陕北地区土地利用及景观格局变化对生态服务价值的影响——基于退耕还林(草)背景

THE EFFECTS OF LAND USE AND LANDSCAPE PATTERN CHANGE ON ECOSYSTEM SERVICE VALUES UNDER THE BACKGROUND OF THE SLOPING LAND CONVERSION PROGRAM IN NORTHERN SHAANXI

[目的]通过揭示退耕还林(草)工程背景下陕北地区近25年生态系统服务价值的演变规律,旨在为陕北地区的土地利用规划及新一轮退耕还林(草)政策的推进提供参考。[方法]以生态环境脆弱的陕北地区为研究对象,基于1990年、2000年、2015年3期的土地利用变化数据,以退耕还林(草)政策的实施为节点,利用土地转移矩阵、景观格局指数、生态服务价值损益表等方法对陕北地区的土地利用情况、景观格局演变以及生态服务价值的变化进行分析,借助相关性系数对土地利用类型、景观格局及生态服务价值之间的关系进行了定量研究。[结果](1)草地、耕地和林地是陕北地区最主要的土地利用类型,耕地面积减少,林草地面积持续增加且增速加快。(2)近25年,陕北地区景观格局的连接性和通达性降低,景观格局主要呈破碎化发展趋势。研究区各景观类型的破碎化程度增大,空间异质性增加,草地是该地区的优势景观类型。(3)陕北地区1990年、2000年和2015年各类生态系统提供的总生态服务价值分别为389.19亿元、394.31亿元和406.22亿元,退耕还林(草)前年均增长率为13.96%,退耕还林(草)后这一比率增加至56.22%。[结论]受退耕还林(草)政策的影响,陕北地区土地利用类型和土地景观格局的变化均对生态系统服务价值有显著的影响,但是不同的景观指数对生态系统服务价值的影响程度和趋势不同,水域和林草地面积对生态系统服务价值呈正相关,未利用地和城乡建设用地面积对生态系统服务价值呈负相关。

Under the background of the Sloping Land Conversion Program,this research reveals the evolution law of ecosystem service value in northern Shaanxi in the past 25 years,aiming at providing reference for the land use planning in northern Shaanxi and the promotion of the new round of the Sloping Land Conversion Program.Based on the land use cover/changes data in 1990,2000 and 2015,taking the implementation of the Sloping Land Conversion Program as the node,this article took the fragile ecological environment of northern Shaanxi as the research object,and analyzed the land use situation,landscape pattern evolution and changes in ecological service value(ESVs)in northern Shaanxi.The methods used included land transfer matrix,landscape pattern index,ecological service value income statement,etc.Finally,the relationship between land use type,landscape pattern and ecological service value was quantitatively studied by means of correlation coefficient.The results indicated:(1)The grassland,farmland and forest were the main land use types in northern shaanxi.The area of farmland were reduced,and the area of forest grass continued to increase with an acceleration.(2)In the past 25 years,the connectivity and accessibility of landscape patterns in northern shaanxi had been reduced,and the landscape pattern was mainly in the trend of fragmentation.The degree of landscape fragmentation and spatial heterogeneity increased in study area,and grassland was the dominant landscape type in this region.(3)ESVs in 1990,2000,and 2010 were 389.19、394.31 and 406.22 billion RMB,respectively.The average annual growth rate of ESVs was 13.96%in 1990-2000,and the ratio increased to 56.22%after returning farmland to forest.Affected by the Sloping Land Conversion Program,changes in land use types and land landscape patterns have a significant impact on ecosystem service value in northern Shaanxi.However,different landscape indices have different influence on ESVs in degrees and trends.The water area and forest-grassland area are positively correlated with ecosystem service value.The area of unused land and urban and rural construction land are negatively correlated with ecosystem service value.