Meltzer Woods photo by Dick Miller

What is an Old Growth Forest?

Part of a series on CILTI’s conservation targets by guest blogger Ed Pope

Old growth forests are forests that have not been disturbed for at least 150 years. While they have some exceptionally large trees, there will also be many younger trees. When one of the giants falls, it opens up a hole in the canopy that younger trees will try to fill.

Standing dead trees, called snags, are common throughout old growth forests. These provide excellent habitat for woodpeckers, which nest in tree cavities and search under the bark for insects. Chickadees, titmice and owls also nest in tree cavities.

On the floor of an old growth forest you will find a significant amount of debris, including fallen trees, limbs and leaves. These provide habitat for insects, fungi and bacteria. They break down the wood and return nutrients to the soil. A significant amount of carbon is sequestered in dead wood. As it is broken down, some carbon is returned to the soil rather than the atmosphere.

Plants like ferns, mosses and lichens often grow on top of logs.

The topography of the forest floor will have pits and mounds. Mounds are formed when large trees fall and break down over time, while the pits are formed when their roots are torn out of the ground.

The core conservation areas of Central Indiana include four tracts of old growth forest:

  • Calvert & Porter (Montgomery county)
  • Davis Woods (Randolph county)
  • Efroymson Woods (Shelby county)
  • Meltzer Woods (Shelby county)

Meltzer Woods, the last of 12 such tracts to be protected, is one of CILTI’s best-loved nature preserves. CILTI’s goal is to buffer old growth forests by establish at least a square mile of woodlands around them. This is in the works with Meltzer Woods.

Ed Pope

Guest Blogger

Ed Pope is a retired engineer from Rolls-Royce and a CILTI member since 2002.