Managing the Lean, Green, Invasive Machine: Phragmites australis
Posted on September 5, 2024
Yesterday, COL staff met up with volunteers and Kowabdanawa odë kė staff for an “experimental” workday at Grand Beach Marsh Preserve. The purpose? Controlling non-native Phragmites (Phragmites australis), an aggressive invasive species that forms dense patches in wetlands, ditches, and along the banks of rivers and streams, colonizing the areas and crowding out native plants. In this particular case, the Phragmites is invading a coastal plain marsh, a globally rare ecosystem chock full of amazing (and rare) native plants. Boooooooooo.
What Do We Mean by “Experimental”?
During the workday, we tried a new invasive control method for the first time. This method is called “spading,” and it goes like this:
Position a spade at a 45-degree angle, 5cm below the ground at the base of the plant. Stomp on the spade to drive it into the soil, aiming to sever the rhizome. Remove the plant from the ground. Collect, bag, and dispose of all plants.
During late summer and early fall, Phragmites plants translocate their energy below ground to store in their rhizomes during winter. We hope our spading will limit the energy storage and weaken the rhizomes (plus, we're disposing of any seed heads in the process, which can’t hurt). While this method is totally herbicide-free, it is also labor-intensive. Oh yeah, and one more thing—we’re not really sure if it’s going to work.
Say what?! We're NOT SURE? Then why on earth would we use our time and human resources this way?
Science, of course!
A Grant That Goes Both Ways
We recently received a grant from the Great Lakes Phragmites Collaborative (GLPC) through the Great Lakes Commission (GLC). to fund one year of Phragmites treatment at three of our properties: Nokmes Creek, Dayton Wet Prairie, and Grand Beach Marsh. The purpose of the grant is twofold: to help us reduce populations of Phragmites on our preserves and for the GLC to collect data that helps them understand the best ways to control Phragmites.
The GLPC will use the data to improve their Phragmites Adaptive Management Framework (PAMF)Phragmites Adaptive Management Framework (PAMF), a collective learning program anyone managing Phragmites can join. PAMF exists to help change the way Phragmites management is done throughout the Great Lakes basin and leads to approaches that maximize the effectiveness and efficiency of Phragmites management.
So, as a grantee, we’re not only treating Phragmites; we’re also contributing to an ongoing study that will help people all over the Great Lakes region effectively manage it! That's what we call a nature high five (which makes people cringe...but we don't care)!
When Will We Know if It Worked?
Next July. We’ll do a second round of spading again next June when the Phragmites is in its growing phase. Then, in July, we’ll conduct our annual Phragmites monitoring and hopefully draw some conclusions about the efficacy of spading. We’ve actually been working on Phrag control at this site using other methods since 2017, and we’ve made significant progress:
With 8 years of data on this site, we should be able to deduce whether the spading was effective. Stay tuned!
Learn more about Phragmites and best management practices here.
This material is based upon work supported by the U.S. Geological Survey under Grant/Cooperative Agreement No. G23AC00436.
