What is meant by 'biodiversity hotspots'?

(N/A) 'biodiversity hotspot' is a biogeographic region that is a significant reservoir of biodiversity and is threatened with destruction. To qualify as a hotspot,a region must meet two strict criteria: $1$. It must contain at least $1,500$ species of vascular plants as endemics (i.e.,species found nowhere else on Earth). $2$. It must have lost at least $70$ percent of its original habitat.