Articles | Volume 22, issue 3
https://doi.org/10.5194/cp-22-561-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-22-561-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Contrasting early- and late-Holocene vegetation and wildfire regimes in a high-value drinking water supply area, Canada
Daniel R. Horrelt
CORRESPONDING AUTHOR
Natural Resources Canada, Northern Forestry Centre, Edmonton, AB, T6H 3S5, Canada
Department of Geography, University of Victoria, Victoria, BC, V8P 5C2, Canada
Kendrick J. Brown
Natural Resources Canada, Northern Forestry Centre, Edmonton, AB, T6H 3S5, Canada
Department of Geography, University of Victoria, Victoria, BC, V8P 5C2, Canada
Department of Earth and Environmental Sciences, University of British Columbia Okanagan, Kelowna, BC V1V 1V7, Canada
Nicholas Conder
Natural Resources Canada, Pacific Forestry Centre, Victoria, BC, V8Z 1M5, Canada
John A. Trofymow
Natural Resources Canada, Northern Forestry Centre, Edmonton, AB, T6H 3S5, Canada
Natural Resources Canada, Pacific Forestry Centre, Victoria, BC, V8Z 1M5, Canada
Christopher Bone
Natural Resources Canada, Northern Forestry Centre, Edmonton, AB, T6H 3S5, Canada
Cited articles
Agee, J. K.: Fire ecology of Pacific Northwest forests, Island press, Washington, DC, ISBN 1-55963-229-1, 1993.
Agee, J. K.: The influence of forest structure on fire behavior, in: Proceedings of the Seventeenth Annual Forest Vegetation Management Conference, Redding, California, USA, 16–18 January 1996, 52–68, https://www.fs.usda.gov/rm/pubs/rmrs_gtr292/1996_agee.pdf (last access: 21 February 2026), 1996.
Agee, J. K.: The complex nature of mixed severity fire regimes, in: Symposium proceedings, Mixed severity fire regimes: ecology and management, Volume AFE MISC03, edited by: Lagene, L., Zelnik, J., Cadwalladera, S., and Hughes, B., Washington State University Cooperative Extension Service/The Association for Fire Ecology, Spokane, Washington, USA, 17–19 November 2004, 1–10, https://www.ltrr.arizona.edu/~ellisqm/outgoing/dendroecology2014/readings/Agee2005.pdf (last access: 21 February 2026), 2005.
Allen, G. B.: Vegetation and Climate History of Southeast Vancouver Island, M.Sc. thesis, School of Earth and Ocean Sciences, University of Victoria, British Columbia, Canada, https://hdl.handle.net/1828/16938 (last access: 21 February 2026), 1995.
Alley, R. B., Mayewski, P. A., Sowers, T., Stuiver, M., Taylor, K. C., and Clark, P. U.: Holocene climatic instability: A prominent, widespread event 8200 yr ago, Geology, https://doi.org/10.1130/0091-7613(1997)025<0483:HCIAPW>2.3.CO;2, 25, 483–486, 1997.
Allen, G. B., Brown, K. J., and Hebda, R. J.: Surface pollen spectra from southern Vancouver Island, British Columbia, Canada, Can. J. Botany, 77, 786–799, https://doi.org/10.1139/b99-038, 1999.
Anderson, L., Presnetsova, L., Wahl, D. B., Phelps, G., and Gous, A.: Assessing reproducibility in sedimentary macroscopic charcoal count data, Quaternary Res., 111, 177–196, https://doi.org/10.1017/qua.2022.43, 2023.
Barber, D., Dyke, A., Hillaire-Marcel, C., Jenning, A. E., Andrews, J. T., Kerwin, M. W., Bilideau, R., McNeely, J., Southon, M. D., and Gagnon, J.-M.: Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes, Nature, 400, 344–348, https://doi.org/10.1038/22504, 1999.
Barlow, C. M., Pellatt, M. G., and Kohfeld, K. E.: Garry oak ecosystem stand history in Southwest British Columbia, Canada: implications of environmental change and indigenous land use for ecological restoration and population recovery, Biodivers. Conserv., 30, 1655–1672, https://doi.org/10.1007/s10531-021-02162-2, 2021.
Barreto, E., Holden, P. B., Edwards, N. R., and Rangel, T. F.: PALEO-PGEM-Series: a spatial time series of the global climate over the last 5 million years (Plio-Pleistocene), Global Ecol. Biogeogr., 32, 1034–1045, https://doi.org/10.1111/geb.13683, 2023.
Bartington Instruments: Bartsoft for PC (4.0), Bartington Instruments Ltd. [computer software], https://www.bartingtondownloads.com/document-category/sw/ (last access: 21 February 2026), 2013.
BC Forest Analysis and Inventory Branch: VRI - 2024 - Forest Vegetation Composite Polygons, Vegetation Resource Inventory [data set], https://catalogue.data.gov.bc.ca/dataset/6ba30649-14cd-44ad-a11f-794feed39f40 (last access: 15 October 2024), 2024.
BC Wildfire Service: Statistics and Geospatial Data: Wildfire Averages, https://www2.gov.bc.ca/gov/content/safety/wildfire-status/about-bcws/wildfire-statistics/wildfire-averages, last access: 10 September 2024.
Beyer, R. M., Krapp, M., and Manica, A.: High-resolution terrestrial climate, bioclimate and vegetation for the last 120,000 years, Scientific Data, 7, 236, https://doi.org/10.1038/s41597-020-0552-1, 2020.
Blaauw, M. and Christen, J. A.: Flexible paleoclimate age-depth models using an autoregressive gamma process, Bayesian Anal., 6, 457–474, https://doi.org/10.1214/11-BA618, 2011.
Blarquez, O., Vannière, B., Marlon, J. R., Daniau, A.-L., Power, M. J., Brewer, S., and Bartlein, P. J.: paleofire: An R package to analyse sedimentary charcoal records from the Global Charcoal Database to reconstruct past biomass burning, Comput. Geosci., 72, 255–261, 2014.
Bone, C., Brown, K. J., and Horrelt, D. R.: Frog Lake charcoal dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/AGV1-H892, 2026a.
Bone, C., Brown, K. J., and Horrelt, D. R.: Frog Lake pollen dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/RY5S-E495, 2026b.
