Forest Preserves of Cook County 2023 Winter Brochure

Playing Tree Detective in Wintertime Without leaves, how do you identify them? The Forest Preserves are the home to more than 10 million trees and more than 100 species. To identify those species, the foremost clues that many amateur arborists use are the size and shape of leaves. But in wintertime in Cook County, trees have no leaves. So what’s a tree detective to do? Here are several tips and tricks for making those identifications while you’re out for a snowy stroll: Consider the location: Different ecosystems and landscape features can help narrow down the options. For example, savannas are more likely than thick woods to feature trees that like sunlight, such as bur oaks. Observe the shape: Trees gain distinct shapes from branches that sprout at varying angles. American elms, to illustrate, have a vase-like form, with sharply angled arms. 14