山东省土壤有机碳库及其时空变化特征

摘要

土壤作为陆地生态系统的重要组成部分,土壤碳储量研究在全球碳循环变化中意义重大.利用山东省多目标区域地球化学调查(2003年)获得的双层网格化大密度、高精度土壤有机碳(sOC)含量数据,估算了全省0～ 20 cm、0～100 cm及0～ 160 cm的土壤碳密度和储量,并对SOC密度和储量的时空变化规律及土壤固碳潜力进行研究.结果表明:(1)山东省0 ～ 20 cm、0～100 cm和0～ 160 cm土层SOC密度分别为2.22 kg/m2、7.64 kg/m2、10.09 kg/m2,各土层SOC密度均明显低于全国平均水平(3.19 kg/m2、11.64 kg/m2和15.34 kg/m2);(2)0 ～20 cm表层SOC密度分布总体呈现为沿海地区低,鲁西北平原、鲁东丘陵中等,鲁中南山区偏高的分布格局;(3)与18年前第二次土壤普查(1985年)数据对比,表层SOC密度从1.43 kg/m2升高到2.22 kg/m2,全省陆域(15.70万km2)0 ～ 20 cm表层SOC储量则由226.41 Mt增加至350.65 Mt,净增了124.24 Mt,SOC密度以0.044 kg/(m2·a)的平均速率在土壤中积累,整体表现为“碳汇”效应;据估算,尚有505.23 Mt的固碳潜力.%Soil is an important component of terrestrial ecosystems,research on soil carbon storage in the carbon cycle and global change is of great significance.Based on the double grid,large density and high accuracy data obtained from previous muhi-purpose regional geochemical survey in 2003,the carbon density and storage of 0-20 cm,0-100 cm and 0-160 cm soil in Shandong Province were estimated,meanwhile,a systematic research was conducted on the temporal and spatial variation of soil organic carbon (SOC) density and storage,as well as the potential capacity of carbon sequestration.It was found as follows.(1) The SOC density in 0-20 cm,0-100 cm,and 0-160 cm soil layers of Shandong Province were 2.22 kg/m2,7.64 kg/m2,and 10.09 kg/m2,respectively,which were all lower than the national average levels.(2) The distribution of SOC density in Shandong Province generally presented that the coastal area is low,the plain area in northwest part and hilly area in east part is medium,and the mountain area in middle-south part is high.(3) Compared with the data obtained from the second soil survey in 1985,SOC density of top soil increased from 1.43 kg/m2 to 2.22 kg/m2.SOC storage of whole land territory in Shandong,totally 157,000 square kilometers,increased from 226.41 Mt to 350.65 Mt,with a net increase of 124.24 Mt,which indicates that the SOC density is growing at a rate of 0.044 kg/(m2· a),and representing a "carbon sink" effect.According to preliminary estimate,there is another 505.23 Mt carbon sequestration potential.