Nature Notebook – Invasive Narrow Leaf Cattails

Cattails are vital components of healthy freshwater ecosystems. They filter water runoff before it enters waterways. They stabilize the soil and prevent erosion. They provide food and shelter for numerous animals.

So why do conservationists cringe when they look at cattails?

They probably see narrow-leaf cattails instead of the native broad-leaf species.

Biologists aren’t sure if this species was introduced to the eastern coast or if it was native there. The seeds have traveled with humans along river waterways and railways to set up shop, quite successfully, in new environments.

Although they can fulfill the “jobs” of the native species, the narrow-leaf cattails do so at the expense of neighboring wetland plants, by forming monocultures. When they become the only plant in an area, critical biodiversity is eliminated. Animal food and shelter resources are drastically limited.

Narrow-leaf cattails also hybridize with native cattails producing even larger, more aggressive offspring. These plants are able to change the ecosystem to benefit their existence. They produce large amounts of plant litter (old parts). Native plants cannot grow in the accumulation but the “mutant” cattails love it. So more of them grow, produce more litter and grow more thus ensuring their control of resources.