Tree leaves also represent the most important source of carbon in the soil. The microbial community in forest soil is dominated by fungi.
Soils vary from forest to forest. The type of vegetation in a forest is an important factor, because it affects the soil acidity. Tropical forest soils usually have more organic matter.
Soil Layers: The different layers of soil are topsoil, subsoil and bedrock. Topsoil is made up of living and decomposed materials like leaves, and plants. Subsoil has clay, mineral deposits and some organic matter. And bedrock, made up of slightly unbroken rock with very little organic matter.