Utility ROW are no place for trees or non-native brush species. This incompatible vegetation can interfere with overhead transmission lines, create accessibility issues for maintenance crews, and impede the development of desirable plant communities that are compatible with utility infrastructure and surrounding wildlife.
Utility companies and their vegetation management partners can effectively protect utility infrastructure and improve environmental sustainability by adapting strategies that effectively control this undesirable vegetation. But how can practitioners know which strategies achieve these objectives most effectively? The State Game Lands 33 (SGL 33) research project in central Pennsylvania may provide ample guidance.
When researchers with Pennsylvania State University (PSU) shared the Floral & Faunal Research Report in 2022, they added to insights driven by nearly 70 years of environmental ROW studies on SGL 33. In addition to exploring the impact mechanical mowing, hand-cutting and herbicide applications can have on tree-resistant ground cover throughout ROW corridors, the report indicates best practices for the creation of early successional plants that support habitat development for breeding birds and pollinator species.
“It’s really amazing to see the results of what we can do from a stewardship and sustainability aspect,” said Damon Palmer, Marketing Leader, U.S. Specialties, Corteva Agriscience. “That’s why it’s key for us to partner with industry leaders, academics and other people in the value chain to bring these new ideas and concepts forward to help the environment and ecology.”
As a long-time funding partner of SGL 33, Corteva Agriscience keeps close tabs on results generated by the environmental research project. While the agriculture company showcases SGL 33 findings on HabitatWithHerbicides.com, the following insights from the recent Floral & Faunal Research Report shared by PSU can help utility companies and their vegetation management partners identify industry-leading strategies that have the potential to enhance service reliability, biodiversity and their public image:
Tree- Resistant Cover Types
Data from the SGL 33 Floral & Faunal Research Report show that herbicide applications consisting of low- and high-volume foliar treatments, as well as low-volume basal applications, generally led to lower incompatible stem densities in the wire zone (95 feet from center of transmission line corridor) and border zone (30 feet beyond wire zone) than mechanical mowing or hand-cutting practices. These outcomes indicate that using selective herbicide applications as part of an Integrated Vegetation Management (IVM) strategy can help practitioners establish tree-resistant cover types that impede the development of incompatible trees that often compromise the integrity of utility infrastructure.
Since the early 1980s, the wire zone-border zone method of IVM has benefited early successional bird species on numerous plots throughout SGL 33. The 2022 research report from PSU details the benefits selective herbicide applications can provide to this strategic approach to ROW and biodiversity management over mechanical treatments or nonselective herbicide applications. Noteworthy results from the report include:
- Breeding bird abundance and richness were higher on plots where selective herbicide treatments were used as part of IVM strategies for wire zone and border zone management.
- Low-volume foliar and low-volume basal applications on sites with accompanying border zones contained a higher abundance and richness of breeding birds than mechanically treated sites or sites with no border zone at all.
- The abundance of breeding birds on sites treated with hand-cutting and mowing strategies was consistently lower.
Habitat loss has contributed to declining pollinator populations for years, and utility ROW corridors represent ideal landscapes for pollinator habitat to exist. That’s why SGL 33 contributors included the collection of flower-visiting insects as part of their most recent three-year research cycle. The following insights detail what SGL researchers observed:
- Plots managed with mechanical mowing or hand-cutting strategies featured a lower abundance of bees than most herbicide-treated plots.
- Plots treated with high-volume and low-volume herbicide applications yielded higher levels of taxa richness.
- Plots treated with low-volume basal applications featured a consistently high abundance and taxa richness of native bees across all three years after treatment.
Reducing Carbon Emissions
The development of biodiverse wildlife habitat isn’t the only environmental benefit of using selective herbicide applications as part of an IVM-based strategy. According to research conducted by Asplundh Tree Expert in support of SGL 33 research, mechanical mowing practices require significantly more fuel than low-volume basal, low-volume foliar and high-volume foliar herbicide treatments.
Asplundh research showed that 24 gallons of fuel were required to mow just 3.04 acres of land. This equated to carbon emissions of 176.68 lbs./acre. In other words, utility companies and their vegetation management partners can expect to release more than 175,000 pounds of CO2 emissions into the atmosphere for every thousand acres they treat with mowing applications. Comparatively, Asplundh research suggests that high-volume foliar applications produce approximately one-eighth of that amount; low-volume basal and foliar treatments require no fuel whatsoever.
Asplundh research data also shows that herbicide applications require significantly less time to complete than mechanized treatments:
- Low-volume basal applications covered an average of 0.62 acres per hour (ac/h)
- High-volume foliar applications fluctuated between 0.7 ac/h and 3.06 ac/h
- Mechanical mowing covered 0.51 ac/h
- Hand-cutting practices covered 0.04 ac/h to 0.09 ac/h
Combining these insights with SGL 33 data shared by PSU showcases how IVM programs can improve biodiversity, productivity and cost efficiency for utility companies that manage thousands of ROW acres each year.
A Call to Action for Vegetation Managers
Utility companies and their vegetation management partners must consider the positive impact IVM strategies can have on the environment, ROW safety and their bottom line. As an added benefit, utility vegetation management programs can contribute to Environmental, Social and Governance (ESG) reporting through effective biodiversity management practices and the disclosure of quantitative and qualitative assessments. In turn, this reporting can enhance a utility’s image and neutralize factors that may sway public perception in the future.
To learn how your program can effectively manage incompatible vegetation throughout utility sites by adapting selective herbicide applications as part of an IVM-based strategy, visit Utility.VegetationMgmt.com.
For more insights regarding research findings most recently shared by SGL 33 contributors with PSU, click here.
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