Tonina Daniele, McKean James A, Isaak Daniel, Benjankar Rohan M, Tang Chunling, Chen Qiuwen
Center for Ecohydraulics Research, University of Idaho, Boise, ID, USA.
Rocky Mountain Research Station, Aquatic Laboratory, Boise, ID, USA.
Geophys Res Lett. 2022 Jun 28;49(12):1-10. doi: 10.1029/2022gl098552.
Climate change threatens biodiversity through global alteration of habitats, but efficient conservation responses are often hindered by imprecise downscaling of impacts. Besides thermal effects, warming also drives important ancillary environmental changes, such as when river hydrology evolves in response to climate forcing. Earlier snowmelt runoff and summer flow declines are broadly manifested in snow-dependent regions and relevant to socioeconomically important cold-water fishes. Here, we mechanistically quantify how climate-induced summer flow declines during historical and future periods cause complex local changes in Chinook salmon () habitats for juveniles and spawning adults. Changes consisted of large reductions in useable habitat area and connectivity between the main channel and adjacent off-channel habitats. These reductions decrease the capacity of freshwater habitats to support historical salmon abundances and could pose risks to population persistence in some areas.
气候变化通过全球栖息地改变威胁生物多样性，但有效的保护措施往往因影响的不精确降尺度而受阻。除了热效应，变暖还会引发重要的辅助环境变化，例如河流水文因气候强迫而演变。更早的融雪径流和夏季流量下降在依赖雪的地区广泛存在，并且与具有社会经济重要性的冷水鱼类相关。在这里，我们从机制上量化了历史时期和未来时期气候导致的夏季流量下降如何在奇努克鲑鱼（）幼鱼和产卵成鱼的栖息地引发复杂的局部变化。这些变化包括可用栖息地面积大幅减少以及主河道与相邻非主河道栖息地之间的连通性降低。这些减少降低了淡水栖息地支持历史鲑鱼数量的能力，并可能对某些地区的种群持续性构成风险。
