Unexpected circumstances can present significant challenges to vegetation managers working to ensure electrical transmission reliability each year. Most recently, the COVID-19 pandemic has impacted the manufacturing industry, which has, in turn, limited funding for many utility managers. Fortunately, a number of cost-effective strategies can be used to help today’s practitioners protect utility infrastructure and provide environmental benefits to ecosystems throughout right-of-way corridors.
Every year, vegetation-related incidents represent one of the most common causes of utility service interruptions across the country. And while vegetation managers have previously used mechanical control methods like cutting or mowing to keep trees and other tall-growing brush from interfering with nearby power lines, these practices alone represent nonselective methods of control that can drain programmatic funding, negatively impact surrounding environments and impede the development of biodiverse habitat for wildlife species. To make matters worse, the COVID-19 pandemic has led to lower productivity levels throughout the manufacturing industry, resulting in budget restrictions for utility management teams. As these budgetary setbacks can hinder the efficacy of vegetation management programs, making the most of the financial support that’s available has become exceedingly crucial for industry professionals.
Now, more than ever, vegetation managers working to ensure electrical transmission reliability are forced to do more with less. And when other unforeseen circumstances, such as turbulent weather patterns or a lack of skilled contract labor, impede annual productivity, completing all planned treatment cycles each year can become exceedingly difficult. As a field scientist with Corteva Agriscience, Chad Cummings understands the implications of deferred maintenance and details the economic impact missed treatments can have on vegetation management programs.
“Brush species can grow up to 40% in size each year,” Cummings says. “Failing to maintain incompatible plant species can double the cost of maintenance when treatments are delayed by a single season.”
Nonselective management methods like mowing can be used to keep right-of-way (ROW) corridors clear of tall-growing trees and brush, but these treatments often impact native plant communities as effectively as incompatible plant species. The results of mowing strategies are also more temporary, as the resprouting of targeted plant species can lead to the reestablishment of incompatible plant communities. Over time, this results in more work and higher maintenance costs for vegetation managers. To prevent these undesirable outcomes, make the most of fiscal funding and enhance the development of native plant communities to benefit wildlife, today’s professionals can adopt Integrated Vegetation Management (IVM) principles to yield higher levels of efficacy as well as a variety of economic and environmental benefits.
Success through selectivity
As defined by the U.S. Environmental Protection Agency, IVM practices help to reduce the need for pesticides and promote the development of healthy ecosystems. On utility rights-of-way, an IVM-based approach includes the use of herbicides and/or mechanical treatments to control incompatible brush species.
The goal of these treatments is to support the development of desirable or compatible plant communities, such as low-growing shrubs or grasses, which can create biological barriers against woody plant establishment and provide beneficial habitat to various wildlife, including pollinator species. To help vegetation managers ensure the success of IVM programs and maintain effective brush control throughout the year, a variety of effective methods can be used during each treatment season. These include biological, chemical, cultural, mechanical and manual treatments. However, few are as effective and environmentally friendly as selective herbicide applications.
“Selective herbicides can be used to effectively control incompatible plant species with minimal impact on native plant communities,” Cummings says. “Nonselective treatment methods like mowing can result in significant site disturbance and eliminate native plants. But selective herbicide applications can be used to target incompatible plant species exclusively, which supports the development of biodiverse habitat by allowing native plant communities to flourish.”
Applicators can use larger equipment like ground-rig booms to apply selective herbicides for broadcast treatments where increased stem densities exist. The selective control offered by these treatments help to reduce populations of incompatible plant species from one treatment season to the next. And as stem densities diminish, backpack sprayers or hydraulic foliar applications can be used to apply low-volume or directed spot treatments, which help to maintain program efficacy, preserve compatible vegetation and provide significant cost savings to vegetation management programs over time.
Embracing flexibility
For vegetation managers using foliar-based herbicide applications, seasonality presents a challenge that is relatively easy to overcome. As air temperatures drop in the fall, many plants lose their leaves, which prevents herbicides from being absorbed through the foliage of targeted plant species. Fortunately, selective herbicide applications provide flexible treatment methods to IVM programs. These applications can be used to help professionals extend the treatment season and steer clear of programmatic setbacks from one year to the next.
“If unexpected circumstances keep a program from completing all planned foliar applications in a given year, the results can be quite costly,” Cummings says. “Luckily, there are a number of supplemental methods that can be used to effectively control target species with selective herbicides after the foliar treatment season has passed.”
As Cummings describes, unforeseen roadblocks can narrow application windows each year, making it difficult for practitioners to complete all planned treatments. However, alternative treatment methods like low-volume basal bark, basal cut-stump and dormant-stem treatments can be used to apply selective herbicides from fall leaf senescence through spring bud break. These applications can help vegetation managers extend the treatment season, make the most of fiscal budgets and cultivate biodiverse ecosystems for a variety of wildlife species.
Environmental impact
Cooperative Energy, which serves as the electrical generation and transmission arm for 11 electric distribution co-ops throughout the state of Mississippi, has used selective herbicides as part of its IVM strategies since 2008. By supplementing selective herbicide applications with routine mowing, Cooperative Energy has been able to not only keep prevalent brush species like sweetgum, volunteer pine and Chinese tallow clear of utility power lines, but also create a habitat in which wildlife species can thrive.
With six counties in its service territory considered prime habitat for the extreme western range of gopher tortoise, Cooperative Energy has used selective herbicide applications to enhance habitat development for the endangered species. The optimum control of incompatible vegetation in those areas led to a 32% increase in gopher tortoise populations over a three-year period. Enhancing prime habitat development along the edges of the rights-of-way also led to a significant reduction in burrows down the centerline, where mowing equipment poses a safety threat to wildlife.
Selectively treating invasive species has also allowed Cooperative Energy to reduce its impact on herbaceous vegetation. This supports the creation of early successional habitat for pollinator species, which help to deliver approximately one-third of the global food supply. With millions of miles of power line rights-of-way weaving throughout the United States, other utility managers have the opportunity to provide similar benefits to ecosystems throughout their respective application sites.
“Enhancing safety and reliability for industry professionals and members of the general public is important,” Cummings says. “But when a strategy allows vegetation managers to reduce maintenance costs, improve work planning, and create biodiverse habitats, everyone wins.”
