Autumn has always been my favorite season. Oaks are my favorite trees. So, it seems fitting in "Oaktober" to write about oaks and oak woodlands
At Nachusa Grasslands and other places in the Midwest, we are trying to restore the health of our oak woodlands. And really, our region is defined by the oaks. The Nature Conservancy calls our eco-region “The Prairie-Forest Border” between the grand prairie to the south and the mixed woodlands in neighboring states to the north. The area was historically maintained as prairie intermixed with oak savanna and woodlands by Native American nations.
Natural plant and animal communities of the region were a direct result of Native Peoples’ use of fire on the land. Without fire, in “The Prairie-Forest Border,” the amount of rain we receive would have yielded dense forests.
Many botanists have defined the various intergrades between savanna, open woodland, and closed woodland by the level of sunlight and density and species of trees. (See https://oaksavannas.org/)
Today, much of our Illinois woodlands have become too shady to allow sun-loving oaks to grow. Shade is the enemy of oaks. Acorns in shade will not thrive after germination and the limbs of oaks will also die if shaded.
How can we tell if the “woods” we are looking at was historically savanna or naturally shady? The presence of large, old oaks with limbs that stick straight out (or used to, but are dead now) indicate the area was likely savanna. An oak growing in full sun without other trees close by will grow limbs horizontally. Oaks that grow close together grow their limbs vertically to reach the sun.
To give the oaks a fighting chance modern prairie restorers make use of controlled burns, as well as actual removal of invasive trees growing under and up into the limbs of the old sentinel oaks. We also remove the non-native bush honeysuckle (and other non-native shrubs) from the understory.
Our region’s historic mixture of prairie interspersed with woodland types — from dry to wet, from open to somewhat shady — had an enormous species diversity of understory flowers, grasses, and native shrubs.
If action is not taken by restorers, the result is a mud forest floor, impenetrable understory with honeysuckle bushes, and an overstory of dead oaks. Elms, maples, and other shade-loving fire intolerant trees move in to take the place of oaks and hickories.
This combination of a solid thicket of invasive honeysuckle and loss of oaks gives hardly any habitat for animals. For example, deer and turkey dislike maple and elm, but they love acorns!
Native oak-hickory savannas and woodlands in the region are disappearing along with bird species that depend on the open structure: red-headed woodpeckers, great crested flycatchers, and eastern bluebirds. Native wildflowers such as kitten tails, wild hyacinth, prairie lily, and starry campion along with grasses such as bottle brush rye, woodland brome, and long-awned wood grass will not grow in heavy shade. And there are the native shrubs: hazelnut, American plum, hawthorn, and Iowa crabapple! None of these tolerate shade either.
I encourage you to read up on oak woodlands, then take a hike. Explore the Stone Barn Savanna and see how we are doing. It’s a work in progress and sometimes messy, but we see the native oak savanna dependent plants and animals are thriving.
Here are some great websites that discuss oak savannas:
Pleasant Valley Conservancy—Oak Savannas
Last of the Oak Savannas Survive in Minnesota
What is an Oak Savanna?
Written by Susan Kleiman, a Nachusa volunteer.
Since May, the seasonal crew has been working hard at killing and removing invasive plants from the prairie including white and yellow sweet clover, birdsfoot trefoil, king devil, bouncing bet, and reed canary grass. We started the year walking transects back and forth through the prairie plantings like a militant marching band, carefully spot-spraying each invasive species with a selective herbicide from backpack sprayers.
Eventually, the herbicide can no longer kill the targeted plants before they produce seed. Then we switch to hand pulling each plant and carrying them out of the prairie in barrels. This prevents the invasive seed from falling back into the soil, causing problems for future crews.
Once the plantings have been swept relatively clean, we slowly drive the trails in small groups, “weed cruising” for the few weeds that were missed during our regular, methodical sweeps. By August, the weed season on the prairie has ended. While it requires painstaking effort to manage hundreds of acres, our methods are working. The invasive populations that once riddled many of our older plantings have been greatly reduced.
