土壤是陆地生态系统的重要组成部分,土壤碳储量研究在碳循环和全球变化中具有重要意义。本文利用江西省鄱阳湖及周边经济区多目标区域地球化学调查取得的土壤碳数据,计算了研究区表层、中层、深层土壤的全碳储量和有机碳储量,分析其有机碳储量和有机碳密度的分布特征。结果表明: 研究区总体碳储量是以有机碳储量为主; 表层土壤(0 ~ 0. 2 m)的有机碳密度为3512 t /km~2,有机碳储量为1. 38亿吨; 中层土壤(0 ~ 1. 0 m)的有机碳密度为11156 t /km~2,有机碳储量为4. 39亿吨; 深层土壤(0 ~ 1. 8 m)的有机碳密度为15617 t /km~2,有机碳储量为6. 14亿吨。与全国农业地质调查数据进行对比,研究区表层土壤的有机碳密度高于全国农业地质调查区内表层土壤有机碳密度的10. 86%,中层及深层土壤的有机碳密度与全国农业地质调查区平均水平接近,显示研究区土壤的有机碳储量巨大。进一步分析研究区不同土壤类型、不同土地利用类型、不同地貌单元、不同行政单元的土壤有机碳密度及有机碳储量,系统查明了土壤有机碳的分布和分配特征。研究认为,区域内各层土壤有机碳密度空间分布具有同一性特征,与所处区域的成土地质背景和植被覆盖率密切相关。土壤有机碳密度高值区均分布在山地和丘陵区,包括江西丰城市北部、高安市南部、乐平市周边地区等古生代炭质岩和煤系地层区,其中乐平市表层土壤的有机碳密度最高; 低值区均分布在湖区和水系河谷地区。该成果可为江西省的碳循环和碳排放研究提供可靠的数据基础。
英文摘要:
Soil is a main component of the terrestrial ecosystem,and soil carbon research is significant in the carbon cycle and global change. Using the geochemical survey data from Poyang Lake in Jiangxi province and the surrounding economic zone multi-target regional,the total carbon and organic carbon from the surface,middle and deep soil in research area was studied and the organic carbon reserves and organic carbon density distribution characteristics analyzed. The results indicate that the overall carbon in the study area consists mainly of organic carbon. The reserve of organic carbon is 138 million tons and organic carbon density is 3512 t /km~2 in the surface soil(0-0. 2 m),439 million tons and 11156 t /km~2 in the middle soil(0-1. 0 m)and 614 million tons and 15617 t /km2 in the deep soil(0-1. 8 m). Compared with the national agricultural geological survey data,organic carbon density of surface soil in the study area is 10. 86% higher than that of the national agricultural geology survey,however,organic carbon density of middle and deep soil is close to the results of national agricultural geology. It shows that the research area has huge reserves of organic carbon. Further studies were conducted to uncover the distribution and the distribution characteristics of organic carbon in soil by using the organic carbon density and organic carbon reserves for different soil types,different land utilization types,different geomorphic units and different administrative units. Research results suggest that each layers of soil possesses the same organic carbon density spatial distribution characteristics,which is closely related to the geological background and the vegetation coverage. A high value area of carbon density is located in hilly areas and mountainous regions,such as the paleozoic carbonaceous rock and coal strata from the north of Fengcheng City,the south of Gaoan City and the surrounding of Leping City. The highest organic carbon density occurred in the topsoil of Leping city. Low organic carbon density is located in lake and river valley areas. The results of this study provide reliable data for studying the carbon cycle and carbon emissions in the Jiangxi countryside.