广东阳江-茂名地区土壤碳储量及其时空变化规律

Soil carbon storage and its time variation in Yangjiang-Maoming area,Guangdong province

本文参照DZ/T0258-2014多目标区域地球化学调查规范(1∶250000),对调查区碳储量进行计算研究。精确计算阳江-茂名地区土壤碳储量,并利用多目标区域地球化学调查实测土壤有机碳密度与1985年广东省第二次土壤普查取得的土壤有机碳密度进行对比,分析30年来,调查区内土壤碳密度及碳储量的时间变化规律,为该区土壤碳循环研究提供数据支撑。研究发现,土壤总有机碳储量为1.19×10~8 t,各层位有机碳占碳总储量的比例与全球土壤水平相当,无机碳储量远小于有机碳储量。从空间分布来看,各层位总碳和有机碳区域分布较为相似,土壤碳密度表现出了明显的垂直地带性和水平地带性特征。水田土壤较旱地土壤有机碳含量多,花岗岩母质对表层土壤有机质的贡献较大,而林地对中层和底层土壤有机碳贡献较大。30年来,阳江-茂名地区在高强度人类活动改造下土壤有机碳的变化情况发现,阳江-茂名地区土壤有机质含量略有增加,其增加趋势及强度在空间上具有较大差异。而林地和农用地这两种利用类型土壤有机碳的改变是影响区域土壤有机碳储量的主要因素。

The calculation of the carbon storage has been made in the Maoming-Yangjiang area based on the DZ/T0258-2014 multi-objective geochemical survey specification（1：250000）.This result,together with the comparison of the soil organic carbon density obtained from the multi-objective geochemical survey and the second soil survey in Guangdong Province in 1985,we further analysis the time variation of the soil carbon density and the carbon storage in recent 30 years.This temporal variation can provide us data support for the research of the soil carbon cycle in the study areas.It shows that the total soil organic carbon storage in the study areas is about 1.19×10~8t,much more than that of the inorganic carbon.In addition,the proportion of the organic carbon storage in each layer is commensurate with that of the global level.Judging from the spatial distribution,we can find that the distribution of the total carbon and the organic carbon in each layer is similar to each other,and the soil carbon density shows characteristics of vertical and horizontal zonality.Moreover,we also find that the organic carbon content in paddy soil is greater than upland soil,and granite has a large soil organic matter contribution to the surface soil,while the forest contributes more to the middle and lower layers.In recent 30 years,although there is a great space difference in increase trend and intensity,the soil organic matter content in the Yangjiang-Maoming area has increased slightly,which may be associated with the high intensity of human activities.Forest and agricultural land,as two main kinds of use type soil,their changes in organic carbon content should be the major factor in influencing the regional soil organic carbon storage.