Biodiversity hotspots were first identified as areas rich in endemic plants and containing a high diversity of species. Their ecosystem was suffering the threats of outsiders and with time, lost most of their original habitat. Today, we are more specific with the identification of hotspots as we apply two specific criteria in their definition. First, a specific territory must contain a minimum of 1,500 species of vascular plants, equalling to more then 0.5% of the world’s total plant species as endemics. Second, it has to have lost at least 70 percent of its original habitat.
What are vascular plants? They are a category of high plant that assures the circulation of nutrients such as water, mineral and photosynthetic product. They have vascular tissues that allow them to reach larger size. They conduct the water and nutrients from bottom to top, and end up in transpiration, absorption or conduction. In this way, vascular plants assure great productivity to the ecosystem. The term endemics mean that the species is unique to the ecological area and it won’t be found elsewhere due to geographical isolation, such as an island.
Biodiversity hotspots were first identified as areas rich in endemic plants and containing a high diversity of species. Painting by Dave Todaro, http://www.davetodaro.com
Secondly, to be considered as a hotspot, 70 percent of the habitat in the spotted area must be lost, meaning that most of the living species disappeared. The lost of species comes frequently from overconsumption and from the destruction of natural forest for agriculture. The isolated situation makes it very vulnerable, since there is no possibility of reproduction in case of extinction. Overall, the hotpots gather the most important population that faces extinction on the planet.
There are 25 areas in the world that correspond to this definition of biodiversity hotspots. All together, they possess 44 percent of the Earth’s high plants on only 11.8 percent of the planet’s surface and they have lost more then 87 percent of their original habitat. Those spots also contained 35 percent of all land vertebrate species. 9 others could possibly be add to the list, which bring the repartition to 4 areas in North and Central America, 5 in South America, 4 in Europe and Central Asia, 9 in Africa and 13 in Asia-Pacific.