Eastern Native Tree Society

Eastern Native Tree Society (ENTS) [http://www.nativetreesociety.org/] : A not-for-profit Internet interest group formally established in 1996 to celebrate trees in the arts, science, mythology, medicine, and related areas. Present ENTS membership is around 150. An important mission of ENTS is to develop advanced field techniques for measuring trees and maintaining a database of outstanding trees and sites within the eastern forest type. ENTS is considered to be the premier tree measuring organization in the eastern United States and holds annual workshops on tree measuring. The workshops concentrate on methods for measuring tree height, girth, crown spread, trunk and limb volume. At workshops, different height methods are demonstrated and compared. The workshops are held periodically in Mohawk Trail State Forest, Massachusetts and Cook Forest State Park, Pennsylvania. A small elite group of ENTS members headed by Will Blozan climb important trees to measure their heights by the method of dropping a tape from the top of the tree down to the base to get a highly accurate measurement. Trigonometry based methods are then compared with the results of tape drops. The vast majority of trees are measured using a combination of lasers, hypsometers, and trigonometry. Accuracies for tree heights measured through trigonometry are generally within +/- 1.0 feet. However, accuracies to within +/- 0.5 feet are regularly obtained when statistics are applied, and can be within +/- 0.25 feet. It is this high level of accuracy that distinguishes ENTS tree measuring methods from other approaches.

The cofounders of ENTS include Robert T. Leverett, Will Blozan, Dr. David Stahle, the late Dr. Michael Perlman, and Dr. Matthew Therrell. The organization maintains a website at www.nativetreesociety.org [http://www.nativetreesociety.org/] and has an open e-mail list on Google Groups. Edward Frank maintains the website. Information available at the website is available for use in scientific research with permission from one of the officers. The present officers of ENTS are Will Blozan, President; Dr. Lee Frelich, Vice President; and Robert Leverett, Executive Director. Dr. Don C. Bragg is the editor of the Bulletin of the Eastern Native Tree Society [http://www.nativetreesociety.org/bulletin/index_bulletin.htm] .

The organization presently devotes much of its time to scientific research associated with determining the maximum sizes and ages to which trees, by species, grow in the eastern United States, locally, regionally, and range wide. ENTS also makes itself available to other organizations in resolving disputes over tree dimensions, particularly tree heights.

ENTS is involved with the identification and documentation for historical purposes of old growth forest sites. Detailed site descriptions are maintained at the ENTS website. ENTS routinely uses an important, numerically based, type of comparative site documentation. The documentation is formally called Rucker Analysis. One of more indices are computed for each site. Collectively, these indices reveal girth and height patterns for the included species.

Key ENTS members are noted old growth forest researchers. ENTS members help identify potential new old growth sites. Managing for old growth characteristics is a research interest of ENTS.

Some noteworthy accomplishments of ENTS include the engineering of tree height measurement techniques that utilize sine-based mathematics. This approach eliminates the often sizable errors associated with the popular percent slope method or tangent-based mathematics. ENTS has also engineered field-based volume measurement techniques for modeling the trunks of trees. By dividing the trunk into sections and applying geometric solids, principally conoid, paraboloid, and neiloid forms, trunk volume can be measured to within +/- 5.0% of the water displacement volume. Cross-sectional areas are usually treated as circular or elliptical. The zone where a tree trunk divides into two or more trunks is handled through a special technique that takes into account shapes that cannot otherwise easily be modeled.

ENTS is in the process of establishing the discipline of dendromorphometry, a term coined by Professor Gary Beluzo of Holyoke Community College, Holyoke Massachusetts. Dendromorphometry is defined as the art and science of measuring trees in the field and incorporates an assessement of measurement error for each measuement technique.

One of the most notable projects of ENTS is the Tsuga Search Project, accomplished jointly with the Great Smoky Mountains National Park (GSMNP). In Tsuga Search, ENTS locates, climbs, and models the largest eastern hemlocks in the GSMNP. Hemlocks as large as 1,600 cubic feet of trunk volume and 173.1 feet in height have been confirmed through the Tsuga Search Project. Details of all ENTS projects are maintained at the ENTS website.

All ENTS tree measurement data are generated by ENTS members who are certified in ENTS measurement techniques. ENTS does not accept measurement data from other sources. ENTS data are frequently cited within in tree species descriptions in Wikipedia in an effort to correct the historical record.

For funding purposes, ENTS falls under the Friends of Mohawk Trail State Forest, a 501c3 not-for-profit environmental organization.