Effects of timber harvest on Cimicifuga elata, a rare plant of western forests

Cimicifuga elata (tall bugbane) is a Species of Concern with the U.S. Fish and Wildlife Service and it is considered by Natural Heritage programs in Oregon and Washington to be endangered. Since the species occurs in forests, its conservation could conflict with other forest uses such as timber harvest. It has been postulated that the species is dependent on old-growth coniferous forests. The objectives of this study were to compare populations of this species among sites with differing forest-management histories. In contrast to previous reports, we found that C. elata in uncut old-growth forest was smaller and less reproductive than in clearcuts, probably because plants responded well to additional light in cut-over areas. Plants in areas with other management histories, such as second growth and thinned stands (both >70 years old), were intermediate in size. Population structure also differed among management types. Herbivory by deer and elk was more frequent in clear cuts andedges than in unmanaged old-growth forests. No populations were known at the time of this study from second growth forests of moderate age (20-30 years), and it is possible that competing vegetation excludes C. elata from clearcuts after a few years. Management actions that retain hardwoods, thin stands, or create gaps may improve at least short-term conditions for this speciesKaye and Kirkland "Effects of timber harvest on Cimicifuga elata, a rare plant of western forests." Northwest Science. 1999; 73(3): 159-16