Habitat fragmentation imperils the persistence of many functionally important species, with climate change a new threat to local persistence due to climate niche mismatching. Predicting the evolutionary trajectory of species essential to ecosystem function under future climates is challenging but necessary for prioritizing conservation investments. We use a combination of population genetics and niche suitability models to assess the trajectory of a functionally important, but highly fragmented, plant species from south‐eastern Australia (Banksia marginata, Proteaceae). We demonstrate significant genetic structuring among, and high level of relatedness within, fragmented remnant populations, highlighting imminent risks of inbreeding. Population simulations, controlling for effective population size (N_e), suggest that many remnant populations will suffer rapid declines in genetic diversity due to drift in the absence of intervention. Simulations were used to demonstrate how inbreeding and drift processes might be suppressed by assisted migration and population mixing approaches that enhance the size and connectivity of remnant populations. These analyses were complemented by niche suitability models that predicted substantial reductions of suitable habitat by 2080; ~30% of the current distribution of the species climate niche overlaps with the projected distribution of the species climate niche in the geographic region by the 2080s. Our study highlights the importance of conserving remnant populations and establishing new populations in areas likely to support B. marginata in the future, and adopting seed sourcing strategies that can help populations overcome the risks of inbreeding and maladaptation. We also argue that ecological replacement of B. marginata using climatically suited plant species might be needed in the future to maintain ecosystem processes where B. marginata cannot persist. We recommend the need for progressive revegetation policies and practices to prevent further deterioration of species such as B. marginata and the ecosystems they support.

中文翻译：

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遗传数据和气候生态位适宜性模型凸显了澳大利亚东南部一种具有重要功能的植物物种的脆弱性。


栖息地破碎化危及许多具有重要功能的物种的生存，而由于气候生态位不匹配，气候变化对当地的生存构成了新的威胁。预测未来气候下对生态系统功能至关重要的物种的进化轨迹具有挑战性，但对于优先考虑保护投资是必要的。我们结合种群遗传学和生态位适宜性模型来评估来自澳大利亚东南部的一种功能重要但高度分散的植物物种（ Banksia marginata ，山龙眼科）的轨迹。我们证明了支离破碎的残余种群之间存在显着的遗传结构以及内部的高度相关性，凸显了近亲繁殖迫在眉睫的风险。控制有效种群规模（ N _e ）的种群模拟表明，在没有干预的情况下，许多剩余种群将因漂移而遭受遗传多样性的迅速下降。模拟被用来证明如何通过辅助迁移和种群混合方法来抑制近亲繁殖和漂流过程，从而增强残余种群的规模和连通性。这些分析得到了生态位适宜性模型的补充，该模型预测到 2080 年适宜栖息地将大幅减少；目前物种气候生态位分布的约 30% 与 2080 年代该地理区域物种气候生态位的预计分布重叠。我们的研究强调了在未来可能支持B. marginata 的地区保护残余种群和建立新种群的重要性，并采用种子采购策略来帮助种群克服近亲繁殖和适应不良的风险。 我们还认为，未来可能需要使用适合气候的植物物种对B. marginata进行生态替代，以维持B. marginata无法持续​​存在的生态系统过程。我们建议需要采取渐进的植被恢复政策和做法，以防止B. marginata等物种及其支持的生态系统进一步恶化。