基于上海市土地利用方式变化下的土壤有机碳储量核算研究

Soil organic carbon storage based on land use change in Shanghai

分析了上海市2009年以来的土地利用类型与表层土壤有机碳储量的变化以及土地利用方式变化对表层土壤有机碳储量的影响。研究结果表明:上海市2012、2016年表层土壤有机碳储量分别为1.061014×10^(10)kg、1.149566×10^(10)kg,表层土壤平均有机碳密度低于全国平均水平的4.70kg/m^(2),表层土壤有机碳储量占全国表层土壤有机碳储量的0.026%;耕地、林地和园地转化为工矿仓储用地、公共设施用地、交通运输用地时造成了表层土壤有机碳的排放,而其他农用地—耕地、公共设施用地、工矿仓储用地和工矿仓储用地—耕地、公共设施用地以及其他土地—耕地、公共设施用地时有利于表层土壤有机碳的汇聚;上海市表层土壤有机碳储量增加主要来源于土地利用类型不变的土地(农用地、滩涂土地等),这些土地表层土壤有机碳储量增加是土壤碳密度(有机碳含量)普遍增高的结果。建议通过进一步加强农用地、滩涂土地的有效保护,并对建设用地上的建筑物实施立体绿化等措施,提升上海市表层土壤有机碳储量。

This study analyzed the changes in land use type and surface soil organic carbon(SOC)storage since 2009 in Shanghai to determine the effects of land use change on surface SOC storage.The results showed that:(1)Surface SOC storage was 1.061014×10^(10)kg in 2012 and 1.149566×10^(10)kg in 2016,revealing that the surface SOC density was lower than the national average of 4.70kg/m^(2),and the surface SOC storage accounted for 0.026% of the national surface SOC storage.(2)Land use changes,such as those from cropland,woodland,and orangery land to industrial and mining storage,public facilities,and traffic lands,can lead to increased carbon emission.Other changes,such as those from agricultural land to cropland,public facilities land,and industrial and mining storage land;from industrial and mining storage land to cropland and public facilities land;and from other land to cropland and public facilities land,can increase the accumulation of surface SOC.(3)The increase in surface SOC storage in Shanghai was mainly the result of an increase in surface SOC storage in lands maintaining their land use type(such as agricultural land and tidal flat).This is because of a general increase in the carbon density(the content of organic carbon)in such areas.By strengthening the effective protection of agricultural land and tidal flats and by implementing vertical greenery in buildings on construction land,the surface SOC storage in Shanghai will improve.