Give an account of latitudinal gradients of biodiversity.
Latitudinal gradients of biodiversity: Species diversity decreases from the equator towards the poles. The tropics (between 23.5°N to 23.5°S) harbor more species than temperate and polar regions. For example, the Western Ghats have a greater amphibian species diversity than the Eastern Ghats. There are more than 2,00,000 species in India of which several are confined to India (endemic). For example, Columbia situated near the equator has about 1400 species of birds, while Hew York (41 °N) has 105 species, Greenland (70°N) has about 56 species and India (in the equator region) has 1200 species. The number of species of vascular plants in the tropics is about ten times more than that of temperate forests. The Amazonian rain forest in South America has the greatest biodiversity on earth; it harbors about 40,000 species of plants, 1,25,0 species of insects, 3000 fishes, 427 amphibians, 378 reptiles, 1300 birds, and 427 mammals.
