深圳市基本生态控制线划定对生态系统服务价值的影响

基于深圳市2002、2005和2010年的土地变更调查数据,分析了基本生态控制线划定前后深圳市土地利用面积变化特征,运用基于单位面积价值当量因子的方法对生态系统服务价值进行评估,并采用倍差法研究了基本生态控制线政策对生态系统服务价值的影响。结果表明:2002—2010年深圳市土地利用总体呈现耕地、园地、草地和水域面积减小,建设用地面积增大,林地面积先减小后增大的趋势;该区生态系统服务价值总体减小,但基本生态控制线划定之后总价值减小的速率降低;各土地利用类型中,林地和水域是构成深圳市生态系统服务价值的主要来源,而各项生态系统服务中,水源涵养产生的价值最大;生态系统服务价值低值范围不断扩大,蚕食价值高的地区,尤其以西部沿海、宝安北部、光明新区、龙华北部以及龙岗南部地区价值降低最为明显;基本生态控制线内生态系统服务价值以中、较高为主,价值变化不明显,线外以低、较低为主,且呈现不断降低的趋势;倍差法结果表明基本生态控制线政策对生态系统服务价值的提高存在促进作用,提升幅度约为1.6%。

Effects of basic ecological control line policy on ecosystem services value in Shenzhen

Based on land use data from three periods, land use/cover change and ecological services values (ESV) in Shenzhen were analyzed based on the value equivalent factor in a unit area. In addition, the effects of the basic ecological control line policy on the ESV in Shenzhen were investigated using the difference in differences method. The results indicated that the quantities of cultivated land, orchard, grassland, and water bodies decreased from 2002 to 2010, whereas construction land area increased. In addition, the forest land first increased then decreased, but the decrease ratio showed a reduction trend after the basic ecological service control line policy was implemented. Among all land use types, forest land and water bodies were the two main sources of ESV, whereas water supply had the top value among all kinds of services. Areas with low ESV expanded and eroded the areas with high ESV. ESV on the western coast, the northern part of Bao''an and Longhua Districts, Guangming District, and the southern part of Longgang District decreased sharply. The grades of ESV within the control line zones were mainly medium and relatively high, while ESV outside the control line were mainly low and relatively low, which showed a decrease tendency. The results of the difference in differences method indicated that the basic ecological control line policy can increase ESV by approximately 1.6%.