Scientific Research
The John Muir Project engages in and supports original scientific research performed by independent scientists, including JMP's own Chad Hanson, Ph.D., in order to find the truth which underlies the many untested assumptions that govern the management of our National Forests today.
Giant Sequoias Thrive in Recent Wildfires
John Muir Project is the national leader in research regarding giant sequoia groves and wildfires. Our recent studies have found that higher-intensity fire patches stimulate by far the best and most vigorous sequoia reproduction. Further, the preliminary claim by government agencies-that 20% of mature sequoias were killed in recent fires-was substantially exaggerated.
Spotted Owls and Wildfire
John Muir Project, working with our research partners, is conducting leading-edge research and conservation work regarding imperiled spotted owls, wildfires, and logging. Our innovative studies discovered that spotted owl occupancy is very high in large mixed-intensity wildfire areas, so long as they are not subjected to post-fire logging, which destroys important spotted owl foraging habitat created by higher-intensity fire patches. JMP co-authored the petition to list the California spotted owl under the Endangered Species Act, and U.S. Fish and Wildlife Service has now proposed to list this species under the ESA, citing studies by JMP and our research partners.
The Truth About "Thinning"
John Muir Project is leading unprecedented research regarding the real impacts of logging projects being conducted under various euphemisms like "thinning". Studies authored or co-authored by JMP have found that "thinning" logging projects kill significantly more trees than they prevent from being killed by wildfires, and thinning removes far more carbon from forests than fires consume. Further, the fundamental premise of "thinning" policies-the claim that historical forests were "open", with low tree densities maintained almost exclusively by lower-intensity fire-is based on a "falsification of the scientific record" by scientists funded by the U.S. Forest Service.
Fisher's Use of Fire Areas, Kern Plateau Sequoia National Forest
A study to learn how Pacific Fisher's respond to mixed-intensity fire. The Pacific fisher, a rare carnivore something like a small wolverine, is strongly associated with dense, old conifer forest for its den and rest sites, so many have assumed for years that mixed-intensity fire would harm fishers.
Black-Backed Woodpecker Nest Density Study, Sierra Nevada
A study of Black-backed Woodpecker nest density in burned and unburned forests of the Sierra Nevada. The Black-backed Woodpecker is a very rare bird that depends heavily upon dense, mature conifer forest that has recently experienced higher-intensity fire (in large patches) and has not been subjected to post-fire logging.
Post-Fire Natural Regeneration of Conifer Seedlings
A study of natural post-fire conifer regeneration. A myth used by the U.S. Forest Service to justify large post-fire clearcut logging projects after wildland fires on National Forest lands is their belief that mixed-conifer and ponderosa pine forests will not naturally regenerate in large high-intensity fire patches.
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- Lindenmayer, D., P. Zylstra, C.T. Hanson, D. Six, and D.A. DellaSala. 2025. When Active Management of high conservation value forests may erode biodiversity and damage ecosystems. Biological Conservation: Volume 305. Download PDF
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- Hanson, C.T., T.Y. Chi, B.C. Baker, M. Khosla, and M.K. Dorsey. 2024. Post-fire Reproduction of a Serotinous Conifer, the Giant Sequoia, in the Nelder Grove, California. Ecology and Evolution (in press).
