Can tiny forests breathe fresh air into our cities? After gaining popularity across Asia, small, dense ecosystems are taking root in Europe's urban areas. Advocates say they improve biodiversity, air quality and even our well-being. But do they live up to the hype? Children in Leicester, UK, plant a tiny forest in their school In 2014 eco-entrepreneur Shubhendu Sharma gave a TED Talk about the value of the mini-woodland ecosystems he was planting across India. He described how they grow 10 times faster, are 30 times denser, and 100 times more biodiverse than a conventional forest. His tiny forests were inspired by Japanese ecologist Akira Miyawaki's technique of creating small, condensed urban forest on degraded soils.