Riparian habitats – wildlife habitats on the banks of a river or stream – are priority areas for conservation under climate change for several reasons. First, riparian habitats (or corridors) often connect warmer climates to cooler climates; second, these habitats have cool, moist microclimates relative to surrounding areas. For species facing a decline in the suitability of their habitats due to climate change, riparian corridors may provide a natural highway for shifting to more suitable climates, as well as a refuge from warming.

Despite recognition of these values, rigorous methods to identify which riparian areas are most likely to allow for species movement and provide refugia are lacking. Our analysis provides critical information on riparian climate-corridors to guide climate adaptation efforts (and riparian management and restoration efforts more generally) in the Pacific Northwest, while offering a novel approach that may be applied to similar efforts in other geographies.

We created an index that ranked riparian habitats in the Pacific Northwest according to how well we expect them to facilitate species movement and provide refugia from warming.. This index gave higher scores to riparian corridors that connect warmer to cooler areas; feature vegetation cover that could provide shading and cooling; are additionally shaded by the surrounding landscape; are relatively wide; and are relatively unmodified by human activity. Using this index, we identified high-ranking riparian corridors at a range of scales, from local watersheds to the entire Pacific Northwest.
Resulting index values for potential riparian corridors in the Pacific Northwest were highest within mountainous areas and lowest within relatively flat, lowland regions. We also calculated index values within ecoregions, to better identify high-value riparian climate corridors within the relatively flat areas most modified by human activity, where the corridors could most contribute to climate adaptation. We found that high-value riparian climate-corridors are least protected in flat, lowland areas, suggesting that such corridors should be high priorities for future conservation efforts.

KING5 | Climate Change Forces Wildlife to Change Migration Routes in Northwest. Scientists are mapping what they're calling ‘wildlife escape routes’ in the Northwest and ranking them by priority for restoration.

UW News | Assessing Riverside Corridors — the ‘Escape Routes’ for Animals Under Climate Change — in the Northwest. Under climate change, plants and animals will shift their habitats to track the conditions they are adapted for. As they do, the lands surrounding rivers and streams offer natural migration routes that will take on a new importance as temperatures rise.