基于土地利用变化的陕西省植被碳汇提质增效优先区识别

在“双碳”目标背景下,陆地植被生态系统碳汇是实现碳中和目标的重要方式。为有效识别植被碳汇服务功能提质增效的优先区,利用InVEST模型定量评估陕西省植被碳储量时空演变特征及分布格局,分析土地利用/覆被类型变化对碳储量变化的影响,研究林草生态建设碳汇增长空间差异,确定林草生态建设提质增效对象区域。结果表明：（1）陕西省土地利用类型主要以耕地、林地、草地为主,土地利用类型转移变化也主要发生在三者之间;（2）1980― 2020年陕西省生态系统碳储量总体增加91.88×10⁶ t,增幅3.16%,呈现出“总体上南高北低、局部地区明显过高或过低”的地带性分布特征;（3）退耕还林（草）工程对碳汇能力提升效果明显,存在全局空间相关性,表现为一定的空间趋同集聚现象;（4）陕北地区为生态保护修复工程极优先区和优先区,陕南地区为中等优先区,关中地区为一般优先区。研究基于不同区县生态系统碳汇年均增长率的差异,确定生态治理优先区域,可为实现生态修复工程主导模式的分区管理以及碳汇能力提质增效提供参考。

Identification of priority areas for improving quality and efficiency of vegetation carbon sinks in Shaanxi province based on land use change

In the context of the "dual-carbon" goal, the carbon sink of terrestrial vegetation ecosystems is an important way to achieve the carbon neutrality. In order to effectively identify the priority areas for improving the quality and efficiency of vegetation carbon sink service, the InVEST model was used to quantitatively evaluate the spatiotemporal evolution characteristics and distribution pattern of vegetation carbon storage in Shaanxi province. Based on this, we analyze the impact of land use/cover types on carbon storage changes, study the spatial differences in the growth of carbon sinks in forest-grass ecological construction, and determine the target areas for quality and efficiency improvement in ecological environment construction areas. The results show that: (1) The land use types in Shaanxi are mainly cultivated land, forest land and grassland, and the change of land use transfer mainly occurs in the mutual transformation among the three types. (2) From 1980 to 2020, the carbon storage of ecosystems in Shaanxi increased by 91.88×10⁶ t, an increase of 3.16%, showing the zonal distribution characteristics of "generally high in the south and low in the north, and obviously high or low in some areas". (3) The conversion of farmland to forest (grass) project has obvious effect on the improvement of carbon sink capacity, and there is a global spatial correlation, which is manifested as a certain spatial convergence and agglomeration phenomenon. (4) Northern Shaanxi is a high priority area and priority area for ecological protection and restoration projects, Southern Shaanxi is a medium priority area, and Guanzhong Plain is a general priority area. Based on the differences in the average annual growth rate of carbon sinks in ecosystems in different districts and counties, the priority ecological governance areas were determined to provide a reference for realizing the regional management of the leading mode of ecological restoration projects and improving the quality and efficiency of carbon sinks.