土地整治的生态系统服务价值评估--参数优化与实证

为定量研究具体区域土地整治前后生态系统服务价值的变化情况,本研究以庆阳市土地整治子项目为例,依据生态系统服务价值评估方法的局限性对其参数进行相应优化的基础上,对研究区内土地整治前后的生态系统服务价值变化进行实证分析。结果表明:①通过尺度推演,将宏观大尺度的生态系统服务价值评估方法进行了市场因素修正、特殊生态系统类型价值当量的制定以及针对区域内部差异的NPP修正,降低了当量因子法应用到具体尺度上的局限性,使其更具合理性。②基于优化参数的实证得到,土地整治前后4 a间生态系统服务价值由2.88×10^8元减少到2.76×10^8元,减少了4.31%。在一级分类体系下,只有调节服务的生态系统服务价值减少了1.84×10^7元,其余服务均相对增加;在二级分类体系下,多项服务较土地整治前均有所增加,且食物生产服务的增加量最大为8.35×10^6元,原料生产、生物多样性以及4项调节服务均相对减少。本研究的实证结果更符合具体区域实际情况,参数优化后的方法可用于坡耕地转变为梯田的生态系统服务价值评估,为区域内部残丘陵、沟谷、坡地等地貌类型的黄土丘陵沟壑区土地整治的生态系统服务价值评估可提供参考。

Evaluation of the ecosystem service value with land consolidation:Parameter optimization and empirical study

To quantitatively study the variations in the ecosystem service value before and after land consolidation in a specific region,a land consolidation sub-project in the Qingyang City was examined based on the optimization of its parameters according to the limitations of the evaluation method of the ecosystem service value.The results show that (1) using scale deduction,the core parameters of the evaluation methods of the ecosystem service value on macro and large scales can be optimized by various methods,including the revision of market factors,the formulation of the value equivalents of special ecosystem types,and the correction of the net primary productivity value equivalence pertinent to the spatial differences observed within the region.The optimized parameters of the evaluation method of the ecosystem service value reduce the limitations of applying the equivalent factor method to specific application scales and are more reasonable.(2) The empirical evidence concerning the variation in the ecosystem service value before and after land consolidation based on the optimized parameters indicates that the ecosystem service value reduced from 2.88 × 10^8 yuan to 2.76 × 10^8 yuan in four years (before to after land consolidation),with a total reduction of 4.31%.Under the first-level classification system of ecosystem services,only the value of the regulating services decreased by 1.84 × 10^7 yuan,whereas the values of the remaining services increased.Under the second-level classification system,the food production,soil conservation,nutrient cycling,aesthetic value,and water supply functions improved compared to those prior to land consolidation;the improvement in the food production function was the largest at 8.35 × 10^6 yuan;meanwhile,raw material production,biodiversity,and the four types of ecosystem services included in regulation services were observed to decrease.The results indicate that this method can be used to evaluate the ecosystem service value of the conversion of sloping farmland to terraced fields and that it can provide a considerable reference value for the evaluation of the ecosystem service value of the loess hilly and gully areas of landforms,including residual hills,valleys,and slopes.