氮沉降对黄河三角洲芦苇湿地土壤呼吸的影响  

Effect of nitrogen deposition on soil respiration in Phragmites australis wetland in the Yellow River Delta, China

作　　者：朱敏[1,2] 张振华[1] 于君宝[2] 吴立新[3] 韩广轩[2] 杨利琼[2] 邢庆会[2] 谢宝华[2] 毛培利[2] 王光美[2] 

机构地区：[1]鲁东大学地理与规划学院,山东烟台264025 [2]中国科学院海岸带环境过程与生态修复重点实验室,中国科学院烟台海岸带研究所,山东烟台264003 [3]黄河三角洲国家级自然保护区管理局,山东东营257091

出　　处：《植物生态学报》2013年第6期517-529,共13页Chinese Journal of Plant Ecology

基　　金：国家科技支撑计划项目(2011BAC-02B01);国家自然科学基金项目(41271236);中国科学院知识创新工程重要方向项目(KZCX2-YW-223)

摘　　要：2012年6月至2012年10月,对黄河三角洲芦苇(Phragmites australis)湿地进行了模拟氮沉降试验,氮沉降水平分别为对照(CK,0kgN·hm–2·a–1)、低氮(LN,50kgN·hm–2·a–1)和高氮(HN,100kgN·hm–2·a–1)。利用LI-8100土壤碳通量测量系统测定土壤呼吸速率。结果表明,氮沉降促进了芦苇湿地土壤呼吸作用,LN和HN处理使芦苇生长季(6–10月)平均土壤呼吸速率比CK分别提高19%和58%。积水改变了芦苇湿地土壤呼吸日动态。地面无积水时,各处理土壤呼吸日动态均呈单峰型曲线;地面有积水时,土壤呼吸日动态峰值推后或无单峰型波动规律。积水影响土壤呼吸作用对温度的响应。地面无积水时,各处理土壤呼吸速率均与气温呈极显著的正指数相关关系,气温分别解释了CK、LN和HN处理下土壤呼吸季节变化的69.9%、64.5%和59.9%;地面有积水时,各处理土壤呼吸与气温相关性不显著。CK、LN和HN处理下土壤呼吸温度敏感性系数Q10值分别为1.68、1.75和1.68,表明LN处理增强了土壤呼吸温度敏感性,HN处理对其影响不显著。Aims Atmospheric nitrogen deposition derived from fossil-fuel combustion, fertilization, land clearing and bio- mass buming is occurring over almost the entire world. As an important ecosystem, wetland in industrialized re- gions has experienced greater rates of nitrogen deposition in recent decades. Our objectives were to determine the effect of increased nitrogen deposition on the diurnal and seasonal variation of soil respiration in a reed （Phrag- mites australis） wetland and to relate the variation to environmental and biological factors. Methods From June to October 2012, we conducted a simulated nitrogen deposition field experiment in a reed wetland in the Yellow River Delta, China. The levels of nitrogen deposition were control （CK）, low nitrogen （LN） and high nitrogen （HN） with 0, 50 and 100 kg N-hm-2.a-1, respectively. Soil respiration was measured during the growing season by using a LI-8100 soil CO2 effiux system. Important findings Nitrogen deposition promoted soil respiration in the reed wetland during the entire growing season. Compared with CK, the LN and HN treatments increased the average rates of soil respiration by 19% and 58%, respectively. Surface ponding had a significant effect on the diumal variation pattems of soil respiration. When there was no surface ponding, the diumal variation of soil respiration in different treatments all showed ＂a unimodal＂ pattern. When surface ponding occurred, the diumal variation of soil respiration did not show a uni- modal pattem or the peak value of soil respiration rate was delayed. In addition, response of soil respiration to air temperature was affected by surface ponding. When there was no surface ponding, soil respiration exhibited a sig- nificantly positive exponential relationship with air temperature, which explained 69.9%, 64.5% and 59.9% of the seasonal variation of soil respiration in CK, LN and HN, respectively. However, there was no significant relation- ship between soil respiration and air temperature when surface ponding

关 键 词：氮沉降 芦苇湿地 土壤呼吸 黄河三角洲 

分 类 号：S154.4[农业科学—土壤学]