Ecology of western redcedar (Thuja plicata): Implications for management of a high-value multiple-use resource

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.