The Cuyahoga River runs for about 100 miles through Northeast, Ohio and through one of just 419 national parks in the United States. For decades and even centuries now invasive flora have existed in the Cuyahoga Valley National Park (CVNP) and the Cuyahoga River.
In the CVNP during the year 1986 a study found that 186 plants were non-native compared to the park’s 943 plants. People walk past invasive plants in the CVNP everyday without a clue that they are invasive. Many people also might have invasive plants within their backyards as well. When I spoke with CVNP Park Ranger Dan Krieger earlier this fall he told me that the number of invasive or non-native plants is the same over thirty years later. He said 20 percent or 1/5 of the park is filled with either non-native or invasive flora.
Both non-native and invasive plants are similar; however, there is distinct difference between them. The Crooked River Cooperative Weed Management Area, an organization composed of several land owners and stewards in the Cuyahoga River Basin that are motivated by land conservation, categorizes invasive plants as either an invasive species or alien species, which are adopted universally among the invasive community.
An alien species (non-native) is “any species, its seeds, eggs, spores, or any biological material capable of propagating (cultivating) that species that is not native to the ecosystem”, while an invasive species is “an alien species whose introduction does or is likely to cause economic or environmental harm, or harm to human health.”
As of right now the major invasive flora in the CVNP include “Japanese knotweed, Bush honeysuckle, a plant called tree of heaven,” according to Krieger. Japanese Knotweed is especially detrimental to the riversides of the Cuyahoga River because of its invasive properties.
“…the problem with Japanese Knotweed that it still outcompetes the other native plants. The native plants should be holding the riverbanks in a semi-solid state gets eroded away because all you have is Japanese knotweed,” CVNP Naturalist Chris Davis said.
The silt then floats down the river and piles up near the city of Cleveland. Krieger explained to me that there should be a delta in this part of the river, but it is non-existent because the dredging that takes place to help clear the river for incoming ships. He said ships need to take less products into port because of the dredging.
To help stop these non-native and invasive plants from spreading naturalists and park rangers can assess the situation and how bad it might be. They can either cut down an entire invasive plant to the stump, spray herbicide on the plant or cut down a significant amount of the plant to limit its growth.
There are ways where everyday people can help put a stop to the spread of invasive plants in their own local ecosystem.
“A big message that I really try and push out to people is that they should purchase and kind of put native plants in their aquariums and water gardens. Here at the Cleveland Metroparks people intentionally try and beautify the park…and that is not something that we need in our region. I think that is a potential threat pathway for aquatic invasive species introduction,” said Mark Warman who is an Aquatic Invasive Species Coordinator with the Cleveland Metroparks.