School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, U.S.A.
Conserv Biol. 2011 Feb;25(1):40-7. doi: 10.1111/j.1523-1739.2010.01557.x.
The rapidity of climate change is predicted to exceed the ability of many species to adapt or to disperse to more climatically favorable surroundings. Conservation of these species may require managed relocation (also called assisted migration or assisted colonization) of individuals to locations where the probability of their future persistence may be higher. The history of non-native species throughout the world suggests managed relocation may not be applicable universally. Given the constrained existence of freshwater organisms within highly dendritic networks containing isolated ponds, lakes, and rivers, managed relocation may represent a useful conservation strategy. Yet, these same distinctive properties of freshwater ecosystems may increase the probability of unintended ecological consequences. We explored whether managed relocation is an ecologically sound conservation strategy for freshwater systems and provided guidelines for identifying candidates and localities for managed relocation. A comparison of ecological and life-history traits of freshwater animals associated with high probabilities of extirpation and invasion suggests that it is possible to select species for managed relocation to minimize the likelihood of unintended effects to recipient ecosystems. We recommend that translocations occur within the species' historical range and optimally within the same major river basin and that lacustrine and riverine species be translocated to physically isolated seepage lakes and upstream of natural or artificial barriers, respectively, to lower the risk of secondary spread across the landscape. We provide five core recommendations to enhance the scientific basis of guidelines for managed relocation in freshwater environments: adopt the term managed translocation to reflect the fact that individuals will not always be reintroduced within their historical native range; examine the trade-off between facilitation of individual movement and the probability of range expansion of non-native species; determine which species and locations might be immediately considered for managed translocation; adopt a hypothetico-deductive framework by conducting experimental trials to introduce species of conservation concern into new areas within their historical range; build on previous research associated with species reintroductions through communication and synthesis of case studies.
气候变化的速度预计将超过许多物种适应或分散到气候更有利环境的能力。为了保护这些物种，可能需要将个体人为迁移（也称为协助迁移或协助殖民）到未来生存可能性更高的地方。世界各地非本地物种的历史表明，这种人为迁移的方法可能并不普遍适用。鉴于淡水生物在高度分支的网络中生存，这些网络包含孤立的池塘、湖泊和河流，人为迁移可能代表一种有用的保护策略。然而，这些淡水生态系统的独特性质也可能增加产生意外生态后果的可能性。我们探讨了人为迁移是否是淡水系统的一种合理的生态保护策略，并为确定候选物种和迁移地点提供了指导方针。对与灭绝和入侵概率高的淡水动物的生态和生活史特征进行比较表明，可以选择物种进行人为迁移，以最小化对受纳生态系统产生意外影响的可能性。我们建议在物种的历史分布范围内，且最佳情况下在同一主要流域内进行迁移，并且将湖泊和河流物种分别迁移到物理上孤立的渗漏湖泊和自然或人工障碍物的上游，以降低景观上二次扩散的风险。为了增强淡水环境中人为迁移指南的科学基础，我们提出了五项核心建议：采用“人为转移”一词来反映这样一个事实，即个体并不总是在其历史原生范围内重新引入；权衡促进个体迁移和非本地物种范围扩张的概率；确定哪些物种和地点可能立即被考虑进行人为迁移；通过在历史范围内的新区域进行实验性试验，采用假设演绎框架将受保护物种引入新区域；通过沟通和综合案例研究，在与物种重新引入相关的先前研究的基础上继续进行研究。
