北京林业大学学报2009，Vol.31Issue(6)：32-38,7.
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
摘要
Abstract
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(CO_2) from the interface of soft-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 CO_2 flux from interface between soil and atmosphere was 230.05 μmol/(m~2·h) with a range from-147.27 to 2 319.55 μmol/(m~2·h). There were some significant differences between soil types in CO_2 flux. The order of CO_2 flux from large to small in different soil types was fragmental soil (351.82 μmol/(m~2·h)) > gray-cinnamonic soil (347.33 μmol/(m~2·h))>chestnut soil (193.36μmol/(m~2·h)) > sierozem (162.37 μmol/(m~2·h)). The flux of CO_2 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 CO_2flux showed a trend of "S" shape. The CO_2 flux came to a summit of 516.79μmol/(m~2·h) with the release from soil into the atmosphere mainly in September, and that of-7.09 μmol/(m~2·h) fell in the minimum with soil absorption from the atmosphere to the soil in January. There was a main tendency in CO_2 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 CO_2flux. In the daily variations, the CO_2 flux showed a "peaks" shape change with the minimum (154.13 μmol/(m~2·h)) at 04:00 and the largest (349.65 μmol/(m~2·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 CO_2flux was affected by some environmental factors, which were air temperature in soil surface, soil temperature (0-10 cm, 10-20 cm and 20-30 cm) and soil moisture content (0-10 cm, 10-20 cm and 20-30 cm). Air temperature in soil surface, soil temperature content (0-10 cm, 10-20 cm and 20-30 cm) and soil moisture content (0-10 cm) were positively correlated to CO_2 flux in soil surface. And the soil moisture content in 10-20 cm and 20-30 cm depth were negatively correlated to the flux of CO_2 in soil surface. There was not significantly different between air relative humidity in soil surface and CO_2 flux. 5) It showed that there was a transfer mechanism of two-way directions in CO_2 flux, I.e. Not only from soil to atmosphere, but also from atmosphere to soil. The thermal energy in the Earth's surface as some differences in distribution may result in a balanced function in the concentration of atmospheric CO_2 in north temperate and boreal areas. These may be a significant feature in north temperate and boreal regions.关键词
土壤-大气界面/CO_2通量/北温带干旱地区/季节变化/日变化Key words
interface between soil and atmosphere/ carbon dioxide flux/ arid area in north temperate/ seasonal variations/ diurnal variations分类
农业科技引用本文复制引用
高程达,孙向阳,张林,李志刚,阿拉塔..北温带干旱地区土壤-大气界面CO_2通量的变化特征[J].北京林业大学学报,2009,31(6):32-38,7.基金项目
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)和"973"国家重点基础研究发展计划项目(2007CB106800). （NSFC:30671660、30590382）
