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Individual Highlight

Collaboration seeks to preserve Chesapeake Bay Watershed health in the face of hemlock decline

Photo of High-quality stream on Tioga State Forest, Penn., located in the headwaters of the Chesapeake Bay.  Decline of eastern hemlock from hemlock woolly adelgid infestations, may affect the hydrology of the local watershed.High-quality stream on Tioga State Forest, Penn., located in the headwaters of the Chesapeake Bay. Decline of eastern hemlock from hemlock woolly adelgid infestations, may affect the hydrology of the local watershed.Snapshot : Few studies have examined how insect outbreaks affect landscape-level hydrologic processes. Anticipating hydrologic impacts resulting from the decline of hemlock trees in watersheds infested with hemlock wooly adelgid, Forest Service scientists are partnering with state and federal conservation agencies and nongovernmental organizations to devise management strategies for ameliorating hydrologic impacts from the pending decline of eastern hemlock in northern watersheds of the Chesapeake Bay.

Principal Investigators(s) :
Fajvan, Mary AnnMorin, Randall
Research Location : Northern counties in PA and NY of the Chesapeake Bay watershed and several watersheds on Tioga State Forest, PA.
Research Station : Northern Research Station (NRS)
Year : 2017
Highlight ID : 1218

Summary

Eastern hemlock (Tsuga canadensis) is a long-lived, shade tolerant tree that is considered a foundation species, especially in riparian corridors. Hemlock stands are characterized by a dense evergreen canopy that creates a unique microenvironment within a broader deciduous forest landscape in eastern North America. Hemlock serves a distinct ecohydrological roles: it maintains year-round transpiration rates, and it increases canopy interception rates. Since the 1950s, the non-native hemlock woolly adelgid (I), or HWA, has caused widespread mortality resulting in permanent reductions in winter transpiration rates. In the southern Appalachians, hemlock loss saw permanent reductions in watershed yield and increases in peak flow. Forest Service scientists used MODIS imagery and tree data from Forest Inventory and Analysis plots located within sub-watersheds of the Chesapeake Bay to estimate hemlock basal area. Watersheds where hemlock basal area is at least 6 percent are located in northern Pennsylvania and southern New York. In partnership with the Pine Creek Watershed Council (Tioga County, Pennsylvania) and the U.S. Geological Survey, Forest Service scientists are prioritizing conservation efforts for field monitoring of hydrologic processes and supplemental conifer planting to protect the unique cold water heritage and trout streams in anticipation of hemlock decline.

Forest Service Partners

External Partners

 
  • Endless Mountain RC&D
  • Pennsylvania Bureau of Forestry
  • Pine Creek Watershed Council
  • Tioga Co. Conservation District
  • U.S. Geological Survey

Strategic
Program Areas

Priority
Areas