The sun-dappled savanna landscape is a hybrid of prairie and woodland, often occurring at the transition zone where the two natural communities gain and cede territory to one another, depending on the frequency of fire.
The general appearance of a savanna is that of an open field of grass and wildflowers with scattered trees, or an occasional cluster of trees. The trees in a savanna are usually thick-barked species that can withstand occasional fire, such as bur oak.
Some specific savanna types include:
Sand savannas. In southeast Cook County’s Calumet region, sand savanna is often found on dry sandy ridges between wetlands. If dominated by black oaks, it may also be called black oak savanna.
>>>See it at Powderhorn Prairie in Chicago; Sand Ridge Nature Preserve in Calumet City; Zander Woods, Lansing.
Bur oak savannas. More typical of black-soil areas, with many species of tallgrass prairie.
>>>See it at Wolf Road Prairie in Westchester; Somme Prairie Grove in Northbrook; Dan McMahon Woods in Palos Hills.
Read more about the ecosystems of the Forest Preserves of Cook County: