The Geographical regions which are particularly rich in endemic, rare and threatened species, found relatively in small areas and facing significant habitat loss are referred to as :

A Biodiversity Hotspot is a biogeographic region with a significant reservoir of biodiversity that is under threat from humans. To qualify as a biodiversity hotspot, an area must meet two strict criteria: it must contain at least 1,500 species of vascular plants as endemics (meaning they are found nowhere else on Earth), and it must have lost at least 70 percent of its primary vegetation. The description provided in the question perfectly matches the definition of biodiversity hotspots: rich in endemic, rare, and threatened species, found in relatively small areas, and facing significant habitat loss.