English: Seen here is a comparison of an old-growth forest (left) and a second growth tree plantation (right). Second growth forests lack the ecological complexity that old-growth develops over hundereds or even thousands of years of evolutionary change. The open canopy structure of old-growth caused by older trees falling down allows for light to reach the forest floor and provide new growing conditions for younger trees and plants. The closed canopy of second growth does not allow for much light to reach the ground, leaving the area homogenous and sparse.