Hotspots of species loss do not vary across future climate scenarios in a drought‐prone river basin
Hotspots of species loss do not vary across future climate scenarios in a drought‐prone river basin
复制标题
在易发生干旱的河流流域，物种丧失的热点在未来气候情景中不会发生变化
作者：
Kenneth C. Gill;R. Fovargue;T. Neeson
摘要气候变化预计将改变世界各地的物种分布，但物种的结果的估计差异很大，在竞争的气候情景。考虑到未来气候的不确定性，应将保护资源用于何处，以最大限度地提高预期的保护效益？在这里，我们探讨了这个问题，通过量化鱼类物种的分布在未来的气候情景在美国中南部的红河流域的变化。我们使用一套来自流域高分辨率水文和气候建模的环境协变量来模拟历史和未来的溪流鱼类分布。我们量化了不同气候情景和不同空间中单个物种的结果变化，并通过总结不同物种发生概率的变化来确定物种损失的热点。在所有气候情景下，我们发现到2050年，红河流域大多数鱼类的分布将收缩。然而，在各种气候情景中，某些物种的变异性比其他物种高出10倍以上。尽管单个物种的结果存在这种不确定性，但在所有气候情景中，物种损失的热点往往发生在流域的同一部分。我们还发现，最常见的物种预计将经历最大的范围收缩，强调需要将保护资源导向常见和稀有物种。我们的研究结果表明，虽然可能很难预测哪些物种将受到气候变化的影响最大，但仍然有可能确定对未来气候不确定性具有鲁棒性的气候减缓行动的空间优先事项。这些研究结果很可能推广到世界各地的其他生态系统，未来的气候条件遵循主要环境协变量的普遍历史模式。
Abstract Climate change is expected to alter the distributions of species around the world, but estimates of species’ outcomes vary widely among competing climate scenarios. Where should conservation resources be directed to maximize expected conservation benefits given future climate uncertainty? Here, we explore this question by quantifying variation in fish species’ distributions across future climate scenarios in the Red River basin south‐central United States. We modeled historical and future stream fish distributions using a suite of environmental covariates derived from high‐resolution hydrologic and climatic modeling of the basin. We quantified variation in outcomes for individual species across climate scenarios and across space, and identified hotspots of species loss by summing changes in probability of occurrence across species. Under all climate scenarios, we find that the distribution of most fish species in the Red River Basin will contract by 2050. However, the variability across climate scenarios was more than 10 times higher for some species than for others. Despite this uncertainty in outcomes for individual species, hotspots of species loss tended to occur in the same portions of the basin across all climate scenarios. We also find that the most common species are projected to experience the greatest range contractions, underscoring the need for directing conservation resources toward both common and rare species. Our results suggest that while it may be difficult to predict which species will be most impacted by climate change, it may nevertheless be possible to identify spatial priorities for climate mitigation actions that are robust to future climate uncertainty. These findings are likely to be generalizable to other ecosystems around the world where future climate conditions follow prevailing historical patterns of key environmental covariates.