Last year’s high waters not only helped Asian carp spread into new waters. It helped disperse an aggressive plant as well.
While invasive fish followed the overflowing Missouri and Mississippi rivers from Louisiana to South Dakota, Japanese knotweed expanded in Vermont, courtesy of flood waters from Tropical Storm Irene and dredging afterward.
Here’s the bad news from the Washington Post, along with what to do about it:
In Vermont, floodwaters and repair work broke off portions of stems and woody rhizomes of the aggressive Japanese knotweed. The perennial, imported from Asia as an ornamental, was already a problem in Vermont and a dozen other states in the Northeast, the Pacific Northwest and the Midwest.
It spreads quickly on riverbanks, floodplains and roadsides, choking out native plants, degrading habitats of fish, birds and insects and weakening stream banks
The plant, which resembles bamboo when mature, spreads quickly in disturbed soils. Just this week, new young plants were inching out of the silt on the banks of the Camp Brook, a tributary of the White River, where the land looks like a moonscape since floodwaters washed away trees, rocks and other native plants. Once these invasive plants take over, their root structure and a lack of groundcover and native plants and trees with deeper roots, weakens the stream banks, causing erosion, and flood damage.
“We’d like to get out the message that if there’s ever a time to hand pull or mechanically control so we can avoid the use of herbicides, this is the one year where that’s possible,” said Sharon Plumb, invasive species coordinator, for the Vermont Chapter of The Nature Conservancy.