Wetland plants that are invasive.
I wanted to address a comment that mentioned my use of the word invasive, and thought I should have been more clear. I showed you cattail in astounding numbers in a local marsh wetland. There are two kinds of cattail, one that is native and one that is an invasive non-native. I did not state the variety in the last post because I had this post coming and would have to go into much detail. In fact, the two are so intermingled that it is almost pointless to differentiate.
The native variety is becoming less common because the invasive cattail grows taller and more dense, crowding it out. This is a big problem on removal as you will see.
The one shown here is predominantly the invasive variety, Typha angustifolia,or Narrow Leaf Cattail. One can tell by the long, thin hotdog shape, the native variety is shorter and thicker. Cattail dispersion occurs underground, by way of rhizomes that form dense monospecific stands. While important, they can also reduce the biodiversity of wetlands.
Typha angustifolia is fast growing and has several strategies for out competing other emergent species, even the native variety, Typha latifolia. Having a tolerance for saline water, the exotic can quickly colonize and establish open sites.
One of the reasons it became so prevalent is that it did not look all that much different. By the time it was noticed, it was far too established. Ironically, it is not prohibited on many state invasive lists though.
Part of the Problem
At Buckhorn Island State Park, the Channel of Burnt Ship Creek filled in with cattail, and water was unable to fill the marsh sufficiently. The water level has been lowered by the diversion of water for industrial plants along the Niagara River. This has decreased the quality of wildlife in this wetland habitat.
The native vegetation is being restored with the help of many agencies and individuals. In addition to Narrow-leaved cattail (Typha angustifolia), a number of other exotic species are present in the marsh, including Common reed (Phragmites australis), Purple loosestrife, European alder, Yellow iris, Garlic mustard, Japanese knotweed, and invasive bush honeysuckles (Lonicera spp).
Removal has concentrated on the Phragmites because it poses the most threat to the marsh land, and the cattail was not part of the study and removal plan below.
“Both Broad-leaved cattail (native, invasive) and Narrow-leaved cattail (exotic, invasive) occur in the marsh and are sometimes intermixed in the same stand. It is therefore possible that hybrid cattails known as Typha x glauca are present as well. Broad and Narrow-leaved cattails have been a dominant fixture in this marsh and surrounding areas since historical surveys conducted more than 80 years ago.” (source)
Ecologically, native cattail offer plenty of benefits. It is a spawning grounds for a variety of fish, including Northern Pike and large mouth bass, but migration is limited due to water levels and the dense stand of cattail in this particular marsh.
Red-winged blackbirds as well as many waterfowl such as Canada geese and mallard ducks nest in their thick coverage. The catbird resides in the thick reeds.
Many upland songbirds will fluff their nests with the flowers.
The birds also use the native Eastern Cottonwood tree, Populus deltoides too which resides in the woods of Buckhorn. Mammals such as beavers and muskrats feed on the rhizomes of cattail for food. But from studies I read, the invasive cattail does not offer all the same benefits.
To Make Matters Worse
The non-native will hybridize with native cattail, Typha latifolia, to produce the hybrid T. x glauca, also a recognized invasive plant of wetlands. The hybrid is thought to be sterile in that it does not produce seed, but it still can form large stands by means of vegetative reproduction.
Now for an even bigger threat …
It is a fast growing threat to native ecosystems due to the plant’s aggressive ability to dominate a variety of ecosystems. It seems to grow many places that have water, like you see roadside along swales and drainage ditches.
A native species of Phragmites exists in the area, but the invasive variety quickly displaces the native variety. It is prevalent in emerging wetlands, very similar to the cattail.
This is due to rapid water level changes and the vast areas of exposed habitat located in emergent wetlands. Phragmites, like the cattail above, can become established quickly because of its underground rhizomes, and will also seed.
These images are the Phragmite at Tifft Nature Preserve. The power authority has been bringing in workers to reduce the plant here, especially around the area they are reintroducing the native cattail.
I do have the birds and critters photos coming from both Preserves.
In my professional life, I worked on a design project (at the firm where I worked) to reclaim a neighboring wetland, Cherry Farms. It was a brownfield reclamation project, so I am familiar with the preservation and conscientious development of wetlands. Unfortunately, the well thought out project never got funded to my knowledge.