Benefits of clean environment and trees:
We like trees around us because they make life more pleasant. Most of us respond to the presence of trees beyond simply observing their beauty. We feel serene, peaceful, restful, and tranquil in a grove of trees. We are “at home” there. Hospital patients have been shown to recover from surgery more quickly when their hospital room offered a view of trees. The strong ties between people and trees are most evident in the resistance of community residents to removing trees to widen streets. Or we note the heroic efforts of individuals and organizations to save particularly large or historic trees in a community.
The stature, strength, and endurance of trees give them a cathedral-like quality. Because of their potential for long life, trees frequently are planted as living memorials. We often become personally attached to trees that we or those we love have planted.
Even though trees may be private property, their size often makes them part of the community as well. With proper selection and maintenance, trees can enhance and function on one property without infringing on the rights and privileges of neighbours.
Trees alter the environment in which we live by moderating climate, improving air quality, conserving water, and harbouring animal and birdlife. Climate control is obtained by moderating the effects of sun, wind, and rain. Radiant energy from the sun is absorbed or deflected by leaves on deciduous trees in the summer and is only filtered by branches of deciduous trees in winter. We are cooler when we stand in the shade of trees and are not exposed to direct sunlight. In winter, we value the sun’s radiant energy. Therefore, we should plant only small or deciduous trees on the south side of homes.
Wind speed and direction can be affected by trees. The more compact the foliage on the tree or group of trees, the greater the influence of the windbreak. The downward fall of rain, sleet, and hail is initially absorbed or deflected by trees, which provides some protection for people, pets, and buildings. Trees intercept water, store some of it, and reduce storm runoff and the possibility of flooding.
Dew and frost are less common under trees because less radiant energy is released from the soil in those areas at night.
Temperature in the vicinity of trees is cooler than that away from trees. The larger the tree, the greater the cooling. By using trees in the cities, we are able to moderate the heat-island effect caused by pavement and buildings in commercial areas.
Air quality can be improved through the use of trees, shrubs, and turf. Leaves filter the air we breathe by removing dust and other particulates. Rain then washes the pollutants to the ground. Leaves absorb carbon dioxide from the air to form carbohydrates that are used in the plant’s structure and function. In this process, leaves also absorb other air pollutants – such as ozone, carbon monoxide, and sulphur- dioxide and give off oxygen.
By planting trees and shrubs, we return to a more natural, less artificial environment. Birds and other wildlife are attracted to the area. The natural cycles of plant growth, reproduction, and decomposition are again present, both above and below ground. Natural harmony is restored to the urban environment.
HEATING AND COOLING COSTS-
A 25 foot tree reduces annual heating and cooling costs of a typical residence by 8 to 12 percent, producing an average $10 savings per American household. Also, buildings and paving in city centers create a heat-island effect. A mature tree canopy reduces air temperatures by about 5 to 10°F, influencing the internal temperatures of nearby buildings.
AIR QUALITY AND CLEANSING-
A typical person consumes about 386 lb of oxygen per year. A healthy tree, say a 32 ft tall ash tree, can produce about 260 lb of oxygen annually – two trees supply the oxygen needs of a person each year! Also, cooler air temperatures created by tree canopies reduce smog levels by up to 6%, producing savings in air clean-up campaigns. Finally, a mature tree absorbs from 120 to 240 lbs of the small particles and gases of air pollution. In Sacramento, CA, for instance, this represents a value of $28.7 million.
IMPROVED WATER QUALITY-
The canopy of a street tree absorbs rain, reducing the amount of water that will fall on pavement and then must be removed by a storm water drainage system. In one study, 32 feet tall street trees intercepted rainfall, reducing storm water runoff by 327 gallons. Savings are possible since cities can install surface water management systems that handle smaller amounts of runoff.
Achievements of SNBS:
Below are the photographs of achievements of SNBS, from beginning up till date.