Why are forest considered biodiversity hotspots ?

First of all, what is a hotspot?

A hotspot, is a place with a hotter temperature in relation to its surroundings.

So, when we think of "biodiversity hotspot", what exactly does that mean?

It's a place with a higher biodiversity in relation to its surroundings, but also with more concentration of species.

So, that's why forests are considered a biodiversity hotspot. If you want some visual content, try finding a geographical map of Africa. In some desert regions you'll see green spots (some really big). These are forests. The interesting thing about them, is when you search their biodiversity, you'll see what a biodiversity hotspot looks like

Hope it helped,

BioTeacher101