甘肃省兰州—白银地区土壤有机碳库储量估算与空间分布特征

RESERVES ESTIMATION AND SPATIAL DISTRIBUTION OF THE ORGANIC CARBON POOL IN LANZHOU-BAIYIN AREA,GANSU PROVINCE

土壤有机碳库是陆地碳库的主要组成部分,并在陆地碳循环研究中有着重要作用。根据甘肃省兰州—白银地区多目标地球化学测量数据,结合各土壤类型分布面积,估算表层土壤(0～20 cm)有机碳密度和储量,并探讨其空间分布特征。研究表明,兰州—白银地区表层土壤有机碳平均密度为1.52～7.73 kg/m2。在空间分布上,榆中县有机碳密度最高,达2.69 kg/m2,会宁县有机碳密度最低,仅1.56 kg/m2,总体上呈四周高,中间低的趋势。从土壤类型上看,草甸土有机碳密度最高,达7.73 kg/m2,灰褐土、栗钙土和石质土次之,为2.96～5.18 kg/m2,红黏土及淡灰钙土有机碳密度较低,仅为1.52～1.53 kg/m2。从土地利用现状看,林地有机碳密度最高,这与气候、植被、人类活动有关。

As a key component of land carbon storage,the soil organic carbon storage plays an important role in the study of land carbon recycle.On the basis of multiple target geochemical survey data and distribution of different types of soil in Lanzhou-Baiyin area,the organic carbon density and storage in surface soil（from 0 to 20 cm） were estimated to illustrate its spatial distribution characteristics.The results show that the average surface soil organic density in Lanzhou-Baiyin area ranges from 1.52 to 7.73 kg/m^2.The soil organic density in Yuzhong is higher than that in other areas and reaches 2.69 kg/m^2,while the density in Huining is the lowest and reaches 1.56 kg/m^2.As for soil types,the soil organic carbon density in meadow is the highest and its density reaches 7.73 kg/m^2.Soil carbon density in gray cinnamonic soil,chestnut soil and lithosol ranges from 2.96 to 5.18 kg/m^2,and that of red clay and light grey desert soil ranges from 1.52 to 1.53 kg/m^2.Viewed from land use status,the soil organic carbon density in woodland is the highest,and it should be affected by the climate,vegetation and human activity.