Ask anyone in my family if I’d ever be celebrating the felling of trees and they would look at you incredulously and start laughing. Cam? The original (occasionally literal) tree hugger?!
I had a favorite 100 year old sugar maple that befriended me as a child and I spent happy hours high in the branches with my books and snacks. When that tree and others were being felled for a housing development in the field next door, my mother – not a born nature lover – went to bat for those trees, even contacting the governor’s office since “environmental protection” was in its infancy then. But to no avail.
So imagine my astonishment at finding myself standing in the western section of Draper Twin Lake Park with Dr. Ben VanderWeide, our township’s Natural Areas Stewardship Manager, delighting in the scene pictured in this video!!
Restoring the Habitat of the Past to Provide for a Healthy Future
My pleasure, of course, stemmed from my growing understanding and appreciation of restoration. That monster of a machine, a forestry mower, was removing a gigantic glut of non-native trees and shrubs. (See the photo above!) For decades, this natural area of grasses, wildflowers and widely spaced native trees had been farmed. The bare soil, depleted of its native diversity, suffered an invasion when farming stopped in the 1970s; trees, shrubs and other plants from Europe and Asia made the most of a great opportunity. Escaping from farms, flower gardens or landscaping, invasive plants found their way to this habitat. Benefiting from the absence of the competitors or conditions they had to contend with at home, they spread wildly. Our local plants and trees couldn’t compete. They didn’t evolve with these new arrivals and so had no defenses for countering their steady increase. It would take millennia for our native insects, birds, diseases, and plants to eventually evolve and adapt to these new plants, too long for the survival of the many species that depend on them.
That’s where our stewardship crew steps in. Ecological restoration attempts to give our local trees, grasses and wildflowers a fighting chance to thrive. When it succeeds, native plants can then provide for the whole food web that evolved with them. As you can see below, the forestry mower opened up fields and forest, beginning the process of restoring the landscape that nature designed eons ago.
It’s not that non-native trees and shrubs are “bad”; they functional beautifully in their home environments. But they aren’t able to effectively nourish and protect the creatures that live and evolved here in Oakland Township. Butterflies may sip at non-native garden flowers, but their caterpillars generally can’t eat non-native leaves or fail to reach maturity if they do. Birds may eat non-native berries but they almost universally feed their nestlings nutritious caterpillars which are full of fat and protein. Fewer native plants means fewer caterpillars which means fewer birds, a ripple effect that then moves on through the food web. Restoring native plants to an area means lots of nature gets fed and sheltered.
Meet the Most Common (and Pesky) Invasives at Draper Twin Lake Park
So let’s get more familiar with the highly invasive shrubs and vines that ended up dominating so many of our natural areas, including Draper Twin Lake Park. For the most part, they started out in nurseries which unwittingly (or occasionally wittingly) sold them to landscapers and homeowners as decorative additions to their gardens. Some of the most infamous and tenacious invasive shrubs in our parks include Autumn Olive (Elaeagnus umbellata), Glossy Buckthorn (Frangula alnus) and Common Privet (Ligustrum vulgare), shrubs that produce plentiful fruits which unfortunately provide scant nutrition for our birds. Generally non-native fruits provide sugars (carbohydrates) for wildlife but don’t have the fats (lipids) that birds, for example, require for migration or winter survival. Research at Michigan State University has shown that birds prefer native fruits when they can get them, but will eat the less healthy non-native fruits if nothing else is available. Once eaten by birds or other animals, invasive trees and shrubs spread far and wide through their droppings.
The fruits of Oriental Bittersweet vines (Celastrus orbiculatus) are particularly pernicious. The outer yellow skins peel back to reveal red fruits, attracting both birds searching for a late season food source, and humans who unwittingly use them for decorative purposes. Birds enjoy the sugars in their fruit during late fall, but since its seeds can last a long time in the guts of birds, the plant can be spread long distances. Once established, the vine climbs quickly, reaching for light in the treetops. As the vine spirals up the trunk, it girdles and slowly strangles the tree. When the vine reaches the crown, its foliage shades out the tree’s leaves, weakening the tree. Its weight makes the tree’s crown heavy and vulnerable to toppling in high winds. It’s a real femme fatale, this vine with its pretty fruits and its deadly growth pattern.
Many invasives quickly form dense thickets in a field or woods through underground stems (rhizomes) or root suckers. Their density chokes out the sun, rain and space that our native plants require. Below is a photo from Bear Creek Nature Park that demonstrates the density that once surrounded a pine tree, killing its lower branches. And on the right at Draper Twin Lake Park, a young oak had the same problem until the restoration began this fall.
Some invasives, like Tree-of-Heaven (Ailanthus altissima), produce giant quantities of seeds which can be carried on the wind and once sown, the trees grow incredibly quickly. Growth of 3.5 to 6 feet each year of its first four years is considered normal! It also releases toxins into the soil to prevent or inhibit the growth of plants around it. In the photo on the right below, Ben placed his hand where the second year growth of one of these trees began! Faster growth means that these trees shade out neighbors and mature faster than others, allowing them to spread quickly.
