The effect of a protected area on the tradeoffs between short-run and long-run benefits from mangrove ecosystems
The effect of a protected area on the tradeoffs between short-run and long-run benefits from mangrove ecosystems
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DOI：
10.1073/pnas.1101825108
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发表时间：
2011-08
期刊：
影响因子：
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通讯作者：
Catherine G. McNally;E. Uchida;A. Gold
中科院分区：
文献类型：
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作者：
Catherine G. McNally;E. Uchida;A. Gold
保护区用于维持生物多样性和生态系统服务。然而，保护区可能在空间和时间上造成生态系统服务之间的权衡，这可能会影响依赖的当地社区的福利。这项研究考察了保护区对红树林的两种采掘生态系统服务之间的权衡的影响：砍伐红树林(薪材)和收获虾和鱼，如果红树林不被砍伐，虾和鱼就会茁壮成长。我们在坦桑尼亚萨达尼国家公园(SANAPA)的背景下展示了这一效果，在那里加强了禁止红树林采伐的执法，以保护生物多样性。在计量经济学框架内，将一段时间内红树林复盖的遥感数据与地理参照的住户调查数据结合起来，以确定红树林保护对与红树林生态系统服务直接相关的收入组成部分的因果影响。我们的发现表明，许多家庭立即失去了红树林柴火的消费，这种损失在较富裕的家庭中最为普遍。然而，所有财富阶层似乎都受益于红树林保护带来的捕虾和捕鱼的长期可持续性收益。平均而言，我们发现SANAPA范围内5平方公里范围内的红树林覆盖率每增加10%，捕虾收入就会增加近两倍。SANAPA的创建改变了该地区未来的发展轨迹，从红树林遭到无控制的砍伐转变为红树林保护正在为当地村庄提供收入，因为保护了苗圃栖息地和生物多样性。
Protected areas are used to sustain biodiversity and ecosystem services. However, protected areas can create tradeoffs spatially and temporally among ecosystem services, which can affect the welfare of dependent local communities. This study examines the effect of a protected area on the tradeoff between two extractive ecosystem services from mangrove forests: cutting mangroves (fuelwood) and harvesting the shrimp and fish that thrive if mangroves are not cut. We demonstrate the effect in the context of Saadani National Park (SANAPA) in Tanzania, where enforcement of prohibition of mangrove harvesting was strengthened to preserve biodiversity. Remote sensing data of mangrove cover over time are integrated with georeferenced household survey data in an econometric framework to identify the causal effect of mangrove protection on income components directly linked to mangrove ecosystem services. Our findings suggest that many households experienced an immediate loss in the consumption of mangrove firewood, with the loss most prevalent in richer households. However, all wealth classes appear to benefit from long-term sustainability gains in shrimping and fishing that result from mangrove protection. On average, we find that a 10% increase in the mangrove cover within SANAPA boundaries in a 5-km2 radius of the subvillage increases shrimping income by approximately twofold. The creation of SANAPA shifted the future trajectory of the area from one in which mangroves were experiencing uncontrolled cutting to one in which mangrove conservation is providing gains in income for the local villages as a result of the preservation of nursery habitat and biodiversity.