Happy Oaktober! October is observed as Oak Awareness Month across the state of Illinois. Oaks deserve attention because they are the Illinois state tree and have been a major majestic component of our landscape for centuries. But its population is in decline and needs our interest and support.
In the 15-county northeastern Illinois region, less than 20% of the pre-settlement oak stand still exists, according to the Morton Arboretum Regional Trees Initiative. Much of that acreage is in smaller, more fragmented areas that are more susceptible to loss. The RTI is composed of local groups and agencies, including The Conservation Foundation, The Morton Arboretum, Kendall County Forest Preserve District, Kendall County Forest Foundation, Illinois Department of Natural Resources Division of Forest Resources and others.
Due to its natural ability to survive the recurring fires in the native Illinois prairie landscape, oaks became a predominant species. When European settlers arrived in the early 1800s, oaks dominated the majority of the wooded landscapes in the area. Although oaks were more tolerant to fires, less-hardy species would be suppressed during the prairie fires, leaving oak woods and savannas in much of northeastern Illinois, often along or near streams and rivers.
The abundance of oaks was significant as it signaled micro-ecosystems where other plant and wildlife species did well, too. For example, oaks support more than 500 species of caterpillars, while non-native plants may not host any.
As settlement progressed, many oaks did not survive. Now, as the native oak stands continue to mature, natural losses continue to occur. Also over the years, there have been less-favorable growing conditions for new seedlings to become established, and older trees have more types of competition. More non-native invasive species, such as buckthorn and honeysuckle, have become prominent and can choke out new desirable plant growth trying to become established. Natural fires no longer exist in the landscape to reduce competition.
Other factors such as disease, construction damage, compaction from lawn mowers and foot traffic, trunk damage, etc., also contribute to the decline and death of the native oaks.
For information, visit the Morton Arboretum’s tree initiative site at .mortonarb.org/science-conservation/chicago-region-trees-initiative.
On a final note, this will be my last Conservation@Home column in this capacity as I am retiring effective Sept. 30. I want to thank all of you for your interest and support. The Conservation Foundation has been a wonderful organization to work for and your continued support will be greatly appreciated. Follow TCF activities online at theconservationfoundation.org or call 630-428-4500, ext. 0.
• John Church is the Kendall County program director at The Conservation Foundation.