基于GIS的陕北黄土高原土地生态系统固碳释氧价值评价

Research on the Values of CO_2 Fixation and O_2 Release by Landuse Ecosystem in Loess Plateau in Northern Shaanxi Province

【目的】定量评价生态系统固定CO2和释放O2功能,是生态系统服务功能研究重要内容之一。论文旨在对土地生态系统固碳释氧价值进行遥感测量和评价,为改善区域生态环境提供参考。【方法】论文依据光合作用方程式,采用遥感估算模型,基于植被NPP(第一性生产力)物质量测算结果,分别测算陕北黄土高原绿色植物固碳释氧物质量。以此为基础,分别采用造林成本法和工业制氧法测算其价值量。探讨陕北黄土高原生态系统固碳释氧价值的时间变化、空间分布。【结果】陕北黄土高原固定CO2的价值在1978、1990、2000和2005年分别为141.27亿元、177.46亿元、170.09亿元和247.08亿元,平均值为187.72亿元;释放O2的价值取两种测评方法的平均值,分别为150.07亿元、188.52亿元、192.97亿元和281.48亿元,年平均值为203.26亿元,比固定CO2的平均值多15.54亿元。从土地利用类型来看,固碳释氧价值表现为林地>耕地>牧草地>园地>其它类型。【结论】陕北黄土高原北部各县的单位面积固定CO2和释放O2价值普遍低于南部各县,总体上分布沿北部向南部逐渐升高。南部的子午岭和黄龙山具有很高的单位面积价值,如黄龙县、黄陵县、富县和甘泉县。北部农牧交错带和中部黄土沟壑区水土流失比较严重的地区固碳释氧的单位面积价值较低,这与生态环境脆弱有关。

[ Objective ] It is important to study quantitative evaluation of CO2 fixation and O2 release function in ecological system. This article attempts to measure and evaluate the value of fixing carbon and releasing oxygen in land ecological system using remote sensing, to provide reference for the regional ecological environment. [Method] Based on photosynthesis, using remote sensing estimation model, based on the results from the electroosimosis NPP vegetation, the fixed carbon and released oxygen amount was estimated. Based on this result, by using forestation costs method and the industrial oxygen producing method, the values of fixed carbon and released oxygen in Loess Plateau in Northern Shaanxi Province were estimated. The spatial and temporal changes and distribution of the fixed CO2 and released O2 in loess plateau ecological system were discussed. [Result] CO2 fixation values in Loess Plateau in Northern Shaanxi Province in 1978, 1990, 2000 and 2005, respectively, were141.27 billion yuan, 177.46 billion yuan, 170.09 billion yuan and 247.08 billion yuan, and the average was 187.72 billion yuan. The value of O2 release from the two evaluation methods, averaged, respectively, 150.07 billion ynan, 188.52 billion yuan, 192.97 billion yuan and 281.48 billion yuan, and the annual average was 203.26 billion yuan, more than an average of CO2 fixation 15.54 billion yuan. From the perspective of land use types, forestland〉cultivated land〉grassland〉garden〉other types. [Conclusion] The value of the fixed CO2 and released O2 in loess plateau ecological system of northern counties is lower than southern counties and in general distribution along the northern south to increasing gradually. HuangLong Mountain in south has the very high ridge and unit area of value, such as the county, Huangling county, Fu county and Ganquan county. The value of fixing carbon and releasing oxygen in northern agriculture and animal region and the central loess endangers region with the serious soil and water loss has lower value, this fragile ecological environment and relevant.