As the electrical generation and transmission arm of 11 distribution co-ops in Mississippi, Cooperative Energy understands the importance of ensuring the availability of utility power. When Hurricane Katrina impacted nearly 1,800 miles of the co-op’s transmission power lines in August 2005, more than 427,000 homes and businesses were left without power. After reclearing right-of-way (ROW) corridors littered with woody plant species and debris, Cooperative Energy had the unique opportunity to revisit their vegetation management practices and assess areas in which they could improve upon the results of physical management methods like mowing and side trimming.
Under the guidance of Wes Graham, right-of-way manager and field biologist at Cooperative Energy, the use of selective herbicides was added to the company’s vegetation management program in 2008 as part of an effort to enhance the control of incompatible plant species throughout ROW sites. Vegetation can grow or fall into utility lines, so it poses a constant threat to electrical transmission safety. Moreover, incompatible plant species can impede the development of native plant communities, which can negatively impact natural ecosystems and habitat for a variety of plants and animals. By using selective herbicides in tandem with physical management methods to effectively control incompatible vegetation on utility rights-of-way, Cooperative Energy has employed Integrated Vegetation Management (IVM) methods on the lands entrusted to the company for well over a decade.
“Our goal is to provide reliable electricity in a safe manner,” Graham says. “We are constantly looking for better ways to do things, and if changes need to be made in this industry, you’ve got to be accepting of them. Anything and everything that we do on our rights-of-way impacts our members.”
Targeted Vegetation Control
Some of the most troublesome species found throughout rights-of-way managed by Cooperative Energy include trees like sweetgum, volunteer pine and the fast-growing Chinese tallow. To eliminate the threat these species pose to native plant communities and mitigate the risk of utility interruptions caused by fallen trees and limbs, Cooperative Energy commonly uses herbicides such as Vastlan® and Garlon® 4 Ultra from Corteva Agriscience for optimum brush control and increased efficacy of multiple woody species. Graham sites dependability as a key factor contributing to his team’s decision to use products from Corteva Agriscience throughout the year.
“We use Corteva because we know that if it’s in the tank and it’s an approved mix, the company is going to stand behind its products,” Graham says.
While low-volume backpack sprayers are used most often to treat right-of-way brush, high-volume foliar treatments are applied by using aerial application methods for control in areas difficult to traverse due to terrain. Having application flexibility is a major benefit to Cooperative Energy’s vegetation management program, and Graham values the ability to target only incompatible vegetation as it allows communities of native plants to flourish.
“By being selective with herbicide applications, we know the desirable plant species around a problematic tree like sweetgum will fill the void when it’s removed,” he says.
Aside from incompatible woody species, Cooperative Energy also focuses on controlling cogongrass, an invasive species that thrives in multiple environments and wreaks havoc on native plants and wildlife habitats. While the use of nonselective herbicides could be used to control a menace like cogongrass, this strategy can cause widespread brownout and enhance the risk of erosion. As selective herbicides target only incompatible plant species and help to establish ecosystems filled with native plants, Graham finds the results are much more desirable to members of surrounding communities.
“Treating undesirable species rather than an entire right-of-way promotes a much more positive public image,” Graham says.
Ensuring electrical transmission safety might be as appealing to the general public as the aesthetics of compatible plant communities, but the impact IVM practices have had on native wildlife is perhaps the most noteworthy of all.
Improvements to Beneficial Habitat
In an ongoing effort to assess the environmental impact of IVM strategies, Graham regularly conducts endangered species surveys whenever maintenance is required in the field. After noting several burrows throughout ROW corridors managed by Cooperative Energy, Graham took particular interest in the gopher tortoise, one of the most prominent endangered species in Mississippi. Over the course of three years, he gathered data on burrow sites in areas where selective herbicides had been applied, and the results were indisputable.
“We’ve got six counties in our service territory that are considered prime habitat in the extreme western range of gopher tortoise,” Graham says. “By minimizing the use of heavy equipment for vegetation management, we have lessened the impact to its critical habitat.”
As incompatible vegetation previously lined edges of rights-of-way across the state, gopher tortoises commonly dug their burrows throughout the centerline of each corridor where compatible vegetation existed but encounters with workers or large equipment often threatened their safety. However, as selective herbicides targeted incompatible plant processes and impeded their development along the borders of each right-of-way, plant species representing the ideal habitat for gopher tortoises began to thrive.
“Herbicide applications opened up the entire corridor,” Graham says. “We saw a tremendous reduction in the amount of gopher tortoise burrows in the centerline, and they started moving toward the edges of the rights-of-way.”
When compatible plant communities grow, incompatible species have less space to develop, which reduces the need for large equipment commonly used for physical vegetation methods like mowing. By yielding sustainable, biodiverse habitats, the use of selective herbicides curtails environmental disturbance and makes natural areas all the more attractive to wildlife species. Over the span of three years, Graham’s data showed a 75% decrease in gopher tortoise presence on the centerline and a 32% increase in gopher tortoise populations overall throughout ROW sites in counties where prime habitat existed.
By reducing human-gopher tortoise interaction and minimizing the use of heavy equipment, Cooperative Energy has created a sustainable environment in which the endangered species can thrive. And the gopher tortoise is not alone. IVM practices have also been shown to aid in the development of habitats that support pollinator populations, which have dwindled in recent years. As pollinators play a significant role in delivering approximately one-third of all foods and beverages around the globe, heightened emphasis has been placed on identifying vegetation management practices that can support the creation of early successional habitats compatible with utility needs on rights-of-way. And while research studies and industry events associated with these efforts have shown IVM practices to provide the most favorable results, Graham recognizes the positive impact these strategies can have in the field.
“By being able to selectively treat invasive species, we are also reducing the impact we might have on herbaceous vegetation for pollinator species,” he says.
A Benefit to All
From meeting the expectations of customers and the general public to identifying and controlling incompatible plant species with solutions that benefit natural habitats and surrounding wildlife, vegetation managers face a number of constant challenges in the field each year. Now recognized as industry best practice for multiple application sites, IVM programs featuring the use of selective herbicides provide management companies like Cooperative Energy with a reliable and long-lasting strategy capable of fulfilling programmatic objectives and the needs of all concerned parties. In Graham’s eyes, tactics associated with IVM practices can pay dividends across the board.
“I like to say it’s a win-win-win: a win for the company, a win for the landowner and a win for wildlife habitats,” Graham says.
To learn more about successful herbicide programs and vegetation management techniques that can promote habitat biodiversity, visit HabitatWithHerbicides.com.
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