Each tree planted significantly reduces the risk of death from cardiovascular disease for people living near the given planting site, the USDA Forest Service researchers have found.
According to the respective publication in the journal Environment International, the aforesaid researchers analyzed well-documented data from a tree-planting company in Portland, Oregon, USA, between 1990 and 2019. During that time, the non-profit group planted 49,246 trees on city streets.
In doing so, they recorded where and when each tree was planted. This enabled researchers to correlate this data with mortality rates from cardiovascular, respiratory disease, or other causes.
And lower mortality rates were observed, especially among men and the elderly, in areas with more trees.
Research has shown that connectivity also increases as trees grow. Trees planted in the previous 1-5 years were associated with a 15 percent reduction in mortality, and trees planted in the previous 11-15 years—with a 30 percent reduction.
The researchers did not study the reasons for this effect, but assumed that it was related to the decrease in temperature and noise, as well as air pollution.
In addition, these researchers concluded that the annual economic benefits of planting trees exceed the costs of protecting them more than a thousand times.