Soil Organic Carbon Storage and Its Spatial Distribution Characteristic in the Sangong River Watershed of Arid Region
Soil Organic Carbon Storage and Its Spatial Distribution Characteristic in the Sangong River Watershed of Arid Region
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发表时间：
2009
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通讯作者：
Lin Qing
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作者：
Lin Qing
陆地生态系统碳循环研究在全球变化中起着举足轻重的作用。准确估算干旱区流域尺度生态系统土壤有机碳储量是研究碳汇和碳源效应的重要前提之一。近50年来，西北干旱区的大规模开发导致了水土资源时空分布的变化。各种人类活动都导致了干旱区土壤有机碳储量的变化。本研究以三工河流域为例，采用改良土壤类型法估算了绿洲区和山区的土壤碳储量。结果表明，整个三工河流域0~20 cm土层土壤有机碳储量为1431.5×104t(14.3tg)，平均有机碳密度为6.70kgC/m2，土壤有机碳含量为34.26g/kg，绿洲地区土壤有机碳含量仅为170.4×104tC。在天山中山区，由于气温较低和森林凋落物对土壤腐殖质积累过程的影响，山地灰褐森林土壤具有最大的碳储量(548.6×104tC)。土壤有机碳密度的分布具有明显的垂直地带性和水平地带性特征，即碳密度从山区、丘陵区、绿洲区到荒漠区呈递减趋势，并随着海拔的升高而变化。在整个流域内，山区的平均土壤碳密度为25.92KGC/m2，高于流域的平均碳密度(6.70KGC/m2)，而丘陵地区的土壤有机碳密度则表现出明显的垂直分带性和水平分带性。在整个流域内，山区的平均土壤碳密度为25.92KGC/m2，高于流域的平均碳密度(6.70KGC/m2)。绿洲区和荒漠区均小于流域平均碳密度，与中国所在的西北干旱区的热力和植被分布相一致。
Carbon cycle research of terrestrial ecosystems plays a pivotal role in global change.Accurate estimation of soil organic carbon storage in the watershed scale ecosystems of arid region is one of the important premise to study the carbon sink and source effect.In the past 50 years,the large-scale exploitation has resulted in the spatio-temporal distribution change of water and land resource in the northwest arid region of China.All the human activities have resulted in the change of SOC storage in the arid region.In this study,the Sangong River watershed was taken as a study case.We have estimated the soil carbon storage in oasis area using the improved soil type method and in mountain area,hilly area and desert area using the soil type method,and analyzed the spatial distribution characteristic of soil organic carbon density in order to offer a data supporting for soil carbon cycle study of arid region.The results showed that the total soil organic carbon storage in 0-20cm depth was 1431.5×104 t(14.3 Tg),mean soil organic carbon density was 6.70 kgC/m2,and soil organic carbon content was 34.26 g/kg in the whole Sangong River watershed,while it is only 170.4×104 t C in the oasis area based on improved soil type method(grid method) estimation.At all soil types,the mountain grey cinnamon forest soil has maximum carbon storage(548.6×104 t C) due to the impact of lower temperature and forest litter on soil humus accumulation process in the mid-mountain zone of Tianshan Mountains.The distribution of soil organic carbon density showed significant characteristic of vertical zonality and horizontal zonality,this is that carbon density tends to decrease from mountain area,hilly area,oasis area to desert area,and change with altitude from high to low.In the whole watershed,mean soil carbon density of mountain area was 25.92 kgC/m2,being more than the watershed mean carbon density(6.70 kgC/m2),while in the hilly area,oasis area and desert area,it was less than the watershed mean carbon density,being consistent with the thermal and vegetation distribution in the northwest arid region of China.