Forests

Woodlands are diverse, complicated habitats – filled with native flora and fauna. The majority of Illinois native wildlife requires the forest habitat for at least a portion of its life. Prior to colonialization – 40 percent of Illinois was forested compared to about 12 percent today.  Illinois has 20 native oak species and about 97 percent of our forests are classified as hardwood. 

The Watershed is home to both upland forests, with soil that drains easily, and lowland forests, where soil stays wet for long periods of time. Soil--its nutrients and whether its often wet or dry-- plays an important role in which plants and animals live inside a forest habitat. 

All forests are made up of many layers. Starting from the ground level and moving up, the main layers of all forest types are the forest floor, the understory and the canopy. Each layer has a different set of plants and animals depending upon the availability of sunlight, moisture and food.

  • The forest floor contains decomposing leaves, animals droppings, and dead trees. All of these decay on the forest floor to create new soil and provide nutrients to plants. The forest floor supports ferns, grasses, mosses, mushrooms and tree seedlings.

  • The understory is made up of bushes, shrubs, and young trees that are adapted to living in the shades of the canopy.

  • The canopy is formed by the mass of intertwined branches, twigs and leaves of fully-grown trees. The tops of the largest trees receive most of the sunlight. This is the most productive part of the trees where maximum food is produced. The canopy forms a shady, protective "umbrella" over the rest of the forest.

A few of the species you may spot during your visit to the Watershed are pictured here. Click on the slideshow and hover over each photo to learn more. 

There's no experience quite like being among the busy and beautiful Watershed forest habitat. Visit for a peaceful stroll or participate in one of our many programs.