Of the four different species of Phragmites, the Phragmites Australis is the species that we most commonly come across in our region. Within this species, one is native and the other is invasive, presenting a crucial difference that can greatly impact our ecosystems. The invasive variety of Phragmites Austalis is much more prevalent in our region, and is what people typically see in our coastal and wetland environments.
The widespread presence of the invasive species, now found in all 49 mainland states, has resulted in growing concerns about its negative effects on local environments, including reducing biodiversity, reducing the ability of wetlands to absorb storm waters, and diminishing habitat value. In contrast, the native phragmites offer numerous benefits, including water filtration and habitat provision for flora and fauna. It is essential to distinguish between the two types which, due to their numerous shared characteristics, needs to be done through the recognition of a few distinguishing factors.
Differentiating Between the Two
Stem Color: The stem of an invasive phragmites will present with a rough texture and dull tan color, whereas the stem of a native phragmites will be smooth with a red tone.
Leaves: Leaves of invasive species are darker with a bluish-gray-green color, while native species leaves are lighter and yellow-green.
Stands: Denser stands are indicative of invasive phragmites while less dense stands are associated with native ones.
Biodiversity: The biodiversity of invasive species are monocultures while native are polycultures.
Leaf Sheath: The leaf sheath of invasive species adhere tightly to culm (reed-like stem) and do not peel off. Leaf sheaths of native species adhere less tightly and peel back / fall off culm.
There are multiple approaches and strategies to prevent invasive phragmites, including biological, physical, and chemical interventions. These various methods have approaches that can target both aboveground growth and underground root systems, so it is important to select the right method at the right time to be most effective.
Biological controls, such as insects, mites, and fungi, can reduce underground energy stores rather than simply removing the plant. Grazing animals, another biological control, can help focus aboveground, where they reduce the plant's density without killing the plant. Physical measures, like controlled burns and repeated cuttings, can be used but primarily address aboveground biomass and fall short of eradicating root systems. For that reason, physical measures are most effective when paired with chemical treatments, such as wetland-aproved herbicides, which focus on root destruction.
Stopping the Spread
Community involvement and the ability to identify the difference between the two species is pivotal in the battle against invasive phragmites. Property owners and residents can contribute to these efforts by reporting sightings to Crawford Land Management. By working together, we can stop the spread of this invasive species and preserve the ecological integrity of our beautiful community.
The conflict between native and invasive phragmites highlights the fragility of our ecosystems and the importance of continued conservation efforts. At Crawford Land Management, we strive to protect the unique biodiversity on Cape Cod, recognizing and managing the impact of invasive species and ensuring a sustainable future for our great community.