Bone, C., Brown, K. J., and Horrelt, D. R.: Worley Lake charcoal dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/PP10-C482, 2026c.
Bone, C., Brown, K. J., and Horrelt, D. R.: Worley Lake pollen dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/5DNG-CS22, 2026d.
Bowman, D. M., Williamson, G. J., Abatzoglou, J. T., Kolden, C. A., Cochrane, M. A., and Smith, A. M.: Human exposure and sensitivity to globally extreme wildfire events, Nature Ecology & Evolution, 1, 0058, https://doi.org/10.1038/s41559-016-0058, 2017.
Brown, K. J. and Hebda, R. J.: Ancient fires on southern Vancouver Island, British Columbia, Canada: a change in causal mechanisms at about 2,000 ybp, Environ. Archaeol., 7, 1–12, https://doi.org/10.1179/env.2002.7.1.1, 2002a.
Brown, K. J. and Hebda, R. J.: Origin, development, and dynamics of coastal temperate conifer rainforests of southern Vancouver Island, Canada, Can. J. Forest Res., 32, 353–372, https://doi.org/10.1139/x01-197, 2002b.
Brown, K. J. and Power, M. J.: Charred Particle Analyses, in: The Encyclopedia of Quaternary Science, edited by: Elias, S. A., Elsevier, Amsterdam, 2, 716–729, 2013.
Brown, K. J. and Schoups, G.: Multi-millennial streamflow dynamics in two forested watersheds on Vancouver Island, Canada, Quaternary Res., 83, 415–426, https://doi.org/10.1016/j.yqres.2015.03.003, 2015.
Brown, K. J., Fitton, R. J., Schoups, G., Allen, G. B., Wahl, K. A., and Hebda, R. J.: Holocene precipitation in the coastal temperate rainforest complex of southern British Columbia, Canada, Quaternary Sci. Rev., 25, 2762–2779, https://doi.org/10.1016/j.quascirev.2006.02.020, 2006.
Brown, K. J., Nielsen, A. B., Fitton, R. J., and Hebda, R. J.: Postglacial evolution and spatial differentiation of seasonal temperate rainforest in western Canada, The Holocene, 18, 715–727, https://doi.org/10.1177/0959683608091783, 2008.
Brown, K. J., Power, M. J., and Hebda, N. J.: Integrating paleoecology into landscape management, in: Proceedings of the VIII International Conference on Forest Fire Research, 2–16 November 2018, edited by: Viegas, D. X., Coimbra, Portugal, 1137–1145, https://doi.org/10.14195/978-989-26-16-506_127, 2018.
Brown, K. J., Hebda, N. J. R., Schoups, G., Conder, N., Smith, K. A. P., and Trofymow, J. A.: Long-term climate, vegetation and fire regime change in a managed municipal water supply area, British Columbia, Canada, The Holocene, 29, 1411–1424, https://doi.org/10.1177/0959683619854523, 2019.
Brown, K. J., Hebda, N. J., Hebda, R. J., Fitton, R., Trofymow, J. A., and Conder, N.: Development and wildfire dynamics of dry coastal temperate forests, BC, Canada, Can. J. Forest Res., 52, 1320–1333, https://doi.org/10.1139/cjfr-2022-0020, 2022.
Brown, K. J., Dietze, E., Walsh, M., Hennebelle, A., and Power, M.: Charred Particles and Other Paleofire Proxies, in: Encyclopedia of Quaternary Science, Vol. 3, edited by: Bradshaw, R., Elsevier, 19 pp., https://doi.org/10.1016/B978-0-323-99931-1.00082-9, 2025.
Burley, D. V.: Marpole: Anthropological Reconstructions of a Prehistoric Northwest Coast Culture Type, Department of Archaeology Publications 8. Archaeology Press, Simon Fraser University, Burnaby, BC, ISBN: 0-86491-026-6, 1980.
Burton, C., Lampe, S., Kelley, D. I., Thiery, W., Hantson, S., Christidis, N., Gudmundsson, L., Forrest, M., Burke, E., Chang, J., Huang, H., Ito, A., Kou-Giesbrecht, S., Lasslop, G., Li, W., Nieradzik, L., Li, F., Chen, Y., Randerson, J., Reyer, C. P. O., and Mengel, M.: Global burned area increasingly explained by climate change, Nat. Clim. Change, 14, 1186–1192, https://doi.org/10.1038/s41558-024-02140-w, 2024.
Bush, E. and Lemmen, D. S.: Canada's changing climate report, Government of Canada, Ottawa, ON, Canada, ISBN: 978-0-660-30222-5, 2019.
Chen, B., Wu, S., Jin, Y., Song, Y., Wu, C., Venevsky, S., Xu, B., Webster, C., and Gong, P.: Wildfire risk for global wildland–urban interface areas, Nature Sustainability, 7, 474–484, https://doi.org/10.1038/s41893-024-01291-0, 2024.
Chevalier, M., Davis, B. A., Heiri, O., Seppä, H., Chase, B. M., Gajewski, K., Lacourse, T., Telford, R. J., Finsinger, W., Guiot, J., Kühl, N., Maezumi, S. Y., Tipton, J. R., Carter, V. A., Brussel, T., Phelps, L. N., Dawson, A., Zanon, M., Vallé, F., Nolan, C., Mauri, A., Vernal, A., Izumi, K., Holmström, L., Marsicek, J., Goring, S., Sommer, P. S., Chaput, M., and Kupriyanov, D.: Pollen-based climate reconstruction techniques for late Quaternary studies, Earth-Sci. Rev., 210, 103384, https://doi.org/10.1016/j.earscirev.2020.103384, 2020.
Clarke, H., Cirulis, B., Borchers-Arriagada, N., Bradstock, R., Price, O., and Penman, T.: Health costs of wildfire smoke to rise under climate change, npj Clim. Atmos. Sci., 6, 102, https://doi.org/10.1038/s41612-023-00432-0, 2023.
Clark-Wolf, K. D., Higuera, P. E., McLauchlan, K. K., Shuman, B. N., and Parish, M. C.: Fire-regime variability and ecosystem resilience over four millennia in a Rocky Mountain subalpine watershed, J. Ecol., 111, 2643–2661, https://doi.org/10.1111/1365-2745.14201, 2023.
COHMAP Members: Climatic Changes of the Last 18,000 years: Observations and Model Simulations, Science, 241, 1043–1052, https://doi.org/10.1126/science.241.4869.1043, 1988.
Conedera, M., Tinner, W., Neff, C., Meurer, M., Dickens, A. F., and Krebs, P.: Reconstructing past fire regimes: methods, applications, and relevance to fire management and conservation, Quaternary Sci. Rev., 28, 555–576, https://doi.org/10.1016/j.quascirev.2008.11.005, 2009.
Crane, M. F.: Pteridium Aquilinum, USDA Forest Service Index of Species Information, https://www.fs.fed.us/database/feis/plants/fern/pteaqu/all.html (last access: 12 October 2024), 1990.
CRD: Regional Water Supply: 2017 Strategic Plan, Capital Regional District, Victoria, British Columbia, Canada, https://www.crd.ca/government-administration/data-documents/regional-water-supply-2017-strategic-plan (last access: 21 February 2026), 2022.
Cunningham, C. X., Williamson, G. J., and Bowman, D. M.: Increasing frequency and intensity of the most extreme wildfires on Earth, Nature Ecology & Evolution, 8, 1420–1425, https://doi.org/10.1038/s41559-024-02452-2, 2024.
Cwynar, L. C.: Fire and the forest history of the North Cascade Range, Ecology, 68, 791–802, https://doi.org/10.2307/1938350, 1987.
Daly, C., Neilson, R. P., and Phillips, D. L.: A statistical-topographic model for mapping climatological precipitation over mountainous terrain, J. Appl. Meteorol. Clim., 33, 140–158, https://doi.org/10.1175/1520-0450(1994)033<0140:ASTMFM>2.0.CO;2, 1994.
DeLuca, T. H., MacKenzie, M. D., Gundale, M. J., and Holben, W. E.: Wildfire-produced charcoal directly influences nitrogen cycling in ponderosa pine forests, Soil Sci. Soc. Am. J., 70, 448–453, https://doi.org/10.2136/sssaj2005.0096, 2006.
Demarchi, D. A.: An Introduction to the Ecoregions of British Columbia, 3rd edn., Ecosystem Information Section, Ministry of Environment, Victoria, B.C., https://coilink.org/20.500.12592/5s1hrlm (last access: 2 March 2026), 2011.
Douglas, G. W., Meidinger, D. V., and Pojar, J. (Eds.): Illustrated Flora of British Columbia. Volume 4: Dicotyledons (Orobanchaceae Through Rubiaceae), B.C. Ministry of Environment, Lands & Parks and B.C. Ministry of Forests, Victoria. 427 pp., ISBN: 978-0-7726-3685-0, 1999.
Dunnette, P. V., Higuera, P. E., McLauchlan, K. K., Derr, K. M., Briles, C. E., and Keefe, M. H.: Biogeochemical impacts of wildfires over four millennia in a Rocky Mountain subalpine watershed, New Phytol., 203, 900–912, https://doi.org/10.1111/nph.12828, 2014.
Dye, A. W., Reilly, M. J., McEvoy, A., Lemons, R., Riley, K. L., Kim, J. B., and Kerns, B. K.: Simulated future shifts in wildfire regimes in moist forests of Pacific Northwest, USA, J. Geophys. Res.-Biogeo., 129, e2023JG007722, https://doi.org/10.1029/2023JG007722, 2024.
Egan, J., Staff, R., and Blackford, J.: A high-precision age estimate of the Holocene Plinian eruption of Mount Mazama, Oregon, USA, The Holocene, 25, 1054–1067, https://doi.org/10.1177/0959683615576230, 2015.
Eldridge, M. and Seip, L.: Sooke Reservoir Expansion: An Archaeological Impact Assessment (Permit 2002–121), Rep., on file at the BC Archaeology Branch, Victoria, BC, 2002.
Enache, M. D. and Cumming, B. F.: Tracking recorded fires using charcoal morphology from sedimentary sequence of Prosser Lake, British Columbia (Canada), Quaternary Res., 65, 282–292, https://doi.org/10.1016/j.yqres.2005.09.003, 2006.
Esri: ArcGIS Map Service World Topographic [basemap], October 26, 2017, https://www.arcgis.com/home/item.html?id=7dc6cea0b1764a1f9af2e679f642f0f5 (last access: 9 November 2024), 2024a.
Esri: ArcGIS Map Service World Imagery, December 12, 2009, https://www.arcgis.com/home/item.html?id=10df2279f9684e4a9 f6a7f08febac2a9 (last access: 9 November 2024), 2024b.
Feurdean, A.: Experimental production of charcoal morphologies to discriminate fuel source and fire type: an example from Siberian taiga, Biogeosciences, 18, 3805–3821, https://doi.org/10.5194/bg-18-3805-2021, 2021.
Finsinger, W. and Bonnici, I.: tapas: an R package to perform trend and peaks analysis, Zenodo [code], https://doi.org/10.5281/zenodo.6344463, 2022.
Fischer, H., Schüpbach, Gideon, G., Bigler, M., Röthilisberger, R., Erhardt E., Stocker, T. F., Mulvaney, R., and Wolff, E. W.: Millennial changes in North American wildfire and soil activity over the last glacial cycle, Nat. Geosci., 8, 723–727, https://doi.org/10.1038/ngeo2495, 2015.
Flannigan, M. D., Logan, K. A., Amiro, B. D., Skinner, W. R., and Stocks, B. J.: Future Area Burned in Canada, Climatic Change, 72, 1–16, https://doi.org/10.1007/s10584-005-5935-y, 2005.
Gavin, D. G., Brubaker, L. B., and Lertzman, K. P.: An 1800-year record of the spatial and temporal distribution of fire from the west coast of Vancouver Island, Can. J. Forest Res., 33, 573–586, https://doi.org/10.1139/x02-196, 2003a.
Gavin, D. G., Brubaker, L. B., and Lertzman, K. P.: Holocene Fire History of a Coastal Temperate Rain Forest Based on Soil Charcoal Radiocarbon Dates, Ecology, 84, 186–201, https://doi.org/10.1890/0012-9658(2003)084[0186:HFHOAC]2.0.CO;2 2003b.
Gavin, D. G., Hallett, D. J., Hu, F. S., Lertzman, K. P., Prichard, S. J., Brown, K. J., Lynch, J. A., Bartlein, P., and Peterson, D. L.: Forest fire and climate change in western North America: insights from sediment charcoal records, Front. Ecol. Environ., 5, 499–506, https://doi.org/10.1890/060161, 2007.
Gedye, S. J., Jones, R. T., Tinner, W., Ammann, B., and Oldfield, F.: The use of mineral magnetism in the reconstruction of fire history: A case study from Lago di Origlio, Swiss Alps, Palaeogeogr. Palaeocl., 164, 101–110, 2000.
Giuliano, C. and Lacourse, T.: Holocene fire regimes, fire-related plant functional types, and climate in south-coastal British Columbia forests, Ecosphere, 14, e4416, https://doi.org/10.1002/ecs2.4416, 2023.
Goring, S., Williams, J. W., Blois, J. L., Jackson, S. T., Paciorek, C. J., Booth, R. K., Marlon, J. R., Blaauw, M., and Christen, J. A.: Deposition times in the northeastern United States during the Holocene: establishing valid priors for Bayesian age models, Quaternary Sci. Rev., 48, 54–60, https://doi.org/10.1016/j.quascirev.2012.05.019, 2012.
Hai, J., Zhang, L., Gao, C., Wang, H., and Wu, J.: How does fire suppression alter the wildfire regime? A systematic review, Fire, 6, 424, https://doi.org/10.3390/fire6110424, 2023.
Hallett, D. J., Lepofsky, D. S., Mathewes, R. W., and Lertzman, K. P.: 11 000 years of fire history and climate in the mountain hemlock rain forests of southwestern British Columbia based on sedimentary charcoal, Can. J. Forest Res., 33, 292–312, https://doi.org/10.1139/x02-177, 2003.
Halofsky, J. S., Donato, D. C., Franklin, J. F., Halofsky, J. E., Peterson, D. L., and Harvey, B. J.: The nature of the beast: examining climate adaptation options in forests with stand-replacing fire regimes, Ecosphere, 9, e02140, https://doi.org/10.1002/ecs2.2140, 2018.
Hamann, A. and Wang, T. L.: Models of climatic normals for genecology and climate change studies in British Columbia, Agr. Forest Meteorol., 128, 211–221, https://doi.org/10.1016/j.agrformet.2004.10.004, 2005.
Hanes, C. C., Wang, X., Jain, P., Parisien, M.-A., Little, J. M., and Flannigan, M. D.: Fire-regime changes in Canada over the last half century, Can. J. Forest Res., 49, 256–269, https://doi.org/10.1139/cjfr-2018-0293, 2019.
Hebda, R. J.: British Columbia Vegetation and Climate History with Focus on 6 ka BP, Geogr. Phys. Quatern., 49, 55–79, https://doi.org/10.7202/033030ar, 1995.
Hebda, N. J., Brown, K. J., Conder, N., Walker, I. R., and Hebda, R. J.: Past wildfire effects on terrestrial vegetation and biogeochemistry in a drinking water supply catchment, Quaternary Sci. Rev., 340, https://doi.org/10.1016/j.quascirev.2024.108663, 2024.
Hebda, N. J. R.: Begbie Lake pollen dataset, Version 1, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/MYT8-WA75, 2021.
Hebda, N. J. R.: Assessing wildfire risk to municipal drinking water using paleoecology, PhD dissertation, University of British Columbia, Canada, 204 pp., https://open.library.ubc.ca/collections/ubctheses/24/items/1.0421622 (last access: 10 October 2024), 2022.
Hessburg, P. F., Miller, C. L., Parks, S. A., Povak N. A., Taylor, A. H., Higuera, P. E., Prichard, S. J., North, M. P., Collins, B. M., Hurteau, M. D., Larson, A. J., Allen, C. D., Stephens, S. L., Rivera-Huerta, H., Stevens-Rumann, C. S., Daniels, L. D., Gedalof, Z., Gray, R. W., Kane, V. R., Churchill, D. J., Hagmann, R. K., Spies, T. A., Cansler, C. A., Belote, R. T., Veblen, T. T., Battaglia, M. A., Hoffman, C., Skinner, C. N., Safford, H D., and Salter, R. B.: Climate, Environment, and Disturbance History Govern Resilience of Western North American Forests, Front. Ecol. Evolution, 7, 239, https://doi.org/10.3389/fevo.2019.00239, 2019.
Higuera, P. E., Peters, M. E., Brubaker, L. B., and Gavin, D. G.: Understanding the origin and analysis of sediment-charcoal records with a simulation model, Quaternary Sci. Rev., 26, 1790–1809, https://doi.org/10.1016/j.quascirev.2007.03.010, 2007.
Higuera, P.: CharAnalysis 0.9: Diagnostic and analytical tools for sediment-charcoal analysis, User's Guide, Montana State University, University of Illinois, http://CharAnalysis.googlepages.com (last access: 9 September 2024), 2009.
Higuera, P. E., Gavin, D. G., Bartlein, P. J., and Hallett, D. J.: Peak detection in sediment–charcoal records: impacts of alternative data analysis methods on fire-history interpretations, Int. J. Wildland Fire, 19, 996–1014, 2011.
Hoffman, K. M., Wickham, S. B., McInnes, W. S., and Starzomski, B. M.: Fire exclusion destroys habitats for at-risk species in a British Columbia protected area, Fire, 2, 48, https://doi.org/10.3390/fire2030048, 2019.
Hoffman, K. M., Davis, E. L., Wickham, S. B., Schang, K., Johnson, A., Larking, T., Lauriault, P. N., Le, N. Q., Swerdfager, E., and Trant, A. J.: Conservation of Earth's biodiversity is embedded in Indigenous fire stewardship, P. Natl. Acad. Sci. USA, 118, e2105073118, https://doi.org/10.1073/pnas.2105073118, 2021.
Holden, P. B., Edwards, N. R., Rangel, T. F., Pereira, E. B., Tran, G. T., and Wilkinson, R. D.: PALEO-PGEM v1.0: a statistical emulator of Pliocene–Pleistocene climate, Geosci. Model Dev., 12, 5137–5155, https://doi.org/10.5194/gmd-12-5137-2019, 2019.
