[TEXT ARCHIVE WEB-PUBLISHED MAY 2001.
ORIGINAL PRINT PUBLICATION DATE: FALL 1997.]

Savanna or Forest?

A degraded forest and a degraded savanna may look very much alike. So how do we distinguish them? Sometimes, only an expert can tell.

One key is the mix of tree species. If the old trees are oaks, especially bur or scarlet oaks, the site may originally have been a savanna. White oaks often suggest the site was once a denser, but still relatively open, woodland. Red oaks, perhaps mixed with black maples, suggest a history as a woodland or forest. But if the reds and maples are young, and if old white or bur oaks are present, then the site was once less shady. So, the density of trees today can fool you.

The presence of other plants and animals - from salamanders to grasses to fungi - can help indicate what ecosystem had long developed on the site. For conservation purposes it is important to maintain conditions that can support the rare and "conservative" species that have adapted to particular natural communities over the millennia.

These subjects are treated in more detail in Chicago Wilderness, An Atlas of Biodiversity.