Fire Refugia
FIRE refugia
A meadow in Yosemite National Park. A large swath of dark green trees blankets the foreground, and snow-covered mountains are seen in the background. Photo: Toni Lyn Morelli.
Fire is a critical component of valued ecosystem processes in the Sierra Nevada, protecting meadows from forest encroachment and supporting the establishment and regeneration of fire-dependent species like Giant Sequoia. Prescribed burns and natural wildfires have long been used as a management tool to promote the persistence of prioritized species and ecosystems. Meanwhile, the region is still recovering from over a century of historical fire suppression that enabled the growth of too much fire-intolerant vegetation. But climate change uncertainty may force managers to adapt their fire-based management approaches in the coming decades: fires may burn hotter and longer, increases in storms may produce more wildfires due to lightning strikes, and the frequency, severity, size, and seasonality of natural wildfires may shift. Within the context of climate change refugia, managers are interested in identifying areas that are likely to burn at lower severities, places that can act as natural barriers to fire, and old growth forests that can be supported under future fire regimes.
Focal Resources identified at November 8, 2019 workshop:
Areas likely to burn at lower severities
Natural ‘barriers’ to fire
Multi-layer canopy old growth forest that can be supported under future fire regimes
Potential Management Actions:
Based on the focal resources, workshop participants identified potential management actions such as:
May be able to re-introduce fire without having to do mechanical pre-treatment in areas unlikely to burn at high severity
Limit human development in areas non-refugial to high severity fire
Manage fire refugia as corridors for forest or cover-dependent species
Allow cover type conversion in areas likely to continuously re-burn at high severity, rather than continuing to waste resources re-planting areas that will be lost
Data Gaps/Future Work:
Fire weather information
Extreme events prediction
Natural firebreaks, like this rocky streambed, may be used to identify fire refugia. Photo: Toni Lyn Morelli.
Current efforts, data, and partnerships that could support identification and mapping of Fire Refugia:
Fire Return Interval Departure (FRID)
Westerling Climate Fire Projections: Wildfire Simulations for California’s Fourth Climate Change Assessment, product by Dr. LeRoy Westerling at the University of California Merced, using a statistical model based on historical data of climate, vegetation, population density, and fire history coupled with regionally downscaled climate projections.
Climate Water Deficit (CWD) data
Topographic and fire weather controls of fire refugia in forested ecosystems of northwestern North America (Krawchuck et al., 2016).
relevant publications
Krawchuk et al. 2020. Disturbance refugia within mosaics of forest fire, drought, and insect outbreaks. https://doi.org/10.1002/fee.2190
Coop, JD, DeLorty, TJ, Downing, WM, Haire, SL, Krawchuk, MA, Miller, C, Parisien, M-A, & Walker, RB. 2019. Contributions of fire refugia to resilient ponderosa pine and dry mixed-conifer forest landscapes. Ecosphere 10(7) https://doi.org/10.1002/ecs2.2809
Downing, WM, Johnston, JD, Krawchuk, MA, Merschel, AG, & Rausch, JH. 2020. Disjunct and decoupled? The persistence of a locally endemic, fire-sensitive conifer species in a historically frequent fire landscape. Nature Conservation. https://doi.org/10.1016/j.jnc.2020.125828
Downing, WM, Krawchuk, MA, Coop, JD, Meigs, GW, Haire, SL, Walker, RB, Whitman, E, Chong, G, Miller, C, &Tortorelli, C. 2020. How do plant communities differ between fire refugia and fire-generated early-seral vegetation? Journal of Vegetation Science 31:26-39. https://doi.org/10.1111/jvs.12814
Downing, WM, Krawchuk, MA, Meigs, GW, Haire, SL, Coop, JD, Walker, RB, Whitman, E, Chong, G, & Miller, C. 2019. Influence of fire refugia spatial pattern on post-fire forest recovery in Oregon's Blue Mountains. Landscape Ecology 34: 771-792 https://doi.org/10.1007/s10980-019-00802-1
Krawchuk MA, Haire SL, Coop J, Parisien M-A, Whitman E, Chong G, Miller C. 2016. Topographic and fire weather controls of fire refugia in forested ecosystems of northwestern North America. Ecosphere 7:12. https://doi.org/10.1002/ecs2.1632
Krawchuk MA, Meigs GW, Cartwright J, et al. In Review. Disturbance refugia within mosaics of fire, drought, and insect outbreaks enable forest persistence. Front Ecol Environ.
Meddens, AJH, Kolden, CA, Lutz, JA, Smith, AMS, Cansler, CA, Abatzoglou, JT, Meigs, GW, Downing, WM, & Krawchuk, MA. 2018. Fire Refugia: What Are They, and Why Do They Matter for Global Change? BioScience, 68(12), https://doi.org/10.1093/biosci/biy103
Meigs, GW, Dunn, CJ, Parks, SA, & Krawchuk, MA. 2020. Influence of topography and fuels on fire refugia probability under varying fire weather in forests of the US Pacific Northwest. Canadian Journal of Forest Research. https://doi.org/10.1139/cjfr-2019-0406
Meigs, G, and Krawchuk, MA. 2018. Composition and structure of forest fire refugia: what are the ecosystem legacies across burned landscapes. Forests 2018, 9(5), 243; https://doi.org/10.3390/f9050243