You might be as surprised as I once was to learn that even some of our common and long-beloved bushes can spread invasively. That’s part of what happened at Draper Twin Lake Park. Ben found huge thickets of non-natives like Forsythia (Forsythia intermedia) from Asia and Common Lilac (Syringa vulgaris) from southeastern Europe on the western section of Draper; they both probably once surrounded the house when a farm was located here.
The Removal of Invasives Goes Beyond Mowing
Once the forestry mower has done its work, hard work lies ahead. Stumps of invasive shrubs that the mower missed are cut and carefully dabbed with herbicide to prevent re-sprouting. Some, like the persistent Tree-of-Heaven, will require further treatment and periodic mowing to discourage new growth. Oriental Bittersweet can only be removed by cutting the vines and then carefully treating the roots to prevent regrowth. New sprouts will also need to be treated repeatedly for some time, a tedious but necessary process. Some larger trees are treated by a process called “drill and fill” in which holes are drilled around the tree and herbicide is introduced. When the tree dies, it will still remain standing, storing its carbon for years to come and providing shelter for woodpeckers and other cavity nesting animals, like red squirrels or raccoons. The stewardship staff will spread native plant seed to help bring back what was choked out by the invasive trees and shrubs – native grasses first, then wildflower seed in a year or two after the invasive shrub re-sprouts have been controlled. Further down the road, prescribed fires may be used to encourage our fire-adapted native plants.
Winter Wildlife and I Explore the Newly Restored Landscape
On one of my visits to the western section of the park, Ben showed me the remains of a beaver dam and the small pond this industrious builder had created. The dam consisted of a few small trees and some plant material patched together with mud. Though we saw a few pencil-shaped stumps in the area, Ben’s guess is that when the beaver began this project a couple of years ago, it couldn’t find enough small willows or cottonwoods, its preferred building materials, to meet the beaver’s need, so it abandoned the idea. However, the beaver did create a lovely little pond behind the dam. And the little dam slowed the water down enough that Ben was surprised to find much drier footing further south in the marsh while doing a plant survey in 2020!
In the fields east of the trail, a few winter birds kept me company as they sought out frozen insect eggs or larvae in the trees newly liberated from the crush of invasive shrubs.
A small group of White-tailed Deer (Odocoileus virginianus) browsed between the newly thinned trees in the forest. Deer consume dry grasses, but unfortunately they much prefer acorns and small oak saplings in fall and winter, affecting the quality of our forests. According to a Tufts University website, in winter they also rely on insulation from stored fat and more of the coarse dark hairs in their coats called “guard hairs.” Glands in their skin produce oils that help their coats repel water, an advantage on snowy days.
One snowy morning, I spent twenty minutes or so tracking a small animal. Its prints lay in a single line, which usually indicates a fox or coyote. Wild canines, unlike domestic dogs, place their hind foot carefully into the track of the front foot on the same side, making a neat row of single, or “direct register” tracks. The tracks that I was following intrigued me because they were much smaller than most that I’d seen. After puzzling a bit, I suddenly noticed that the tracks had no nail prints at the end of the toes. And with that, I remembered that wild canines share direct register tracks with another group of animals – cats! What I’d been tracking was the small, roundish, direct register prints of a house cat! Cats, unlike canines, walk with their toenails withdrawn in order to keep them sharp for hunting – or they may have had them removed by pet owners. I shook my head, laughing at myself for tracking a cat and went back to the trail.
Squirrels and squirrel tracks were everywhere that morning! Their tracks usually appear as a block of four prints like the ones below. I think these belong to the American Red Squirrel (Tamiasciurus hudsonicus), because the larger five-toed tracks of their hind feet are slightly in front of the four-toed tracks of their front feet; that’s the pattern left when these little guys take off and land, pushing down with the front feet while swinging the hind feet forward. I also saw a larger Fox Squirrel (Sciurus niger) high up in the small branches of a tree, probably making a meal of the tiny leaf buds.
Down by the Lake, a Little Avian Hysteria
Winter silence had descended when I arrived at the dock on Twin Lake one cloudy afternoon. In the deep quiet, I got intrigued by strange ovals on the lake surface. It was fun to imagine a squadron of flying saucers landing on the surface, but I was curious to do some research when I reached home. From assembling the hints I could find online, I’m guessing that they may be caused by rotating convection currents created by warm water rising and cold water falling during a frost/freeze cycle, inhibiting ice formation. But if you have better information, please let me know in the comments.
Suddenly far across the lake, a pair of Red-tailed Hawks (Buteo jamaicensis) began circling high above the trees. I caught one with my camera as it spiraled lazily. Red-tail hawks are believed to mate for life, though they quickly choose another mate if one of them dies. This pair may be nesting in the area since the Wednesday bird group saw two of them in the trees across the lake a couple of weeks later.
