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

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.

The Impact of Deer Browsing on the Allegheny Forest Type

In many areas of the Allegheny Plateau, natural forest regeneration fails to occur after harvest cuttings. Browsing by an unusually large population of white-tailed deer is the primary cause of many of these regeneration failures. In this study, vegetational surveys were made of the woody and herbaceous plants inside and outside 20, 13-year-old, 1 ac deer exclosures in the Allegheny National Forest, Pennsylvania. Deer browsing had reduced the height of the seedlings in the unfenced areas, thereby maintaining large numbers of smaller stems. In the fenced areas, seedlings grew to normal height, and the competition that resulted from crown closure reduced the total number of stems present. Deer browsing also caused a significant reduction in Rubus sp. and a corresponding increase in grass and sedge in the unfenced areas. North. J. Appl. For. 6:162-165, December 1989.