Temperate rainforest may once have covered up to one-fifth of Britain and played host to a dazzling variety of luminous life-forms, inspiring Celtic druids, Welsh wizards and Romantic poets. Though only fragments now remain, they form a rare and internationally important habitat, home to lush ferns and beardy lichens, pine martens and pied flycatchers. But why are even environmentalists unaware of their existence? And how have we managed to excise them so comprehensively from our cultural memory?

Taking the reader on an awe-inspiring journey through the Atlantic oakwoods and hazelwoods of the Western Highlands and the Lake District, down to the rainforests of Wales, Devon and Cornwall, the writer and campaigner maps these under-recognised ecosystems in exquisite detail – but underlines that without political and public support, we risk losing them from the landscape, and perhaps our collective memory, for ever.

In conversation with journalist and editor Kitty Corrigan