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Plant Focus

Quercus macdougallii
A rare oak endemic to the Sierra Juárez in Oaxaca

Oak Woodland Regeneration and the 2017 Tubbs Fire

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Michelle Halbur, Sasha Berleman, Michael Gillogly, Devyn Friedfel, and Tosha Comendant

Published May 2019 in International Oaks No. 30: 153–160


Multiple oak species in California have evolved to withstand fire disturbance through association with a Mediterranean climate and Native American peoples. Future climate models forecast increased fire frequency in the North Coast region of California (Krawchuk and Morritz 2012). Combined with fire suppression and increasing fuel loads and fire severity, the resiliency of coastal oak forests to future wildfires is not well understood. In October 2017, the Tubbs Fire burned through Pepperwood Preserve. Prior to this disturbance, multiple sites were undergoing treatment for Pseudotsuga menziesii var. menziesii (Douglas-fir) encroachment including seven hectares of Quercus kelloggii (black oak), Q. agrifolia var. agrifolia (coast live oak), and mixed oak forest. These areas had been thinned from below and prescribed burns were planned. In management areas, modified plots of Brown’s (1974) transects were used to sample approximately 10% of the management area for pre- and post-fire effects on the herbaceous understory community, tree canopy cover, seedling recruitment, and fuels. After the 2017 Tubbs Fire, about 66% of all trees (n=100) exhibited full canopy leaf scorch and another 13% (n=20) had no leaves due to full canopy consumption. We also detected a statistically significant decrease in fuels and the number of tree seedlings. Given an 80% reduction in the litter/duff layer, future oak seedling recruitment may be enhanced by the direct contact of acorns with the soil. During 2018 surveys we documented mortality, regeneration, and recruitment in all fuel treatment plots. Through long-term monitoring of fuel treatment efforts and interactions with wildfire in this region, we will increase knowledge of factors impacting oak-forest resiliency.


Tubbs Fire, fire management, oak woodlands, fire suppression


Ackerly, D.D., W.K. Cornwell, S.B. Weiss, L.E. Flint, and A.L. Flint. 2015. A Geographic Mosaic of Climate Change Impacts on Terrestrial Vegetation: Which Areas Are Most at Risk? PLOS ONE 10(6): e0130629.

Allen-Diaz, B., R. Standiford, and R.D. Jackson. 2007. Oak woodlands and forests. In Terrestrial Vegetation of California, 3rd edition, edited by M. Barbour, T. Keeler-Wolf, and A.A. Schoenherr. Berkeley: University of California Press.

Barnhart, S.J., J.R. McBride, and P. Warner. 1996. Invasion of northern oak woodlands by Pseudotsuga menziesii (Mirb.) Franco in the Sonoma Mountains of California. Madroño 43(1): 28-45.

Brown, J.K. 1974. Handbook for Inventorying Downed Woody Material. Gen. Tech. Rep. INT-16. Ogden, UT: USDA Forest Service.

California Interagency Wildlife Task Group [CIWTG]. 2014. California Wildlife Habitat Relationships (CWHR) System, version 9.0. California Department of Fish and Wildlife, Sacramento, CA. https://www.wildlife.ca.gov/Data/CWHR. 

Gillogly, M., C. Dodge, M. Halbur, L. Micheli, C. McKay, N. Heller, and B. Benson. 2017. Adaptive Management Plan for Pepperwood Preserve, Sonoma County, CA. Santa Rosa, CA: Dwight Center for Conservation Science. 

Krawchuk, M.A., and M.A. Moritz. 2012. Fire and Climate Change in California. Publication number: CEC-500-2012-026. Sacramento: California Energy Commission. 

Larson, C. 1999. Vineyard Development Turns Environmentalist Heads; The Best Defense Against Possible Offense. Wine Business Monthly (May, 1999).

Mann, M.L., E. Batllori, M.A. Moritz, E.K. Waller, P. Berck, A.L. Flint, L.E. Flint and E. Dolfi. 2016. Incorporating Anthropogenic Influences into Fire Probability Models: Effects of Human Activity and Climate Change on Fire Activity in California. PLOS ONE 11(4): e0153589. 

McIntyre, P.J., J.H. Thorne, C.R. Dolanc, A.L. Flint, L.E. Flint, M. Kelly, and D.D. Ackerly. 2014. Twentieth-century shifts in forest structure in California: Denser forests, smaller trees, and increased dominance of oaks. Proceedings of the National Academy of Sciences of the United States of America 112(5): 1458-1463.

R Core Team. 2017. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing. www.r-project.org

Rizzo, D.M., M. Garbelotto, J.M. Davidson, G.W. Slaughter, and S.T. Koike. 2002. Phytophthora ramorum as the Cause of Extensive Mortality of Quercus spp. and Lithocarpus densiflorus in California. Plant Disease 86(3): 205-214.

Thomas, J.W. 1996. California’s Oak Woodlands: Where We Have Been, Where We Are, Where We Need to Go. In Proceedings of a Symposium on Oak Woodlands: Ecology, Management, and Urban Interface Issues, General Technical Report PSW-GTR-160, edited by N. Pillsbury, J. Verner, and W.D. Tietje. San Luis Obispo, CA: US Department of Agriculture Forest Service. 

USDI National Park Service. 2003. Fire Monitoring Handbook. Boise, ID: Fire Management Program Center, National Interagency Fire Center.