Carbon dioxide and methane fluxes by a forest soil under laboratory-controlled moisture and temperature conditions
Carbon dioxide and methane fluxes by a forest soil under laboratory-controlled moisture and temperature conditions
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DOI：
10.1016/s0038-0717(97)00228-9
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发表时间：
1998-10-01
影响因子：
9.7
通讯作者：
Rullo, GM
中科院分区：
文献类型：
--
作者：
Bowden, RD;Newkirk, KM;Rullo, GM
二氧化碳和甲烷是重要的温室气体，它们在土壤和大气之间的交换速率受土壤温度和湿度的强烈控制。通过室内研究，定量分析了土壤湿度和温度对森林土壤与大气之间CO（2）和CH（4）通量的相对重要性。从哈佛森林的混合阔叶林中收集森林地面和矿物质土壤材料。长期生态研究中心（MA），并在实验室中在一定范围的湿度（风干至接近饱和）和温度条件（5-25摄氏度）下孵育。随着森林地表物质温度的升高，二氧化碳排放量呈指数增长，在土壤水分含量最低和最高时，排放量减少。森林地面Q（10）为2.03（从15-25摄氏度），表明CO（2）排放主要受土壤生物活动控制。温度和水分的多元多项式回归模型（r（2）= 0.88）可以预测森林地表CO2排放量，但预测矿质土壤呼吸的拟合度较弱（r（2）= 0.59）。甲烷吸收强烈控制土壤水分，在很低或很高的土壤水分含量的条件下，减少通量。多元多项式模型能准确地描述矿质土壤物质对CH（4）的吸收（r（2）= 0.81），但仅能较弱地预测森林地面物质对CH（4）的吸收（r（2）= 0.45）。矿质土壤对CH（4）的吸收Q（10）为1.11，表明甲烷吸收主要受物理过程控制。我们的工作表明，包括水分和温度可以改善土壤和大气之间的土壤CO（2）和CH（4）交换的预测。此外，全球变化模型在评估全球气候变化对痕量气体通量的影响时需要考虑温度和湿度的相互作用。(C)1998爱思唯尔科技有限公司版权所有。
Carbon dioxide and methane are important greenhouse gases whose exchange rates between soils and the atmosphere are controlled strongly by soil temperature and moisture. We made a laboratory investigation to quantify the relative importance of soil moisture and temperature on fluxes of CO(2) and CH(4) between forest soils and the atmosphere. Forest floor and mineral soil material were collected from a mixed hardwood forest at the Harvard Forest. Long-Term Ecological Research Site (MA) and were incubated in the laboratory under a range of moisture (air-dry to nearly saturated) and temperature conditions (5-25 degrees C). Carbon dioxide emissions increased exponentially with increasing temperature in forest floor material, with emissions reduced at the lowest and highest soil moisture contents. The forest floor Q(10) of 2.03 (from 15-25 degrees C) suggests that CO(2) emissions were controlled primarily by soil biological activity. Forest floor CO(2) emissions were predicted with a multiple polynomial regression model (r(2) = 0.88) of temperature and moisture, but the fit predicting mineral soil respiration was weaker (r(2) = 0.59). Methane uptake was controlled strongly by soil moisture, with reduced fluxes under conditions of very low or very high soil moisture contents. A multiple polynomial model accurately described CH(4) uptake by mineral soil material (r(2) = 0.81), but only weakly (r(2) = 0.45) predicted uptake by forest floor material. The mineral soil Q(10) of 1.11 for CH(4) uptake indicates that methane uptake is controlled primarily by physical processes. Our work suggests that inclusion of both moisture and temperature can improve predictions of soil CO(2) and CH(4) exchanges between soils and the atmosphere. Additionally, global change models need to consider interactions of temperature and moisture in evaluating effects of global climate change on trace gas fluxes. (C) 1998 Elsevier Science Ltd. All rights reserved.