Dee Laura E, De Lara Michel, Costello Christopher, Gaines Steven D
Bren School of Environmental Science & Management, University of California, Santa Barbara, 2400 Bren Hall, Santa Barbara, CA, 93106, USA.
Institute on the Environment, University of Minnesota, St. Paul, MN, 55108, USA.
Ecol Lett. 2017 Aug;20(8):935-946. doi: 10.1111/ele.12790. Epub 2017 Jun 28.
Society increasingly focuses on managing nature for the services it provides people rather than for the existence of particular species. How much biodiversity protection would result from this modified focus? Although biodiversity contributes to ecosystem services, the details of which species are critical, and whether they will go functionally extinct in the future, are fraught with uncertainty. Explicitly considering this uncertainty, we develop an analytical framework to determine how much biodiversity protection would arise solely from optimising net value from an ecosystem service. Using stochastic dynamic programming, we find that protecting a threshold number of species is optimal, and uncertainty surrounding how biodiversity produces services makes it optimal to protect more species than are presumed critical. We define conditions under which the economically optimal protection strategy is to protect all species, no species, and cases in between. We show how the optimal number of species to protect depends upon different relationships between species and services, including considering multiple services. Our analysis provides simple criteria to evaluate when managing for particular ecosystem services could warrant protecting all species, given uncertainty. Evaluating this criterion with empirical estimates from different ecosystems suggests that optimising some services will be more likely to protect most species than others.
社会越来越关注对自然的管理，目的是获取自然为人类提供的服务，而非特定物种的存续。这种调整后的关注点会带来多少生物多样性保护呢？尽管生物多样性有助于生态系统服务，但哪些物种至关重要以及它们未来是否会功能性灭绝等细节充满了不确定性。明确考虑到这种不确定性，我们开发了一个分析框架，以确定仅通过优化生态系统服务的净值能实现多少生物多样性保护。使用随机动态规划方法，我们发现保护一定数量的物种是最优的，而且生物多样性如何产生服务的不确定性使得保护比假定为关键的物种更多的物种成为最优选择。我们定义了经济上最优的保护策略是保护所有物种、不保护任何物种以及介于两者之间情况的条件。我们展示了要保护的最优物种数量如何取决于物种与服务之间的不同关系，包括考虑多种服务的情况。我们的分析提供了简单的标准，用于评估在存在不确定性的情况下，为特定生态系统服务进行管理何时可能需要保护所有物种。用来自不同生态系统的实证估计来评估这一标准表明，优化某些服务比其他服务更有可能保护大多数物种。
