Soils of the rainforest are rich in humus because of the

The soils of the rainforest are rich in humus because of the large quantity of decayed leaves. In the rainforest, there is a dense vegetation cover with a variety of plant species. The canopy of the trees forms a dense layer that blocks out much of the sunlight at the surface. This leads to a lack of photosynthesis in the lower layers, and dead organic matter accumulates on the forest floor. This organic matter gradually decomposes to form humus, which is a nutrient-rich layer of soil. The heavy rainfall in the rainforest helps to accelerate the decomposition process, as it provides the moisture necessary for the breakdown of organic matter. This humus layer provides essential nutrients for the growth of the rainforest vegetation, and it also helps to retain moisture in the soil.