They also take up a lot of space both above and below ground. A forest has several layers, each of which has its own set of dominant plant and animal species. Four of the most readily identifiable layers are the canopy, the understory, the shrub layer, and the herb layer. One important part of the forest which many people forget about is the soil. Most forest plants have their roots in the soil.
Trees often establish symbiotic relationships with fungi.
The fungi live in the soil and become attached to the roots of the trees, helping the trees to absorb water and soil nutrients more easily.