小兴安岭5种林型土壤呼吸时空变异  

Temporal and spatial variability in soil respiration in five temperate forests in Xiaoxing′an Mountains,China

作　　者：史宝库[1] 金光泽[1] 汪兆洋 

机构地区：[1]东北林业大学生态研究中心,哈尔滨150040 [2]吉林省林业勘察设计研究院,长春130022

出　　处：《生态学报》2012年第17期5416-5428,共13页Acta Ecologica Sinica

基　　金：国家科技支撑计划(2011BAD37B01);林业公益性行业科研专项经费项目(200804001);长江学者和创新团队发展计划(IRT1054)资助

摘　　要：原始阔叶红松林、谷地云冷杉林、阔叶红松择伐林、次生白桦林、人工落叶松林是小兴安岭乃至东北地区的重要森林类型。采用红外气体分析法比较测定了这几种森林类型的土壤呼吸及其相关环境因子,分析探讨了这几种森林类型土壤呼吸的时空变异。结果表明:各林型土壤呼吸与5 cm深土壤温度(T5)呈显著的指数相关,并且土壤呼吸与土壤温度、土壤湿度及其相互作用的回归模型可以解释各林型土壤呼吸约71%的季节变异。生长季平均土壤呼吸速率为次生白桦林(3.59μmolCO.2m-.2s-1)>谷地云冷杉林(3.52μmolCO.2m-.2s-1)>阔叶红松择伐林(3.44μmolCO.2m-.2s-1)>原始阔叶红松林(2.58μmolCO.2m-.2s-1)>人工落叶松林(2.29μmolCO.2m-.2s-1),说明土壤呼吸对原始阔叶红松林人为干扰的响应是不同的。各林型Q10值介于1.84(人工落叶松林)—2.32(次生白桦林)之间。在整个生长季,各林型之间土壤呼吸的变异系数变化幅度为19.74%—37.39%,而各林型内土壤环间其变化幅度为32.13%—60.20%,显著大于样地间的变化幅度14.28%—35.70%(P<0.001),说明土壤呼吸在细微尺度上的差异更大。土壤湿度可以解释各林型(阔叶红松林除外)内部土壤呼吸15.8%—33.5%的空间异质性。Soil CO2 efflux （Rs） is the second largest terrestrial carbon flux. Even a relatively small change in the carbon flow into, or out of, soils could have a large impact on atmospheric CO2 concentration. Conversion of forest ecosystems can potentially be a major contribution to greenhouse gas emissions. Therefore, reviewing measured rates and spatial and temporal variability of soil respiration from different terrestrial ecosystems and evaluating the effects of environmental factors and human disturbance on them provides essential data for the global carbon budget and its estimated effect on climate change. The representative disturbance gradient （virgin forest 〈 secondary forest 〈 plantation） in the Liangshui Nature Reserve of the Xiaoxing＇an Mountains of Northeast China provides an excellent opportunity to examine how soil respiration responds to human disturbances. Throughout the growing season （May--October） in 2010, an infrared gas exchange analyzer was used to measure and compare soil respiration rates and related environmental factors in various forest systems. The forest systems investigated were virgin mixed broadleaved-Korean pine forest, valley spruce-fir forest, selectively cut mixed broadleaved-Korean pine forest, secondary birch forest and Dahurian larch plantation. The results showed that there was significant seasonal variation in soil respiration in the different forest types during the growing season where the peak soil respiration rate was in July and August and the lowest respiration rate was in the early and late growing season. There was a significant exponential correlation between soil respiration and soil temperature at 5 cm （ T5 ） in the five forest types （P〈0.001）. Furthermore, soil temperature and soil moisture and the interactions between them could explain 71% of seasonal variation in soil respiration, and incorporating soil moisture into the pure Rs temperature model improved the prediction of Rs in most forest types. The average soil respiration rates in th

关 键 词：土壤呼吸 森林转换 季节动态 空间变化 土壤温度 土壤湿度 阔叶红松林 

分 类 号：S714[农业科学—林学]