Seed collecting, an important aspect of restoration, takes place throughout the year. This provides a species-rich, diverse ecosystem. Species diversity encourages a more stable food source for creatures such as insects, bugs, and birds.
Last year, the crew’s goal was to plant 103 acres of prairie, Nachusa’s largest planting to date. This year, our goal is to plant 83 acres of diverse habitat ranging from a woodland/savannah border to prairie to more mesic and wetland habitat. However, that doesn’t mean the crew is collecting in small quantities. Thus far we have broken the record for the amount of seed collected in a given year for 17 species!
To manage these large, high quality plantings, many days involve a grueling grind of trekking through dense vegetation in the blazing sun and humidity, our socks and pants soaked from the morning dew. For breaks, the crew take refuge at headquarters or in the airconditioned bunkhouse basement. Popsicles, sunflower seeds, and other salty snacks fuel us between meals. This year we were lucky enough to have some dedicated volunteers regularly joining the crew, giving our efforts a huge boost!
The expertise of the stewards’ immaculate plantings have fueled our motivation and their expertise exemplifies the knowledge the crew strive to attain. The stewards have been a huge help with plant identification and recommendations of seed species to collect, and they have fantastic seed sources.
In return, when the stewards have called for help, the crew has acted as reinforcements in the attack against weeds.
The crew also found time to work on side projects which promote better efficiency. We built two 3’ tall, 4’x20’ raised beds for prairie violets and other small species that are hard to collect in large quantities. The hope is that weed management in these beds will be easier than a ground weed mat. It also affords the plants protection from predating ground squirrels. Also, we have begun converting a shed into a seed milling shed, providing future crews more space in which to collect more seed, dry it more quickly, and mill it faster.
Phil and Kaleb have returned to NIU as full-time students, and Sandra became a part-timer; therefore we have brought on two new crew members. Daniel Crosby, from Rochelle, has been volunteering with us two days a week since July. Nate Scott, from New York, is experienced in a variety of restoration techniques.
The crew members that have been here longest — Avery, Cody, Nathaniel, and Sandra — will be taking turns as crew leader for the rest of the year. Next time you see one of these energetic young faces, be sure to give them a high five!
Written by Kaleb Baker, Nachusa's Crew Boss.
Decades ago, across a patch of land where cattle grazed, two students of Aldo Leopold recognized the call of the upland sandpiper. That eerie sound helped Doug and Dot Wade to recognize a highly degraded remnant prairie. Against all odds, a process started that would save this piece of ground for nature. Over the next few years a small group of people would demonstrate that given the right conditions, mainly the exclusion of cattle and return of fire, that rare prairie plants would once again thrive. In One Man’s Endeavor to Save the Prairie Kim W. Johnsen writes . . .
This group of listeners, thinkers, and activists led The Nature Conservancy to purchase the land that would become Nachusa Grasslands. On August 26, 1986 the first 130 acres were purchased. (Prairie Smoke 2016 Annual Stewardship Report; p. 4-5) Over time, more and more land containing degraded remnants was purchased, followed by farm fields of row crops that connected the remnants. These farm fields would need to be planted with native plant seeds and nurtured to bring back a prairie with a diversity of grasses and flowers.
Some area ecologist observed the restoration work in progress at Nachusa, and in small areas within the Cook County Forest Preserve District, and labeled it gardening. After all, he thought, the succession of plants and trees from an area, to be followed by others, is a normal ecologic function. When weather conditions change, or fire is absent, or a river changes course, or a natural barrier creating a dam breaks to expose the lake bottom to sunshine and air, plants and animals that are better suited to the changed conditions move into those areas and nature heals itself. Normally this happens over very long periods of time, but it happens. So, when groups of people began to step in and remove some plants in favor of others and began harvesting nearby seeds and planting them, it appeared to that ecological purist, to be gardening.
People doing ecological restoration start with the premise that the natural environment has been altered by humans to a degree that normal processes of succession no longer work. A restoration starts by researching the plants and animals that have historically been present. This is done by studying old diaries, maps, land surveys and any other document that can be obtained. Museum collections are reviewed to see what was collected or recorded in the area. An effort is made to return the land to pre-settlement conditions. When seeds are selected, with a few exceptions, great effort is made that they are locally sourced and the species are historically part of the landscape. Once the plant community is restored, it is hoped that the insects, birds, and mammals will return.
