Urban Shade Trees
By planting trees and
shrubs, we return to a more natural, and 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.
Trees have both environmental and economic
Reduce stormwater runoff and erosion
Trees intercept water, store
some of it, reduce storm run-off and the possibility of flooding.
roots hold soil in place so it cannot easily be washed away by wind or
water; the decaying of dead tree parts returns nutrients to the soil.
The root systems of trees hold in place soil that, if washed
away by heavy rains, would flow into streams and rivers, making them
shallower and allowing flood waters to overflow protective banks.
planting of trees means improved water quality, resulting in less
runoff and erosion. This allows more recharging of the ground water
supply. Wooded areas help prevent the transport of sediment and
chemicals into streams."
USDA Forest Service
Trees have been called the
"low tech" solution to energy conservation. Shade from trees
reduces the need for air conditioning in summer. In winter, trees
break the force of winter winds, lowering heating costs.
Studies have shown that parts of cities without cooling shade
from trees can literally be "heat islands," with
temperatures as much as 12 degrees Fahrenheit higher than surrounding
areas. By using trees in the cities, we are able to moderate the heat
island effect caused by pavement and buildings in commercial areas.
"The net cooling effect
of a young, healthy tree is equivalent to ten room-size air
conditioners operating 20 hours a day."
Department of Agriculture
"Trees properly placed
around buildings can reduce air conditioning needs by 30 percent and
can save 20 - 50 percent in energy used for heating."
An average tree stores 13 pounds of carbon
every year and a community forest can absorb enough carbon dioxide
annually to compensate for driving a car 26,000 miles. Keeping the earth's carbon levels in balance is
critical; carbon build-up in the atmosphere is a major contributor to
global warming. The
burning of gasoline and other fossil fuels has added more carbon
dioxide to the atmosphere than trees and the oceans can absorb. That
is the principal cause of global warming. The more trees there are,
the more carbon dioxide is absorbed, and the less global warming we
acre of forest absorbs six tons of carbon dioxide and puts out four
tons of oxygen. This is enough to meet the annual needs of 18
U.S. Department of Agriculture
are about 60-to 200- million spaces along our city streets where
trees could be planted. This translates to the potential to absorb
33 million more tons of CO2 every year, and saving $4 billion in
National Wildlife Federation
water and air quality
leaves and roots act as natural filters of air and water (rain and
ground), removing particulate matter and polluting nutrients. The hair-like root
fibers of trees help filter ground water, trapping nutrients and
pollutants that could contaminate it.
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 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 sulfur dioxide, and give off
property values and attract economic growth
Trees increase in value from the time they
are planted until they mature. Trees are a wise investment of funds
since landscaped homes are more valuable than non-landscaped homes.
The savings in energy costs and the increase in property value
directly benefit each homeowner.
The indirect economic benefits of trees
are even greater. These are available to the community or region.
Lowered electricity bills are paid by customers when power companies
are able to use less water in their cooling towers, build fewer new
facilities to meet peak demands, use reduced amounts of fossil fuel in
their furnaces and need fewer measures to control air pollution.
Communities can also save if fewer facilities must be built to control
storm water in the region. To the individual these savings are small,
but to the community, reductions in these expenses are often in the
thousands of dollars.
especially with trees, can increase property values as much as 20
Management Information Services/ICMA
can be a stimulus to economic development, attracting new business
and tourism. Commercial retail areas are more attractive to
shoppers, apartments rent more quickly, tenants stay longer, and
space in a wooded setting is more valuable to sell or
The National Arbor Day Foundation
mature trees add an average of 10 percent to a property's
USDA Forest Service