First Aid for the Forest

How saws and fire bring back wilderness

By Justin Pepper

I can clearly remember the moment, standing there in room 1005 Haworth Hall at the University of Kansas as my environmental policy teaching assistant described the new job he had accepted working with volunteers to restore nature on protected lands. Cutting honeysuckle and pulling garlic mustard — it all sounded like a lot of work. And was it even necessary? In time, wouldn’t Mother Nature get the whole thing sorted out anyway? Shouldn’t we just let nature take its course? § I think that question started my ecological education in earnest. In the dozen years since, I have encountered many other nature lovers with the same initial response to habitat restoration. Sometimes surprised, sometimes dubious, they are mostly just interested in better understanding what is happening in the woods or grasslands they care about. To better understand what this growing group of conservationists is doing, it is also important to understand why it is necessary in the first place.

What if we just left nature alone?

“Based on what I’ve seen, if we let go, we’d end up with a half-dozen, or a dozen, plants and trees,” says Pam Holy, president of the Chiwaukee Prairie Preservation Fund. “And it just goes down the line. We’d be left with starlings, house sparrows; maybe a few crows would stick around.”

Habitat loss and degradation are leading causes of species extinction. Intuition tells us that building a strip mall on a prairie — habitat loss — is not going to serve that ecosystem well. Perhaps less intuitive is that purchasing that same remnant prairie for conservation alone is not enough to protect that ecosystem for long either. Within Chicago Wilderness, nature now exists as scattered, isolated parcels of land, separated from health-sustaining processes — fire, predation, natural water flows, and others — by our roads and neighborhoods, our habitats.

The symptoms of separation are all too common. One sign is a preserve dominated by a few aggressive species where there once was a rich habitat. Gradually, we are losing thousands of species of birds, insects, plants, fungi, and other organisms that have been a part of this region for millennia.

Restorationists see their role as the re-empowerment of living systems. “We have disrupted the ecological processes that kept our natural communities healthy,” says John Oldenburg, director of natural resources for the Forest Preserve District of DuPage County. “Now, through adaptive management, we play that role by mimicking those processes.” Adaptive management boils down to making a plan based on current and desired conditions, then acting and observing. Over decades, land managers have seen patterns in their failures and successes. They’ve identified common conditions reducing ecosystem function and have seen that a sequence of repeatable actions can gradually nudge our degraded lands back toward ecological health.

Brush removal: bringing back the sun

A few months ago I received a phone call from a worried birder. “It’s just terrible what they have done,” she said. “All the shrubs are gone; it looks like they’ve been shredded. What will happen to all the birds?”

After a few clarifying questions, I shared my opinion that what had happened was, from a bird conservation perspective, most likely a very good thing.

In North America, no group of birds has suffered larger declines in recent decades than grassland birds (see “Plight of the Common Bird,” CW Fall ’07). Habitat loss and degradation leave fewer and fewer places for meadowlarks, bobolinks, or Henslow’s sparrows to raise their young.

This concerned nature lover had seen the work of a “Seppi,” a tractor-mounted brush mower, at Nelson Lake Marsh in Kane County. Though it looked rough then, she was seeing an aggressive first step toward restoring grassland habitat. Very little of our protected land is large enough for grassland birds, but this site, at nearly 1,000 acres, offered a rare opportunity to restore habitat for these birds and countless other plants and animals.

In the two years following similar work at Cook County’s Spring Creek preserve, a small population of grassland birds showed substantial increases, with bobolink numbers spiking 950 percent. (Statewide, bobolinks have declined 97 percent since 1967.)

Encroaching brush doesn’t just evict prairie birds. Entire plant communities are lost to the growing darkness. As invasive trees and shrubs soak up light, they cast shadow on all sorts of sun-loving plants.

Audubon–Chicago Region recently completed a study of 14,000 acres of priority conservation land in Cook County, revealing a worrisome lack of young oaks. In fact, not a single seedling of bur or white oak was found within any of the 1,764 herbaceous plots, and only a single sapling of bur oak was found in 588 shrub plots, despite these being among the dominant trees of our savannas and woodlands.

“Oaks are not regenerating in our preserves — we only see one age class,” says John McCabe, who supervises resource management crews for the Forest Preserve District of Cook County. “When a mature oak dies from lightning strike, oak wilt, or storm damage, a young oak should be there to take its place, but due to invasives, they are not there.” Shade tolerant species seem to be doing fine, but those that need sun are losing out. As odd as it may sound, we need to cut trees to save our woodlands.

Perhaps the most common stewardship opportunity in our region is brush control, typically done with hand tools. While not as dramatic as the Seppi, a group of volunteers can surgically clear around small brush-choked bur oaks or distinguish between invasive buckthorn and Iowa crabapple.

The beauty of burning

The Chicago Wilderness Biodiversity Recovery Plan calls fire “by far the single most important management technique” available to land managers. It is not only an economical way to maintain most of our region’s natural communities, it also allows managers to address a range of issues and provides benefits that no other management practice can deliver.

