Conservation of Hemlock Species in the Eastern United States

CONTACT INFORMATION

Please visit our Hemlock Slideshow to view photos taken over the
last 7 years depicting our hemlock conservation work.

High elevation Eastern hemlock at Mountain Lake Resort in Virginia.

Conservation of Hemlock Genetic Resources in the Eastern United States

Eastern (Tsuga canadensis) and Carolina (Tsuga caroliniana) hemlock are endemic species in eastern North America that are under threat due to infestations of the exotic insect pest Hemlock Woolly Adelgid (HWA, Adelges tsugae).  Eastern hemlock has an extensive geographic distribution that extends from Nova Scotia west into Wisconsin and Minnesota and south along the Appalachian Mountain chain into northern Georgia and Alabama, with several peripheral disjunct populations occurring to the east and west of the main range.  Carolina hemlock has a much smaller distribution restricted to a relatively small number of populations located in the southern Appalachian Mountains of the Carolinas, Georgia, Tennessee, and Virginia.  Both hemlocks are foundation species in the ecosystems in which they occur, helping to create unique microenvironments that support unique floral and faunal assemblages.   HWA, introduced from Japan to the United States in 1951, currently infests approximately 50% of hemlock ecosystems in the eastern United States, has caused widespread hemlock mortality and local population extinctions in the southeastern and mid-Atlantic regions, and may cause the functional elimination of Eastern and Carolina hemlocks from their native habitats. 

Andy Whittier climbs a Carolina hemlock at Looking Glass Rock in Western North Carolina

As part of the larger integrated effort to mitigate the impacts of HWA, Camcore has been cooperating, since 2003, with the USDA Forest Service Forest Health Protection to conserve the genetic resources of Eastern and Carolina hemlocks through seed collections, seed banking, and conservation seed orchard establishment.  The goal is to maintain, in perpetuity, hemlock genetic material with high levels of diversity and adaptability that will be available for the eventual restoration of degraded or eliminated populations. 

 

The following is list of some significant accomplishments through December 2010.

• Seed has been collected from 134 mother trees in 19 populations of Carolina hemlock in the southeastern U.S. (see Map No.1).
  

Figure 1: Carolina hemlock sites collected and explored from 2003 to 2010.

• Seed has been collected from 237 mother trees in 35 populations of Eastern hemlock in the southeastern U.S. (see Map No.2).

Figure 2: Southeastern US Eastern hemlock sites collected and explored from 2005 to 2010.

• Seed has been collected from 32 mother rees in 4 populations of Eastern hemlock in the northern U.S. (see Map No.3).

Figure 3: Northern Eastern hemlock sites collected and explored from 2005 to 2010.

Mature Carolina hemlock cones are picked, dried, cleaned, and packaged for either placement in seed banks or shipped for ex situ establishment.

• Seed from 83 Eastern hemlock and 47 Carolina hemlock mother trees has been sent to the US Forest Service National Seed Laboratory (NSL) for long-term preservation and cataloging in the GRIN (Germplasm Resources Information Network) database.
  
  
• In 2008, Camcore established a Carolina hemlock conservation orchard at the Upper Mountain Research Station  in Ashe County, North Carolina. 
  

Jaime Zapata from Bioforest-Arauco holds a healthy Carolina hemlock seedling in Chile.

 

• In 2008, a Carolina hemlock conservation orchard was established by Bioforest-Arauco in the Bio-Bio region of Chile.
  
• In 2010, Bioforest-Arauco began to root stem cuttings from the Carolina hemlock conservation bank so that it can be replicated on a second site in Chile.
  
  
  
  
  
  
  
• We have sent Eastern and Carolina hemlock seed to the US Forest Service for conservation bank establishment at the Beech Creek Seed Orchard in Murphy, NC.
  

Laercio Duda and Riccardo Paim with Rigesa-MeadWestvaco help to establish hemlock orchards in southern Brazil.

• In 2010, conservation orchards for both Eastern andCarolina hemlock were established by Rigesa MeadWestvaco in Santa Catarina, Brazil.
  
  
  
  
  
  
  
  
• We have completed a range-wide study of population genetic structure and diversity in Eastern hemlock using microsatellite molecular markers and are planning a similar study for Carolina hemlock to begin in 2011/2012.
  
  

Robert Jetton evaluates germination at the NCSU Phytotron..

 

• We have developed pre-germination seed stratification protocols for both hemlock species.

