Ecological Succession
There are 2 types of ecological succession, primary and secondary. If it were to happen in a temperate rain forest, in the first stage, the lichen and moss would be the pioneer species.
Later when soil and other things are present, small low-lying plant would take over the place. In this forest, those plant might be small shrub and fern. Later, big coniferous tree would take over.
These tree are canopy tree, which allow little sunlight to be access by low-lying plant, causing them to die. Later, the plant that can grow would be the one who could survive in shade with inadequate sunlight.
Later when soil and other things are present, small low-lying plant would take over the place. In this forest, those plant might be small shrub and fern. Later, big coniferous tree would take over.
These tree are canopy tree, which allow little sunlight to be access by low-lying plant, causing them to die. Later, the plant that can grow would be the one who could survive in shade with inadequate sunlight.