湖泊湿地利用与保护临界的经济学准则探讨

Economic Criteria for Exploitation and Preservation Limitation of Lake Wetland Resources:A Case Study of Baoying Lake

湖泊湿地资源开发利用与保护临界(简称“湿地临界”)的经济学准则是指湿地开发利用的边际净收益应不低于边际净损耗,也就是当生态损失发生特大变化,超出净收益,或者直接经济效益下降,小于净损耗时的湿地利用规模。其核心是生态服务功能之间的相容性分析及其效益的经济评估,即与开发利用功能相容的服务效益作为净收益的组成部分,与开发利用功能不相容或有条件相容的服务作为净损耗的组成部分。宝应湖围网养蟹的净收益包括围网养蟹、调节小气候和吸收二氧化碳的效益,净损耗包括供水、净化水质、调蓄洪水、生物多样性保育、科研教育、休闲娱乐的效益。经计算得到,宝应湖围网养殖的年净收益为37 304元/hm2,净损耗为16 222元/hm2,ΔE值为21 082元/hm2,因此认为,在目前的社会经济水平下,宝应湖围网养蟹的利用方式尚未超出湖泊湿地开发利用临界的经济学准则,仍具有一定的开发利用潜力。

Economic Criteria of Exploitation and Preservation Limitation of Lake Wetland Resources （ECEPLLWR） means that net marginal earnings of lake should not less than net marginal losses when lake wetland is exploited, i.e., it is the lake wetland exploitation scale when ecological losses decrease dramatically and are more than the net earnings. The crucial process is the analysis of compatibility of each ecosystem service with another and the estimation of ecosystem service values. The functions of biodiversity aegis and inheriting pool of resources are not compatible with the functions of shipping and assimilating and decomposing waste. The former is compatible with many other functions conditionally and compatible with minor functions completely. Excepting these two functions, the remaining ones are compatible with each other conditionally or completely. So the net earnings are the values of those ecosystem services that are conforming to the exploitation functions while the net losses are the values of those ecosystem services that are not compatible with the exploitation functions. For Baoying Lake wetland, net earnings include the values of breeding crabs, adjusting regional climate and absorbing CO2 while net losses are the values of water supply, water purifying, sluicing, biodiversity aegis, scientific research, education, and entertainment. The estimation is based on environmental and ecological economics. The result shows that net earnings are 37 304 yuan/hm^2 and net losses are 16 222 yuan/hm^2, so the values of AE, which is the economic criteria of exploitation and preservation limitation, is 21 082 yuan/hm^2. The preliminary study shows that the ECEPLLWR of Baoying Lake wetland is not overstepped under the current social and economic conditions and Baoying Lake wetland can be exploited potentially to some extent.