The plants in the subcanopy receive less sunlight than the canopy trees. There may be a shrub layer below this subcanopy and an herbaceous layer below the shrub layer. Mosses may grow on the forest floor. Each of these layers has openings in them which allow light to penetrate deeper into the forest. If a species cannot grow in the shade, its seedlings will not survive unless an opening in the forest canopy occurs.
Storms often create openings big enough to allow full sunlight to reach the forest floor.
Species requiring high light levels for successful growth can survive when this happens. Competition And Change Forest plants compete with each other for space, light, water, and soil nutrients. The species found in a forest at any one time are the species that have successfully competed for resources. They adapted to conditions that other species found unsuitable. Forests are constantly changing.