Zone of Three Gorge Tributary During the Dry Period

作　　者：林俊杰[1,2] 张帅[1] 刘丹[3] 周斌 肖晓君[1] 马慧燕[1] 于志国[5] 

机构地区：[1]重庆三峡学院三峡库区水环境演变与污染防治重庆高校市级重点实验室,重庆404100 [2]中国科学院重庆绿色智能技术研究院中国科学院水库水环境重点实验室,重庆400714 [3]重庆三峡职业学院农林科技系,重庆404100 [4]辽宁省气象科学研究所,沈阳110166 [5]南京信息工程大学水文气象学院,南京210044

出　　处：《环境科学》2016年第2期697-702,共6页Environmental Science

基　　金：国家自然科学基金项目(41301248);中国科学院水库水环境重点实验室开放基金项目(RAE2014BA01B);重庆高校市级重点实验室开放基金项目(WEPKL2013MS-06)

摘　　要：为揭示季节性温度升高对消落带落干期土壤氮矿化的影响,分别采集三峡支流澎溪河消落带上游和下游两个水文断面,155 m（低）、165 m（中）和175 m（高）这3个水位高程表层土壤,结合落干期气温变化特点,在25℃和35℃两个温度下进行恒温培养.结果表明,消落带土壤总氮和硝态氮在上游断面和高水位高程含量更高,而下游和低水位高程含量更低,铵态氮分布与其相反.硝态氮是无机氮的主要存在形式,占无机氮的57.4%~84.7%.相同培养温度下,氨化、硝化、净氮矿化速率均表现为随水位高程增加,随流域断面由下至上而显著增加（P〈0.05）;总体上,在水位高程和流域断面上均表现为：温度升高使硝化速率和净氮矿化速率显著增加（P〈0.05）,而对土壤氨化速率无显著影响（P〉0.05）.To reveal the effect of seasonal temperature increasing on nitrogen mineralization in soil of the water level fluctuating soil zone of three gorge reservoir areas in the Yangtze river tributary during the dry period,surface soils were collected from the water level fluctuating zone of Pengxi river crossing two hydrological sections,i. e. upstream and downstream and three water level altitudes,155m（ low）,165 m（ middle） and 175 m（ high）. We incubated the soil at 25℃ and 35℃ to determine the transformation rates of nitrogen in soil of Pengxi river basin during the dry period. The result showed that TN and NO-3-N contents in the soil of upstream section and higher（ 175 m） altitude of water level were higher than those in downstream and low（ 165 m） altitude of water level,whereas the pattern for NH＋4-N was different,with higher NH＋4-N contents in downstream and low water level. The inorganic nitrogen was dominated by NO-3-N,which accounted for up to 57. 4%-84. 7% of inorganic nitrogen. Generally,soil ammoniation,nitration and net N mineralization increased with the rising water level altitude and stream sections（ P 0. 05）. In summary,nitration and net N mineralization significantly increased with increasing temperature,（ P 0. 05）,while ammoniation showed no difference（ P 0. 05）.

关 键 词：三峡支流 氮矿化 温度升高 落干期 消落带 

分 类 号：X144[环境科学与工程—环境科学] X53