Form

As the tree grows, it begins to assume a characteristic size and shape. Appearance is influenced by the form of the trunk; the shape, size, and density of the crown; and the number of branches and direction of their growth. For example, firs and spruces develop a conical, or “Christmas tree” shape. The round dome of the mature white oak distinguishes the tree, from a distance. The American elm is known for its graceful, vaselike crown. Other helpful identifying characteristics are the persistence of dead branches (some trees do not drop their lower dead branches) and buttressing or swelling of the lower trunk (often found in swamp species).

Habitat and Range

Most trees require specific site conditions to grow and survive, including moisture, light, and soil type. Trees will commonly grow in association with other species that favor the same conditions. A quick survey of the site is useful for predicting the type of species the site will support.