Just as I spotted the hawks in the distance, a screech of alarm calls broke out from a flock of American Crows (Corvus brachyrhynchos) nearby. They flashed out of the trees in a large group, flying away to the south. Evidently, the hawks must have gone unnoticed in the forest until they rose into the air to do a little scouting together. Their appearance startled the crows who were too flustered to harass or “mob” them as they often do. My camera managed to catch one in mid-caw after it launched off a limb.
After the noise subsided, I turned to look at a Muskrat lodge (Ondatra zibethicus) off the side of the dock. Muskrats may have been dozing inside since their metabolism slows way down in the winter. Or it may have left its dry sleeping chamber above the water line, swum down through its underwater entrance and begun cruising slowly along under the ice, searching for a meal. Note that unlike beavers who build their much larger lodges with trees, branches and sticks, muskrats build with mud and cattail stems or other aquatic plant material. This one was also surrounded by graceful stalks carrying the dried pom-poms of Whorled Loosestrife seed heads (Lysimachia quadrifolia). A tidy winter abode, I think.
My Evolving Understanding of “Letting Nature Takes Its Course.”
It took me a few years of working in the parks with Ben before I fully understood the beauty and power of restoring our natural areas. I approached restoration suspiciously at first, having grown up with the ethos,”Let nature take its course.” How could altering the landscape through mowing, felling trees and shrubs, and the occasional use of herbicides be good for nature?
Remembering the Landscape of My Childhood
The first step to understanding restoration was noticing what was missing today. One day early on as a Parks volunteer in 2015, I asked Ben what birds might return if we restored the Oak Savannah landscape – grass, trees and widely spaced oaks – that had existed here before European settlement. Among other birds, he mentioned the Northern Bobwhite (Colinus virginianus). Ah! That name instantly brought back memories of the two-note song of that quail whistling from summer fields around my parents’ home on Lake George Road when I was a child. I live very near my family home now, but I haven’t heard a Bobwhite sing for more than 50 years. The native Big Bluestem grass (Andropogon gerardii) that towered over my head as a little girl was replaced by housing and short, green, non-native lawns in my teen years. As ground feeders and nesters, the Bobwhites needed that tall, stiff grass to protect them and their young from hawks and other predators and they no doubt fed off the seeds that fell from those dry stalks in the autumn. The increasing use of pesticides in farming plus habitat loss have both contributed to an 85% decline in the numbers of the Bobwhite Quail since the 1970’s. I miss them.
Listening to Doug Tallamy, author of Bringing Nature Home, at a Michigan Wildflower Conference in 2019, I was reminded of the moths that used to dance in groups around our porch light on summer nights – or splattered against the windshields of my parents’ car. I suddenly realized that I don’t see as many moths clinging to our porch windows or fluttering in the headlights now as I did years ago. The reason, I learned, was that the caterpillars of most moths and butterflies need native plants in order to feed and mature into adults; my yard, like most of my neighbors, was filled with decorative plants, shrubs and trees native to places all over the world – like Norway and Japanese Maples – but fewer of the ones more common in my childhood. Native oaks and other native trees provide sustenance for the caterpillars of many species of butterflies and moths. Here are two examples of what we may be missing: Wild Black Cherry (Prunus serotina) and Pagoda/Alternate Leaf Dogwoods are the preferred hosts for many insects including the spectacular Cecropia Moth (Hyalophora Cecropia). Oaks are especially generous, hosting the caterpillars of hundreds of species of Lepidoptera (moths and butterflies), including the impressive Polyphemus Moth (Antheraea polyphemus).
When I was a child in Oakland Township, seeing a White-tailed Deer was a rare treat. At that time, large expanses of active or abandoned farm land surrounded by woods allowed them to stay out of sight. Today development has crowded deer closer to our homes and gardens and on to our roads. The forest floor, once covered in wildflowers like trillium are more often choked with non-native shrubs or vines that take advantage of the open ground left by herds of deer browsing on the tender sprouts of wildflowers in spring or saplings in winter.
So it turns out that I was wrong. The non-native plants that fill our fields and surround our personal property were not a matter of “letting nature takes its course.” Quite the opposite, in fact. The carpets of invasive plants were the effect of humans unwittingly but actively changing our native habit over the last two hundred years.
The Good News? We Can Work to Restore What Nature Created
So finally I understood that what humans had done could in some measure be undone. True, we can’t completely recreate nature’s original landscape design on any large scale or in such rich diversity. But the people of Oakland Township have made an ongoing commitment to preserving and restoring natural areas here wherever possible. Thanks to them, Ben and his crew are systematically decreasing the invasive plants in our natural areas and giving the plants that nature provided eons ago a chance to thrive again. Homeowners like us are choosing to integrate native plants and trees into our landscapes and turning turf into meadows and wildflower gardens. If enough of us create native neighborhoods, perhaps I will live to hear the whistle of the Bobwhite once more.
That’s why I, an inveterate tree lover, could celebrate the felling of invasive trees that day at Draper. What I was seeing as the forestry mower cleared away the brush was stewardship – restoring and caring for a productive, diverse ecosystem that nature took thousands of years to perfect. As the old hymn goes, I “…was blind but now I see.”