The soil in a forest depends on the climate, vegetation, and the rocks underneath from which the soil is made . Bacteria and fungi, millipedes, earthworms and other small animals live in the forest soil.
Tree leaves also represents the most important source of carbon in the soil. The microbial community in forest soil is dominated by fungi.
Soil vary from forest to forest. The type of vegetation in the forest is an important factor, because it affects the soil acidity. Tropical forest soil have high clay content and less soil organic matter. Temperate forest soils usually have more organic matter.