广东韶关地区土壤有机碳储量特征及其影响因素

Characteristics and Influencing Factors of Soil Organic Carbon Storage in Shaoguan,Guangdong Province

采用单位土壤碳量计算方法,分别对韶关市不同母质类型、地貌类型、土地利用类型以及土壤类型中有机碳储量及平均碳密度等参数进行统计,初步探讨了广东韶关地区土壤有机碳储量特征及其影响因素。结果表明,调查区表层土壤(0-20 cm)有机碳平均碳密度和储量分别为3.62 kg/m^(2)和5.45×10^(7) t;中层土壤(0-100 cm)有机碳平均碳密度和储量分别为11.64 kg/m^(2)和1.75×10^(8) t;深层土壤(0-180 cm)有机碳平均碳密度和储量分别为15.63 kg/m^(2)和2.35×10^(8) t。从地貌上看,有机碳储量低值区主要为盆地(如南雄盆地、翁源盆地、乐昌盆地)、平原等地势较低处,高值区主要分布在中低山区域;其次,花岗岩出露地区表层有机碳含量较高。研究发现,近34年来调查区表层土壤有机碳储量总体呈下降趋势。影响土壤有机碳分布特征的因素主要为土壤类型、地貌类型、成土母质类型、土地利用类型等;其次,气候条件、植被状况、海拔高度等因素也是影响有机碳分布的重要因子。

This paper used the calculation method of unit soil carbon to calculate the organic carbon storage and average carbon density of different parent material types,landform types,land use types and soil types in Shaoguan City of Guangdong Province,and preliminarily discussed the characteristics and influencing factors of the soil organic carbon storage.The statistic results showed that the average carbon density and storage of organic carbon were 3.62 kg/m^(2) and 5.45×10^(7) ton in surface soil(0-20 cm),11.64 kg/m^(2) and 1.75×10^(8) ton in middle soil(0-100 cm),and 15.63 kg/m^(2) and 2.35×10^(8) ton in deep soil(0-180 cm).From the perspective of geomorphology,the low value areas of organic carbon storage are in mainly basins(such as Nanxiong basin,Wengyuan basin,Lechang basin),plains and other low-lying areas,while the high value areas are mainly distributed in the middle and low mountain areas;secondly,the surface organic carbon content is higher in the granite exposed areas.The total organic carbon storage of topsoil in the survey area has been decreasing in recent 34 years.The main factors affecting the distribution characteristics of soil organic carbon include mainly soil type,landform type,soil parent material type,land use type,and minor climate conditions,vegetation status,altitude.