Johnson et al. ______

MANAGING AND BALSAM WOOLLY ADELGID AT NATIONAL PARK

Kristine Johnson, Glenn Taylor, and Thomas Remaley

ABSTRACT Great Smoky Mountains National Park (GRSM) was established in 1935 to protect 525,000 acres of the Blue Ridge Mountains in western North Carolina and east . It is the largest area in the eastern US managed as wilderness and the most heavily visited National Park. While about 80% of the Park’s forests were at least selectively logged (including several billion board feet of hemlock), some of the most extensive old growth forests in the east remain, and a majority of the remote higher elevations were spared (Pyle 1985, Stupka 1964). A 1994 study verified 726 acres of old growth hemlock, with ages over 400 years and tree heights over 160 feet (Johnson 1995 and Yost et al. 1994). Fire suppression has caused an increase in hemlock in the understory of several forest types, including cove and pine-oak, over the past 30 years (Jenkins and White 2002). Hemlocks are a key species as habitat for many upland birds, invertebrates and mammals and shade miles of riparian areas (Shriner 2002). The Park contains the largest remaining area (48,721 acres) of the southern Appalachian 232 red spruce/Fraser forest type (USDA Forest Service 1988). The balsam woolly adelgid (BWA) was discovered in the northeastern section of the Park in 1962; initial management consisted of clearcutting dozens of acres in an attempt to confine the infestation, such as was done to control southern pine beetle. BWA had spread throughout the range of fir in the Park by 1985, when the National Park Service and USDA Forest Service began a program of insec- ticidal soap spraying in two accessible areas, Clingman’s Dome and Balsam Mountain Road. Remnant fir stands have been mapped and bark samples evaluated for juvabione, a juvenile hormone-related compound thought to inhibit BWA reproduction. A genotype preservation plantation was established in cooperation with the University of Tennessee, and a 2001 study delineated remnant stands surviving on several peaks (Kloster 2001). Soap spraying continues on Balsam Mountain Road, and BWA is annually monitored at four locations. Hemlock woolly adelgid (HWA) was discovered in the Park in April, 2002, near Fontana Lake. The Park had already begun documenting pre-infestation baseline conditions with the 1994 old growth survey and cooperative studies with entomologists at the University of Ten- nessee and North Carolina State University to inventory invertebrates associated with hem- lock (Johnson et al. 1999). A new vegetation map prepared by the University of Georgia (Welch et al. 2002) provided detailed maps of various forest types, which became an impor- tant tool in surveying hemlock stands for HWA. This new map shows a total hemlock re- source of 87,473 acres in all forest types with a hemlock association, including 5,000 acres of pure hemlock.

Third Symposium on Hemlock Woolly Adelgid Presentations ______Managing HWA and BWA at Great Smoky Mountains National Park

Management priorities were established according to tools available (insecticidal soap and oil, systemic insecticides, and biological control), importance of hemlock resources, and accessibility. While the remote old growth stands are the most valuable ecologically, they are the most difficult to treat logistically, and biological control agents are the best possibility for maintaining a viable forest. Roadside and developed areas (campgrounds, picnic areas, and visitor centers) are relatively easy to manage using insecticides. Biological control has been used at a total of 30 sites, and 900 acres of hemlock were treated for HWA with insecticides in fiscal year 2004.

REFERENCES Jenkins, M.A. and P.S. White. 2002. Cornus florida L. mortality and understory composi- tion changes in western Great Smoky Mountains National Park. The Journal of the Torrey Botanical Society 129(3):194–206. Johnson, K.D, F.P. Hain, K.S. Johnson, and F. Hastings. 1999. Hemlock Resources at Risk in the Great Smoky Mountains National Park. Proceedings: Symposium on sustainable Management of Hemlock Ecosystems in North America. USDA-USFS publication GTR-NE-276 Johnson, K.S. 1995. Eastern Hemlock Forest Delineation in Great Smoky Mountains National Park. In-house publication- Resources Management and Science Division, Great Smoky Mountains National Park, Gatlinburg, Tennessee. 39 p. 233 Kloster, M. 2001. Delineation of Surviving Stands. Great Smoky Mountains National Park report. Pyle, C. 1985. Vegetation Disturbance History of Great Smoky Mountains National Park: An Analysis of Archival Maps and Records. Research/Resources Management Report SER-77 NPS, Southeast Region. 69 p. Shriner, S. 2002. Personal communication regarding hemlock in vegetation monitoring points in Great Smoky Mountains National Park for a Ph.D. dissertation at North Carolina State University Department of Zoology. Stupka, A. 1964. Trees, Shrubs and Woody Vines of the Great Smoky Mountains National Park. University of Tennessee Press, Knoxville Tennessee.186 p. USDA Forest Service. 1988. Evaluation of Spruce and Fir Mortality in the Southern Appa- lachian Mountains. Protection Report R8-PR 13 October 1988. Welch, R., M. Madden, and T. Jordan. 2002. Photogrammetric and GIS techniques for the development of databases of mountainous areas: Great Smoky Mountains National Park. ISPRS Journal of Photogrammetry and Remote Sensing 57:53-68 Yost, E.C., K.S. Johnson, and W.F. Blozan. 1994. Old Growth project: stand delineation and disturbance rating. National Park Service, Great Smoky Mountains National Park, Technical Report NPS/SERGSM/NATR. 102 p.

Presentations Third Symposium on Hemlock Woolly Adelgid