Parks in Partnership: Great Lakes Commission

November 13, 2024

By Julie McLaughlin, Natural Resources Coordinator

Fall is the time of year when most plants begin to shut down for the winter. We see the trees change colors, the late wildflowers go to seed, and our first frost has already occurred. Meanwhile, one particular plant becomes the focus of natural areas stewardship– common reed, aka Phragmites, aka Phragmites australis subsp. australis.

Phragmites is a large wetland grass with distinct tassels at the top of a 6-15 foot tall plant. There are two subspecies: the introduced and invasive Phragmites australis subsp. australis, and the native Phragmites australis subsp. americanus – yes, we do have a native Phragmites!

Unfortunately, due to its invasive nature, the introduced species is much more common, especially in developed areas like ditches, roadsides, urban wetlands, and Great Lakes shorelines.

The introduced Phragmites was originally found along roadsides in southern Michigan in 1979, with the first official collection documented in 1975. Since then, it has become ubiquitous in wet areas, and is infamously difficult to get rid of once it has established. It forms monocultures, or large areas of a single plant, spreading far and wide from horizontal stems and fluffy seeds. Not only are monocultures of phragmites thick and difficult for wildlife to move through, these plants shade out and compete for resources with native wet meadow plants. These non-indigenous plants aren’t beneficial for wildlife, as few animals recognize them as a food resource.

Reducing and removing

Organizations and landowners throughout the Great Lakes have tried every known tactic to remove this plant. Phragmites management is a good example of what is called Integrative Species Management (IPM), which involves using a combination of different techniques such as mowing, herbicide, burning, and grazing, to control an invasive species. However, the lack of a simple, “tried-and-true” approach has often frustrated land managers. That’s where the Phragmites Adaptive Management Framework (PAMF) comes in.

PAMF uses a scientific approach to develop management guidelines for Phragmites infestations. Directed by the plant’s annual life cycle, land managers collect data like density, size, and hydrology from an enrolled Management Unit (MU). PAMF collects this data and uses modeling to provide a customized management plan for each stand enrolled in the program. The more stands enrolled in the program (148 as of the time of this writing), the more accurate the model, and ideally the more successful the management will be. A key word in the program name is Adaptive, meaning that the management guidance changes over time depending on each stand’s annual monitoring and management reports.

“This program is such a great opportunity to not only take advantage of this important resources, but also to be able to contribute to the scientific community so that we can improve best management practices for phragmites control,” said Katie Carlisle, Chief of Natural Resources and Regulatory Compliance.

This year, HCMP enrolled 5 Management Units totaling 31 acres within Stony Creek Metropark in the PAMF program. Natural areas staff completed a virtual training, collected leaf samples for genetic analysis, and then met with PAMF employees to conduct monitoring in July. Monitoring entails walking a transect through the widest part of the Phragmites patch and collecting data at 5 points along the line. Using a 1-meter-square frame as a sampling plot, they collected data for the point location, counted the number of stems within the plot, measured the width of 3 stems, described the overall health of the plants, and took photos of the surroundings.

Management guidance based on monitoring results was provided for each unit and included a combination of chemical and mechanical control. The first chemical treatment was implemented in September and October, while the plant was in its translocating phase, which means it is sending resources to its roots ahead of the deep freeze of winter. Through this specific grant funding from the Great Lakes Commission, the management recommendations for this year and for 2025 were able to be privately contracted, which added to the amount of management HCMA was able to accomplish through the park system.  The last treatment for this year (or early next year) will be to remove biomass from one of the stands using prescribed fire. Stands will be monitored again next year and managed again under the PAMF guidance.

Science of management

By participating in the PAMF program, not only are the Metroparks getting customized guidance and funding, but we are also contributing data to the larger database, which is then used to fine-tune management suggestions for everyone in the program. We may not know all the organizations enrolled, but every one of us is providing important scientific information to benefit wetlands throughout the Great Lakes basin. With this framework in place, work in southeast Michigan is directly connected to sites as far as the western Upper Peninsula.

This partnership is helping to restore invaded wetlands, and provide critical habitat for wetland plants and animals, as well as filtering and slowing water runoff. It’s estimated that Michigan has lost 40-50% of its original wetlands due to agriculture and development. We hope that with science-based management, we can reverse the trend from becoming more invaded to becoming a more diverse wetland full of native plants that are still hanging on under the thick canopy of Phragmites – like boneset, Joe-Pye Weed, swamp milkweed, monkey flower, and blue vervain.

Sources:

https://www.greatlakesphragmites.net/pamf/

https://www.canr.msu.edu/news/a_history_of_wetlands_in_michigan_part_1_hintzen15