吉林省耕层土壤有机碳储量及影响因素

为了了解最易受人类活动影响的耕地表层土壤有机碳库对土壤碳库变化及土壤固碳的潜力,以吉林省为研究区域,基于吉林省土肥站提供的2010年耕地地力评价数据(5742个耕地表层土壤采样点数据)以及1∶500 000土壤图等用于分析的基础图件资料,结合ArcGIS技术及统计分析软件SPSS,分析计算了研究区耕地表层土壤有机碳密度、储量及其空间分布特征,并且对吉林省耕地表层土壤有机碳与影响因素之间的关系进行研究。结果表明:吉林省耕地表层有机碳平均密度为3.95kg·m-2,土壤有机碳总储量约为0.206Pg;吉林省东部、中部和西部三大自然地理区域的耕地表层有机碳平均密度分别为4.94、3.66kg·m-2和3.22kg·m-2,自东向西有递减的趋势。各土壤类型中,暗棕壤、白浆土、黑土、黑钙土、草甸土5种土壤类型的耕地表层有机碳储量约占耕地表层土壤有机碳总储量的75.37%,高于其他土壤类型。土壤有机碳含量与年积温呈不显著负相关关系,与年降雨量、土壤阳离子交换量呈显著正相关关系,与pH呈显著负相关关系,在对土壤有机碳进行空间预测和碳库估算时,需要考虑以上四个重要因子。总之,吉林省耕地表层土壤有机碳密度具有高度的空间变异性,整体上呈现自东向西逐渐减小的趋势,年降雨量、年积温、土壤pH及CEC与耕地表层土壤有机碳含量密切相关。

Organic Carbon Storage of Cultivated Topsoils and Its Influencing Factors in Jilin Province

Soil carbon pool is a major component of terrestrial carbon storage. Organic carbon in cultivated topsoils is most vulnerable to human activities. Here we calculated soil organic carbon density and storage in cultivated topsoils(0~20 cm) and their spatial distribution in Jilin Province using 2010 cultivated soil fertility evaluation data and 1:500 000 soil map and combining ARCGIS and SPSS analysis. Correlation analysis between soil organic carbon content and temperature, annual precipitation, soil pH and CEC was also performed. Average organic carbon density and total organic carbon storage of cultivated topsoils in Jilin Province was 3.95 kg·m^-2 and about 2.06 × 10¹¹ kg, respectively. Soil organic carbon density showed a decreasing trend from east (4.94 kg·m^-2) to west(3.22 kg·m^-2). Soil organic carbon content had no significant correlation with annual temperature, but was significantly positively correlated with annual precipitation and soil cation exchange capacity. A significantly negative correlation was found between soil organic carbon and soil pH. Soil organic carbon storage of dark-brown earths, albic soils, black soils, chernozem and meadow soils accounted for 75.37% of the total topsoil organic carbon pool in this region. The present results indicate that the annual precipitation, pH and CEC are main factors influencing topsoil organic carbon content.