Plants, animals, landscapes: our planet is home to a wealth of species. But some places host a greater variety than others and are considered worthier of protection. What makes a place such a “biodiversity hotspot”?
Why is there a need to define biodiversity hotspots?
Well, the answer is at once simple and sad: Because mankind won’t be able to save all species, experts agreed that given our limited (financial) resources there needs to be a strategy that helps save the greatest possible variety of life on our planet.
What are “biodiversity hotspots”?
Very rich in species and highly endangered - that are the two criteria that make a place a biodiversity hotspot. Of course, there are many places where lots of species grow and live. But to qualify as a hotspot, a place needs to host more than 0.5 percent (that is 1,500) of the world’s vascular plant species as “endemics”. Species are endemic to a region, when they naturally grow/live only within that region instead of being artificially introduced by agriculture or humans for example.
If that is the case, it still needs to pass another hurdle: Only a place that is highly endangered can be designated a hotspot, which means that it must already have lost at least 70 percent of its surface area. In fact, the hotspots put together once covered 15.7 percent of the Earth's land surface - today that number is down to 2.3 percent.
What about animals?
Animals don’t count when it comes to designating a hotspot. Though, back in the 1990s the number of mammals, birds, reptiles and amphibians was considered by experts as a “back-up criterion.” Insects were not separately investigated as researchers assumed their population will highly correlate with the plants' abundance.
Where are the biodiversity hotspots located?
So far, 35 places in the world meet the criteria outlined above and are thus called “biodiversity hotspots.”
Who defines which place is considered a hotspot?
The list of the 35 biodiversity hotspots was put together by scientists for the non-profit-organization Conservation International (CI). In 1999, the organization published a first edition listing 25 hotspots with a follow-up containing the current list in 2005.
Apart from CI, other environmental organizations have compiled lists with a similar intention: The World Wildlife Fund (WWF) talks about the “Global 200 Ecoregions,” while Birdlife International came up with a map showing 218 Endemic Bird Areas.
Though many of the regions overlap, the term “biodiversity hotspot” is above all used to refer to the hotspots defined by Conservation International.
How does climate change influence biodiversity hotspots?
Climate change disturbs the balance within several ecosystems by altering temperature and water scarcity for example. And rising sea levels pose a grave threat to three of the hotspots: the Caribbean islands, the Philippines and Sundaland in the Indian Ocean. Depending on the extent of sea level rise, they will suffer habitat loss affecting 300 endemic species.
Let’s create a biodiversity album together!
Do you live close to a biodiversity hotspot? Or have visited one? Then send us your snapshot of that place! We’ll collect all incoming pictures on an interactive map, which allows you to explore the world’s biodiversity in photos.
To participate send your picture to klimaonline (at) dw (dot) de together with a short declaration, that you have taken the picture yourself (or hold the the rights for it respectively) and grant DW the rights to use it for this project.