List the short-term and long-term effects of forest destruction  (a) on hillsides, (b) in the tropics. 

(a) Deforestation on hillsides exposes the soil to erosion by rain and leads to silting of rivers and lakes. Floods may be caused by

(i) the rapid run off from deforested slopes, (ii) the silting up of rivers and lakes by the eroded topsoil.

(b) Deforestation in the tropics also leads to erosion. If followed by agriculture, it causes   impoverishment of the soil. There might also be local climatic changes and a global enhance in   atmospheric carbon dioxide. Biodiversity is reduced.