Horrelt, D. R., Brown, K. J., and Bone, C.: Swanson Lake charcoal dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/31J5-S285, 2026a.
Horrelt, D. R., Brown, K. J., and Bone, C.: Swanson Lake pollen dataset, Version 1.0, Neotoma Paleoecology Database [data set], https://doi.org/10.21233/KG7B-9G33, 2026b.
Jensen, K., Lynch, E. A., Calcote, R., and Hotchkiss, S. C.: Interpretation of charcoal morpohtypes in sediments from Ferry Lake, Wisconsin, USA: do different plant fuel sources produce distinctive charcoal morphotypes?, The Holocene, 17, 907–915, https://doi.org/10.1177/0959683607082405, 2007.
Juggins, S.: riojaPlot: Stratigraphic diagrams in R, package version 0.1-20, GitHub [code], https://github.com/nsj3/riojaPlot (last access: 6 November 2024), 2023.
Kajak, Z, Kacprzak, K., and Polkowski, R.: Tubular bottom sampler, Ekol. Pol. B, 11, 159–165, 1965.
Kapp, R. O.: How To Know Pollen and Spores, W. C. Brown Co. Iowa, Dubuque, ISBN 0-697-04849-7, 1969.
Kassambara, A.: rstatix: Pipe-Friendly Framework for Basic Statistical Tests, R package version 0.7.2, Datanovia [code], https://rpkgs.datanovia.com/rstatix/ (last access: 30 October 2024), 2023.
Kelly, R. F., Higuera, P. E., Barrett, C. M., and Hu, F. S.: A signal-to-noise index to quantify the potential for peak detection in sediment–charcoal records, Quaternary Res., 75, 11–17, https://doi.org/10.1016/j.yqres.2010.07.011, 2011.
Knutti, R. and Sedláček, J.: Robustness and uncertainties in the new CMIP5 climate model projections, Nat. Clim. Change, 3, 369–373, https://doi.org/10.1038/nclimate1716, 2013.
Lea, T.: Garry Oak and Associated Ecosystems: Distribution and Description, Chapter 2, in: Restoring British Columbia's Garry Oak Ecosystems Principles and Practices, edited by: Clements, C., Carnahan, T., Dumoulin, L., Evans, A., Gonzales, E., Kohler, T., Kroeker, N., Lea, L., and Miller, M., Gary Oak Ecosystems Recovery Team (GOERT), Victoria, British Columbia, Canada, ISBN: 978-0-9732181-4-5, 2011.
Lemmen, J. and Lacourse, T.: Fossil chironomid assemblages and inferred summer temperatures for the past 14,000 years from a low-elevation lake in Pacific Canada, J. Paleolimnol., 59, 427–442, https://doi.org/10.1007/s10933-017-9998-3, 2018.
Leonardi, M., Hallett, E. Y., Beyer, R., Krapp, M., and Manica, A.: pastclim 1.2: an R package to easily access and use paleoclimatic reconstructions, Ecography, 3, e06481, https://doi.org/10.1111/ecog.06481, 2023.
Littell, J. S.: Drought and fire in the western USA: is climate attribution enough?, Curr. Clim. Change Rep., 4, 396–406, https://doi.org/10.1007/s40641-018-0109-y, 2018.
Livingstone, D. A.: A lightweight piston sampler for lake deposits, Ecology, 36, 137–139, https://doi.org/10.2307/1931439, 1955.
Liu, Y., Stanturf, J., and Goodrick, S.: Trends in global wildfire potential in a changing climate, Forest Ecol. Manag., 259, 685–697, https://doi.org/10.1016/j.foreco.2009.09.002, 2010.
Loader, C.: locfit: Local regression, likelihood and density estimation, R package version 1.5, CRAN [code], https://cran.r-project.org/web/packages/locfit/index.html (last access: 17 October 2024), 2023.
Lucas, J. D. and Lacourse, T.: Holocene vegetation history and fire regimes of Pseudotsuga menziesii forests in the Gulf Islands National Park Reserve, southwestern British Columbia, Canada, Quaternary Res., 79, 366–376, https://doi.org/10.1016/j.yqres.2013.03.001, 2013.
MacCarthy, J., Tyukavina, A., Weisse, M. J., Harris, N., and Glen, E.: Extreme wildfires in Canada and their contribution to global loss in tree cover and carbon emissions in 2023, Glob. Change Biol., 30, https://doi.org/10.1111/gcb.17392, 2024.
Magiera, T., Łukasik, A., Zawadzki, J., and Rösler, W.: Magnetic susceptibility as indicator of anthropogenic disturbances in forest topsoil: A review of magnetic studies carried out in Central European forests, Ecol. Indic., 106, https://doi.org/10.1016/j.ecolind.2019.105518, 2019.
Marlon, J. R.: What the past can say about the present and future of fire, Quaternary Res., 96, 66–87, https://doi.org/10.1017/qua.2020.48, 2020.
Marlon, J. R., Bartlein, P. J., Walsh, M. K., Harrison, S. P., Brown, K. J., Edwards, M. E., Higuera, P E., Power, M. J., Anderson, R. S., Briles, C., Brunelle, A., Carcaillet, C., Daniels, M., Hu, F. S., Lavoie, M., Long, C., Minckley T., Richard, P. J. H., Scott, A. C., Shafer, D. S., Tinner, W., Umbanhowar, C. E., and Whitlock, C.: Wildfire responses to abrupt climate change in North America, P. Natl. Acad. Sci. USA, 106, 2519–2524, https://doi.org/10.1073/pnas.0808212106, 2009.
Marlon, J. R., Bartlein, P. J., Gavin, D. G., Long, C. J., Anderson, R. S., Briles, C. E., Brown, K. J., Colombaroli, D., Hallet, D. J., Power, M. J., Scharf, E. A., and Walsh, M. K.: Long-term perspective on wildfires in the western USA, P. Natl. Acad. Sci. USA, 109, E535–E543, https://doi.org/10.1073/pnas.1112839109, 2012.
Marlon, J. R., Bartlein, P. J., Daniau, A. L., Harrison, S. P., Maezumi, S. Y., Power, M. J., Tinner, W., and Vanniére, B.: Global biomass burning: a synthesis and review of Holocene paleofire records and their controls, Quaternary Sci. Rev., 65, 5–25, https://doi.org/10.1016/j.quascirev.2012.11.029, 2013.
