Trees have lots of known benefits, including providing shade, mitigating floods and being sources of fruits and wood.

Now, researchers have shown that trees have another benefit: living near them can make a person healthier both physically and psychologically.

The researchers, led by psychologist Omid Kardan of the University of Chicago, arrived at this conclusion after collecting and analysing vast records on public, urban trees kept by the city of Toronto, and satellite measurements of non-public green space.

The researchers collated these geographical data with records for over 30,000 Toronto residents, including data on self-perception of health and statistics on various illnesses such as cancer, heart problems, diabetes and psychological problems.

Based on these datasets, the study concluded that having 10 more trees in a city block, on average, has good effects on health perception, comparable to an increase in annual personal income of $10,000.

"Controlling for income, age and education, we found a significant independent effect of trees on the street on health," psychologist and co-author Marc Berman explained

"It seemed like the effect was strongest for the public [trees]. Not to say the other trees don't have an impact, but we found stronger effects for the trees on the street," he added.

That's not all: the study, which was published in the open access journal Scientific Reports, also found out that having 11 more trees per city block had the same effect on health as having an increase in annual personal income of $20,000.

The researchers attribute these health benefits to a better air quality and people getting more encouragement to exercise because there are shady trees in the surroundings.

"People have sort of neglected the psychological benefits of the environment. And I think that's sort of gotten reinvigorated now, with these kinds of studies," Berman said.