Once the effects of those disturbances become negligible, the species that will become the old growth forests are those that succeed, dominate the terrain and endure the environment. Forests in the later stages of ecological succession are defined by the dominant trees species that will regenerate in the absence of external disturbances. Thus the death of overstory trees and the regeneration of understory trees is not continued by forces such as fire or flood. The old growth stage of forest succession has the most variation of horizontal and vertical structures. This is one reason for the abundant diversity of wildlife.
More structures means more niches available for wildlife.
LSOG-dependent animal species require some or all of these features for feeding, shelter, and reproduction. The large trees house many of the birds, small mammals, mosses, fungus, and lichens. They hold the seeds and fruits for food, the foliage for cover and forage, and the building materials like bark, twigs, branches for homes. The dead trees give birth to new life. Snags make homes for insects, insect larvae, squirrels, bats, lichen, moss, fungus, even bears in some large diameter trees.