栾城县农田生态系统服务功能正负效应综合评价

An integrated assessment of positive and negative effects of high-yielding cropland ecosystem services in Luancheng County,Hebei Province of North China

农田生态系统具有半自然半人工化特性,其既接受相邻生态系统提供的服务,也对其他生态系统产生正、负双面性影响。本文根据生态系统服务的内涵,建立了高产农田生态系统服务功能正负效应评价指标与方法体系,并利用环境经济学方法,对2008年栾城县农田生态系统服务功能的正负效应价值进行了综合评价。结果表明:1)栾城县农田生态系统服务功能的正、负效应价值分别为46.20×108元和4.05×108元;2)农产品生产功能价值为17.61×108元,是栾城县农田生态系统最主要的服务功能;3)不合理的农业活动造成农田生态系统服务功能整体效益的下降,扣除环境成本后的净效益值与农产品价值之比由扣除前的2.62:1降低为2.39:1;4)地下水资源紧缺是栾城县农田生态系统最突出的生态问题,其造成的环境成本占总环境成本的76.0%。

As a human-managed ecosystem,cropland ecosystem offers ecosystem services to and accepts ecosystem disservices from other ecosystems.According to the connotation of ecosystem services,an evaluation index and the evaluation methodology for high-yielding cropland ecosystem services were established,and the positive and negative values of cropland ecosystem services in Luancheng County in 2008 were evaluated by the methods of environmental economics.The positive and negative values of the cropland ecosystem services were 46.20×108 Yuan and 4.05×108 Yuan,respectively.The service value of food production was 17.61×108 Yuan,contributing 38.11% of the total positive value,and being the dominant service.Irrational agricultural activities induced a decline of the overall value of cropland ecosystem services,with the ratio of net benefit value to food production value declined from 2.62：1 to 2.39：1 before and after the deduction of environmental cost.The abysmal lack of groundwater resource was the most prominent ecological problem,and its induced environmental cost occupied 76.0% of the total.