Meadows Resource Brief 2023

The Grand Parade is Valley Forge's most culturally and ecologically significant meadow.

NPS Photo / L. Schmel

Meadow Resources at Valley Forge

Current management objectives focus on managing this landscape in such a
way that it retains its historic appearance while promoting high habitat
values and native plant communities, which in turn support ecologically
important bird and insect species.

A Red-banded hairstreak (Calycopis cecrops) above, feeds on Goldenrod (Solidago spp.), an important fall nectar source for many butterfly and pollinator species.

NPS Photo / L. Schmel

Objectives of the Meadow Management Plan

---

• Enhance grassland value by increasing native biodiversity

• Preserve and restore native plant and animal populations and their habitats

• Maintain and improve cultural resources

---

To measure how well the plan objectives are being met, data are collected from 177 points across park meadows. Using a 5m by 5m grid, researchers document which native and invasive plant species are present and the percent cover for each.

These data help the park determine if the grassland plant communities have the necessary native species and diverse mix of food plants needed to support native wildlife species, including populations of special status plant, butterfly, and bird species.

A Critical Habitat

Valley Forge National Historical Park contains more than 1,300 acres managed as meadows and grasslands; one of the largest occurrences of such habitat in Eastern Pennsylvania.

Bobolinks (Dolichonyx oryzivorus), female shown here, have returned to breed in the park. Bobolinks are ground-nesting birds who require large grassland habitats. Meadow indicator species like Bobolinks reflect good meadow diversity and habitat.

Bill Moses

Meadow Restoration Techniques

There are a variety of approaches currently in use at Valley Forge for meadow restoration. Overall, management is two-pronged: suppress non-native invasive plant growth while encouraging native grasses and flowering plants to grow.

For invasive plant suppression, fields may be treated with alternating mowing regimes, haying (removal of plant material from area), manual cutting and removal, controlled burns, or chemical control by application of targeted herbicides on select species.

Restoring meadows through deer reduction, herbicide application, and mowing and haying.

NPS Photos / L. Schmel

Non-native invasive plant species, such as Small carpetgrass (Arthraxon hispidus)
shown above, form dense monocultures that frequently outcompete shorter native plants such as Indian Tobacco (Lobelia inflata) shown below. The invasives often have no natural predators, allowing them to proliferate.

NPS Photo / L. Schmel

Sometimes, suppression of non-native plants is enough to allow the native seedbank in the soil to germinate and grow. Other times, native grass and flowering plant seed is sown directly into the soil of areas where invasive plants have previously been removed. Reduction of deer helps native forb populations in the meadows.

The Grand Parade

The Grand Parade is Valley Forge’s most culturally and ecologically significant meadow. Once the location where General Friedrich von Steuben drilled soldiers during the Valley Forge Encampment, it is now the largest meadow habitat within the park at over 300 contiguous acres. Much effort has been put into restoring its historical and environmental value in the last several years.

Recent data indicate that the percent cover of native forb (herbaceous flowering plants) and woody species has maintained or increased since 2021. This year saw a large decrease in invasive Japanese stiltgrass (Microstegium vimineum) cover by almost 50%.

Recent data indicate that the percent cover of native forb (herbaceous flowering plants) and woody species has maintained or increased since 2021.

NPS Graphic

The presence of Native Field thistle (Cirsium discolor) can indicate the health of the meadows.

NPS Photo / L. Schmel

Metrics of Meadow Restoration

The most recent data available (2023) indicates that the meadows are already reaching some desired thresholds*. The very mild winter with no snow events, dry conditions throughout spring 2023, followed by heavier rains in early summer led to some changes in the plant communities.

Presence of Native Field thistle (Cirsium discolor), image on the left, meets the criteria for “good” and native Ragwort percentage nearly doubled. Thistles and ragwort are key larval food and nectar sources for butterflies and other pollinators throughout the season. Ragwort appears early in the growing season, and thistles bloom into the fall. The meadows provide invaluable habitat, food, and breeding ground for many migrating species.

Native wildflower seeds were collected by NPS staff to be distributed to areas of low diversity in the future. New in 2023: All three meadow indicator bird species, Bobolinks, Meadowlarks, and Grasshopper sparrows, have been observed in our meadows!

_{*Thresholds from ‘Desired Meadow Condition Report’ for Valley Forge, Latham, 2012}