A declining oak population in Illinois has incited Evanston to work with other environmental organizations in a group effort to increase awareness of the issue during October, which Gov. Bruce Rauner has declared Oak Awareness Month.

Oak trees, which serve as an ecologically important species to the Illinois ecosystem, have fallen from comprising 60 percent of the state’s canopy in the 1880s to just 5 percent. As a result, Evanston held several events earlier this month to promote the issue including an “OAKday” celebration at the Ecology Center and a tree walk in Perkins Woods.

“A primary issue is that over the past decades, there’s been a decrease in the percentage and number of oaks in Evanston … due to development and also blight,” Evanston sustainability fellow Kumar Jensen said. “This is one of the reasons why it’s really important to emphasize the value and importance of oaks in the tree canopy.”

In addition, researchers from member organizations of the Chicago Region Trees Initiative are conducting surveys of trees around the area and making recommendations for the future as part of a comprehensive Oak Ecosystems Recovery Plan.

Lydia Scott, the director of the CRTI and the community trees program manager at The Morton Arboretum in Lisle, Illinois, stressed the status of oaks as an Illinois keystone species that provide habitat and food sources for native animal species.

Scott also emphasized a lack of regeneration in the Illinois oak population, as the majority of oak trees in the area are 18 inches or taller because older and taller trees prevent younger trees from receiving sunlight. Furthermore, other species of trees such as maples can tolerate partial sunlight and thus outcompete younger oaks necessary to recover the flagging oak population, Scott said.

“While species diversity is important, age diversity is also important for healthy ecosystems,” she said.

Evanston’s oak programs are the third species-specific conservation efforts the city has undertaken in recent years, Jensen said. Two other species, the elm and the ash, are also experiencing a decline due to Dutch Elm Disease and the Emerald Ash Borer respectively.

Scott noted that oaks can even be advantageous for homeowners and landscapers to plant.

“Oaks also do grow relatively fast, about a foot or two per year,” Scott added. “They’re also long-lived, and so while we don’t live as long, you’re planting oaks for generations to follow.”

Email: [email protected]
Twitter: @jaewookjerrylee