Burns during spring, for example, are particularly good for setting back the cool-season Eurasian grasses of pastures and hay meadows. The benefits of fire can perhaps best be seen by walking a fire break separating a burned and unburned patch, especially during the growing season that follows a spring burn. In burned areas, native plants flower more and longer. They also produce more seed, capitalizing on thatch-free soil. The fire’s ash adds nutrients to the soil, and its dark color helps raise soil temperatures, stimulating germination.

Fallen oak leaves carry autumn fires through the woods where other dried vegetation is sparse. One well-timed fire can kill thousands of invasive buckthorn seedlings.

Since the needs of species vary, uniform treatments across a site may not be preferred. By segmenting a preserve’s habitats into multiple “burn units,” a manager can maintain unburned refuges for less mobile inhabitants. Rotating an annual burn through those units helps maximize the structural variety within each of the habitats. Why is this important? If large enough, a prairie restoration could support any of 15 grassland bird species known to nest in Chicago Wilderness. But the thick grasses preferred by Henslow’s sparrows are too rank for bobolinks and grasshopper sparrows. Varied grass structure welcomes more species. Other types of “structural diversity” benefit many other animals as well.

Both staff and volunteers may participate in controlled burns. Well trained and equipped crews follow site-specific burn plans that identify the weather conditions needed to safely and effectively achieve the desired outcomes. Once problem weeds have been controlled, periodic “maintenance burns” may be the only regular management needed to maintain health in restored natural areas.

Herbicides that heal

It may surprise some to know that the same nature lovers who go out of their way to buy organic produce support the judicious use of herbicide in the context of restoration.

Particularly bad invasives including wild parsnip, leafy spurge, crown vetch, and reed canary grass cannot be burned out. Though not adapted to fire, their prodigious seed production allows them to expand when treated with fire alone.

“Herbicide is the only effective way to remove some of the most aggressive invasive species,” says Tom Vanderpoel of Citizens for Conservation. “These are the species that most need to be removed from the ecosystem, and this is the least disruptive way to accomplish that. All the herbicides that we use are approved by the Illinois Nature Preserves Commission, and we use a tiny amount of chemical, especially relative to the acres of weed-free lawns that surround most of our remaining natural areas.”

Volunteer stewards Barbara and George Birmingham used herbicide to control reed canary grass at Ted Stone Forest Preserve in Cook County and were delighted to see cardinal flower emerge amid dead invasives.

Applying herbicide is not for everyone. To legally apply it on public land in Illinois, one must pass an exam and be licensed by the Illinois Department of Agriculture. The most common volunteer application is to paint a small amount of herbicide on a cut stump to keep it from resprouting. As one longtime steward described it, “We started off just cutting the brush, but after cutting the same shrub year after year, we finally realized we had to do something different.”

The herbicides most used in restoration are well tested and are on the lower end of the toxicity scale. “Still,” Vanderpoel emphasizes, “it is important to be safe and careful when you are using any chemical.”

Seeding change

Once light gradients have been restored and problem weeds removed, most sites need an infusion of seed to reestablish the dazzlingly complex collections of plants that make up healthy woodlands, wetlands, prairies, and savannas.

Seeds can be collected with machines such as “flail-vacs” and modified combines, but they’re very often collected by hand. The prized yields are then blended into habitat-tailored seed mixes.

Tractor-pulled seed drills and broadcast seeders can quickly seed vast acreages, but often volunteers broadcast seeds by hand so as to find the best few square feet for this precious resource.

Of all the seasons of the restoration year, I find the fall’s seed collection and distribution workdays the most inspiring and reflective. The gentle resistance of lead plant seed against my hand, the clean-smelling seeds of prairie clover — these days are quiet, subtle, and powerful, offering time to reflect and consider the work ahead.

Here, in our roaded wilderness, the same streets and neighborhoods that isolate our natural lands also bring people close to them. As we learn about the nature in our neighborhoods and begin acting based on that knowledge, our relationship with these precious fragments fundamentally shifts and deepens. With this action, we reestablish a reciprocal, nurturing relationship with the land, and our own community broadens as we work alongside new friends and neighbors. The human community, once a source of ecological disruption, is now the key to lasting ecological sustenance.

Even those who do not plan to directly participate in these activities can still support good stewardship by sharing what they know with others, including friends, local officials, and neighbors. Or they can simply go for a walk in a nearby natural area and tell someone about what they see.

Our roads, homes, and communities have altered nature’s course. Our dedicated and informed actions help get it back on track. We act, observe, and, if needed, adapt our approach. As rare species rebound and vanishing natural communities return, I have come not only to a deeper understanding of ecology, but also found validation for a hopeful and optimistic attitude.

Justin Pepper is deputy director of Audubon–Chicago Region. Most weekends, he’s out in the forest preserves working alongside volunteers. He has also worked for The Nature Conservancy of Minnesota and the Missouri Department of Conservation. For more about restoration and other volunteer projects, visit The Habitat Project.

Related Articles:
The Chicago Wilderness Workday, CW Fall 2006
Burn & Rebirth, CW Spring 2007
The Burn That Wasn’t, CW Fall 1999
The Herbicide Helper, CW Winter 2001
The Seed Sharers, CW Winter 2006