Question

Why is biodiversity higher at the equator than it is near the poles?

Answer 1

Scientists aren't in agreement about what causes higher diversity at the equator.

Explanation:

This idea is also referred to as the latitudinal diversity gradient, meaning that as you move from the equator towards the poles, diversity lessens.

There are multiple theories as to why this is the case.

One of the more recent studies on this issue concluded that species turnover is higher in temperate regions.

Other theories explaining the latitudinal diversity gradient include that there is greater habitat diversity towards the equator, creating more niches for species to inhabit.

Some also believe greater primary productivity at the equator has lead to greater biodiversity. Having more energy available in this area means more consumers can be supported.

Net primary productivity:

That the are is relatively stable in terms of environment when compared to polar regions has also been suggested as a reason for increased biodiversity at the equator. This stability has meant species are less likely to go extinct.

To read a lot more about this topic, see this article or check out this great read.