Every year during the summer months, there is a major battle going on everywhere that plants grow. That battle is simply referred to as vegetation management.

Vegetation management is waged by a variety of personnel, ranging from homeowners trying to get rid of unwanted vegetation to forest rangers attempting to limit the vegetation that provides kindle for forest fires.

The most critical vegetation management needed today is that which impacts us directly. For example, we are accustomed to a way of life that depends on our ability to use electricity and reliable road and rail networks. The nation’s electrical grid, and road and rail networks are typically referred to as rights of way. Rights of waymust be kept free of unwanted vegetation for the benefit of our livelihoods.

What are rights of way?

Rights of way are areas used for common transport. These include highways and roads, airports, railroads, electric utilities, pipelines, public surface drainageways, public irrigation waterways, banks of barge ways, locks, and dams, and bicycle paths and trails.

Rights of way are essential for the proper functioning of modern society, and they are placed on every terrain, soil, climate, vegetation complex, and land-use area. Managing vegetation on rights of way is desirable and necessary for several reasons including aesthetic and practical purposes. For example, vegetation management:

• Improves visibility on transportation rights of way.
• Reduces fire hazards by encouraging less fire-prone vegetation.
• Ensures continuity of utility services, like electricity.
• Helps promote the health and comfort of the public.
• Enhances the control of nuisance vegetation such as noxious and invasive weeds.

Vegetation management in the electrical grid

The electrical grid is probably the most important utility we have.  Electricity in the United States is transported from generating facilities to local distribution substations through a grid of high-voltage transmission lines that is over 2.5 million miles long. Along the way, the electrical grid must go through areas dominated by vegetation. A high level of vegetation management is necessary to ensure that the high-voltage transmission lines function without disrupting the flow of electricity.

Utility companies spend $6 – 8 billion annually on vegetation management in rights of way. Without this investment, the consequences of having unmanaged vegetation can be devastating. For example, in August 2003, the largest electricity blackout in the United States and Canada happened when powerlines and trees came into contact with each other in Ohio. A short circuit then led to a blackout that affected 50 million people, was connected to at least 11 deaths and caused a loss of $6 billion.

Vegetation management on roadways

The National Highway System is a network of strategic highways within the United States, that includes the Interstate highways and roads serving major airports, ports, military bases, rail or truck terminals, railway stations, pipeline terminals, and other strategic transport facilities. Altogether, it constitutes 160,000 miles that pass through areas dominated by vegetation.

The federal government and state government departments of transportation spend billions of dollars each year on vegetation management along roadways.  Vegetation management along roads seeks to improve visibility for vehicle operators and pedestrians to ensure safety. When managing vegetation along roadways, the main goals include:

• Keeping signs and road users visible to drivers.
• Improving visibility of livestock and wildlife near the road.
• Helping pedestrians and cyclists see motor vehicles.
• Keeping sidewalks and pedestrian paths clear and free from overhanging vegetation.
• Removing trees close to the roadway which could otherwise result in a severe crash if hit.
• Improving winter road maintenance in snow and ice areas.
• Helping drainage systems function as designed.
• Controlling noxious weeds in accordance with local laws and ordinances.

Best practices of vegetation management in rights of way

There are a variety of methods used in rights of way vegetation management, including hazardous tree removal, brush removal, tree pruning, and herbicide application.

Hazardous tree removal

When a tree is unhealthy it can fall on powerlines or onto roads. Therefore, it must be physically removed to prevent it from hitting powerlines, causing blackouts, and/or wildfires, or causing vehicular accidents on roads.

Brush removal

Brush removal is important because the low-lying brush has the potential to cause outages and fires and can limit access of line crews to powerlines when they are inspecting them. Overgrown brush on roadways can lower visibility for drivers leading to accidents.

Tree pruning

Tree pruning involves the maintenance of healthy trees that have the potential to grow close to powerlines or roadways. Tree pruning helps guide tree branches away from powerlines and roadways and also reduces the internal decay of trees.

Herbicide application

Herbicides are used to kill off unwanted vegetation. Herbicides have been proven to greatly reduce the cost and environmental impact of vegetation management in all rights of way. Herbicides have been a key method for controlling vegetation along rights of way, and if they are not used the costs associated with vegetation management may double.

The major success of herbicide usage is because herbicides allow utilities to manage vegetation while it is low, rather than having to deal with tall vegetation later on.

Even though herbicide use is the most cost-effective utility vegetation management technique, it does come with some challenges. Public concern about environmental contamination has initiated a push for alternative methods to control unwanted vegetation. Specifically, herbicide residues are being found regularly in storm, ground, and stream water which has increased the amount of exposure for humans and the environment.

To optimize herbicide use in rights of way vegetation management, applicators need to:

1. Understand the target species’ biology and ecology. This is information about a species that allows the applicator to apply the herbicide at a time when the target species is most vulnerable and the likelihood for maximum control is highest.
2. Be knowledgeable about the chemical mechanism of the herbicide. For the best control, the applicator must match the target species with the appropriate herbicide, while ensuring it is least harmful to the environment and nontargets.
3. Be familiar with the different factors that will influence the effectiveness of foliar herbicide spray applications. For example, using an adjuvant that reduces the potential for herbicide spray drift will reduce the likelihood of the herbicide harming nontargets and the environment.

Further Reading.

• Brewer 90-10 Surfactant for Excellent Vegetation Management
• Optimize Your Weed and Brush Control with Silnet 200 – A Superior Nonionic Surfactant
• Best Practices of Utility Vegetation Management
• Control of Woody Vegetation in Rights-Of-Way using Basal Applications
• Basal Bark Treatment: What is it and How is it Used?

References

• Green, J.D., et al. Training Manual for Right-of-Way Vegetation Management. Univ. Kentucky Coop. Ext. Serv. Bull. PAT-1-6. https://www.uky.edu/Ag/PAT/pat1-6/pat1-6.pdf. [Accessed, July 29, 2022]