About Oak Savanna
Oak Savanna is the term used to describe the mosaic of woodlands and prairie openings in south central Iowa. Before early European settlement it was the transitional zone between the eastern deciduous forest and tall grass prairie. A two-tiered community it consisted of open canopied trees that spread over an herbaceous ground layer of grasses, sedges and wildflowers. There was no woody understory. That said it is important to remember that each piece of land is unique with its own assemblage of plants. Giving it a name does not mean that it should fit a specific prescription for “oak savanna”, “prairie”, or “wetland”.
Before early European settlement thirty million acres of savanna stretched from Minnesota and Wisconsin south to the Texas hill country. Now only .02% remains. The rarest ecosystem in temperate North America it is classified G-1, globally endangered. Decatur County, Iowa has 20,000 acres of highly restorable oak savanna. Timberhill is just one example of what could be done if these acres were managed for oak savanna restoration.
More detailed information provided on the following pages:
- The Management History page summarizes our restoration methods beginning with thinning of the understory and canopy in 1993 and implementation of prescribed fire in 1995. A link to Wilhelm & Rericha’s “Timberhill Savanna Assessment of Landscape Management” report which provides more specific information and a discussion of the results of our methods is also available on this page.
- Observations regarding the resulting increase in plant and mushroom diversity are found on the Plants & Fungi page. This page also includes links to the Timberhill plant list and an article about Boletus dupainii, a rare bolete. Timberhill is the only site in the continental United States where B. dupainii is known to fruit regularly.
- New posts discussing what’s on our mind are added to the Blog page the first and third Monday each month.