Soils of the humid and sub-humid tropics

The tropics are between the equator and Tropics of Cancer and Capricorn. They change with latitude from perhumid to seasonal rainfall. The vegetation period extends to the entire year around the equator down to at least 90 days at higher latitudes. Parent materials and age of the landscapes also differ. They include old strongly weathered landscapes (e.g., Southern India), young river basins (e.g., Amazon Basin) and active volcanic areas (e.g., Indonesia). The older fluvial landscapes are rather levelled, but in tectonically active and volcanic landscapes relief energy can be large. Characteristic zonal soils are Ferralsols in the perhumid and Acrisols in sub-humid climate zones. In addition, depending on parent rock and relief Nitisols, Luvisols, Plinthosols, Andosols and Vertisols also occur.