There is a growing body of scientific research into the health benefits of urban forests, such as improving air quality and providing recreational space. However, new research challenges the assumption that their overall impact on quality of life is always positive and land planners need to take into account ecosystem disservices as well as services, say the researchers.

Most visitors think of New York's Parks as the only place to find trees. However, a new study found New York City has  over 5 million 'forested natural areas' along with 666,000 street trees.