Species Spotlight | Phragmites

Phragmites (Phragmites australis), also known as common reed, inhabits Michigan as well as locations around the globe. The invasive species was introduced to the east coast in the late 1700s and has continued to spread since.

Even though invasive Phragmites has been present in North America sometime between the late 1700s and early 1800s, it has only been present in the Great Lakes region for a few decades. The most commonly accepted theory of how invasive Phragmites was introduced to the US was that; the invasive species was introduced by ships traveling from European countries. Early ships used soil as ballast to weigh down their ships until cargo could be loaded and the soil was dumped in a new location. There were likely multiple introductions of soil infested with Phragmites along the Eastern coast of the United States from this and other pathways. Once Phragmites was established on the east coast it has slowly made its way across to the western side of the country.

Phragmites is a perennial, wetland grass. The species has a native and an invasive variety. Native Phragmites has leaves that are yellowish in color, and steams that appear reddish/ purple in color. The seed heads on native Phragmites are less dense and are brown in color. Native stands are usually integrated with a more diverse plant community and not as dense as invasive stands. These stands typically reach a maximum of six feet in height. Invasive Phragmites has leaves that appear blush in color with stems that are a dull green color. The seed heads on invasive Phragmites are denser and silver/ brown in color. Stands of non-native Phragmites are typically very large, tall, and dense. These stands can grow as tall as 20 feet. Non-native Phragmites is becoming widespread throughout the Great Lakes region. This invasive species is threatening the ecological health of wetlands and the Great Lakes coastal shoreline.

Invasive Phragmites is established along many Michigan shorelines and inland lakes. It’s tall, dense stands degrade wetlands and coastal areas by crowding out native plants and animals. Phragmites stands can also cause severe alteration of the water regime in wetland areas that can cause the soil to lose moisture and ultimately destroy the wetland. Invasive Phragmites also causes recreational harm by, blocking shoreline views, reducing access for swimming, fishing, hunting and can create fire hazards from dry plant material. While invasive Phragmites does inhabit the Upper Peninsula to a point that it needs to be managed, the Lower Peninsula is more heavily infested. In the UP we make it a priority to manage the invasive species that are present and work towards eradicating them as well as not introducing any new species, all in efforts to preserve the natural species.

When invasive Phragmites becomes established in an ecosystem it can become difficult to reduce the infestation to a more manageable size. If incorrectly managed Phragmites can easily spread to new locations and establish strongly. Which due to its aggressive reproductive strategies can cause it to become quite overwhelming and challenging to manage. Invasive Phragmites can originally spread one of two ways. The first is through seed distribution, which can be carried to new areas by wind, animal or human dispersal. The second is through its rhizomes. Their rhizomes grow horizontally under the stand and are capable of growing new roots and stems from its nodes when dislodged and re-rooted elsewhere. This can occur by human actions near the stand or simply by wave action breaking apart the rhizomes. Established Phragmites continue to expand due to not only their rhizomes but also their stolon’s. Stolons are similar to rhizomes in that they also grow horizontal stems that can form roots at each of its nodes, but the stolon grows above ground and can grow up to four inches in one single day. Which allows a small Phragmites stand to become a large infestation very quickly. 

It forms monocultures that are so dense they can dominate wetlands within three years and push out all native species. The native strand inhabits Michigan as well but grows in far less dense patches and does not crowd out other species.

Phragmites stands can be seen along coastal marshes and Michigan shorelines. There are many management efforts underway that involve conducting mapping and treatment of invasive Phragmites. It is imperative this work continues to be done to ensure a slower spread of the non-native species. Michigan is the home to many unique species and ecosystems. Our goal is to preserve them so that they can be enjoyed and viewed for centuries. Invasive species play a large role on the threat to these species and ecosystems.

Michigan’s Upper Peninsula is home to many unique native species and ecosystems. These unique features are being threatened by non-native invasive species which have found their way to our region. An invasive species is defined as: an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. One, if not the greatest threatening invasive species is invasive Phragmites.

**Proper treatment of invasive species will help aid in controlling these invading species; however, the most successful management tool is still education and outreach. Your local CISMA strives to educate public and private landowners throughout UP counties on identification and the importance of working collaboratively to manage invasive species across jurisdictional boundaries. Such tasks are accomplished through public workshops and education events informing thousands of individuals each year on the importance of invasive species management. These accomplishments would not be possible without the support of CISMA partners and volunteers. To learn more about invasive phragmites visit Michigan.gov/invasives or to locally get involved contact your local CISMA.