Restoring a degraded landscape
For nature lovers, restoration ecologists sure seem to spend a lot of time killing things. Much of this wrath is aimed at invasive plants, alien species that evict native plants and wildlife from established natural areas. And at The Highlands, the turf grasses planted for the golf course persist as a carpet over the landscape, excluding native plants from getting established in the first place. Left alone, former fairways and greens become unsightly tangles of overgrown lawn grasses and weeds – brome, teasel, thistle – that have little diversity and almost no benefit to wildlife.
The solution, of course, is to plant new things. Over the past four years at The Highlands, hundreds of volunteers have planted new vegetation with the goal of restoring healthy, biodiverse ecosystems. Seven distinct wetland zones and nearly 60 acres of native grasslands have already been established, along with thousands of trees, shrubs, and wildflowers throughout the property. But long before a seed hits the soil or a shovel enters the ground, the ground needs to be cleared of what’s there. Otherwise, planting efforts will be wasted, the new plants choked out by overgrown turf grasses and weeds.
Although there are a variety of methods to prepare a site for restoration, there is one tried-and-true tool used by natural areas managers nationwide: herbicides.
Herbicides should give us pause. After all, they are synthetic chemicals that have been designed to poison and kill. Their destructive properties are aimed at plants, but we know that some herbicides can persist in the environment, negatively impact wildlife, or lead to human health issues. Herbicides like glyphosate have become controversial in recent years as evidence of human health impacts has come to light. For land managers, these issues are deeply concerning. If the intent is to restore healthy natural areas where all creatures – people included – can thrive, why even use the stuff in the first place? Aren’t there other ways to approach restoration?
“We don’t love using herbicides. But when applied carefully and strategically, herbicides are one of the most effective tools we have for restoring native habitats,” says Julie Batty, Land Stewardship Manager at Blandford Nature Center.
While many alternatives to herbicides have been used or proposed, most either aren’t effective, cost-efficient, or feasible to implement, especially across many acres. And some aren’t any safer than the herbicides they’re designed to replace.
“Developing herbicide alternatives is a growing field of research,” explains Lucas Dykstra, Stewardship Specialist at the Land Conservancy of West Michigan, “and we’re always keeping our eye out for feasible, scalable options we can try that will reduce our use of synthetic chemicals.”
To that end, land managers at The Highlands follow the principles of Integrated Pest Management, otherwise known as IPM. IPM is just a way of saying that non-chemical methods of controlling vegetation like pulling, cutting, mowing, or burning are always considered before using herbicides, and that those methods can be combined with herbicide use to reduce the amount of chemical applied to the landscape.
But IPM isn’t just jargon. It’s applied every day at The Highlands. Staff have spent countless hours hacking down bull thistle – an aggressive, thorny, 8-foot megaweed – with a weed trimmer to keep it from developing seed heads. Each year, volunteers fill bags of invasive garlic mustard they’ve pulled by the roots from woodlines and thickets around the property. And precisely-timed mowing and prescribed burning regimens are used to target unwanted vegetation at susceptible stages. All this significantly reduces the amount of herbicide used in the process of restoration.
The transition of The Highlands from a golf course to a natural area – along with a commitment to IPM – has vastly reduced the amount of chemicals applied to the landscape. According to national statistics, an average golf course applies nearly 50,000 pounds of chemicals to the ground every year. While much of that is chemical fertilizer, manicured golf courses are doused in least 1,650 pounds of synthetic pesticides annually.
By any measure, the amount of herbicide now applied at The Highlands for ecological restoration is a fraction of that former figure. And each year, as habitat at The Highlands transitions away from an overgrown golf course toward established ecosystems, the reliance on herbicides decreases even further.
“Eventually, our management will move into a maintenance mode, where we’re able to cut, pull, or spot-treat very small infestations, rather than treat large areas,” says Justin Heslinga, Stewardship Director at the Land Conservancy of West Michigan. “We’re looking forward to that.”
This is a familiar pattern in ecological restoration. Natural areas that are severely degraded usually require a lot of work – herbicide use included – up front to repair the damage caused by invasive species or related factors. But once the ecosystems are on a sustainable trajectory, the need for herbicides decreases considerably.
“ Maas Family Nature Preserve and Lamberton Lake Fen Nature Preserve are two great examples,” says Heslinga. Once in danger of being overrun with encroaching vegetation, Maas now harbors a population of the endangered Karner blue butterfly, and Lamberton Lake supports one of the most biodiverse prairie fen communities in Michigan. Both of those are considered major restoration success stories. “Those projects wouldn’t have been possible without using herbicides at the outset of restoration. Now our herbicide use at those sites is almost negligible.”
The Highlands is on a similar journey, though both the path and the destination look different. Once a wild mix of forests and wetlands, The Highlands underwent a century of ecological abuse as a golf course, subjected to land clearing, altered hydrology, and heavy chemical applications. Reversing that abuse, ironically, sometimes requires using the same tools that brought about destruction – including strategic doses of herbicide.
When larger-scale herbicide applications are needed at The Highlands, signs will be posted to help visitors avoid the areas where herbicides are in use. Those with questions or concerns are encouraged to contact the Land Conservancy of West Michigan or Blandford Nature Center.
Over time, the tools used to restore The Highlands will become softer and gentler. The focus will shift away from sweeping changes in the landscape to subtler shifts in habitats and species. The Highlands will become a place where we finally work with the land, instead of against it. A place where people live alongside the foxes and bluebirds and frogs who have entrusted us to treat the land with great care.