Only a small fraction of North America’s original forest remains undisturbed; in the eastern US, for example, an estimated 0.5% of original forest remains (forests outside of this 0.5% have regrown following clearing for agriculture or extensive logging).
Forests that have never been cleared or transformed by humans may be called ancient forest, primary forest, or primeval forest. Ancient forest is valuable because it provides a baseline for understanding natural forest ecosystems, and is habitat for a variety of species. Old-growth forests are a subset of ancient forests that have been free of disturbance (natural or human) long enough for trees to grow old. We discuss the definition of old growth forests in our post what is old-growth forest?
We have in-depth articles in our Ancient Forest Journal, where you can read about old-growth forest ecology and history, and threats to our forests.
Explore old-growth forests in Canada and the U.S. using our database, maps, or hiking and canoeing guides. Start your explorations using the map below, check back as we update and improve this map and our database of old growth forests.
If you know of an old growth forest that should be included in the map and database, let us know. We are especially seeking old hemlock forests in southern Ontario, which may be at risk to hemlock woolly adelgid.