In young rainforests there are generally many small trees and in old rainforests there are generally fewer but larger trees. As one tree dies or is removed, others will grow up and fight for the available light. As the rain falls to the ground it helps leaf mould develop, which allows nutrients to be brought up through the soil to the plants. Condensation in the atmosphere leads to rain again, so a nutrient cycle is successfully completed. Giant emergent trees often project well above the canopy and reach even more impressive heights, spreading their crown over it.
Leaves are of great variety, differing in shape, size, texture and colour.
These sometimes provide food for species like the ringtail possum and tree-kangaroo. It may enclose one or many seeds. Fruit-eating pigeons, bowerbirds, and flying foxes eat succulent fruits whereas parrots eat harder woody nuts and seeds. Indigestible seeds voided by the birds will germinate in a tree crevice or hole. Most tree seedlings have to start their struggle for survival on the forest floor.