Assisted migration is a controversial conservation measure that aims to protect threatened species by moving part of their population outside its natural range. While this could save species from extinction, it also introduces a range of risks. The magnitude of the threat to recipient ecosystems has not been investigated quantitatively, despite being the most common criticism levelled at the action. In this study, we use an ensemble modelling framework to estimate the risks of assisted migration to existing species within ecosystems. The approach calculates the consequences of an assisted migration project across a very large combination of translocated species and recipient ecosystems. It predicts both the probability of a successful assisted migration, and the number of extinctions that will results from the establishment of the translocated species. Using an ensemble of 1.5 × 106 simulated 15-species recipient ecosystems, we estimate that translocated species will successfully establish in 83% of cases if introduced to stable, high-quality habitats. However, the ensemble estimates that assisted migration projects will cause an average of 0.6 local extinctions, with 5% of successful translocations triggering four or more extinctions. Quantifying the impacts to species within recipient ecosystems is critical to help managers weigh the benefits and negative consequences of assisted migration. Article impact statement: Assisted migration is controversial conservation initiative because its effects on recipient ecosystems are not easily predicted. This article is protected by copyright. All rights reserved.

中文翻译：

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使用集成模型预测辅助迁移对接收生态系统的影响

协助迁徙是一项有争议的保护措施，旨在通过将部分种群移出自然范围来保护受威胁的物种。虽然这可以使物种免于灭绝，但也会带来一系列风险。对受援生态系统的威胁程度尚未进行定量调查，尽管这是对这一行动最常见的批评。在这项研究中，我们使用集合建模框架来估计辅助迁移到生态系统内现有物种的风险。该方法计算了跨迁移物种和接收生态系统的非常大的组合的辅助迁移项目的后果。它预测了成功辅助迁移的概率，以及因易地物种的建立而导致的灭绝数量。使用 1.5 × 106 模拟的 15 个物种接收生态系统的集合，我们估计如果将易地物种引入稳定、高质量的栖息地，将在 83% 的情况下成功建立。然而，该团队估计，辅助迁移项目将导致平均 0.6 次本地灭绝，其中 5% 的成功易位引发 4 次或更多次灭绝。量化对接收生态系统内物种的影响对于帮助管理者权衡辅助迁移的好处和负面后果至关重要。文章影响声明：辅助迁移是有争议的保护举措，因为它对受援生态系统的影响不容易预测。本文受版权保护。