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Response of Seedlings and Saplings to Canopy Gaps in Coastal Old-Growth Forests

Updated: Sep 18, 2021

Jennifer Passmore, M.R.M. Project (2007)

School of Resource and Environmental Management, Simon Fraser University, Burnaby

[Thesis] Response of Seelings and Saplings to Canopy Gaps in Coastal Old-Growth Forests, 2
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Fine-scale disturbances involving the death of one to a few trees create gaps in the forest canopy and, where large-scale disturbances are rare, exert a dominant influence on community and population dynamics. I examine the natural regeneration and recruitment of seedlings and saplings following fine-scale, gap forming disturbances in old-growth stands within the Capilano, Seymour and Coquitlam River watersheds. I compared the abundance of western redcedar, western hemlock, and Pacific silver fir seedlings and saplings between plots located within and adjacent-to 20 gaps of known date of origin. I also destructively sampled seedlings and saplings of each species and applied dendroecological methods to determine the age of each sample, and to elucidate patterns of suppression and release in radial growth. My results support the paradigm of gap-scale canopy replacement. Seedlings and saplings were more abundant in gap versus forest environments, and exhibited increased rates of establishment and radial growth.

KEYWORDS: canopy gap; temperate rainforest; Tsuga heterophylla; Abies amabilis; Thuja plicata; forest dynamics

Research Contributions

Research Reports

Daniels, L.D. J. Passmore, A.B. Stan, K. Golinski, and T.A. Jones. 2007. Part 7. Regional comparisons of species composition and gap attributes. Pp. 69-83 in Canopy gaps in the Bamfield Huu-ay-aht Community Forest: baseline information for variable retention silviculture. Report to the BC Forest Science Program, Forest Investment Account, Victoria, BC. October 2007.

Conference Presentations and Posters

Recruitment and regeneration following fine-scale disturbances in coastal old-growth forests. Presented by J. Passmore. Co-Authors: L.D. Daniels K.P. Lertzman and A.B. Stan. Presented at Northwest Scientific Association Meeting, Victoria, BC, February 2007.

Current Position

Jen Passmore is now an ecological consultant and works with FORREX, the Forum for Research and Extension in Natural Resources of BC.

For further information, contact Dr. Lori Daniels, Department of Forest Sciences, University of British Columbia,


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