The Most Irreplaceable Sites On Earth

A new study published in Science identified more than 100 irreplaceable environments - regions where many animal and plant species cannot be found anywhere else on Earth.

A total of 137 sites were selected from 173,000 "Protected Areas." Protected Areas cover 13% of the Earth's land. These are some of the most biologically rich ecosystems in the world, but face continued threats and are often poorly managed.

The top sites were the result of two combined rankings: irreplaceability for threatened species and irreplaceability for all (threatened and non-threatened) species.

Each protected area was analyzed individually. But sometimes the regions overlap, effectively protecting the same species. For this reason, researchers combined adjacent or overlapping protected areas into 78 clusters around the world.

Here are some of the most irreplaceable areas - from 10 different clusters.