太岳山油松人工林土壤呼吸对模拟氮沉降的短期响应  

Short-term response of soil respiration to simulated nitrogen deposition in a Pinus tabulaeformis plantation on Taiyue Mountain,China

作　　者：陈平 赵博[1] 闫子超 杨璐 赵秀海[1] 张春雨[1] CHEN Ping;ZHAO Bo;YAN Ziehao;YANG Lu;ZHAO Xiuhai;ZHANG Chunyu(Research Center of Forest Management Engineering of State Forestry and Grassland Administration,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学国家林业和草原局森林经营工程技术研究中心,北京100083

出　　处：《生态学报》2018年第22期8184-8193,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31340022)

摘　　要：通过对山西太岳山油松人工林进行模拟氮沉降实验,探究土壤呼吸对模拟氮沉降刺激的短期响应动态。2015年7—8月,分3次分别对同一样地进行模拟氮沉降处理,水平皆为100 kg hm^(-2)a^(-1),同时采用LI-COR8150土壤碳通量自动观测系统全天候连续监测土壤呼吸动态,探究土壤施氮前后呼吸速率的动态变化以及呼吸速率与土壤温度和湿度的关联。结果表明:3次氮沉降处理均呈现出相同规律,土壤呼吸值在施氮后1 d内达到最大值,随即下降,在施氮后第3天土壤呼吸趋于稳定;第一、二次氮沉降处理3 d后土壤呼吸恢复到处理前的状态,并未表现出显著差异(P>0.05)。第三次氮沉降处理后土壤呼吸并未恢复到施氮前的状态,土壤呼吸均值由1.99μmol m^(-2)s^(-1)显著上升到3.39μmol m^(-2)s^(-1)(P<0.05)。这表明,氮处理对土壤呼吸产生了持续效应。施氮后土壤呼吸与土壤温度呈极显著(P<0.001)指数相关(R_s=ae^(bT)),随着时间的推移,施氮处理解释土壤呼吸的相对贡献值由60%—69%下降到14%—59%。施氮提高了土壤温度敏感系数Q_(10)值;土壤温度和湿度(R_s=ae^(bT)W^c)能更好的解释土壤呼吸变化,解释率达到49%—91%。在全球变化的背景下,研究模拟氮沉降对土壤呼吸、Q_(10)的影响,可以对进一步模拟、预测全球暖温带地区森林碳循环和碳储量提供理论基础。To investigate the short-term effect of nitrogen (N)deposition on soil respiration (R)of a Pinus tabulaeformis plantation on Taiyue Mountain,a simulated nitrogen deposition experiment was conducted.Field work was carried out on Shanxi Taiyue mountain form July to August 2015.Simulated N deposition was conducted three times with the level of 100 kg hm^-2a^-1in the same plot,while using the LI-COR8150automatic soil carbon flux observation system to monitor soil respiration dynamics.The dynamic change of soil respiration rate and its relationship with soil temperature and humidity before and after nitrogen application were studied.The results showed that the three nitrogen deposition events showed the same pattern.The soil respiration reached a maximum in 1day after N treatment,then decreased.R tended to be stable during the third day after N deposition;the ANOVA showed that there were no significance differences in mean soil respiration before and after N treatment for the first and the second treatment (P>0.05).However,average soil respiration increased significantly from 1.99μmol m^-2s^-1to 3.39μmol m^-2s^-1during the third treatment (P<0.05).This indicated that nitrogen treatment showed a continuous effect on soil respiration.The relationship between soil respiration and soil temperature (Rs =ae^bT )was extremely significant (P <0.001),and nitrogen deposition increased the determinationcoefficient R2of Rs =ae^bT for a short time.The soil temperature at 5cm depth could explain 60%--69%of the variation in soil respiration.As .time passes,nitrogen deposition decreased the determination coefficient R^2of Rs =ae^bT.The soil temperature at 5cm depth could explain 14%--59%of the variation in soil respiration.Furthermore,the nitrogen deposition increased the Q10.Moreover,the two-variable model (Rs =ae^bTW^c)with soil temperature and moisture appeared to have good precision when used to predict soil respiration compared with the one-variable model.The soil temperature and soil moisture at 5cm depth could explain 49%--9

关 键 词：土壤呼吸 氮沉降 连续监测 短期效应 油松林 

分 类 号：S714[农业科学—林学]