Infertile soils result. However, the climate is warm to hot, humid with high rainfall and no dry season. Leaching of bases is intense, so that hydrolysis of minerals is rapid. These are absorbed by the rapidly growing vegetation. The dead vegetation or forest floor litter is decomposed rapidly.
Nutrient cycling is therefore rapid, but the amounts are small.
Silica is leached from the soil leaving behind concentrations of iron and aluminum. The soil may lose fertility rapidly if the forest cover is removed. The soil is waterlogged for one reason or another, and low evaporation occurs. Reduction of iron, organic matter, and silicate compounds occurs under the waterlogged conditions. Gray or bluish colors in the profile result.