Oak Savanna

Oak Savanna. . , Survival Through Fire , Ecologists manage prairies and savannas with fire. When prairie plants die back at the end of season, they create a thick matt of dry plant material on the ground. Ecologist use fire through controlled burns to remove the plant material, along with any invasive plant species that may have moved in. , , Traditional turf grass, such as you would find on somebody's lawn, has roots that only go about two inches deep. The roots of prairie plants often go down ten to fifteen feet below the surface of the ground. Prairie plant roots are great at holding water and soil in place, which prevents soil erosion. , , Prairie plants survive occasional fires because of their deep roots. Fires are best done in the spring when weeds and invasive plants are just starting to grow. The fire kills everything in its path, but the prairie plants survive because the fire doesn't touch their deep roots. , , Historically, lightning was the first source of fire in prairies. When a prairie fire approaches a woodland area, most trees that have grown outside the edge of the woodland don't survive. Certain trees have very thick bark and are fire-resistant. Their bark enables them to survive prairie fires. Hickories and Burr Oaks are common savanna tress in Illinois. , , A savanna is the transition ecosystem between a prairie and a woodland. Typically, a savanna is filled with prairie plants and is sparsely populated with a few trees. Fire is essential to the survival of savannas. , , Oak savanna plant communities used to be very common in Illinois. Currently, due to population growth and urban expansion, they are few and far between. , , Animals of the Savanna , Deer are often found grazing in savannas. They enjoy browsing the prairie plants for food but like to stay close to the shelter of the woodland. , , Birds of prey enjoy roosting in the tree canopy over savannas. Because the tree canopy of a savanna only covers approximately 10 to 30 percent of a typical forest canopy, birds have a clear view of their prey on the ground below.