Power, pipeline corridors are becoming wildlife habitat

No one particularly likes electric transmission lines and gas pipelines marching through communities and fragmenting forests. But some believe these linear strips collectively offer the last best hope for fostering fast-disappearing pollinator insects and grassland birds.

Spurred on by a more environmentally attuned public, as well as stockholders and the promise of saving money, more utilities and pipeline companies are grooming the tens of thousands of miles of rights of way in Chesapeake Bay drainage states to benefit wildlife and increase biodiversity.

The conventional practice of maintaining ground under power lines and over pipelines as close-cropped grass, with weeds controlled by mowing and heavy doses of herbicides, is getting an overhaul.

Federal law has long required controlling vegetation under power lines, and regulations were tightened further in 2003, after a widespread power failure in the northeastern U.S. and Canada — at least partly caused, investigators said, by improperly managed tree growth in rights of way. Gas pipeline rights of way must also have low-growing vegetation to keep an open line of sight for spotting gas leaks.

The easiest — and initially cheapest — method of complying with those laws is to mow and apply herbicides.

But now, a more environmentally friendly approach known as integrated vegetation management, or IVM, is taking root.

First, invasive trees and plants are removed by pulling them up or spot-spraying with a small amount of environmentally safe herbicides. This allows native plants to increase their foothold or clears the way for seeding meadow or prairie plant communities.

For electric transmission lines, plants in the so-called wire-zone must be kept low to the ground to avoid interfering with the power lines. But outside of that zone, native tall grasses, shrubs and small trees can offer different habitat.

Together, these types of vegetation provide food for pollinators such as bees and butterflies, egg-laying sites for ground-nesting birds, safe cover for insects and small mammals, basking spots for snakes, habitat for reptiles and amphibians, and a home for rare plants.

What’s more, with climate change, scientists say long, unimpeded corridors of vegetation are important for plants and animals that can only survive by migrating to cooler conditions. The strips can also help rare plant communities from being genetically isolated. They also allow wildlife to travel between otherwise disconnected landscapes, even if they aren’t migrating north.

“There are 60 million acres of rights of way in the United States. All of it has to be maintained, and all of it is potential pollinator and wildlife habitat. That’s bigger than the national parks system,” said Rick Johnstone, president of IVM Partners, a Delaware-based nonprofit that works with utilities and others to adopt IVM practices.

There are 19,647 miles of transmission line rights of way in Pennsylvania, 11,727 miles in Virginia and 4,047 miles in Maryland, according to PJM Interconnection. There are thousands more miles of pipeline corridors in the three states that could be valuable wildlife habitat.

The initiative is still in its infancy. Rights of way under mowing and spraying protocols far exceed those that have been converted to managed wildlife habitat, but the idea is gathering steam.

Baltimore Gas and Electric Co., an Exelon subsidiary, has installed native habitat on 2,800 acres in its service territory so far in central Maryland. The goal is to convert 400 acres a year from mowing to IVM through 2025.

The Maryland sites include Patuxent National Research Refuge in Laurel, South River Greenway Partnership in Davidsonville, Liberty Reservoir in Baltimore County, Flag Ponds in Calvert County, American Chestnut Land Trust in Prince Frederick, Morgan Run Natural Environment Area, Soldiers Delight Natural Environment Area, Patapsco State Park, Gunpowder Falls State Park and the Torrey C. Brown Trail.

At one revamped corridor in Anne Arundel County, researchers discovered 10 species of bees that had never been recorded in the county before.

“This conversion also improves the water quality of the Chesapeake Bay by improving water holding and filtration capacities and reduces our carbon footprint by reducing the need to use fossil fuel-powered tractors in mechanical mowing,” said BGE spokeswoman Stephanie Ann Weaver.

In 2023, the Maryland General Assembly helped advance IVM by passing a law that exempts power companies from local weed-height ordinances.

As forester for Delmarva Power’s properties, Johnstone persuaded the electric and gas utility to adopt IVM on its rights of ways.

FirstEnergy, which provides power to parts of Maryland, Virginia, Pennsylvania and West Virginia, has developed its own pollinator-friendly seed mixes, with more than 20 flowering species native to those the states.

FirstEnergy is one of eight utilities in the U.S. so far to earn certification from the Right-of-Way Stewardship Council. The nonprofit was created in 2013 by environmental groups, academia, the utility vegetation management industry, utilities and the federal government to promote IVM and best management practices.

The Central Virginia Electric Cooperative, which serves portions of 14 counties, has adopted IVM for new transmission corridors and is in the process of converting old ones into meadow environments.

The Pennsylvania Game Commission, which owns 1.5 million acres of land that is open to public use, has an estimated 841 miles of power line rights of way and 1,015 miles of gas pipeline swaths. That’s 12,688 acres of potential wildlife habitat for the agency responsible for overseeing the state’s wild birds and mammals, both those hunted and those not.

All disturbances to game lands are required to be managed for wildlife, said Scott Bearer, the agency’s chief land manager.

“What we push for and like to see is as much habitat as possible. These pipeline and power corridors are great habitat for nongame. They are continuous travel corridors for our tree bats, and they can offer woodrat and pollinator habitat that is the basis for the food chain for all our migratory songbirds, and everything in between.”

Bearer said the agency’s commitment to creating more nongame habitat has evolved over time. For example, in the 1950s, sportsmen became worried that herbicide being applied on game lands under transmission corridors was harming habitat for rabbits, deer, turkeys, grouse and other game.

In response, a study was launched in 1953 on 3.5 miles of rights of way through State Game Lands 33 in Centre County. That initial study has turned into 70 years of continuous monitoring and experimentation with IVM practices, providing a knowledge base for managing land for wildlife. Partners include utilities, Asplundh and nonprofits.

Studies there and elsewhere are confirming the benefits of a more holistic approach to vegetation under power lines and along pipelines.

A 2019 study on the game lands reinforced previous studies that have found that pollinating insects can survive small amounts of herbicides, used to selectively kill invasive and nonnative plants.

Another study, published in 2019 in Biodiversity and Conservation, compared the presence of pollinator bees on sites where IVM was used in power line rights of way in Maryland’s Anne Arundel, Prince George’s and Howard counties. They were compared to 29 sites subject to conventional mowing.

The IVM sites had “significantly higher abundance and species richness,” according to the study. The researchers noted that the newly created habitat also benefitted butterflies, birds and small mammals.

“Transmission line easements should stop being viewed solely as scars on the landscape and instead be viewed as potential linear wildlife preserves,” the study concluded.

Still, utilities and IVM advocates sometimes hear complaints when mowing is stopped. “For every person that’s thrilled to see native plants and meadows, there’s someone who says it looks messy and our kids are going to be covered in ticks,” said Carolyn Mahan, a professor of biology and environmental studies at Penn State Altoona and the current overseer of Game Lands 33 research.

And IVM proponents say they sometimes struggle to convince utilities and companies that IVM saves stockholders and customers money in the long term by cutting back on mowing and herbicides. There is an initial investment to get a new array of plants established. But once the ecosystem takes hold, they say, it protects itself with only occasional maintenance afterward.

“It requires professionalism, dedication and knowledge of the landscape to do it properly, but it can be done,” Mahan said.

She would like to see tax incentives that encourage utilities to participate.

Although use of herbicides in IVM is minimal, some agencies and land managers still are uneasy about using them at all.

But Johnstone said it’s a necessary evil. “We can’t manage without herbicides,” he said. “We need the conservation and environmental organizations to get over the ‘we don’t want any [herbicides].’ Make it difficult to use, but don’t ban it.”

With the growing push for right of way owners to support sustainability, Johnstone and others predict that IVM will continue to spread across the landscape.

“The native stuff is lying there in the soil waiting for the right opportunity. They’re there waiting to come back.”