Wetlands are one of the world’s most valuable ecosystems; as well as providing a rich habitat for plants and animals, they also store carbon and help reduce floods by soaking up excess rain.
But around the world, vast swathes of them are being destroyed, and in England alone, 90 percent of wetlands have disappeared in the last 400 years.
Now English farmer Derek Gow has a novel plan to restore these precious habitats - bring back beavers, the massive semi-aquatic rodents that once played a crucial role in shaping the British countryside.
Using their sharp teeth, beavers chop down small trees and branches to build dams across streams, creating a large network of pools and channels to live in, which form a brand new wetland.
Sylvia Rowley travels to Devon, UK, to see what nature's construction workers can do, and to help release a pair of beavers into their new home on Derek's farm.
earthrise can be seen each week at the following times GMT: Tuesday: 2230; Wednesday: 0930; Thursday: 0330; Friday: 1630; Saturday: 2230; Sunday: 0930; Monday: 0330; Tuesday: 1630.
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