Northern White-Cedar Ecology and Silviculture in the Northeastern United States and Southeastern Canada: A Synthesis of Knowledge

Abstract

Sustainability of the northern white-cedar (Thuja occidentalis L.) resource is a concern in many regions throughout its range because of regeneration failures, difficulty recruiting seedlings into sapling and pole classes, and harvesting levels that exceed growth. Management confusion has resulted from the scarcity of research on northern white-cedar ecology and silviculture, particularly because northern white-cedar is an anomalous tree species. This article synthesizes recent and historical northern white-cedar literature, with a focus on ecology, regeneration, cedar-wildlife interactions, and silviculture. Although a number of past studies have produced contradictory findings, some generalizations of use to the practitioner can be made: northern white-cedar is of small stature, slow growing, decay prone except on cliff sites, and found in both early- and late-successional stands. Northern white-cedar appears to be a highly variable species that can adapt to a wide range of environmental stresses. Because management of this resource has proven difficult, northern white-cedar silvicultural guidelines are needed throughout its range.

Pre‐industrial landscape composition patterns and post‐industrial changes at the temperate–boreal forest interface in western Quebec, Canada

“…Finally, the area co-dominated by white cedar and pines in the pre-industrial period represents a contradictory association (Group 3a). White cedar is a fire-sensitive and shade-tolerant late successional species Hofmeyer et al 2009), while white pine (Pinus strobus) and red pine (Pinus resinosa), which are currently the main pine species in this area, are fire-adapted species (Wendel & Smith 1990;Flannigan 1993;Abrams 2001). Small-scale surface fires could maintain uneven-aged stands of white pine (Quinby 1991;Abrams 2001), and could also allow the maintenance of white cedar in the landscape.…”

Unexpected warming‐induced growth decline in Thuja occidentalis at its northern limits in North America

“…This could result in a delay of soil frost thawing, which has been shown to be a growth limiting factor for Pinus sylvestris L. (Repo et al, 2005) and Picea abies L. Karst (Jarvis & Linder, 2000). The paradoxical shift from a water excess constraint during the spring to a drought constraint in the summer may be attributed to the shallow root system that cedar develops in hydric edaphic conditions (Musselman et al, 1975;Hofmeyer et al, 2009). During the summer lowering of the water table, the upper layer of organic soils becomes dry and the cedar's shallow roots cannot supply water.…”

“…Cedar is a long-lived and shadetolerant evergreen tree species native to eastern North America, with a latitudinal distribution ranging from James Bay, Canada, to southern New York, Ohio and Michigan, USA (Little, 1971). It displays a very plastic tolerance to edaphic moisture conditions, occupying both poorly drained lowland sites and xeric rocky sites (Hofmeyer et al, 2009). Two hypotheses concerning the growth responses of cedar to climate from 1953 to 2010 were postulated and tested statistically.…”

Arbuscular mycorrhizal inoculation has similar benefits to fertilization for Thuja occidentalis L. seedling nutrition and growth on peat soil over a range of pH: implications for restoration

“…Cedar is a dominant tree in rich swamps or forested rich fens with calcium rich groundwater and a pH above six in northeastern North America (Johnston 1990;Fraver et al 2009;Ott and Chimner 2016). Although cedar is most dominant in high pH soils, cedar can also be found in more acidic soils (pH < 5.5), often as an associate species in mixed stands (Johnston 1990;Hofmeyer et al 2009). Cedar swamps are a valuable ecosystem in the Great Lakes region.…”