The City Tree bench (see above) is a great innovation. But it can’t fully replace real trees. There is, for instance, growing research that urban trees and green spaces in cities provide physical, mental and social health benefits. Here’s an innovative way to protect trees in urban environments. In Australia, the city of Melbourne is considering introducing tree bonds. A tree bond requires a land developer to deposit a certain amount of money with the local authority during development. If the identified tree or trees are not present and healthy after the development, the funds are forfeited.