Modern Herbicides Play a Key Role in Ecosystem Restoration
- leahfuller36
- 2 days ago
- 4 min read
The modern environmental movement, largely sparked by Rachel Carson’s ‘Silent Spring,’ marked a turning point in how society views the natural world. During the 1960s and 1970s, public concern over pollution and pesticide use led to extensive environmental reforms, including the establishment of the U.S. Environmental Protection Agency and the expansion of laws to protect air, water, and land.
Today, we live in a vastly different pesticide landscape, shaped by scientific advances and regulatory oversight. And while the term “herbicide” often raises alarm, experts say it’s important to recognize the nuance, particularly when it comes to herbicides used in conservation.
Without the selective use of herbicides, ClearWater Conservancy would face significant challenges in
restoring native plant communities and managing invasive species at a meaningful scale. Mechanical removal alone is often impractical, labor-intensive, and ineffective.
“Invasive control rarely works with mechanical methods alone,” said Art Gover, a retired Penn State researcher with 37 years of experience in vegetation management. “They’re disruptive, expensive, and not always successful. Herbicides, when used appropriately, are the most effective way to get conservation work done.”
Gover now volunteers with the Penn State Extension Master Watershed Steward program, sharing his expertise on managing invasive plants in natural settings.
“There is risk in everything. We do not exist without risk,” said Gover.
On educating the matter, Gover likens the use of herbicides to everyday risks that society accepts. “We all drive cars. Automobile accidents are one of the leading causes of death in this country, but we’ve decided the benefit outweighs the risks. It’s the same idea here.”
In many cases, herbicides cause far less disturbance than mechanical methods, particularly in riparian areas where soil disruption can have cascading ecological effects. When applied carefully, such as with hand tools or backpack sprayers, herbicides can target only invasive species while leaving desirable native plants intact.
Emily Rojik, a Penn State Extension educator in forestry and wildlife, emphasizes that many herbicides used today are designed to be highly specific to plants. “Herbicides are generally the lowest-toxicity class of pesticides when it comes to people and animals,” Rojik said. “Thanks to advances in chemistry, we’ve developed herbicides that interfere only with biochemical processes unique to plants.”
Because these pathways do not exist in animals, the risk to humans, pets, pollinators, and other wildlife, is extremely low.
But why is it so important to remove invasive species and promote native plantings?
Suzy Yetter, ClearWater Conservancy’s staff ecologist, expresses the critical role native plants play in maintaining biodiversity and wildlife habitat. With more than 20 years of experience in riverine benthic macroinvertebrate ecology, water quality assessment, and interdisciplinary research, Yetter draws on both academic and field knowledge in this article.
“First, let’s return to evolutionary biology,” said Yetter. “Insect and plant communities that have evolved together over time in the same locale have developed special relationships that capitalize on the specific traits or characteristics of one another.”
Insects can only tolerate a narrow range of chemical compounds, specifically, those they’ve adapted to over thousands of generations. The biggest barrier to insects feeding on non-native plants is in the plants’ leaf chemistry. Many plants produce secondary metabolites, which are compounds not essential for growth or reproduction, but critical for defense against insects.
As entomologist Doug Tallamy notes in Bringing Nature Home (Timber Press, 2007), the secondary metabolites give their plant a very specific and unique taste, toxicity, and digestibility.
It’s a dynamic similar to how certain plants are toxic to humans. Take belladonna, or deadly nightshade, for example. Despite its innocuous appearance (dull green leaves and shiny black berries), its compounds can paralyze involuntary muscles, including the heart.
If a plant community contains only exotic species, it cannot support the local ecosystem. If insects can't feed on the plants, birds and bats then have no insects to eat. This would continue until you have a sterile landscape. Restoring native plant communities supports the local insects, birds, and animals that live there.
According to an article from Cornell University, “Cumulative loss of nearly three billion birds since 1970, across most North American biomes, signals a pervasive and ongoing avifaunal crisis” (Science 2019). One contributing factor to this decline is the prevalence of exotic landscaping and exotic plants invading our forests and fields. Birds largely raise their young on caterpillars. If there are no native plants for butterflies and moths to lay eggs on, which then become caterpillars, birds cannot successfully reproduce, which disrupts the food chain for the entire ecosystem.
The Conservation Team at ClearWater aims to restore native plant communities whenever and wherever they are able. “We would not be able to accomplish this important conservation work at the scale and pace we do without using herbicides,” said Jennifer Dombroskie, Riparian Program Manager. ClearWater’s Riparian Program is planting more than 30 acres of native trees and shrubs along streams in Centre County this year. These new plantings would not survive without herbicide use due to exotic, invasive plants outcompeting them, which have no competition here from insects or diseases. Herbicide use will be temporary until the new plantings are well established, which is a small risk for a big reward.
To learn more about planting natives and herbicide use, check out these resources below:
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