The Battle Against Invasive Species
With Evan Wilson in control the howling chainsaw quickly sliced through the 15-foot clump of bush honeysuckle. As the limbs fell away in all directions sunlight flooded into the newly exposed ground, a thick, overgrown limb-littered section of Floyds Fork floodplain just below Echo Trail near the southern gateway to Beckley Creek Park.
Wilson is a natural areas technician with The Parklands of Floyds Fork. Dressed in protective gear from his orange safety helmet, goggles and ear guards to his thick chaps and boots he moved on to clear another area of Floyds Fork bottomland of invasive plants, leaving behind more patches of sunlight in various shapes and sizes.
The good news was the newly opened areas would allow more native plants to grow.
The bad news was the invasives could also reclaim the open areas without a few follow-up treatments and regular monitoring.
That’s the continuing challenge for Andrew Oost, Wilson’s supervisor and the Parklands Natural Areas Team Leader who has spent almost two years dealing with the invasives in the 3,800-acre park.
“You’re not going to win on a global scale,” said Oost of the interminable, world-wide problems with invasive plants, “and maybe not even on a local scale… but we are going to win in this park.”
Oost lists bush honeysuckle at the top of the Five Worst Invasive Species in Floyds Fork, with Japanese honeysuckle, bradford pear, multi-flora rose and Johnson grass the others on what amounts to a “job security” list.
Honorable mention would include wintercreeper, privet, Russian olive, garlic mustard, poison hemlock, giant ragweed and the absurdly named Tree-of-Heaven.
But it is the bush honeysuckle that best illustrates the pernicious nature and history of invasive plants not only in the Parklands but across Kentucky the Eastern United States.
A native of Asia, China and Japan, it was grown for its ornamental benefits and brought to the United States for hedges and erosion control. With its seeds easily spread by birds, Bush honeysuckle soon raged out of control, forming dense groves shrubs in deciduous forests while shading out the native plants.
The Japanese honeysuckle (Lonicera japonica) had much the same history, desired for its fragrant flowers and then invading the native forests with vines that can reach 30 feet, smothering the trees.
Oost has some experience with the problem. A Louisville native and Ballard High School graduate, he received a degree is Geography from the University of Kentucky.
An outdoor kid by nature, and unhappy with any job that included staring out an office window, he found an internship on a traveling Exotic Plant Management Team with the U.S. National Park Service that was based at Point Reyes National Seashore but took eight-day work stints to almost all national parks in California, including Yosemite National Park. It was there his outdoor enthusiasm first met almost serendipitous learning experience.
“I was on an exotic plant management team,” he said. “We went to all the National Parks in California as a traveling crew. They sent us into areas where the people who worked there full time didn’t want to work.
“When I got into it I probably couldn’t tell you three different trees. I never thought about the botanical side of things.
“We got to see the worst of the parks, but it was cool. We got to camp out. It was a lot of fun.”
His exotic plant learning curve bent straight up from there. He returned to Louisville and was the first person hired when the Louisville Olmsted Parks Conservancy began cleaning out invasives.
After three years there he worked invasive plants management at Rocky Mountain National Park in Colorado.
“That wasn’t my niche,” he said. “I just wanted to be outside. But invasives became my thing.”
That led to a job at Nativescapes, a Louisville company that deals with forestry consulting and natives eradication. He joined The Parklands team in 2011.
“I knew I wanted to get on with this project,” he said. “It’s just so big…so neat.”
Oost estimated about 75 percent of the Parklands has some sort on invasives infestation. The basic invasive eradication plan has been to move south with the construction of the various sites, moving downstream from Beckley Creek Park after the heavy equipment left.
Outside firms such as Nativescapes have been hired to help in the battle, along with Eco Logic out of Bloomington, IN., and Eco-Tech in Louisville
About half of Pope Lick Park has had its initial invasive removal completed, including the Big Beech Woods and Prairie Preserve. Work has also been started in Turkey Run Park. But it’s not a “one-and-done” proposition.
The job is immense; The Parkland’s 3,800 acres is surrounded by many more thousands of privately-owned acres where no eradication will even be attempted. Birds, rodents and honeysuckle plants are no respecters of boundaries. The Parklands sites often have to be revisited several times to stay on top of the invasives.
One recent job site was the riparian floodplain off Echo Trail just below The Great Wall, the massive, almost 4,000 block construction that brings all pedestrian, bike and automobile traffic up out of the bottom.
The area was dominated by skinny box elder and Osage trees with vines climbing up into their limbs. Floodwaters had washed up thick piles of dead branches below them. Honeysuckle and privet was pushing up through the debris. It’s an area also often ripe with invasive garlic mustard. In the middle of all that was a hopeful patch of native ginger.
The invasive plant weapons of choice that day were a chainsaw in one hand and a spray canister filled with 50 percent water and 50 percent glyphosate – a broad-spectrum systemic herbicide – in the other.
Oost said glyphosate is considered the safest herbicide to use in invasive situations because it has the least amount of residual action. A percentage of only 2 or 3 percent glyphosate will kill smaller plants, grasses and weeds when sprayed on the green foliage.
The bigger honeysuckle bushes, those in the 12 to 15 foot range, are a different matter. There’s no living foliage left to spray after the bushes are cut to the ground. The 50-percent solution is required so that the herbicide can be absorbed into the living cambium layer of the stump. Even then, a return trip might be necessary to finish the job. Without the spray a living stump might push up many suckers, creating more problems.
“I tell people all the time if you’re not going to spray the trunk I’d rather you not even cut it down.” Oost said.
With invasives such as garlic mustard the spraying must be done in the spring when the rosettes first emerge, and maybe again in the fall.
“The key with annuals or bi-annuals is timing,” said Oost. “The main goal is to prevent them from setting seed. Once they set viable seed you’ve lost the battle for that year and treating them is pointless.”
Oost labeled the eradication method as “Hit and move on.” He and his crew will walk the woods for hours slicing off invasives with the chain saw or hitting it with spray. The words he used are “back and forth and back and forth.”
He said after two or three years you can get an area to a managed level. There are even now some areas where the natives are beginning to dominate. He said the work is therapeutic.
About the Author
Bob Hill
Former Louisville-Courier columnist Bob Hill is a historian for The Parklands of Floyds Fork. He travels Floyds Fork writing of the people, the places and the history of the stream within the 20-mile park system – all of which is to be preserved in the Filson Historical Society. Some of Hill’s stories appear in A Landscape and its Legacy, the commemorative book for The Parklands of Floyds Fork project. Hill has also compiled a Floyds Fork “Places & Faces” presentation that adds imagery to the words.