What is an Oak Savanna?
An oak savanna is a plant community with scattered "open-grown" fire tolerant oak trees. Other terms for these savannas are "oak openings" and "barrens". In contrast to a forest, which has a closed canopy, the oak savanna canopy ranges from about 10% to 50%. In such a habitat, the ground layer receives sun and shade, which permits growth of a wide diversity of grasses and flowering plants. There is usually enough sun to the ground to permit the growth of typical prairie species, such as big and little bluestem grass, and many goldenrods and asters. Oak savannas have their own characteristic and complex communities of ground-layer grasses, flowering plants, and shrubs. An oak savanna is a fire-controlled vegetation community.
What Should an Oak Savanna Look Like?
Savanna design for a new undeveloped field should take into account management objectives, topography, soils, pre-settlement history and cost. This practice should only be applied on fields with transitional or woodland derived soils that comprise at least 50% of the field primarily in upland landscapes.
Species selection for trees
A minimum of two native tree species should be used from an approved list for savanna species. Some suggested oaks are: Black, Bur, Chinquapin, White, Swamp White, Shingle, Shagbark Hickory, Sawtooth, Scarlet, Cherrybark, Swamp Chestnut, Overcup, Red, and Shumard.
In oak savannas, plant trees at the rate of 25 trees per planted acre at no less than 30-foot spacing. Tree cover should be at least 10% but no more than 50% cover of any field.
If possible plant the trees in clusters or blocks rather than evenly spaced across a field. This will allow for some parts of the savanna to be more open (greater spacing or "openings") than other parts and create a more natural appearance.
Historically trees in oak savannas were more common on south and west slopes, along ridge lines and knolls, and in protected draws or ravines. Well, drained, shallow soil sites and those with gently rolling topographies that carried fire well, characteristically had more open (wider spacing) tree cover. Tree cover was more closed (closer spacing) on moist, deep soil, highly dissected, or poorly drained sites where fire usually became a less intense or frequent factor.
Tree planting stock
Tree planting stock should be at lease 3 feet tall with at least ½ inch caliper. The large initial size is required to facilitate their protection from fire, and reduce competition from grass. It is recommended that container grown air root pruned stock be used because these seedlings have thick fibrous roots as opposed to a large taproot, which may be difficult to plant.
Seedlings should be planted by hand or using an auger. Soil should be firmly packed around seedling roots.
Other important criteria to consider for savanna development and design are planting stock care, planting dates and weed control.
Grasses: Plant any combination of at least 4 of the following species:
No more than ¼ pound pure live seed per acre. No less than 1 pound pure live seed per acre.
- Big Bluestem
- Canada Wild Rye
- Indian Grass
- Little Bluestem
- Switchgrass (Blackwell)
- Side Oats Grama
A minimum of 10 forb species should be selected.
Some examples of suitable species are listed below.
- Rigid Goldenrod
- Swamp Milkweed
- Ohio Spiderwort
- Prairie Dock
- Blazing Star
- Purple Coneflower
- Prairie Coneflower
- Lance leaved Coreopsis
- Wild Bergamot
- Black-eyed Susan
- New England Aster
- Perenniakl Lupine
- Blue Lupine
- Autumn Sneezeweed
- Round-headed Bush Clover
- Gray-headed Coneflower
- Partridge Pea
- Golden Alexander
- Canada Tick-trefoil
- White Wild Indigo
Animals of the Oak Savannas
Oak savanna habitats provide outstanding conditions for a variety of wildlife. Oak trees provide nesting sites for birds as well as food for insects. Acorns provide excellent food for rodents, deer, and wild turkey, among other species.
Also, wildlife played an important role in pre-settlement times in maintaining the integrity of oak savannas. Together with fire, wildlife aided in cleaning understory brush, thus helping to create the sparsely wooded character of the savanna.
Restoring an oak savanna should be an important wildlife management objective and has been so recognized by the USDA-NRCS Wildlife Habitat Incentives Program (WHIP). Some of the animals in an oak savanna are deer, wild turkeys, ruffed grouse, woodpeckers, squirrels, chipmunks, mice, ducks, and bluejays.
Incentives to install an Oak Savanna
The USDA-FSA and ODNR have monetary incentives to restoring or installing an oak savanna. The Conservation Reserve Enhancement Program (CREP) provides incentives by cost-sharing on the installation of the oak savanna. If you are enrolled in CREP you are in the Conservation Reserve Program (CRP) which pays an annual payment for the ground that you have in the oak savanna.
The Fulton SWCD can plant an oak savanna for you.
For more information call or e-mail Pete Carr at 419-337-9662.
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