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- Hanson, C.T., T.Y. Chi, M. Khosla, B.C. Baker, and C. Swolgaard. 2024. Reproduction of a serotinous conifer, the giant sequoia, in a large high-severity fire area. Fire 7: Article 44. Download PDF
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- Baker, W.L., C.T. Hanson, and D.A. DellaSala. 2023. Harnessing Natural Disturbances: A Nature-Based Solution for Restoring and Adapting Dry Forests in the Western USA to Climate Change. Fire 6: Article 428. Download PDF
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- Baker, W.L., C.T. Hanson, M.A. Williams, and D.A. DellaSala. 2023. Countering Omitted Evidence of Variable Historical Forests and Fire Regime in Western USA Dry Forests: The Low-Severity-Fire Model Rejected. Fire 6: Article 146. Download PDF
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- Baker, B.C., and C.T. Hanson. 2022. Cumulative tree mortality from commercial thinning and a large wildfire in the Sierra Nevada, California. Land 11: Article 995. Download PDF
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- Harmon, M.E., C.T. Hanson, and D.A. DellaSala. 2022. Combustion of Aboveground Wood from Live Trees in Megafires, CA, USA. Forests 13: Article 391. Download PDF
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- DellaSala, D.A., B.C. Baker, C.T. Hanson, L. Ruediger, and W.L. Baker. 2022. Have western USA fire suppression and megafire active management approaches become a contemporary Sisyphus? Biological Conservation 268: Article 109499. Download PDF
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- Hanson, C.T. 2022. Cumulative severity of thinned and unthinned forests in a large California wildfire. Land 11: Article 373. Download PDF
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- Hanson, C.T. 2021. Is "Fuel Reduction" Justified as Fire Management in Spotted Owl Habitat? Birds 2: 395-403. Download PDF
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- Hanson, C.T., D.E. Lee, and M.L. Bond. 2021. Disentangling post-fire logging and high-severity fire effects for spotted owls. Birds 2: 147-157. Download PDF
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- Hanson, C.T., and T.Y. Chi. 2021. Impacts of postfire management are unjustified in spotted owl habitat. Frontiers in Ecology and Evolution 9: Article 596282. Download PDF
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- Hanson, C.T., and T.Y. Chi. 2020. Black-backed woodpecker nest density in the Sierra Nevada, California. Diversity 12: Article 364. Download PDF
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- DellaSala, D.A,, and C.T. Hanson. 2019. Are wildland fires increasing large patches of complex early seral forest habitat? Diversity 11: Article 157. Download PDF
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- Baker, W.L., C.T. Hanson, and M.A. Williams. 2018. Improving the use of early timber inventories in reconstructing historical dry forests and fire in the western United States: reply. Ecosphere 9: Article e02325. Download PDF
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- Hanson, C.T. 2018. Landscape heterogeneity following high-severity fire in California's forests. Wildlife Society Bulletin 42: 264-271. Contact us for study.
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- Hanson, C.T. 2018. Wildfire in the age of climate change. BioScience 68: 146-148. Contact us for study.
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- Hanson, C.T., M.L. Bond, and D.E. Lee. 2018. Effects of post-fire logging on California spotted owl occupancy. Nature Conservation 24: 93-105. Download PDF
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- Baker, W.L., and C.T. Hanson. 2017. Improving the use of early timber inventories in reconstructing historical dry forests and fire in the western United States. Ecosphere 8: Article e01935. Download PDF
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- DellaSala, D.A., R.L. Hutto, C.T. Hanson, M.L. Bond, T. Ingalsbee, D. Odion, and W.L. Baker. 2017. Accomodating mixed-severity fire to restore and maintain ecosystem integrity with a focus on the Sierra Nevada of California, USA. Fire Ecology 13: 148-171. Download PDF
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- Bradley, C.M. C.T. Hanson, and D.A. DellaSala. 2016. Does increased forest protection correspond to higher fire severity in frequent-fire forests of the western USA? Ecosphere 7: article e01492. Download PDF
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- Hanson, C.T., and D.C. Odion. 2016a. Historical forest conditions within the range of the Pacific Fisher and Spotted Owl in the central and southern Sierra Nevada, California, USA. Natural Areas Journal 36: 8-19. Contact us for study.
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- Hanson, C.T., and D.C. Odion. 2016b. A response to Collins, Miller, and Stephens. Natural Areas Journal 36: 229-233. Contact us for study.
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- Odion, D.C., C.T. Hanson, W.L. Baker, D.A. DellaSala, and M.A. Williams. 2016. Areas of agreement and disagreement regarding ponderosa pine and mixed conifer forest fire regimes: a dialogue with Stevens et al. PLoS ONE 11: e0154579. Download PDF
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- Appendices for Hanson C.T. and D.C. Odion 2016 (In Press). Natural Areas Journal. Appendix A (1911 forest survey excerpts) and Appendix B (1911-1916 correspondence excerpts).
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- Hanson, C.T. 2015. Use of higher-severity fire areas by female Pacific fishers on the Kern Plateau, Sierra Nevada, California, USA. The Wildlife Society Bulletin (in press). Contact us for study.
