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Conservancy Treats Terrestrial Invasive Species Along Important Waterway

The following article was written by Tyson Johnston, Land Stewardship Coordinator with the Western Pennsylvania Conservancy, and was originally included in the Summer/Fall 2020 edition of the "Tracking Invasive Species with Pennsylvania iMapInvasives" newsletter.

French Creek in northwest Pennsylvania. Credit: Wikipedia - Finetooth/CC BY-SA (link)

In December 2019, the Western Pennsylvania Conservancy was awarded a grant from the Crawford Heritage Community Foundation for the treatment of invasive species in the Conservancy's Venango Riffle Natural Area, an 8.5-acre preserve protecting about 1,600 feet along French Creek in the borough of Venango, Crawford County.

French Creek is documented as having the highest level of aquatic biodiversity of any stream of its size in Pennsylvania and all states to the northeast of Pennsylvania. This reach of French Creek is part of a longer segment containing riffles, runs, and islands, and is an area identified as one of the very highest priorities along French Creek for the Conservancy to protect. The waters here support state-listed fish species, state-listed freshwater mussel species, and federally-listed freshwater mussel species.

The Venango Riffle Natural Area is comprised of two parcels; the first acquired in 1995 and the second in 2012. In 2013, Conservancy staff and volunteers planted all of what had previously been maintained as lawn with native trees and shrubs, including white pine, silver maple, sycamore, black willow, box elder, silky dogwood, elderberry, and pin oak. While the native species that were planted began to grow, the unwelcomed exotic invasive species also quickly moved in. Multiflora rose, Morrow's honeysuckle, garlic mustard, dame's rocket, and Japanese barberry were all present on the site and in need of control.

Multiflora rose shrubs post-herbicide treatment next to a planted maple tree at the Venango Riffle Natural Area in Crawford County. Credit: Andrew Zadnik, WPC

Courtesy of the generous funding provided by the Crawford Heritage Community Foundation, the Conservancy was able to hire a local firm, Ecological Field Services, to provide foliar herbicide treatment across the entire preserve. The treatment occurred in May, and today the results are hard to miss.

Christian Maher, Executive Director of the Crawford Heritage Community Foundation, said, "As a community foundation, we're devoted to improving our natural environment through grants to forward-thinking organizations like the Western Pennsylvania Conservancy. This is our third collaboration and we're excited to see how this will improve the watershed."

To learn more about this invasive species management effort conducted at the Venango Riffle Natural Area by the Western Pennsylvania Conservancy, please query the iMapInvasives database for Treatment record #18998. By creating this query, you'll be able to see the area treated as well as specific details about this management effort.


About the Author

Tyson Johnston holds a B.S. in Geography and Environmental Studies from Slippery Rock University. He has been employed by the Western Pennsylvania Conservancy since 2010 and has managed the Conservancy's preserves across seven counties in northwestern Pennsylvania since 2016. Tyson currently resides near Meadville with his wife, Sarah, and daughters, Morgan and Ashley.

Tyson can be reached via email at



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