Download (PDF 356 KB): https://research.fs.usda.gov/download/treesearch/14748.pdf
Abstract
Eastern hemlock (
Tsuga canadensis (L.) Carr.) occurs in old-growth stands sometimes over 400 years old, throughout its principal range from Nova Scotia to Wisconsin. Studies based on aging as well as diameter distributions indicate a stand structure often dominated by an initial multi-decade post-disturbance pulse of seedling establishment, followed after a century or more by one or more subsequent pulses of seedlings and saplings. Over 400 years these new stems tend to produce a truly all-aged forest. The seedling and sapling layers are eliminated when white-tailed deer populations exceed 3 to 4 per km² (12-15/sq. mile), and entire stands are lost periodically to wind storms and accidental fires. Management for this old growth type requires two major components: control of deer populations, and maintenance of a mosaic of developmental age classes so that, if the oldest stand is lost, mid-aged younger stands in the area are poised to replace it.
Parent Publication
Citation
Loucks, Orie L.; Nighswander, James. 2000. Recognizing all-aged hemlock forests. In: McManus, Katherine A.; Shields, Kathleen S.; Souto, Dennis R., eds. Proceedings: Symposium on sustainable management of hemlock ecosystems in eastern North America. Gen. Tech. Rep. NE-267. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 183-187.
