What is an old-growth deciduous forest from the nonfiction book, The Hidden Life of Trees?

An old-growth deciduous forest is another type of forest that Wohlleben often refers to, another kind commonly found in Germany. Beeches, oaks, and other leafy trees are found coexisting in undisturbed forests in moderate German climates. Many of these forests have been cut down to be replaced with the conifer plantations, and Wohlleben is trying to preserve them.