保存完整的红树林地区的总的纯现值至少为每公顷1 000美元(甚至可能高达每公顷36000美元),而当红树林被开垦为养虾场后,其纯现值仅约为每公顷200美元。此处所指的保存完整的湿地总的纯现值,即包括鱼类等上市交易产品的经济价值,也包括湿地所提供的抵御风暴侵袭和吸收碳等未上市交易的服务功能的价值。一旦红树林系统遭到围垦,原红树林覆被所产生的大量社会效益(木材、木炭、非木材林产品、海洋渔业以及抵御风暴等产生的效益)就会丧失殆尽。 The total net present value of preserved mangrove areas is at least $ 1,000 per hectare (and may even be as high as $ 36,000 per hectare), while the net present value of mangrove forests after being reclaimed as shrimp farms is only about 200 per hectare Dollars. The total net present value of a well-preserved wetland, referred to here, includes the economic value of traded products such as fish, as well as the value of services provided by wetlands to combat unselling transactions such as storms and carbon uptake. Once the mangrove system has been reclaimed, the substantial social benefits of mangrove cover (timber, charcoal, non-timber forest products, marine fisheries, and the benefits of storms) are lost.