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- Hanson, C.T. 2014. Conservation concerns for Sierra Nevada birds associated with high-severity fire. Western Birds 45: 204-212. Download PDF
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- Odion, D.C., C.T. Hanson, C.T., D.A. DellaSala, W.L. Baker, and M.L. Bond. 2014. Effects of fire and commercial thinning on future habitat of the Northern Spotted Owl. The Open Ecology Journal 7: 37-51. Download PDF
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- DellaSala, D.A., M.L. Bond, C.T. Hanson, R.L. Hutto, and D.C. Odion. 2014. Complex early seral forests of the Sierra Nevada: what are they and how can they be managed for ecological integrity? Natural Areas Journal 34: 310-324. Contact us for study.
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- Odion, D.C., C.T. Hanson, A. Arsenault, W.L. Baker, D.A. DellaSala, R.L. Hutto, W. Klenner, M.A. Moritz, R.L. Sherriff, T.T. Veblen, and M.A. Williams. 2014. Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America. PLoS ONE 9: e87852. Download PDF
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- Hanson, C.T., and D.C. Odion. 2014. Is fire severity increasing in the Sierra Nevada mountains, California, USA? International Journal of Wildland Fire 23: 1-8. Contact us for study.
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- DellaSala, D.A., R.G. Anthony, M.L. Bond, E.S. Fernandez, C.A. Frissell, and C.T. Hanson. 2013. Alternate views of a restoration framework for federal forests in the Pacific Northwest. Journal of Forestry 111: 420-429. Contact us for study.
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- Hanson, C.T. 2013. Pacific fisher habitat use of a heterogeneous post-fire and unburned landscape in the southern Sierra Nevada, California, USA. The Open Forest Science Journal 6:24-30. Learn More
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- Odion, D.C., and Hanson, C.T. 2013. Projecting impacts of fire management on a biodiversity indicator in the Sierra Nevada and Cascades, USA: the Black-backed Woodpecker. The Open Forest Science Journal 6: 14-23. Download PDF
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- Hanson, C.T., D.A. DellaSala, and M.L. Bond. 2013. The overlooked benefits of wildfire. BioScience 63: 243. Contact us for study.
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- DellaSala D., M. Bond, W. Baker, D. Odion, and C. Hanson. 2010. A reply to North et al. Wildlife Professional, Summer 2010. Download PDF
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- Hanson, C.T., D.C. Odion, D.A. DellaSala, and W.L. Baker. 2010. More-comprehensive recovery actions for Northern Spotted Owls in dry forests: Reply to Spies et al. Conservation Biology 24: 334-337. Download PDF
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- Hanson, C.T., and M.P. North. 2009. Post-fire survival and flushing in three Sierra Nevada conifers with high initial crown scorch. International Journal of Wildland Fire 18: 857-864. Learn More
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- Bond, M.L., D.E. Lee, C.M. Bradley, and C.T. Hanson. 2009. Influence of pre-fire mortality from insects and drought on burn severity in conifer forests of the San Bernardino Mountains, California. The Open Forest Science Journal 2: 41-47. Download PDF
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- Hanson, C.T., D.C. Odion, D.A. DellaSala, and W.L. Baker. 2009. Overestimation of fire risk in the Northern Spotted Owl Recovery Plan. Conservation Biology 23: 1314-1319. Download PDF
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- Hanson, C.T., and M.P. North. 2008. Postfire woodpecker foraging in salvage-logged and unlogged forests of the Sierra Nevada. The Condor 110: 777-782. Download PDF
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- Odion, D.C., and C.T. Hanson. 2008. Fire severity in the Sierra Nevada revisited: conclusions robust to further analysis. Ecosystems 11: 12-15. Contact us for study.
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- Hanson, C.T. 2007. Post-fire management of snag forest habitat in the Sierra Nevada. Ph.D. dissertation, University of California at Davis. Davis, CA. Download PDF
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- Hanson, C.T., and M.P. North. 2006. Post-fire epicormic branching in Sierra Nevada Abies concolor (white fir). International Journal of Wildland Fire 15: 31-35. Download PDF
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- Odion, D.C., and C.T. Hanson. 2006. Fire severity in conifer forests of the Sierra Nevada, California. Ecosystems 9: 1177-1189. Download PDF
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- Hanson, C.T., Odion, D.C. 2006. Fire Severity in mechanically thinned versus unthinned forests of the Sierra Nevada, California. In: Proceedings of the 3rd International Fire Ecology and Management Congress, November 13-17, 2006, San Diego, CA. Contact us for study.