The gardener and the person doing ecosystem healing share many common procedures that some think have similar results. Both sow seed into the ground, use cuttings and plants grown in containers, pollinate plants by hand, and use herbicides to eliminate unwanted plants. Each prepare the ground to maximize chances for success. Many of the tools and methods used in the healing process were first used by gardeners. The result of all the effort in both cases, is a landscape beautified with flowers, grasses, shrubs, and trees. So why is ecological restoration not gardening?
The gardener is looking for maximum visual impact and will select plants originating from distant lands to accent a garden. A gardener will place plants to offer coordinating and contrasting, colors, heights, shapes, and varied bloom times. A gardener may crossbreed plants, often pollinating plants by hand to maximize and enhance desired qualities, allowing only the plants with those qualities to propagate. A neighbor, who loved to garden, would hand pollinate his snapdragons and then isolate the flower so only the pollen he provided could become seed. Every year, his snapdragons had robust and colorful blooms. The efforts of the gardener are directed to provide a display pleasing to the human eye.
Restoration efforts promote plants that are native to the area — plants that need special habitat to thrive and that are now rare. Habitat, once abundant, has been converted to roads, parking lots, buildings, and farms. Neglect has degraded other natural areas where native plants find it difficult to survive and reproduce. The suppression of fire has allowed honeysuckle, multi-flora rose, and other invasive species to crowd out fire adapted plants. A friend, who loved native plants, would hand pollinate an endangered plant whose population was no longer large enough to reproduce; the insect most likely to pollinate the plant was no longer present or the plants too far apart for insect pollination to be effective. This plant, the federally endangered eastern prairie fringed orchid, painstakingly hand pollinated, and caged to prevent deer browse, began to thrive on a few new sites where seeds were scattered. In time, seeds of this orchid from a population in Lake County were spread in many places at Nachusa. For years no orchids were found, but in one wetland, it now thrives at Nachusa, uncaged and once again pollinated by insects. Nachusa’s population is now one of the largest in the state and among the largest in the world. (Prairie Smoke 2015 Stewardship Report; p. 6) To a person doing ecosystem healing, placement of a plant in conditions it will thrive is important, thus matching the seeds or young plants to the environment best suited to its needs. Conditions such as whether an area is naturally wet or dry, sunny or shaded by trees, or even a north facing or south facing slope may determine a native plants success in growing and reproducing. Ultimately it will be nature that decides whether a plant succeeds or fails in any given location, just as it did before Europeans arrived.
When gardening, the gene pool for the next generation is selected by the gardener for qualities that please people. It might be size, color, shape or some other unique feature that people choose to pass forward to the next generation. In ecosystem healing, the goal is to let nature do the work of selecting the next generation. A diverse plant mix, matched to the right ecological conditions will self-assemble over time, to fit back into its native environment. As the insects, birds, and mammals return, they select the gene pool for the next generation; thus, providing an opportunity for the normal processes of change and succession to be restored.
The greatest compliment for the work done at Nachusa won’t come from people visiting to admire the view, although the views at Nachusa are spectacular. Every visit offers something different in bloom, often changing the color and look of the landscape from one week to the next. Many of the flowers and plants were once abundant and covered vast tracks of land as far as the eye could see, but now they only survive in small isolated patches and have become rare. Many require special conditions of associate plants or companion soil microbes to thrive, conditions that are slowly being restored at Nachusa. The greatest compliment comes from the variety of insects, birds, and mammals that find their way to Nachusa and begin to thrive. Recently the upland sandpiper not seen in the area since 1988, returned to Nachusa to add its voice to the prairie remnants; when it nests and raises it's young this will be viewed as the greatest compliment of all.
Written by Paul Swanson, a volunteer at Nachusa.
Eugene Jones Baldwin
He is a journalist, fiction writer and blogger. He writes history pieces for the Alton Telegraph and is the author of "The Genehouse Chronicles," a collection of essays on nature, people and places along the Mississippi River.