Published: April 06, 2008 11:51 pm         

Plant Attack: Asian bush honeysuckle is threatening Indiana’s native flora and fauna

TERRE HAUTE — “Invasive” and “disaster” are hardly the first words that come to mind when peering at the first bits of green leaves peeking out along Indiana’s roads and in parks and forests.

However, one local group is working to bring awareness of just how dangerous some of those leaves can be for native plants and animals.

Members of the Wabash Valley Audubon Society have been working to identify and remove at least one species of a highly-aggressive invasive plant from the Dobbs Park Nature Preserve, on the city’s east side.

The plant, Asian bush honeysuckle, has proliferated in the park, as well as along roadsides, and in other parks and forests.

It is drowning out native wildflowers and other plants and may also be harming trees, according to the Indiana Department of Natural Resources Web site.

Asian bush honeysuckle, which is native to Japan and other parts of East Asia, began coming to the United States shortly after World War II, to be used as a decorative landscape plant. Since then, the plant’s seeds have been spread from private gardens to forests, prairies and wetlands.

The plant uses several aggressive methods to thrive and decrease its competition for nutrition, water and sunlight. Bush honeysuckle grows very quickly; it is one of the first plants to put on leaves in the spring, and one of the last to drop its leaves in the winter. Each root is capable of putting out multiple runners, which are the beginnings of new plants. In addition, bush honeysuckle puts off a chemical that poisons the soil around it, keeping other plants from growing. Once growing, bush honeysuckle grows so densely that it shades out other plants, leaving only bare soil below.

Denise Sobieski, who teaches biology at Terre Haute North Vigo High School, and who is a member of the Audubon Society, said the reason the birding group got involved was “we wanted to become more active environmentally, and help to protect habitat … you need to have habitat for the birds.”

Bush honeysuckle, by leaving bare soil beneath its branches, reduces available food and cover for birds, and often leaves them exposed to predators that they would not otherwise encounter, according to the Indiana Department of Natural Resources Web site.

Another problem environmentalists and biologists are noticing is that in areas where the plant has proliferated, honeybees and other native bee species are absent, making pollination of native plants impossible.

Dale Sparks, president of the Wabash Valley Audubon Society, said, “When you’re inside this ‘honeysuckle jungle,’ there’s not a single pollinator in there. Even if you have a few plants that are growing in there, they have no chance of reproducing.”

Bush honeysuckle has become a huge economic issue in the state and in the rest of the country, according to Sparks and Sobieski.

Sparks, who also is a wildlife biologist in the Department of Ecology and Organismal Biology at Indiana State University, said by having volunteers go into the forests and parks a couple of hours a month to remove the aggressive plants, the group has been able to make a dent in the problem – a small dent, he admits, but a dent nonetheless.

On Earth Day, April 22, the Audubon Society is inviting the general public to come out to Dobbs Park to assist in removing some of the sinister bushes. They hope to increase awareness of some of the more problematic invasive plant species that are killing native plants.

The only other way to reduce the problem, according to Sobieski, is to “be careful what you plant in your gardens.”

Deb Kelly can be reached at (812) 231-4254 or deb.kelly@tribstar.com.