The leaves are often large to absorb as much light as possible. Trees tend to be fully grown by 10 metres. Shrubs get even less opportunity to grow in their dingy lot. Growth is sparse which enables animals to move freely about. Down in the Basement - the Forest Floor Dark, damp and warm.
Vegetation is sparse.
The jungle growth which you see in the movies can be only found along the edges of river banks and the outskirts of the actual forest, where sunlight is more abundant. On the forest floor away from rivers, the air is still. Ground dwelling animals make their homes in this habitat. The above layers drop their litter down onto the basement. It rots quickly in the warm humid conditions with termites, ants, centipedes and other small animals helping the process.