关中地区表层土壤碳储量问题的研究

土壤碳储量问题是碳循环和全球变化研究的基本问题,关系到全球生态环境的发展、平衡与兴衰。论文利用多目标区域地球化学调查取得的大量数据,用实测方法计算出关中地区表层土壤(0～0.2m)全碳(TC)储量为1.50×108 t,平均储量为4994.16t/km2;其中,有机碳(TOC)储量为0.71×108 t,平均储量为2350.14t/km2。通过对研究区内表层单位土壤碳储量分布规律的研究发现,TOC储量在基岩山地和低山丘陵等植被覆盖较高的地区相对较高。对表层土壤的平均碳储量分别按照土壤类型、土地利用、地貌单元和成土母质类型进行分类统计,结果表明研究区内:粗骨土的平均有机碳和全碳储量均最高,风沙土均最低,黑垆土的平均无机碳(TIC)储量最高,棕壤最低;农用地中,林地的平均TOC和TC储量最高,TIC储量最低;各地貌单元平均TOC储量的大小顺序为:基岩山地﹥低山丘陵﹥平原﹥黄土高原﹥黄土塬;成土母质为山前洪冲积的土壤平均TOC储量最高,渭河冲洪积土壤最低。

Study on the Topsoil Carbon Reserves of Guanzhong Region

The quantity of soil carbon reserves is the fundamental issue of carbon cycle and global change which is closely related to the development,balance,and rise and fall of the global ecological environment.In this paper,the topsoil(from 0 to 0.2 m) carbon reserves in the Guanzhong region have been calculated by the measurement calculation method based on a huge amount of topsoil carbon content data from a multipurpose regional geochemical survey.The results showed that the topsoil total carbon(TC) reserves from 0 to 0.2 m are 1.50×108 t with an average value of 4994.16 t/km2,and organic carbon(TOC) reserves are 0.71×108 t with an average value of 2350.14 t/km2.It is found that the unit topsoil TOC reserves of bedrock mountain and hilly area which have a fine vegetation cover are high by the study of carbon reserves distribution laws in the whole area.The statistical results of topsoil average carbon reserves according to the classification system of soil type,land use type,geomorphic units and parent material type indicated that both average TOC reserves and average TC reserves of skeletal soils are highest,while those of aeolian sandy soils are lowest.The average inorganic carbon(TIC) reserves of dark loessial soils are highest while those of brown soils are lowest.The average values of TOC and TC of woodland are highest while their TIC reserves are lowest in different agricultural lands.The average TOC reserves in every geomorphic unit follow the order of bedrock mountain> hilly area> plain> loess plateau> loess yuan.In different kinds of parent materials the value of piedmont diluvium-alluvium soil is highest and that of Weihe alluvium-diluvium soil is lowest.