Marlon, J. R., Kelly, R., Daniau, A.-L., Vannière, B., Power, M. J., Bartlein, P., Higuera, P., Blarquez, O., Brewer, S., Brücher, T., Feurdean, A., Romera, G. G., Iglesias, V., Maezumi, S. Y., Magi, B., Courtney Mustaphi, C. J., and Zhihai, T.: Reconstructions of biomass burning from sediment-charcoal records to improve data–model comparisons, Biogeosciences, 13, 3225–3244, https://doi.org/10.5194/bg-13-3225-2016, 2016.
Mathewes, R. W. and Heusser, L. E.: A 12 000 year palynological record of temperature and precipitation trends in southwestern British Columbia, Can. J. Botany, 59, 707–710, https://doi.org/10.1139/b81-100, 1981.
Mattioli, W., Ferrara, C., Lombardo, E., Barbati, A., Salvati, L., and Tomao, A.: Estimating wildfire suppression costs: a systematic review, Int. For. Rev., 24, 15–29, https://doi.org/10.1505/146554822835224801, 2022.
McAndrews, J. H. and Power, D. M.: Palynology of the Great Lakes: the surface sediments of Lake Ontario, Can. J. Earth Sci., 10, 777–792, https://doi.org/10.1139/e73-071, 1973.
McDadi, O. and Hebda, R. J.: Change in historic fire disturbance in a Garry oak (Quercus garryana) meadow and Douglas-fir (Pseudotsuga menziesii) mosaic, University of Victoria, British Columbia, Canada: A possible link with First Nations and Europeans, Forest Ecol. Manag., 256, 1704–1710, https://doi.org/10.1016/j.foreco.2008.03.012, 2008.
Meidinger, D. and Pojar, J.: Ecosystems of British Columbia, BC Min. of For., Victoria, Special Rep. Series No. 6, 330 pp., ISSN 0843-6452, 1991.
Moore, P. D., Webb, J. A., and Collison, M. E.: Pollen analysis, Blackwell Scientific Publications, Oxford, UK, viii, 216 pp., ISSN 978-0-632-02176-5, 1991.
Moritz, M. A., Parisien, M. A., Batllori, E., Krawchuk, M. A., Van Dorn, J., Ganz, D. J., and Hayhoe, K.: Climate change and disruptions to global fire activity, Ecosphere, 3, 1–22, https://doi.org/10.1890/ES11-00345.1, 2012.
Moritz, M. A., Batllori, E., Bradstock, R. A., Gill, A. M., Handmer, J., Hessburg, P. F., Leonard, J., McCaffrey, S., Odion, D. C., Schoennagel, T., and Syphard, A. D.: Learning to coexist with wildfire, Nature, 51, 58–66, https://doi.org/10.1038/nature13946, 2014.
Mustaphi, C. J. C. and Pisaric, M. F. J.: A classification for macroscopic charcoal morphologies found in Holocene lacustrine sediments, Prog. Phys. Geog., 38, 734–754, https://doi.org/10.1177/0309133314548886, 2014.
Nakagawa, T., Tarasov, P., Staff, R., Ramsey, C. B., Marshall, M., Schlolaut, G., Bryant, C., Brauer, A., Lamb, H., Haraguchi, T., Gotanda, K., Kitaba, I., Kitagawa, H., van der Plicht, J., Yonenobu, H., Omori, T., Yokoyama, Y., Tada, R., and Yasuda, Y.: The spatio-temporal structure of the Lateglacial to early Holocene transition reconstructed from the pollen record of Lake Suigetsu and its precise correlation with other key global archives: Implications for palaeoclimatology and archaeology, Global Planet. Change, 202, 103493, https://doi.org/10.1016/j.gloplacha.2021.103493, 2021.
Oksanen, J., Simpson, G., Blanchet, F. G., Kindt, R., Legendre, P., Minchin, P., O'hara, R. B., Solymos, P., Stevens, H. M. H., Szöcs, E., Wagner, H. H., Barbour, M., Bedward, M., Bolker, B., Borcard, D., Carvalho, G., Chirico, M., Caceres, M., Durand, S., Evangelista, H., Fitzjohn, R., Friendly, M., Furneaux, B. R., Hannigan, G., Hill, M. O., Lahti, L., McGlinn, D., Oulette, M.-H., Cunha, E. R., Smith, T. W., Stier, A., ter Braak, C., and Weedon, J.: vegan community ecology package version 2.6-2 April 2022, CRAN [code], https://cran.r-project.org/ (last access: 6 October 2024), 2022.
Overpeck, J. T., Rind, D., and Goldberg, R.: Climate-induced changes in forest disturbance and vegetation, Nature, 343, 51–53, https://doi.org/10.1038/343051a0, 1990.
Parisien, M.-A., Dawe, D. A., Miller, C., Stockdale, C. A., and Armitage, O. B.: Applications of simulation-based burn probability modelling: a review, Int. J. Wildland Fire, 28, 913–926, https://doi.org/10.1071/WF19069, 2019.
Parisien, M. A., Barber, Q. E., Bourbonnais, M. L., Daniels, L. D., Flannigan, M. D., Gray, R. W., Hoffman, K. M., Jain, P., Stephens, S. L., Taylor, S. W., and Whitman, E.: Abrupt, climate-induced increase in wildfires in British Columbia since the mid-2000s, Communications Earth & Environment, 4, 309, https://doi.org/10.1038/s43247-023-00977-1, 2023.
PCIC: Plan2Adapt: Summary, Pacific Climate Impacts Consortium, https://services.pacificclimate.org/plan2adapt/app/, last access: 29 October 2024.
Pellatt, M. G., Smith, M. J., Mathewes, R. W., Walker, I. R., and Palmer, S. L.: Holocene treeline and climate change in the subalpine zone near Stoyoma Mountain, Cascade Mountains, southwestern British Columbia, Canada, Arct. Antarct. Alp. Res., 32, 73–83, https://doi.org/10.1080/15230430.2000.12003341, 2000.
Pellatt, M. G., Hebda, R. J., and Mathewes, R. W.: High-resolution Holocene vegetation history and climate from Hole 1034B, ODP leg 169S, Saanich Inlet, Canada, Mar. Geol., 174, 211–226, https://doi.org/10.1016/S0025-3227(00)00151-1, 2001.
