Forum topic: Local groups determined to save mature oak

This article from Horticulture week (hortweek.com) on 13 July 2015, by Elizabeth Henry,suggests there may be a lot more tree benefit than envisaged so far

Living on a tree-lined street could have the same impact on health as earning an extra £6,440 per year or being seven years younger, new research shows.

The study, published in online journal Scientific Reports, looked at data for residents of Toronto in Canada. It combined satellite imagery and tree data with questionnaire-based reports of general health perception, cardio-metabolic conditions and mental illnesses from the Ontario Health Study.

A research team led by Omid Kardan found those people living in neighbourhoods with a higher density of trees on their street reported better health, even when controlling for socio-economic factors and demographics.

Researchers found the improvement in health perception from having 10 more trees on a block was equivalent to earning an extra $10,000 (£6,440) per year, being seven years younger or living in a neighbourhood where the median annual income was $10,000 higher.

It also found that having 11 more trees in a city block, on average, was correlated with an improvement in cardio-metabolic conditions in ways comparable to an increase in annual personal income of $20,000 (£12,880) or moving to a neighbourhood with $20,000 higher median income or being 1.4 years younger.
The study specifically looked at tree canopy on streets, rather than other types of planting such street shrubbery or flowers.