Urban forestry

Urban forestry is the care and management of single trees and tree populations in urban settings for the purpose of improving the urban environment. Urban forestry involves both planning and management, including the programming of care and maintenance operations of the urban forest. Urban forestry advocates the role of trees as a critical part of the urban infrastructure. Urban foresters plant and maintain trees, support appropriate tree and forest preservation, conduct research and promote the many benefits trees provide. Urban forestry is practiced by municipal and commercial arborists, municipal and utility foresters, environmental policymakers, city planners, consultants, educators, researchers and community activists. Heat waves cause 1,300 deaths each year in the United States alone, which is more than any other weather-related event. As temperatures continue to rise due to global warming, we can expect to see this number increasing in coming years. The risk is exacerbated for low-income households who do not have access to air conditioning, as well as heat-sensitive populations such as the elderly, infants, and those who have chronic health problems. Urban forests mitigate the effects of urban heat island through evapotranspiration and the shading of streets and buildings. Reforesting a 10-meter radius corresponds to 0.7 degree Celsius decrease in daytime air temperature, compared to a 1.3 degree decrease in a 30-meter radius, and over 1.5 degrees in a 60 or 90 meter radius. This reduces the risk of heat stroke, decreases cooling costs, and improves general well-being. Trees have saved 1,200 lives annually in the U.S, by preventing heat related deaths. Urban forests improve air quality by absorbing pollutants such as ozone, nitrogen dioxide, ammonia, and particulate matter as well as performing carbon sequestration. Communities with better air quality measures demonstrate lower levels of childhood asthma. Urban forestry can be an important tool for stormwater management as trees intercept rainwater in the canopy, and can slow down, filter and pump water back into the atmosphere via their roots.