Pellatt, M. G. and Gedalof, Z. E.: Environmental change in Garry oak (Quercus garryana) ecosystems: the evolution of an eco-cultural landscape, Biodivers. Conserv., 23, 2053–2067, https://doi.org/10.1007/s10531-014-0703-9, 2014.
Pellatt, M. G., McCoy, M. M., and Mathewes, R. W.: Paleoecology and fire history of Garry oak ecosystems in Canada: implications for conservation and environmental management, Biodivers. Conserv., 24, 1621–1639, https://doi.org/10.1007/s10531-015-0880-1, 2015.
Perrakis, D. P., Brown, K. J., Morrison, K., Taylor, S. W., and Horrelt, D. R.: Assessing wildfire potential in a coastal forest watershed, British Columbia, Canada, Forest Ecol. Manag., 590, 122796, https://doi.org/10.1016/j.foreco.2025.122796, 2025.
Pojar, J. and MacKinnon, A. (Eds.): Plants of the Pacific Northwest coast: Washington, Oregon, British Columbia and Alaska, Lone Pine Publishing, Redmond, WA, 526 pp., ISBN: 9781772130089, 1994.
Power, M. J., Marlon, J., Ortiz, N., Bartlein, P. J., Harrison, S. P., Mayle, F. E., Ballouche, A., Bradshaw, R. H. W., Caracaillet, C., Cordova, C., Mooney, S., Moreno, P. I., Prentice, I. C., Thonicke, K., Tinner, W., Whitlock, C., Zhang, Y., Zhao, Y., Ali, A. A., Anderson R. S., Beer, R., Behling, H., Briles, C., Brown, K. J., Brunelle, A., Bush, M., Camill, P., Chu, G. Q., Clark, J., Colombaroli, D., Connor, S., Daniau, A-L., Daniels, M., Dodson, J., Doughty, E., Edwards, M. E., Finsinger, W., Foster, D., Frechette, J., Gaillard, M-J., Gavin, D. G., Gobet, E., Haberle, S., Hallett, D. J., Higuera, P., Hope, G., Horn, S., Inoue, J., Kaltenrieder, P., Kennedy, L., Kong, Z. C., Larsen, C., Long, C. J., Lynch, J., McGlone, M., Meeks, S., Mensing, S., Meyer, G., Minckley, T., Mohr, J., Nelson, D. M., New, J., Newnham, R., Noti, R., Oswald, W., Pierce, J., Richard, P. J. H., Rowe, C., Sanchez Goni, M. F., Schuman, B. N., Takahara, H., Toney, J., Turney, C., Urrego-Sanchez, D. H., Umbanhowar, C., Vandergoes, M., Vanniere, B., Vescovi, E., Walsh, M., Wang, X., Williams, N., Wilmshurst, J., and Zhang, J. H.: Changes in fire regimes since the Last Glacial Maximum: an assessment based on a global synthesis and analysis of charcoal data, Clim. Dynam., 30, 887–907, https://doi.org/10.1007/s00382-007-0334-x, 2008.
Power, M. J., Bartlein, P. J., and Harrison, S. P.: Fire history and the Global Charcoal Database: A new tool for hypothesis testing and data exploration, Palaeogeogr. Palaeocl., 291, 52–59, https://doi.org/10.1016/j.palaeo.2009.09.014, 2010.
Ramsey, C. B.: Bayesian analysis of radiocarbon dates, Radiocarbon, 51, 337–360, https://doi.org/10.1017/S0033822200033865, 2009.
Reimer, P. J., Austin, W. E., Bard, E., Bayliss, A., Blackwell, P. G., Ramsey, C. B., Butzin, M., Cheng, H., Edwards, R., Friedrich, L. M., Grootes, P. M., Guilderson, T P., Hajdas, I., Heaton, T. J., Hogg, A. G., Hughen, K. A., Kromer, B., Manning, S. W., Muscheler, R., Palmer, J.G., Pearson, C., van der Plicht, J., Reimer, R. W., Richards, D. A., Scott, E. M., Southon, J. R., Turney, C. S. M., Wacker, L., Adolphi, F., Buntgen, U., Capano, M., Fahrni, S M., Fogtmann-Schulz, A., Friedrich, R., Kohler, P., Kudsk, S., Miyake, F., Olsen, J., Reinig, F., Sakamoto, M., Sookdeo, A., and Talamo, S.: The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0–55 cal kBP), Radiocarbon, 62, 725–757, https://doi.org/10.1017/RDC.2020.41, 2020.
Renssen, H., Seppä, H., Crosta, X., Goosse, H., and Roche, D. M.: Global characterization of the Holocene thermal maximum, Quaternary Sci. Rev., 48, 7–19, https://doi.org/10.1016/j.quascirev.2012.05.022, 2012.
Ripley, B.: MASS: Modern applied statistics with S, R package version 7.3, CRAN [code], https://cran.r-project.org/web/packages/MASS/index.html (last access: 17 October 2024), 2023.
Rosenberg, S. M., Walker, I. R., Mathewes, R. W., and Hallett, D. J.: Midge-inferred Holocene climate history of two subalpine lakes in southern British Columbia, Canada, The Holocene, 14, 258–271, https://doi.org/10.1191/0959683604hl703rp, 2004.
Rowe, J. S.: Concepts of Fire Effects on Plant Individuals and Species, in: The Role of Fire in Northern Circumpolar Ecosystems, edited by: Wein, R. W. and MacLean, D. A., John Wiley and Sons, New York, 135–155, ISBN 0 471 10222 9, 1983.
Rummery, A. T.: The effects of fire on soil and sediment magnetism, Doctoral dissertation, University of Liverpool, 1981.
Senande-Rivera, M., Insua-Costa, D., and Miguez-Macho, G.: Spatial and temporal expansion of global wildland fire activity in response to climate change, Nat. Commun., 13, 1208, https://doi.org/10.1038/s41467-022-28835-2, 2022.
Sheehan, T., Bachelet, D., and Ferschweiler, K.: Projected major fire and vegetation changes in the Pacific Northwest of the conterminous United States under selected CMIP5 climate futures, Ecol. Model., 317, 16–29, https://doi.org/10.1016/j.ecolmodel.2015.08.023, 2015.
