While Wolf Road Prairie occupies only 80 acres today, tallgrass prairies spanned across the entire Midwest as early as 170 years ago. According to the US Geologic Survey, less than 1% of tallgrass prairies remain in Illinois. That means if you live in the Chicagoland area you have one of the most endangered ecosystems in the world practically in your backyard.
But what defines this incredibly rare ecosystem? When most think of what characterizes tallgrass prairies they think of just that—an area covered primarily in tall grasses. This is for the most part correct, however nature is never so simple. While scientists have widely categorized prairies based on their vegetation, soil, landscape, climate, etc, the tallgrass prairie ecosystems are difficult to pigeonhole. As Ladd and Oberle state in their book Tallgrass Prairie Wildflowers:
There is no single model of a tallgrass prairie but rather an endlessly variable, dynamic tapestry of plants and animals that for thousands of years have been responding to and in turn influencing their landscape and each other.
Wolf Road Prairie is no exception; even within its 80 acres the prairie can be divided into 3 different broadly defined prairie types.
You may typically think of a savanna as an ecosystem that occurs on another continent, such as the Serengeti, but savannas are any tallgrass prairies that include trees. But unlike a forest where little to no sunlight can penetrate the canopy, these trees are interspersed. Trees, such as Wolf Road Prairie’s 250 year old Bur Oaks are often found on tallgrass prairie savannas. You can find the savanna on the southern end of Wolf Road Prairie.
North of the savanna is the mesic prairie. Mesic prairies, like wetlands, retain moisture but are able to drain excess water. This produces rich soil and allows mesic prairies to support some of the most abundant and exquisite flora of any prairie ecosystem. The sidewalks laid down before the Great Depression provide walking paths through this highly threatened ecosystem.
The northern 40 acres of Wolf Road Prairie host the wetland portion of the prairie. Wetlands are defined by being heavily hydrated by means of groundwater seepage, bodies of water such as rivers, or other natural means to keep the soil completely saturated throughout springs and summers. Normally, it is not even possible to trek through the Wolf Road’s wetland until the dry season (unless you have the proper gear!) when a narrow pathway opens. But because of this year’s harsh and severe drought, most of the wetland has been relatively dry. We are hoping the winter and spring weather will help the wetland recover.
Next time you visit Wolf Road Prairie, remember how complex, subtle, and nuanced nature is as you walk through one of the rarest ecosystems in the world.
– F. Martino
Last edited 12/9/2012
Ladd, Doug , and Frank Oberle. Tallgrass Prairie Wildflowers. 2nd ed. Guilford, CN: Morris Book Publishing, LLC, 2005. Print.