Select the statements that are CORRECT regarding patterns of biodiversity.

(A) Species diversity increases as we move away from the equator towards the poles.

(B) The tropical Amazon rain forest in South America has the greatest biodiversity on earth.

(C) There is more solar energy available in the temperate region than tropics.

(D) Tropical environments are less seasonal relatively more constant and predictable

(E) A. Humboldt observed that within a region, species richness decreases with increasing explored area, up to a limit.

Choose the correct answer from the options given below:

(B) and (D) only

The correct answer is Option (3) - (B) and (D) only

In general, species diversity decreases as we move away from the equator towards the poles. With very few exceptions, tropics (latitudinal range of 23.5° N to 23.5° S) harbour more species than temperate or polar areas.

The largely tropical Amazonian rain forest in South America has the greatest biodiversity on earth- it is home to more than 40,000 species of plants, 3,000 of fishes, 1,300 of birds, 427 of mammals, 427 of amphibians, 378 of reptiles and of more than 1,25,000 invertebrates.

There is more solar energy available in the tropics. Sunlight falls directly at the tropics. Because of straight illumination, the duration of day is longer at the tropics than at higher latitudes. Due to this, plenty of sunlight is available in the tropics. Better availability of solar energy results in higher productivity which is evident from the rich biodiversity in this region.

Tropical environments, unlike temperate ones, are less seasonal, relatively more constant and predictable. Such constant environments promote niche specialization and lead to a greater species diversity, and  there is more solar energy available in the tropics which contributes to higher productivity; this in turn might contribute indirectly to greater diversity.

Alexander von Humboldt observed that within a region, species richness increased with increasing explored area but only up to a limit. In fact, the relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola.