Anatomy of the Temperate Forest

Trees are a defining feature of the structure of a temperate forest. Image by Adbar.

It’s all about the trees. Trees are the most important members of the temperate forest community. They provide the structure and create the environment for everything beneath them. The forest can be thought of in “layers” with the treetops being the top layer, called the canopy. Small plants grow in the understory, on the bottom right above the forest floor.

Stunted by Shade

There can also be subcanopy or intermediate layers, where young trees grow; these will be giants some day when they reach the canopy.  The shade that the canopy makes can make it hard for some plants to survive in the forest, because they can’t get enough light to grow. While a tree may produce thousands of seeds in a given year to blanket the forest floor with seedlings, less than one out of every 100 of these seedlings will survive.  It’s a harsh life for a little seedling.

Many forests go through a process called succession. Click for more information.

Changing Seasons

As green chlorophyll is broken down, we can see the other leaf pigments (yellow here). Nitrogen is also released from this break down and the plants reabsorb it for future use. Image by Lite.

Fall brings beautiful colors of all different shades to the deciduous forests. Some maples turn orange, oak leaves show dark reds, and hickories become bright yellow. These colors are clues that the trees are shutting down for the winter.

Peeking Underneath

Microbes break down leaves and other matter on the forest floor, but different plant litter decays at different rates. Click for more information.

But the trees and understory aren't where all the action happens in a temperate forest. There’s a lot more to soil than just dirt. If you go out to the forest and pick up a pinch of soil, how many species do you think you’d be holding? There’s a good chance there are more than 50,000 species between your fingertips!

Very diverse communities of microbes, including bacteria and fungi, populate temperate forest soils, consuming and decomposing the plant litter and animal remains that fall there.

These microbes go dormant in the winter too, just like the trees. This allows nutrients and dead plant litter to build up in the soil so that it can be rich enough to support lots of plant growth. When spring comes, they start decomposing again.