In recent years, ecologists – especially in Britain, Ireland and continental Europe, but also in places that have more recently adopted hedgerows, such as California – have come to view these man-made structures as important ecosystems in their own right. They form a vital reservoir of biodiversity in human-dominated landscapes where many species might otherwise struggle to survive. By nurturing pollinating insects, they can enhance the yield of crops. And they do it all while pulling carbon out of the atmosphere.