Across from the good shepherd hospital on Northwest Highway, a white clapboard farmhouse acts as a porter to the beautifully restored Flint Creek Savanna. A black walnut tree is planted there by its side. Large black husks cover rough, brown shells encasing sweet, fruity, thumb-size nuts. Deer browse on the buds of the lower branches at dawn. Squirrels and birds consume the nuts in the shadows to avoid predation. A screech owl rests in its branches on a moonless night.
“Black walnuts were planted by farmers to provide shade for their farmhouse, produce more food, and make money,” explains Citizens for Conservation Restoration Director Tom Vanderpoel. In addition to its value for food, its dark outer husks were used to create a black dye and its shells were used as a filler for dynamite, a flour-like carrying agent for pesticides, and a filtering agent in smokestacks.
Here we take a look at what is happening to the nut trees that flourished in years past across Illinois.
According to the U.S. Forest Service's Urban Trees and Forest of the Chicago Region, our regional forest is in a state of transition due to “various invasive species, insects, diseases, and lack of regeneration.” Buckthorn and honeysuckle that are frequently retained as visual buffers are gangly invasive species that perpetuate their own monocultures, make nesting songbirds more susceptible to predation, and offer undesirable food to wildlife.
Some trees are threatened by insects. First discovered in Wisconsin nearly 50 years ago, butternut cankers have been gradually killing native butternuts throughout our area with a fungus transmitted by beetles that girdles the tree and drains its reserves. Currently, the U.S. Forest Service classifies butternuts (J. cinerea) as “a species at risk” while "Thousand cankers disease" (TCD) threatens black walnuts (J. nigra). Much like butternut cankers, TCD is transmitted by insects that gravitate toward stressed trees. The closest infestation of TCD is in Southern Indiana. “Just like people, it isn’t one thing that kills a tree,” says arborist Charlie Keppel.
Walnuts are not the only native nut trees disappearing. Once comprising 60 percent of the Chicago region’s tree canopy, oaks now only cover about five percent. Displaced by development and unable to regenerate in areas that are either suffocated by invasive garlic mustard or covered with turf grass and neatly mowed, oak seedlings do not have a place to take root.
To raise awareness for Illinois’ increasingly less common state tree, the white oak, Governor Bruce Rauner designated October as Oak Awareness Month, giving it the moniker “OAKtober.” Events throughout the state including Barrington Area Conservation Trust’s Oaktober Fest and Great Oaks Contest were designed to foster an appreciation of oak trees and the critical ecosystems they support.
“There’s a wide variety of oaks,” says Morton Arboretum plant knowledge specialist Sharon Yiesla. “Some have a better growth rate and become established faster than others,” adds Yiesla, noting, “smaller trees catch up and outgrow the larger specimens [because] they adapt better and establish more quickly.” The fibrous root systems of red oaks combined with meticulous care further promote vigorous growth.
White (Q. alba), bur (Q. macrocarpa), red (Q. rubra), northern pin (Q. ellipsoidalis), and swamp white oaks (Q. bicolor) are species that are indigenous to our area that can be readily found at native tree sales, as well as some nurseries. Although an insect and root-transmitted fungus that causes oak wilt threatens members of the red oak family, Yiesla suggests to, “see what your neighbors have and put in something else.” White, red, and northern pin oaks add brilliant shades of scarlet to the fall palate.
As a source of protein, acorns of the white oak (containing less tannic acid than other types of acorns) were once cooked and used to make food and dye. White oak continues to be used to make barrels, flooring, and woodwork. Blue jays, crows, red-headed woodpeckers, deer, quail, mice, squirrels, chipmunks, wood ducks, and raccoons eat its acorns.
Sweet hickory nuts hide in the depths of a thumb-size shell surrounded by a hard, thick husk. Long strips of bark covering the shagbark hickory tree (C. ovata) offer a roost for Indiana bats. Its sunny yellow leaves light up an autumn woodland. Wood is used to make furniture, flooring, tool handles, ladder rungs, athletic equipment, and flavorful smoke for cooking. Bitternut hickory (C. cordiforumis), named for its more bitter nuts, has bright yellow buds in winter that make it easy to identify.
In a class by itself, the American hazelnut (C. americana) is more than a source of flavoring for coffee or chocolate spread. It is a shrub with nuts that have a higher nutritional value than acorns. American Indians ate hazelnuts raw, used them to flavor soup, ground them to make flour for cake-like bread, and extracted essential oils to nourish their skin. Each fall hazelnut leaves turn beautiful hues of orange to purple, and low, dense growth provides cover for nesting birds each spring.
“The best means to a healthy urban forest is broad diversity and improved care so that trees are not stressed and better able to resist infections and problems,” says Chicago Region Trees Initiative Director Lydia Scott. Sharon Yiesla concurs. “People have an unnecessary bias against nut trees because they’ve identified them as a mess to be cleaned up. We need to get past this bias because there are so many good nut trees.”
Native nut trees don’t just offer resources for people, they add beauty, shade, and most important, habitat that wildlife can’t live without.
April Anderson is a naturalist and freelance writer who can be contacted at email@example.com.
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Attend Citizens for Conservation (CFC) Community Education program on Sat., January 14, 2017 to learn about fascinating dragonflies and damselflies. The insect order Odonata is an ancient group with ancestors dating back over 300 million years to a time when dragonfly-like creatures with two and a half-foot wide wingspans ruled the air. Today, these successful aquatic insects represent a diverse group of carnivores with a complex life cycle. The more than 100 species known in Illinois are excellent indicators of wetland quality and are truly fascinating to observe.
Experience an image-intensive, up-close, and personal presentation of this intriguing and visually splendid group of insects. Through macro and micro photography, explore the captivating world of local dragonflies and damselflies, including their life histories, behaviors, diversity, and value to the ecosystem.
Presenter Marla Garrison is a biology faculty member at McHenry County College. She sits on the Executive Council of the Dragonfly Society of the Americas and is the author of Damselflies of Chicagoland, a local area field guide available online. (For free download through Chicago's Field Museum of Natural History http://fieldguides.fieldmuseum.org/guides/guide/388.) Garrison conducts field studies and surveys in McHenry County and throughout the state of Illinois and is active in monitoring the federally endangered Hine’s Emerald Dragonfly.
Here are program details, including other upcoming events.
All programs will be held at the Barrington Village Hall beginning at 10 a.m. and lasting about an hour, plus questions. Come at 9:30 a.m. for coffee, displays, handouts, and conversation. Programs are free for CFC members; non-members pay $10. Register online at www.citizensforconservation.org (be sure to indicate which program(s) you will attend) or call CFC at 847-382 (SAVE).
February 11, 2017—Living Soils, by Jeff Weiss, Horticulture Department, College of Lake County. / March 11, 2017—Native Shrubs as Habitat and Host Plants, by Connor Shaw, owner, Possibility Place Nursery. / April 8, 2017—Personal Land Restoration, by Ders Anderson, Greenways Director, Openlands.