University of Vermont Extension
Department of Plant and Soil Science
Anytime News
Article
THE ENVIRONMENTAL VALUE OF LANDSCAPING
Dr. Leonard Perry, Extension Professor
University of Vermont
In addition to economic benefits, and
benefits to the well being of individuals and society, landscaping and plants
benefit the environment. This can be indoors as well as outside.
Much research was done in the past by
NASA showing how plants can improve the quality of indoor air. Leaves of indoor plants can remove low levels
of volatile compounds such as carbon monoxide and formaldehyde. Potting media, especially those with
activated carbon, filter higher leaves of toxic chemicals. Details of how to use such plants, and which
are best, can be found online by the researcher Dr. Bill Wolverton
(www.wolvertoneenvironmental.com) or Green Plants for Green Buildings
(greenplantsforgreenbuildings.org).
Landscape plants improve air quality
outdoors by removing smoke, dust, and other pollutants. One average tree can remove 26 pounds of
carbon dioxide from the air each year, equivalent to the emissions of cars
driven 11,000 miles. This average tree
also releases enough oxygen in a year to supply a family of four. An acre of trees removes 13 tons of particles
and gases annually.
An environmental assessment in 2003 of
the 687 trees on the main campus of the University of Arkansas at Ft. Smith
showed these trees removed 661 pounds of pollutants (ozone, particulates,
sulfur dioxide and similar) annually.
These trees also stored 307 tons of carbon, removing or “sequestering”
an additional half ton yearly.
The Ft.
Smith Arkansas campus landscaping reduced
stormwater discharge 3.4 percent, with
a 36.7 reduction in their heavily forested area of campus. Rain gardens, swales, and plant
buffers
along streambanks are some of the ways landscapes filter pollutants from
stormwater.
Noise pollution is decreased through proper
plantings and landscaping. Desirable
noises are increased as from the wind through particular plants, and birds
living in plantings.
Even odor pollution is reduced by plants,
such as the shelterbelts studied by Iowa
State University
around swine farms. Other research there
concerns “phylloremediation”—how leaves (the “phyllo” part) and their
microflora cleanse the air. Their
results showed how corn leaves can hold the gas phenol until microbes on the
leaf surface break it down. Phenol
causes the foul odors one smells in car exhaust, cigarette smoke, decomposing
manure, burning coal, and municipal waste.
Plantings around homes and buildings, through
direct economic benefits from energy savings, indirectly help the environment
by reducing fuel and energy use.
Deciduous trees provide shade in summer, evergreens serve as windbreaks
in winter, and foundation plantings create dead air spaces for insulation.
Plantings in urban ecosystems directly
help the environment, indirectly resulting in economic savings. The tree cover in San
Antonio (Texas),
through improving storm water management, air quality, and energy conservation,
is calculated to save the city $70 million a year in ecological services.
More on the environmental, as well as
social and economic, benefits of plants can be found online at the Magic of
Landscapes (www.magicoflandscaping.com).
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