Barrens are a unique combination of forest (oak) opening and prairie, surrounded by mesic or dry upland forests (which have greater tree cover and less herbaceous cover than barrens).
Barrens are restricted to poor, thin, or excessively drained soils over bedrock that is often exposed in places. Because these soils contain little moisture or plant nutrients, the trees growing on them often have a stunted or gnarled growth form.
Barrens are typically dominated by post oak (Quercus stellata) with black oak (Quercus velutina), blackjack oak (Quercus marilandica), black hickory (Carya texana), and sometimes, Spanish oak (Quercus falcata) in the canopy
The understory is usually dominated by little bluestem and big bluestem grasses (Andropogon scoparius and Andropogon gerardii, respectively) and other prairie plants. Shrubs may include blueberry (Vaccinium arboreum) and hazel (Corylus americana) which were formerly much more abundant.
are barrens found in Illinois?
The barrens in the extreme southern portion of the state (southern portions of Alexander, Pulaski, and Massac counties) have a better-developed soil layer and are less dry than those in the Shawnee Hills and those on dry ridges along rivers in western parts of the state. These barrens are rare and support a greater diversity of forest vegetation, including white oak and Spanish oak, with big bluestem and little bluestem in the understory.
role of fire in barrens forests
by humans, grazing, logging, and cultivation have degraded most of the
original barrens in the state. The existing barrens in Illinois are probably
remnants of communities that were more extensive prior to the 1900s. They
are probably the result of a disturbance such as fire (used to maintain
the barrens as a protected natural area) or the result of their location
on rocky, thin soils or on excessively drained slopes with thin soils.
Copyright © 2000 Illinois State Museum