 

 

 

 

 

 

 

 

 

HEMLOCK CONSERVATION CONTACTS

If you would like more information about Camcore’s hemlock conservation program or would like to contribute to our effort please feel free to contact one of the following individuals:

Research Forester Andy Whittier and Project Leader Robert Jetton inspecting Eastern hemlock foliage.

Robert Jetton, Research Assistant Professor and
Hemlock Project Leader

Phone: 919.515.6425
Email: [email protected]

Andy Whittier, Hemlock Conservation
Research Forester

Phone: 919.513.4878
Email: [email protected]

Bill Dvorak, Director of Camcore
and Professor of Forestry &
Environmental Resources

Phone: 919.515.6424
Email: [email protected]

 

Camcore Hemlock Publications

K.M. Potter, R.M. Jetton, W.S. Dvorak, V.D. Hipkins, and W.A. Whittier, 2011. Widespread inbreeding and unexpected geographic patterns of genetic variation in eastern hemlock (Tsuga canadensis), an imperiled North American Conifer. Conservation Genetics DOI 10/1007/s10592-011-0301-2. November 30, 2011.

R.M. Jetton, J.F. Monahan, and F.P. Hain, 2010. Laboratory studies of feeding and oviposition preference, developmental performance, and survival of the predatory beetle, Sasajiscymnus tsugae on diets of the woolly adelgids, Adleges tsugae and Adelges piceae. Journal of Insect Science Vol. 11, Article 68: 1-14.

R.M. Jetton, F.L. Hastings, and F.P. Hain, 2009. Arthropod diversity associated with old and secondary growth eastern hemlock (Tsuga canadensis) in the Great Smoky Mountains National Park. Journal of the North Carolina Academy of Sciences 152(2). pp,70-77.

K.M. Potter, W.S. Dvorak, B.S. Crane, V.D. Hipkins, R.M. Jetton, W.A. Whittier, and J.R. Rhea. 2008. Allozyme variation and recent evolutionary history of eastern hemlock (Tsuga canadensis) in the southeastern nited States. New Forests 35:131-145.

R.M. Jetton, F.P. Hain, W.S. Dvorak, and J. Frampton, 2008. Infestation Rate of Hemlock Woolly Adelgid (Hemiptera: Adelgidae) Among Three North American Hemlock (Tsuga) Species Following Artificial Inoculation. Journal of Entomological Science Vol. 43, No. 4: 438-442.

R.M. Jetton, W.A. Whittier, W.S. Dvorak, and K.M. Potter. 2008. Status of Ex situ Conservation Efforts for Eastern and Carolina Hemlock in the Southeastern United States. Forth Symposium on Hemlock Woolly Adelgid in the Eastern United States. USDA Forest Service. FHTET-2008-01. Hartford, CT.

R.M. Jetton, W.S. Dvorak, and W.A. Whittier. 2008. Ecological and genetic factors that define the natural distribution of Carolina hemlock in the southeastern United States and their role in ex situ conservation. Forest Ecology and Management 255: 3212-3221.

M.E. Tighe, W.S. Dvorak, W.A. Whittier, J.L. Romero, and J.R. Rhea. 2005. The ex situ conservation of Carolina hemlock. pp. 180-190. In: B. Onken and R. Reardon (Eds.), Third Symposium on Hemlock Woolly Adelgid in the Eastern United States. USDA Forest Service. FHTET-2005-01. Asheville, NC.

Posters

Jetton, R.M., Mayfield, A.E., and Hain, F.P. 2011. Operation Adelgification: Evaluating a Rain Down Technique to Artifically INfest Seedlings with the Hemlock Woolly Adelgid. NC. Presented at: Reclaiming Hemlocks and Fires, A Symposium. Waynesville, NC. October 26, 2011.

Jetton, R.M., Potter, K.M., Dvorak, W.S., Whittier, W.A., and Rhea, J.R. 2011. Ex situ Seed Collection Represents Genetic Variation of Carolina Hemlock (Tsuga caroliniana), a Southern Appalachian Endemic Threatened by the Hemlock Woollu Adelgid (Adeldges tsugae).

Jetton, R.M., Potter, K.M., Dvorak, W.S., Whittier, W.A., and Rhea, J.R. 2011. Population Genetics and Ex situ Gene Conservation of Eastern Hemlocks Tsuga canadensis) Threatened by the Hemlcok Woolly Adelgid (Adelges tsugae).

For addtional Information on HWA please visit the following sites

US Forest Service HWA Webpage

Alliance For Saving Threatened Forests