Which of the following organisms show latitudinal gradients?
The Amazon rainforests and the rainforests of Malaysia lie right at the equator, while the Arctic Tundra lies at the North pole farthest away from the equator. This example explains that species richness decreases as you move away from the equator. This is one of the most widely studied patterns of biodiversity, and is called the latitudinal gradients.
It is not merely the vegetations that show this sort of diversity distribution, even the animal species are distributed along a latitudinal gradient. All this data indicates that species diversity decreases along a latitudinal gradient, as we move away from the equator.