Forest Continues to Recover at Valley Forge National Historical Park - Summer 2016

Chestnut Oak seedling and trout-lily in VFNHP
Chestnut Oak seedling and trout-lily sprouting on forest floor.

NPS Photo

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News Release Date: June 21, 2016

Contact: Kate Jensen, (610) 783-1035

VALLEY FORGE, PA - The forest at Valley Forge National Historical Park is continuing to recover from decades of over-browsing by White-tailed Deer. Following six years of implementation of the park's White-tailed Deer Management Plan/Environmental Impact Statement (plan), monitoring by National Park Service staff continues to document native seedlings that had not been seen just a few years ago, including maple, red bud, maple-leaf viburnum, dogwood, oak, tulip-poplar, black gum, hickory, cherry, hackberry, ash, and sassafras. The mean number of woody seedlings within 3-square meter test plots has increased from two in 2010 to 20 in 2015 and this past year saw a increase in the number of woody stems in the 26-50cm height class, indicating two or more years of survival.Kate Jensen, the park's Ecologist, noted, "Park staff and visitors continue to report native trees, shrubs and wildflowers parkwide.It's exciting to see the forest recover."

These sightings indicate that the deer management plan is continuing to achieve its objective of allowing the native forest to grow and mature in order to provide habitat for a range of native wildlife species. Prior to the impelentation of the plan, the increasing deer population over the last two decades and the pressure of over-browsing had stopped forest regeneration. No seedlings outside fenced areas had been left uneaten and the absence of vegetation had led to elimination of habitat, soil erosion, and the spread of exotic invasive species.

In March, the park completed the sixth year of plan implementation. Park staff worked with the United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services on five nights between November 2015 and March 2016 to remove 100 deer from the park through sharpshooting. A total of 3,072 pounds (over one ton) of meat resulting from this action were donated to the Central Pennsylvania Food Bank and provided to food pantries, soup kitchens, and other organizations across 21 counties in Pennsylvania.

The deer management action included extensive measures to ensure a safe, humane, and successful operation, such as using highly qualified and experienced marksmen familiar with the park's geography and with conducting reduction activities in a suburban environment, conducting population reduction actions only when the park is closed, observing safety zones, and using special, non-lead ammunition that is safe for use in the environment. The NPS closely coordinated all activities with township and state law enforcement officials, and with the Pennsylvania Game Commission.

The estimated deer density in the park is 44 deer per square mile (234 deer). Although above the plan's initial target level of 31-35 deer per square mile, this represents a significant reduction from the estimated 241 deer per square mile (1,277 deer) present in 2009.

The number of deer removed in future years will be based on the results of annual deer population monitoring, updated calculations of deer reproductive rates, and regular forest health monitoring. This summer, park staff again will count trees within long-term monitoring plots to assess progress toward the forest regeneration goal of 8,079 tree seedlings per acre.

The park will continue to use lethal reduction until the initial target deer density is achieved or forest regeneration reaches its target. Once the target deer density or adequate forest regeneration is achieved, and once an acceptable reproductive control agent becomes available, the park will use reproductive control to maintain the target deer density level.

About Valley Forge National Historical Park. Valley Forge is the site of the 1777-78 winter encampment of George Washington and the Continental Army. The park commemorates the sacrifices and perseverance of the Revolutionary War generation and honors the ability of citizens to pull together and overcome adversity during extraordinary times. Learn more at

Last updated: June 21, 2016

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King of Prussia, PA 19406


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