Impacts of Beech Bark Disease

Research Issue

Aerial photos of the Tionesta Scenic and Research Natural area revealed large areas of discoloration of foliage and defoliation suspected to be beech bark disease (BBD). In 2000, very high populations of the beech scale (Cryptococcus fagisuga) were observed when ground-truthing these areas of discoloration on the Tionesta Scenic and Research Natural Area. In anticipation of mortality, a small number of American beech trees were selected for continued monitoring. These trees were selected to mirror existing long term BBD monitoring plots elsewhere in its range. With beech mortality reaching 52% in 5 years it became obvious that the impact of BBD on old growth American beech-eastern hemlock forest required a more in-depth evaluation. We turned to plots installed by George Zimmermann in 1980. He established a grid of 676 plots on this 855 hectare remnant of unmanaged old growth hemlock–beech forest.  In 1998 and 1999 USDA personnel relocated 588 of these plots and documented their GPS location and differential correction. 

Our Research

• To provide an in depth evaluation of the impact of BBD on the Tionesta, old growth, beech-hemlock forest type by re-measuring part of the long established Zimmermann grid of plots. The data will be of dual use for it will be used in an assessment of the BBD module of the FVS model being developed by Jones et al. (The Forest Vegetation Simulator (FVS) is the USDA Forest Service's nationally supported framework for forest growth and yield modeling.) 
• To document, and seek an explanation for, beech mortality levels detected in off plot observations that far exceed expectations derived from an existing dispersed grid of FHM and FIA plots on the ANF. 
• Uses the documented impact of Beech Bark Disease on unmanaged old-growth stands of the beech-hemlock forest type as an indicator of potential long term outcomes in areas where management promotes northern hardwoods dominated by beech and hemlock.  

Expected Outcomes

• This research will contribute to our understanding of the impact of BBD on the Allegheny plateau old growth remnant American beech-Eastern hemlock forest.  
• It was in forests very similar to this type that Ehrlich made his seminal observations of BBD in 1934 and now nearly 100 years later, we can observe BBD impacting an old growth forest and learn a lot about this disease complex with the hindsight of  those earlier observations  
• This project will provide data which can be used to test the USDA FS Forest Vegetation Simulator BBD keyword add-file.

Research Results

Morin, Randall S.; Liebhold, Andrew M; Gottschalk, K.W.; Woodall, Chris W.; Twardus, Daniel B.; White, Robert L.; Horsley, Stephen B.; Ristau, Todd E. 2006. Analysis of forest health monitoring surveys on the Allegheny National Forest (1998-2001). Gen. Tech. Rep. NE-339. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northeastern Research Station. 102 p. 

Research Participants

Principal Investigator

• Richard Turcotte, USDA Forest Service-Forest Health Protection, Northeastern Area

Research Partners

• Susan Stout, USDA Forest Service, Northern Research Station, NRS Research Project Leader and Silviculturist
• Todd Ristau, USDA Forest Service, Northern Research Station, Research Ecologist 
• Robert White, USDA Forest Service, Allegheny National Forest, Silviculturist 
• Andrea Hille, USDA Forest Service, Allegheny National Forest , Silviculturist 
• Randall Morin, USDA Forest Service, Northern Research Station, Research Forester

For further information log on website :
http://www.nrs.fs.fed.us/sustaining_forests/conserve_enhance/timber/contrasting_silvicultural_systems/