One tree in London's Cheapside district has existed since the 18th Century, hemmed in by buildings and roads in a polluted area. The plane tree, a blend of an American sycamore and an Oriental plane, is large, beautiful, robust, fast growing, and has survived in one of earth's harshest environments: human cities. But increasingly, they are in trouble. City planners are exploring strategies to help these urban trees survive, and it is complicated. Biodiversity matters, so city planners are seeking a varied supply that can thrive in harsh conditions. There is also the challenge of getting enough of these trees to populate a city. Plant nurseries want to know if there will be a market for the trees as they take time and money to grow. But even more than that, new homes must allow them to develop healthy root systems in larger pockets of land. And, like children, they need care in the early years.

Read Full Story