Recent Studies on the Benefits of Mixed-Intensity Fire for Wildlife Species
- Roberts L.J., A.M. Fogg, R.D. Burnett 2015. Sierra Nevada National Forests Avian Management Indicator Species. Point Blue Conservation Science 2014 Annual Report. Contact us for Report.
- Rota C.T. 2013. Not all Forests are disturbed equally: population dynamics and resource selection of Black-backed Woodpeckers in the Black Hills, South Dakota. Ph.D. dissertation, University of Missouri-Columbia. Download PDF.
- Rota C.T., J.J. Millspaugh, M.A. Rumble, C.P. Lehman, D.C. Kesler 2014. The role of wildfire, prescribed fire, and Mountain Pine Beetle infestations on the population dynamics of Black-backed Woodpeckers in the Black Hills, South Dakota. PLoS ONE 9: e94700. Contact us for study.
- Rota C.T., M.A. Rumble, J.J. Millspaugh, C.P. Lehman, D.C. Kesler 2014. Space-use and habitat associations of Black-backed Woodpeckers (Picoides articus) occupying recently disturbed forests in the Black Hills, South Dakota. Forest Ecology and Management 313: 161-168. Contact us for study.
Some of the Recent Studies that Have Found Historical Mixed-Conifer and Ponderosa Pine Forests
to Have Been Dominated by Mixed-Intensity Fire (Not Low-Intensity Fire)
- Baker, W.L. 2014. Historical forest structure and fire in Sierran mixed-conifer forests reconstructed from General Land Office survey data. Ecosphere 5: Article 79. Contact us for study.
- Baker, W.L. 2012. Implications of spatially extensive historical data from surveys for restoring dry forests of Oregon's eastern Cascades. Ecosphere 3: article 23. Contact us for study.
- Williams, M.A., W.L. Baker. 2012a. Spatially extensive reconstructions show variable-severity fire and heterogeneous structure in historical western United States dry forests. Global Ecology and Biogeography 21: 1042-1052. Contact us for study.
- Williams, M.A., W.L. Baker. 2012b. Comparison of the higher-severity fire regime in historical (A.D. 1800s) and modern (A.D. 1984-2009) montane forests across 624,156 ha of the Colorado Front Range. Ecosystems 15: 832-847. Contact us for study.
Finding that Mixed-Intensity Fire Benefits Spotted Owls
- Lee, D.E., and M.L. Bond. 2015. Occupancy of California spotted owl sites following a large fire in the Sierra Nevada, California. The Condor 117 (in press). Contact us for study.
- Ganey, J.L., S.C. Kyle, T.A. Rawlinson, D.L. Apprill, and J.P. Ward, Jr. 2014. Relative abundance of small mammals in nest core areas and burned wintering areas of Mexican spotted owls in the Sacramento Mountains, New Mexico. The Wilson Journal of Ornithology 126: 47-52. Contact us for study.
- Bond, M. L., D. E. Lee, R. B. Siegel, & J. P. Ward, Jr. 2009. Habitat use and selection by California Spotted Owls in a postfire landscape. Journal of Wildlife Management 73: 1116-1124. Learn More
- Franklin, A.B., D.R. Anderson, R.J. Gutiérrez, and K.P. Burnham. 2000. Climate, habitat quality, and fitness in northern spotted owl populations in northwestern California. Ecological Monographs 70: 539-590 [See Figure 10]. Download PDF
- Lee, D.E., M.L. Bond, and R.B. Siegel. 2012. Dynamics of breeding-season site occupancy of the California spotted owl in burned forests. The Condor 114: 792-802. Learn More
Finding that Logging (a.k.a "thinning") Adversely Affects California Spotted Owls
- Stephens, S.L., S.W. Bigelow, R.D. Burnett, B.M. Collins, C.V. Gallagher, J. Keane, D.A. Kelt, M.P. North, L.J. Roberts, P.A. Stine, and D.H. Van Vuren. 2014. California Spotted Owl, songbird, and small mammal responses to landscape fuel treatments. BioScience (in press). Contact us for study.
The battle we have fought, and are still fighting for the forests is a part of the eternal conflict between right and wrong, and we cannot expect to see the end of it. … So we must count on watching and striving for these trees, and should always be glad to find anything so surely good and noble to strive for.
John Muir, "The National Parks and Forest Reservations" in a speech by John Muir
(Proceedings of the Meeting of the Sierra Club Held November 23, 1895.) Published in Sierra Club Bulletin, (1896)