模拟氮沉降对樟树人工林土壤呼吸的短期效应  

Short-term effects of nitrogen deposition on soil respiration of Cinnamomum camphora plantation

作　　者：张徐源[1] 闫文德[1,2] 马秀红 郑威[1,2] 王光军[1,2] 梁小翠[1,2] 

机构地区：[1]中南林业科技大学生命科学与技术学院,湖南长沙410004 [2]南方林业生态应用技术国家工程实验室,湖南长沙410004 [3]北京市天竺苗圃,北京100621

出　　处：《中南林业科技大学学报》2012年第3期109-113,共5页Journal of Central South University of Forestry & Technology

基　　金：国家林业公益性行业科研专项(200804030);国家林业局"948"项目(2007-4-19;2008-4-36);国家自然科学基金项目(31070410);教育部新世纪优秀人才支持计划项目(NCET-10-0151);湖南省科技厅项目(2010TP4011-3);湖南省教育厅项目(湘财教字[2010]70号);长沙市科技局项目(K1003009-61);中南林业科技大学青年科学研究基金重点项目(QJ2010008A)

摘　　要：通过对中亚热带地带性植被樟树林进行模拟氮沉降试验,氮沉降水平分别为对照(CK,0 g.m-2a-1)、低氮(LN,5 g.m-2a-1)、中氮(MN,15 g.m-2a-1)和高氮(HN,30 g.m-2a-1),利用LI-8100土壤呼吸测定系统,研究了模拟氮沉降对其土壤呼吸速率的影响以及与土壤表层温湿度的响应。结果表明,不同浓度氮沉降处理水平下的土壤呼吸速率平均值分别为CK 4.09±0.66μmol.m-2s-1、LN 2.39±0.29μmol.m-2s-1、MN 2.18±0.19μmol.m-2s-1、HN 2.28±0.25μmol.m-2s-1。对照处理显著高于其它3种处理(P<0.01);土壤呼吸温度敏感系数Q10值分别为CK1.80、LN 1.67、MN 1.77、HN 1.53,各处理土壤呼吸速率与土壤地表温度呈显著正相关关系;5 cm土壤体积含水率在0.266 6～0.294 4(m3.m-3)之间,各月份土壤体积含水率差异不大(1.8%～9.4%),土壤呼吸速率与5 cm土层土壤体积含水率相关性不显著(P>0.05),模拟氮沉降初期明显抑制了樟树人工林土壤呼吸。The nitrogen deposition experiments on Cinnamomum camphora plantation of Hunan provincial botanical garden were simulated from June the 7th to October the 7th 2010,the nitrogen deposition levels was respectively as control（CK,0 g·m^-2a^-1）,low nitrogen（LN,5 g·m^-2a^-1）,medium nitrogen（MN,15 g·m^-2a^-1） and high nitrogen（HN,30 g·m^-2a^-1）.The soil respiration speed and soil surface temperature and the surface water content of the soil were determined by LI-8100 measuring instrument.The results show that the average values of soil respiration speed were CK（4.09±0.66 μmol·m-2 s-1）,LN（2.39±0.29 μmol·m-2 s-1）,MN（2.18±0.19 μmol·m-2 s-1）,HN（2.28±0.25 μmol·m-2 s-1）,that of the CK was obviously higher than the other three treatments（P〈0.01）.With different nitrogen concentrations deposition treatments,the Q10（temperature sensitivity coefficients） for soil respiration of CK,LN,MN and HN treatments were 1.84,1.71,1.83 and 1.56.It was positive correlation between the respiration speed and the surface（≤10 cm） temperature of tested soil.It was negative correlation between the respiration speed and the surface（≤5 cm） water content of tested soil（P〈0.05）.Volumetric water content of 5 cm soil was between 0.266 6～0.294 4（m^3·m^-3）,it did not vary much monthly during the research period（1.8%～9.4%）.The findings suggest that the initial stage of nitrogen deposition obviously influenced the soil respiration of Cinnamomum camphora plantation.

关 键 词：土壤呼吸 氮沉降 Q10值 樟树人工林 

分 类 号：S792.23[农业科学—林木遗传育种]