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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