Invasive Phragmites the Wetland Reed Wanting to Take Over our Wetlands!

If you have driven down I-75 while traveling downstate, you have probably noticed large
reeds with quite puffy seed heads, commonly in the median or in road ditches, maybe
even in a swamp or marsh or any kind of wetland. Those reeds are probably a plant
known as Phragmites. Phragmites is a perennial wetland reed that can spread
thousands of seeds on an annual basis. It has a root structure that contains both above-
ground (stolons) and below-ground (rhizomes) that grow vigorously and deep. This
adaptation allows invasive phragmites to spread quickly and outcompete native species.
In the summer, this quick-spreading reed will have blue-green blade-shaped leaves with
a green and tan stalk, growing anywhere from six feet to twelve. Seed heads are
typically very full and puffy with a purple-brown hue.

The Upper Peninsula is also home to a native Phragmites. This is typically not as tall as
invasive Phragmites. It will have more yellow-green blade-shaped leaves with a green
stalk that often has red at the base of each segment of the stalk. Stalks can get four to
six feet tall. The seed head is typically more wispy and less full, with a more distinct
brown color. Unfortunately, in wetlands where there are both native and invasive
Phragmites, identification can be difficult as hybrids can grow from cross-pollination.
Typically, hybrid Phragmites will have characteristics of both Phragmites species
combined. The characteristics of each hybrid plant can vary as it is hard to tell exactly
how each stand will hybridize and what characteristics it will show.

Native Phragmites are beneficial compared to invasive Phragmites because native
Phragmites filter the water without taking out beneficial nutrients. Invasive Phragmites,
however, quickly drain a wetland of important nutrients such as nitrogen and
phosphorus. This, in turn, can cause the wetland to be depleted of vital nutrients and
oxygen, limiting its ecosystem services.

Another way invasive Phragmites are spread is through vectors such as humans and
animals. One may think invasive Phragmites is beneficial to habitats, but it has been
shown that birds and other animals struggle to navigate through invasive phragmites
and the reed is too smooth to hold birds’ nests. Additionally, invasive Phragmites have
long been used as a natural camouflage by waterfowl hunters due to their abundance
and thickness. This activity has led to increased spread and habitat loss. Invasive
Phragmites also becomes dry and brittle every year creating dead biomass capable of
being ignited by lightning strikes and starting a wildfire.

So, the next time you are adventuring through the Upper Peninsula, be on the lookout
for this wetland bully. Without proper management, Phragmites can get to an
unmanageable size, creating opportunities for a greater spread of the plant and reduced
availability for native plants. Please report any sightings to MISIN or call Three Shores
CISMA at 906-630-7139 if you are in Mackinac, Chippewa, or Luce counties.

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