Soils of Tropical and Temperate Forests
Although soils of tropical forests are generally poor in nutrients they are able to maintain high productivity under natural conditions due to these nutrient-conserving mechanisms that almost bypass the soil by having a plant to plant cycling. When such forests are cut or cleared for agriculture these mechanisms are destroyed and productivity declines very rapidly. Forest removal takes away the land's ability to hold nutrients as well as to combat pests in the face of year round high temperatures. Crop production declines and in a few years the land is abandoned.
Soils in temperate forest have relatively large nutrient pools and when these forests are cleared, the soil retains nutrients and may be cultivated for many years by ploughing one or more times a year, planting short season annual plants and applying inorganic fertilisers. During winter, freezing temperatures help hold in nutrients and combat disease and pest. It is for these reasons that agricultural practices suitable for temperate areas may be inappropriate for tropical areas and should not be applied unmodified in the tropics.