Stantec Consulting Ltd.: Capital Regional District, Regional Water Supply, 2022 Master Plan, IWS Report No. 1186, Victoria, BC, Canada, https://www.crd.ca/media/file/regional-water-supply-2022-master-plan (last access: 21 February 2026), 2022.
Uchytil, R. J.: Pseudotsuga menziesii var. Menziesii, in: Fire Effects Information System, U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, https://www.fs.usda.gov/database/feis/plants/tree/psemenm/all.html (last access: 3 November 2024), 1991.
Vincent, R., Mathews, D., and Eldridge, M.: Sooke Lake Reservoir Expansion Phase II: An Archeological Impact Assessment, Permit 2202-336, Victoria, Capital Regional District, 2002.
Walker, I. R. and Mathewes, R. W: Chironomidae (Diptera) and postglacial climate at Marion Lake, British Columbia, Canada, Quaternary Res., 27, 89–102, https://doi.org/10.1016/0033-5894(87)90052-4, 1987.
Walker, I. R. and Pellatt, M. G.: Climate Change in Coastal British Columbia – A Paleoenvironmental Perspective, Can. Water Resour. J., 28, 531–566, https://doi.org/10.4296/cwrj2804531, 2003.
Walsh, M. K., Marlon, J. R., Goring, S. J., Brown, K. J., and Gavin, D. G.: A regional perspective on Holocene fire–climate–human interactions in the Pacific Northwest of North America, Ann. Assoc. Am. Geogr., 105, 1135–1157, https://doi.org/10.1080/00045608.2015.1064457, 2015.
Wang, T., Campbell, E. M., O'Neill, G. A., and Aitken, S. N.: Projecting future distributions of ecosystem climate niches: Uncertainties and management applications, Forest Ecol. Manag., 279, 128–140, https://doi.org/10.1016/j.foreco.2012.05.034, 2012.
Wang, T., Hamann, A., Spittlehouse, D., and Carroll, C.: Locally downscaled and spatially customizable climate data for historical and future periods for North America, PloS ONE, 11, e0156720, https://doi.org/10.1371/journal.pone.0156720, 2016a.
Wang, X., Thompson, D. K., Marshall, G. A., Tymstra, C., Carr, R., and Flannigan, M. D.: Increasing frequency of extreme fire weather in Canada with climate change, Clim. Change, 130, 573–586, https://doi.org/10.1007/s10584-015-1375-5, 2015.
Wang, X., Parisien, M. A., Taylor, S. W., Perrakis, D. D., Little, J., and Flannigan, M. D.: Future burn probability in south-central British Columbia, Int. J. Wildland Fire, 25, 200–212, https://doi.org/10.1071/WF15091, 2016b.
Wang, X., Parisien, M. A., Taylor, S. W., Candau, J. N., Stralberg, D., Marshall, G. A., Little, J. M., and Flannigan, M. D.: Projected changes in daily fire spread across Canada over the next century, Environ. Res. Lett., 12, 025005, https://doi.org/10.1088/1748-9326/aa5835, 2017.
Wang, Z., Wang, Z., Zou, Z., Chen, X., Wu, H., Wang, W., Su, H., Li, F., Xu, W., Liu, Z., and Zhu, J.: Severe global environmental issues caused by Canada's record-breaking wildfires in 2023, Adv. Atmos. Sci., 41, 565–571, https://doi.org/10.1007/s00376-023-3241-0, 2024.
Wanner, H., Beer, J., Bütikofer, J., Crowley, T. J., Cubasch, U., Flückiger, J., Goosse, H., Grosjean M., Joos, F., Kaplan, J. O., Küttel, M., Müller, S. A., Prentice, I. J., Solomina, O., Stocker, T. F., Pavel, T., Wagner, M., and Widmann, M.: Mid-to Late Holocene climate change: an overview, Quaternary Sci. Rev., 27, 1791–1828, https://doi.org/10.1016/j.quascirev.2008.06.013, 2008.
Westerling, A. L., Hidalgo, H. G., Cayan, D. R., and Swetnam, T. W.: Warming and earlier spring increase western U.S. Forest Wildfire Activity, Science, 313, 940–943, https://doi.org/10.1126/science.1128834, 2006.
Whitlock, C., Shafer, S. L., and Marlon, J.: The role of climate and vegetation change in shaping past and future fire regimes in the northwestern US and the implications for ecosystem management, Forest Ecol. Manag., 178, 5–21, https://doi.org/10.1016/S0378-1127(03)00051-3, 2003.
Wirth, C.: Fire regime and tree diversity in boreal forests: implications for the carbon cycle, in: Forest diversity and function: temperate and boreal systems, edited by: Scherer-Lorenzen, M., Körner, C., and Schulze, E.-D., Springer, Berlin Heidelberg, 309–344, https://doi.org/10.1007/b137862, 2005.
Wong, C., Sandmann, H., and Dorner, B.: Historical variability of natural disturbances in British Columbia: A literature review. FORREX–Forest Research Extension Partnership, Kamloops, B.C. FORREX Series 12, ISBN: 1-894822-13-7, 2004.
Wright, H. E.: A square-rod piston sampler for lake sediments, J. Sediment. Res., 37, 975–976, https://doi.org/10.1306/74D71807-2B21-11D7-8648000102C1865D, 1967.
Wu, D., Zhou, A., Liu, J., Chen, X., Wei, H., Sun, H., Yu, J., Bloemendal, J., and Chen, F.: Changing intensity of human activity over the last 2,000 years recorded by the magnetic characteristics of sediments from Xingyun Lake, Yunnan, China, J. Paleolimnol., 53, 47–60, https://doi.org/10.1007/s10933-014-9806-2, 2015.
Short summary
By analyzing charcoal and pollen in lake sediments from a high-value drinking water supply area, this research found that forests on southern Vancouver Island, British Columbia experienced more frequent wildfires in the past. Recently, cooler and moister climate has led to fewer fires and denser forests, with western sites experiencing the most change. Findings suggest that as climate warms in the future, wildfire occurrence could increase with implications for water supply management.
By analyzing charcoal and pollen in lake sediments from a high-value drinking water supply area,...