—  Refugia In the pacific Northwest —

Warmer temperatures, changing drought patterns, increasing pressure from pests and pathogens, and altered fire regimes associated with climate change threaten many important natural and cultural resources in the Northwestern U.S. However, not all places on the landscape are changing in the same way. Climate change refugia are areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources (Morelli et al. 2016).

Across the Northwest, many different types of refugia are currently being defined, mapped, and evaluated. In 2016, the NW RRC was established to encourage new translational research on climate change refugia and clarify opportunities to integrate this research into the work of regional managers.  This work was largely conducted through in-person meetings and web-based video conferences where dialogue between scientists and regional managers informed the development of deliverables including: (1) a co-produced statement of the priority research and management areas for climate refugia in the Pacific Northwest; (2) novel, manager-informed refugia products to increase accessibility to existing refugia science; and (3) a Special Issue of cutting-edge refugia science and management applications in Frontiers in Ecology and the Environment. These efforts hope to provide a foundation for incorporating refugia research into regional climate adaptation strategies.

For more information on the NW RRC process and products:

Identifying and Evaluating Refugia from Drought and Climate Change in the Pacific Northwest

Climate Refugia and Resilience Atlas

Refugia research provides tools for protecting whitebark pine forests

Of all Northwest forests, whitebark pine (Pinus albicaulis)-dominated forests are one of the most threatened due to interactions between white pine blister rust (Cronartium ribicola), bark beetles, drought, changing fire regimes, and climate change. Scientists at the U.S. Forest Service and the University of Idaho, have developed new methods for mapping “genetic refugia” in whitebark pine forests. By using spatial datasets of white pine blister rust resistance, drought tolerance, late winter cold hardiness, and genetic diversity, they are able to identify populations with favorable genetic attributes that are more likely to persist, despite changing environmental conditions. The areas, identified as genetic refugia, are priorities for active conservation and restoration efforts. However, only 1% of the mapped refugia currently exist in protected wilderness areas.

Fire refugia are integral to management of northwest forests

With an average of 4,100 wildfires burning nearly 758,000 acres annually, fire is a common element of the Northwest landscape. In every fire, there are islands of vegetation that remain unburned or burn at a lower severity—i.e., fire refugia. These fire refugia serve as important resources in the post-fire forest environment. Scientists at the University of Idaho have employed remote-sensing techniques to identify unburned islands by examining 2300 fires occurring between 1984-2014 in the interior Northwest. New research at Oregon State University has resulted in models that predict fire refugia by classifying areas dependent on their fire weather conditions and topographic complexity. These new models suggest that many fire refugia are created by an area of a landscape that endures through repeated fire events and assists in the development and maintenance of forest ecosystems, including old-growth. However, current fire management, aiming to reduce diversity in burn severity, may be altering or removing fire refugia needed for the establishment, persistence, and movement of organisms. Identification and management of fire refugia needs to be an integral part of maintaining ecosystem resilience to future fire conditions.

Hydrologic refugia buffer northwest forests and sage steppe habitats from a hotter, drier future

As with other types of refugia, wetter micro-environments that maintain relatively high water availability—i.e., hydrologic refugia—may help species persist in the face of changing climate conditions. Hydrologic refugia may be especially important in buffering forest species from interacting disturbances like drought and insect outbreaks. Researchers at the USGS and the University of Washington are developing new methods of identifying hydrologic refugia. These methods have recently been applied to identify potential refugia in dry mixed-conifer forests in southern Oregon by studying recent drought events in the region. The persistent landscape features that create hydrologic refugia, allow their continued functioning in the face of climate change. Therefore, their identification and management is an important strategy for conserving old-growth forests and other high priority forest resources.