When you walk through a forest, you probably see a lot of what's happening at about eye level. But that's just a tiny slice of the picture. The forest ecosystem stretches all the way from the tops of the highest trees to the tips of their deepest roots. Though the specifics vary from forest to forest, each layer has its own stories to tell.
- The canopy, or top layer, is the powerhouse of the forest. Here millions of leaves combine sunlight, carbon dioxide, and water to create food for themselves and the rest of the ecosystem. Canopy critters in a northern Minnesota forest may include northern flying squirrels, red-eyed vireos, and tent caterpillars.
- In the understory, the layer directly beneath the canopy, smaller trees such as balsam fir pick up whatever light trickles through. Here, squirrels and a variety of birds make their homes.
- The shrub layer, from about head height on down, is home to small woody plants such as hazel and raspberry, as well as to deer, bears, and other animals. Mosquitoes and blackflies may flourish here.
- Closer to the ground, the herb layer is the flower garden of the forest. Insects, chipmunks, and other ground dwellers thrive among plants such as big-leafed aster and bracken fern that make up this layer.
- The forest floor is the domain of decomposers—worms, bacteria, fungi, insects, and others. These creatures make their way in life by recycling bits and pieces of once-living things into raw materials that can once again be used to support new life.