Phragmites

I suspect that a few among us have been out collecting bittersweet, cattails, or perhaps common reed for fall arrangements. I was thinking about all that recently when I read an article on the invasiveness of some introduced forms of what most of us call common reed or slough grass.

Most everyone is familiar with common reed (Phragmites australis). It is the grass that grows to ten or perhaps fifteen feet tall in wet areas and has large feathery seedheads. It is native to much of North America, Argentina and Chile, Eurasia, Africa, and Australia. As you might expect, most plant manuals list the plant as “cosmopolitan.”

Common reed often forms dense, pure stands on a wide variety of wet habitats ranging from shorelines and ditches to wet ground and shallow marshes. It might surprise you, but these stands of common reed have little or no wildlife value, as habitat or food.

But there is an interesting twist to this species. Non-native forms of common reed have been introduced to North America and some of these forms have become quite invasive. These forms have been particularly problematic along the eastern seaboard and Great Lakes area. The species is now considered a noxious weed in some states. No doubt it will continue to spread.

Even though common reed is widely known to form dense monotypic stands that provide little or no value to wildlife, the exotic types may be even more aggressive. The species is a prodigious seed producer, and once established, the rhizomes can spread outward to as much as thirty feet over the course of a summer. If the water levels drop, the rhizomes function like stolons and spread across the ground. It may eventually replace a more diverse and desirable mix of species, so diversity plummets.

Within the stand, the stem density may be up to 19 stems per square foot.

This impenetrable quagmire not only chokes out our more desirable native plants but may also prevent many wildlife species from utilizing the stand. With the exception of perhaps marsh wrens and a maybe a few other songbirds, these stands are a sort of biological desert.

If you get the opportunity, explore a stand of Phragmites. I think you will be surprised at the lack of other species and evidence of wildlife use in the stand. Then go find a more diverse place to enjoy fall in your area.

Chuck Lura

Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.