Fighting an Invader in the Ojibway Prairie Provincial Nature Reserve

This is a roadside ditch full of invasive phragmites, which can be a lot taller than native phragmites. Field technician, Jennifer Barden, for scale!

Habitat enhancement, or improvement, is an important part of the Ojibway Prairie Reptile Recovery program (OPRREC) in Ontario. That is because species recovery initiatives (including conservation translocations) are more likely to be successfull in areas with high quality habitat. One of the ways that we are enhancing habitat for endangered massasauga rattlesnakes and other species at risk is by removing large patches of invasive plants. In doing so we open up new basking sites for snakes and create space for rare tallgrass prairie plants to flourish. This past fall, a roughly 4.6 ha area in the Ojibway Prairie Provincial Nature Reserve (OPPNR) that contains dense patches of the invasive Phragmites australis was the focus of our efforts. To tackle this sizeable task, we were fortunate enough to have enlisted the help of Dover Agri-Serve Inc., a local company that specializes in phragmites control. But what exactly is phragmites, and why does it deserve so much attention?

What is phragmites?

Phragmites (Phragmites australis australis) is also known as the European common reed. This invader is native to Eurasia and is out-competing our local species and damaging important habitats, like the sensitive tallgrass prairie habitat found in OPPNR and surrounding parks. Though mostly found in wetlands and moist areas, phragmites can have very deep roots, allowing it to occupy a wide range of habitats. It is common to see phragmites in disturbed areas (such as construction sites), along shorelines, and in roadside ditches. Phragmites can spread by airborne seed or underground rhizome or very easily and accidently by human activity.  

Why remove phragmites?

Invasive phragmites impacts the environment it occupies in many ways. It takes up water faster than native species and can therefore lower the water table. It spreads very quickly, crowds native vegetation, and releases toxins from its roots into the soil to kill other plant species. Stands are denser and more ridged than many native wetland plants, making it difficult for wildlife to travel through. All of this leads to a monoculture (i.e., only one species present) that reduces habitat quality, and ultimately reduces plant and animal biodiversity. This is a concern for the OPRREC team as large stands of invasive phragmites occupy Massasauga Critical Habitat, reducing availability of the already limited tallgrass prairie habitat found in the area. Our goal is to contribute to the enhancement of tallgrass prairie via the removal and restoration of such patches.

How to remove phragmites

Control of invasive phragmites varies depending on the location but usually includes some combination of cutting, rolling, flooding, herbicides and/or prescribed burning. The location of the OPPNR patches limit the management practices available to us. For example, the stands are too close to hydro lines for prescribed burning. With some of our local partners, we evaluated the patches that needed to be controlled and decided on a management plan. The first stage of the phragmites removal project was rolling. This process requires the use of 8-wheeled all-terrain vehicles on tracks, pulling a large roller. Only dense patches of phragmites within the project area were rolled, which compresses the vegetation and breaks down the old stems. Rolling does not actually kill or remove phragmites, but prepares the site for future targeted application of herbicide. In the year after rolling, the amount of herbicide needed is far reduced because the stand is now dominated by new growth and herbicide isn’t unnecessarly applied to dead stems. So while the first stage is now complete, the next stage of this project is not planned until late summer 2020. We will eagerly keep you all posted on the resurgence of massasauga habitat and the beautiful prairie wildflowers that come along with it!

One of the phragmites patches in the OPPNR, before (left) and after (right) rolling. You can still see the path going through the area.

This Argo has a roller attachment for rolling phragmites.

So what can the average person do to avoid spreading invasive phragmites?

Click here to learn more about phragmites, including how to identify the native vs invasive subspecies. When visiting natural areas it is important to keep dogs on a leash, stick to trails while walking, avoid areas where invasive phragmites is present, and remove seeds and plant matter from clothing before departing. These are good habits for anyone that visits natural areas and sensitive habitats! Finally, if you are considering planting a variety of phragmites in your garden make sure it is the native variety.

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This quick video shows the oddly satisfying process of rolling from inside the Argo. Thanks again for the help Dover Agri-Serve Inc!

Jennifer Barden, Lead Field Technician – Ojibway Prairie Reptile Recovery