AP BIOLOGY

Detailed explanation-1: -Even though the savanna and the tropical rainforestes are VASTLY different in organisms and extent, they both have a climate that results in deep, highly weathered soils. The intense weathering causes these soils to be nutrient poor and low in organic matter.

Detailed explanation-2: -Vegetation in these regions is lush, with large trees and dense vegetation on the ground surface. However, due to high amounts of rainfall and fast uptake of nutrients from decomposing organic matter by plants, the soils in the tropical rainforest are generally nutrient-poor and non-fertile.

Detailed explanation-3: -The answer lies in the very thin topsoils, made up mainly of decaying vegetal and animal remains. An amazing cycle exists between the huge body of vegetation above ground and this thin topsoil. The rainforest depends for its nutrients on the constant recycling of its enormous biomass.

Detailed explanation-4: -SOIL COMPOSITION Over two-thirds of the world’s rainforests–including much of those in Madagascar–can be considered “wet-deserts” in that they grow on extremely poor soils which are acidic and low in minerals and nutrients.

Detailed explanation-5: -The high temperature and moisture of tropical rainforests cause dead organic matter in the soil to decompose more quickly than in other climates, thus releasing and losing its nutrients rapidly. The high volume of rain in tropical rainforests washes nutrients out of the soil more quickly than in other climates.