北温带干旱地区土壤-大气界面CO_2通量的变化特征  

Changing characteristics of CO_2 flux from the interface of soil-atmosphere at arid area in north temperate

作　　者：高程达[1,2] 孙向阳[1] 张林[1] 李志刚 阿拉塔[4] 

机构地区：[1]北京林业大学水土保持学院,水土保持与荒漠化防治教育部重点实验室 [2]中国林业科学研究院资源信息所 [3]宁夏贺兰山国家级自然保护区管理局 [4]内蒙古农牧业科学院

出　　处：《北京林业大学学报》2009年第6期32-38,共7页Journal of Beijing Forestry University

基　　金：国家自然基金(NSFC:30671660;30590382);教育部高等学校博士学科点专项科研基金(20050022014);教育部新世纪优秀人才支持计划(NCET-05-0137);"973"国家重点基础研究发展计划项目(2007CB106800)

摘　　要：采用箱法对栗钙土、灰钙土、粗骨土和山地灰褐土4种有代表性的干旱土壤表面CO2通量进行观测和研究。结果表明:森林土壤(粗骨土和山地灰褐土)的通量显著大于草原土壤(栗钙土和灰钙土)。干旱区土壤表面CO2通量的平均值为230.05μmol/(m2·h),变化范围为-147.27～2319.55μmol/(m2·h)。不同土壤类型之间存在差异,粗骨土(351.82μmol/(m2·h))>山地灰褐土(347.33μmol/(m2·h))>栗钙土(193.36μmol/(m2·h))>灰钙土(162.37μmol/(m2·h))。土壤表面CO2通量存在季节变化,趋势呈"S"形。9月份最高(516.79μmol/(m2·h)),以土壤向大气释放为主;1月份最低(-7.09μmol/(m2·h)),以大气进入土壤为主;具有春夏秋冬交替规律,与气候变化趋势基本一致,土壤表面CO2通量稍有后滞。全天候土壤表面CO2通量呈"山峰"形变化,04:00最小(154.13μmol/(m2·h)),12:00最大(349.65μmol/(m2·h)),具有昼夜交替规律,比气候日变化稍有滞后。影响土壤表面CO2通量的环境因子有地表空气温度、土壤温度(0～10cm、10～20cm和20～30cm)、土壤含水量(0～10cm、10～20cm和20～30cm);其中,地表空气温度、土壤温度(0～10cm、10～20cm和20～30cm)和土壤含水量(0～10cm)分别与土壤表面CO2通量呈正相关关系,而10～20cm和20～30cm深度的土壤含水量与土壤表面CO2通量呈负相关关系,地表空气相对湿度与土壤表面CO2通量的关系不显著。大气与土壤之间的CO2存在双向转移机制,CO2不仅从土壤向大气转移,而且也从大气向土壤转移,热量在地球表面的差异性分布,导致温带和寒带地区的土壤具有平衡大气CO2浓度的功能,是温带、寒带地区的显著特征。In 2006—2008,the research was carried out in northwestern China＇s Inner Mongolia and Ningxia Hui Autonomous Region on the flux of carbon dioxide（CO2） from the interface of soil-atmosphere in 4 types of soil：chestnut soil in typical grassland,sierozem in desert grassland,fragmental soil in Elm stand and gray-cinnamonic soil in Chinese pine stand by closed-chamber method. Results showed that：1）The average of CO2 flux from interface between soil and atmosphere was 230.05 μmol/（m2·h） with a range from -147.27 to 2 319.55 μmol/（m2·h）. There were some significant differences between soil types in CO2 flux. The order of CO2 flux from large to small in different soil types was fragmental soil （351.82 μmol/（m2·h））〉gray-cinnamonic soil（347.33 μmol/（m2·h））〉chestnut soil （193.36 μmol/（m2·h）） 〉sierozem （162.37 μmol/（m2·h））. The flux of CO2 from forest soil （fragmental soil and gray-cinnamonic soil） was significantly higher than that from grassland soil （chestnut soil and sierozem）. 2）It was found that the seasonal variation in CO2 flux showed a trend of ＂S＂ shape. The CO2 flux came to a summit of 516.79 μmol/（m2·h） with the release from soil into the atmosphere mainly in September,and that of -7.09 μmol/（m2·h） fell in the minimum with soil absorption from the atmosphere to the soil in January. There was a main tendency in CO2 flux as climate change of spring,summer,autumn and winter,and the tendency in the CO 2 flux was slightly rear than climate changes. 3）It was also found that there was a diurnal variation in CO2 flux. In the daily variations,the CO2 flux showed a ＂peaks＂ shape change with the minimum （154.13 μmol/（m2·h）） at 04：00 and the largest （349.65 μmol/（m2·h）） at 12：00. There was a daily turn in the flux at day and night as following the daily changes of climate. 4）It indicated that the transfer of CO2 flux was affected by some environmental factors,which were air temperature in soil surf

关 键 词：土壤-大气界面 CO2通量 北温带干旱地区 季节变化 日变化 

分 类 号：S718.516[农业科学—林学]