What separates shelterwood cuttings from other regeneration systems, such as clearcutting or seed tree, is that the new seedlings are established before the mature trees are fully (or mostly) removed. This gives the forester more control over the species that are regenerated, and is more forgiving if the first regeneration effort fails. All mature trees may be removed, creating a young even-aged forest, or a considerable number of reserves may be kept to provide a two-aged structure.