1. Glenn Kohler FS 533 Background photo: eastern hemlock mortality, Bill Ciesla Silvicultural treatments for management of the hemlock woolly adelgid in the northeastern U.S.

2. Hemlock woolly adelgid (HWA), an exotic pest, is causing widespread mortality to eastern hemlocks in the eastern U.S. Connecticut Agricultural Experiment Station

3. Following HWA caused mortality ► sites colonized by birches, oaks, and maples; resulting in a more homogenous hardwood dominated landscape William M. Ciesla, Forest Health Management International

4. ► exotic plants may invade the site Anne Eschtruth, UC Berkeley

5. salvage logging? ► 3 silvicultural options following hemlock mortality  do nothing  cut 20-50% dead hemlock  cut >50% dead hemlock Haliburton Forest, Ontario, CanadaShaughnessy Forest Products, New Hampshire

6. PURE HEMLOCK ZERO20-50>50 HARDWOODS +CHANGED UNDERSTORY PLANTED REGEN. (ie PINE) CAN COMPETE WITH HARDWOODS DAMAGE HEALTHY HEMLOCK SEEDLINGS?SNAGS = HABITAT EROSION? INVASIVES? +WEEDY SPECIES

7. ► Salvage logging may cause more environmental damage than HWA alone.  increased nitrification, soil pH, and nitrogen leaching ► Pre-emptive salvage is not recommended.  eliminates possible HWA tolerant seed source.

8. Rehabilitation planting ► Replacement conifers:  native pine, spruce, or fir ► Breeding  HWA resistant Chinese hemlock has been crossed to Carolina hemlock Single tree/group selection in Red spruce (Picea rubens), Eastern Hemlock (Tsuga canadensis), Balsam fir (Abies balsamea) stand on the Penobscot Experimental Forest. Photo: Doug Maguire, Oregon State University

9. Regeneration ► Hemlock regeneration site selection  Factors that increase tolerance to HWA: ► soil moisture ► low nitrogen ► cold temperatures Photo: Chris Evans, University of Georgia

10. Regeneration cont. ► plant hemlock in small gaps (<100 m 2 ) to reduce competition from hardwoods. ► expose mineral soil if seeding hemlock. ► vegetation control is needed in open areas.

11. Take home ► surviving hemlocks can be regenerated on cold, wet, low N sites. ► group selection cutting, soil prep., and weed control help natural hemlock regeneration. ► protect unique seed sources for the future! www.geocaching.com