Environmental Technical Assistance Program Newsletter

The Pennsylvania Invasive Species Council or ISC is preparing to pilot test an invasive species management program this summer – and the Pennsylvania Department of Transportation is one of several state agencies on tap to play a key role in that pilot test.

[Above image by PennDOT]

The program is built around findings from the first statewide survey of impacts from invasive plants, insects, pathogens, and animals, ISC conducted in late 2022 – the Pennsylvania Invasive Species Impacts Survey.

“A biodiverse native ecosystem provides the natural resources that are essential to our lives, from agricultural food production to outdoor recreation and fishery, timber, and other industries,” explained Rich Negrin, acting secretary for the Pennsylvania Department of Environmental Protection, in a statement.

He added that the ISC believes a statewide program is necessary to respond to growing number of invasive species in Pennsylvania – including the spotted lanternfly, mile-a-minute vine, Japanese stiltgrass, barberry shrub, zebra mussels, and many others.

The pilot will bring together expertise from local and state government, industry, community, and academic organizations to create a Partnerships for Regional Invasive Species Management or “PRISM” program.

The Council and the Pennsylvania Association of Conservation Districts or PACD will partner to pilot-test a small-scale version of a PRISM program in 13 northwest counties in July.

Using $210,000 from the U.S. Department of Agriculture Forest Service, PACD plans to conduct on-the-ground projects to remove invasive species and conduct educational outreach to help prevent the introduction of invasive species. In addition, PACD will develop a strategic plan identifying priorities and committed partners for the region – including PennDOT.

“PennDOT has worked with federal, state, and local partners to encourage native plant growth and target invasive species in our right of way,” noted Mike Carroll, acting PennDOT secretary. “We look forward to continued partnership through this council to address this statewide challenge.”

Other state departments of transportation are also engaged in efforts to eradicate a variety of invasive species in their regions to improve protections for native plant and animal life, as well as encourage pollination efforts.

For example, the Kentucky Transportation Cabinet recently began cranking up its annual weed control program to keep a dozen unwanted and noxious weeds from encroaching on the bluegrass state’s transportation infrastructure.

Meanwhile, in November 2022, the Illinois Department of Transportation recounted in a blog post how it changed its mowing practices over the years to better protect roadside landscapes that are vital to pollinators and native planet life.

The agency has adopted mowing policies to protect the habitat and migratory patterns of the monarch butterfly and other pollinators that use it as a food source. That policy allows for mowing of the state’s roads in a four-year rotation during the summer.

Finally, in October 2022, ecologists at Idaho State University began working with the Idaho Transportation Department to turn state roadsides into veritable “Swiss army knives” of vegetation so they are both more fire-resistant and more welcoming to pollinating insects. They are working with three different types of ecosystems, figuring out how to make the land more hospitable to native plants and less so for invasive weeds.

The Kentucky Transportation Cabinet is cranking up its weed control program to keep a dozen unwanted and noxious weeds from encroaching on the bluegrass state’s transportation infrastructure.

[Above photo by KYTC]

Weeds are more than a gardening nuisance; they can obscure sightlines, compromise drainage, wipe out native plantings, and kill off roadside turf, leading to roadbed erosion and serious maintenance issues.

“Some weeds are highly destructive and difficult to control,” said Naitore Djigbenou, executive director of the KYTC Office of Public Affairs.

“Weeds clog storm-water drainage systems and can compromise pavement and structures which can lead to potholes and structures failures,” Djigbenou noted, which is why KYTC uses Integrated Roadside Vegetation Management or IRVM to “suppress and control noxious and invasive weeds on state-maintained highways.”

Weed control is accomplished through mowing, turf-grass establishment, insect biological control, and the use of herbicides approved by the Environmental Protection Agency that are applied by licensed applicators.

“If left untreated, some weeds can grow several feet tall and impact driver visibility,” KYTC Secretary Jim Gray pointed out in a recent news release. “Actively treating the weeds on state-maintained property enhances safety, prevents damage to ditches and drains and minimizes the presence of plants that attract deer near highways,”

The agency also reaches out to private landowners, he said, encouraging them to request that highway crews treat some noxious weeds on adjacent state-owned right-of-way.

Kentucky law dictates which 12 plants are considered “noxious weeds” that should be eradicated. They are Amur Honeysuckle, Canada Thistle, Common Teasel, Cutleaf Teasel, Japanese Knotweed, Johnsongrass, Kudzu, Marestail, Multiflora Rose, Nodding Thistle, Poison Hemlock, and Spotted Knapweed.

Noxious weeds often invade and destroy the roadside turf grass, leaving those areas vulnerable to erosion, KYTC added. They can also smother native plants through rapid reproduction and long-term persistence. Twenty years ago, the Federal Highway Administration published a compendium of resources aimed at removing invasive species of plants that might take root along roadways nationwide. They can cause “significant changes” to local ecosystems, upsetting ecological balances and causing economic harm to the country’s agricultural and recreational sectors.