Canadian Forest Service Publications
Ecology of western redcedar (Thuja plicata): Implications for management of a high-value multiple-use resource. 2016. Antos, J.A.; Filipescu, C.N.; Negrave, R.W. Forest Ecology and Management. 375: 211–222
Issued by: Pacific Forestry Centre
Catalog ID: 36933
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Western redcedar (Thuja plicata) is an important tree in western North America that produces high value wood. The species is common in natural forests, but much less abundant in post-harvest stands and presents a variety of challenges for management. We review the ecology of redcedar to provide context for innovative management strategies. Redcedar is a stress tolerator that grows across a wide range of sites, from high-productivity to very nutrient poor or wet. Trees can grow very large, but tend to grow slower than associated species. Redcedar can establish directly after disturbance, but also establishes in mature forests. Species abundance tends to increase during succession but the mechanism for this is unclear given that following stand-replacing disturbance the number of regenerated trees tends to be limited. High survival of established trees under both abiotic and biotic stress may be a key to the extensive range and abundance of the species. Knowledge gaps about population dynamics in natural forests hinder the assessment of specific management options, but it is clear that multiple-aged, mixed species management needs to be considered for more widespread use. Relying on clear-cut systems and even-aged regeneration strategies limit management options for western redcedar. We recommend that more consideration be given to alternative practices, such as using advanced regeneration, promoting understory redcedar or implementing targeted site preparation to stimulate natural regeneration. The ecology of the species is most consistent with various partial-cut systems and extended rotations used for shade-tolerant species in many parts of the world. Redcedar has the potential to be a larger component of managed forests but this will require use of innovative management practices.
Plain Language Summary
Western redcedar, the provincial tree of British Columbia, is an important forest species in western North America. It provides a wide range of social, economic and environmental benefits to forest dependent communities, industry and First Nations. We summarize the current scientific knowledge on western redcedar in order to promote innovative practices for managed forests. Current management strategies are faced with a number of challenges, such as regeneration difficulties, damage of young trees by wildlife, and reduced growth. These challenges are potentially magnified by the use of clearcutting and plantations. We propose a series of alternative management practices more closely aligned with the ecological characteristics of redcedar in natural forests, such as use of partial cuts systems, natural regeneration and use of mixed-species and multiple-aged forests. These innovative practices have the potential to alleviate current regeneration challenges, and fulfil both ecological and economic objectives. Our work will contribute to refining management strategies for western redcedar and will support the development of policies for multiple uses and sustainable production of this high-value forest resource.