FOR IMMEDIATE RELEASE: July 14, 1998
CONTACTS: Craig Noble - 202/955-4500 x234, Dan Smith - 202/955-4500 x208, Ron DeHart - 425/744-3573
Study Documents Dramatic Tree Loss in Puget Sound Area
Seattle, WA—A new study by the national conservation group AMERICAN FORESTS documents a dramatic loss of tree cover in a 3.9-million-acre Puget Sound area, encompassing the urban corridor from Olympia to Tacoma to Seattle to Everett. The analysis calculates previously unreported costs and benefits of tree cover as it relates to stormwater management and air quality in this increasingly urbanized region.
The analysis of three satellite images from 1972, 1986 and 1996 found that areas with high vegetation and tree canopy coverage declined by 37 percent from 1.64 million acres to 1.04 million acres. During the same 24-year period, areas with very low tree cover more than doubled from 25 to 57 percent of the total study area. High canopy coverage was defined as 50 percent tree cover or more.
Very low canopy coverage was defined as less than 20 percent tree cover.
"While much attention has been focused on the rural forests in the Pacific Northwest, our study underscores the importance of also understanding what’s happening in the region’s growing urban areas," said Gary Moll, study author and vice president, AMERICAN FORESTS' Urban Forest Center. "Urban forests offer substantial dollar benefits that are not replaced easily by costly, manmade alternatives. This presents an opportunity to utilize trees in designing more cost-effective city infrastructures."
The loss in tree cover and increase in impervious surfaces, such as roads and buildings, increased the costs of stormwater management. The study found that stormwater flow during a peak storm event increased by an estimated 1.2 billion cubic feet or 29 percent. Replacing this lost stormwater retention capacity with reservoirs and other structural systems would cost $2.4 billion ($2 per cubic foot). This service was provided previously by trees, vegetation and natural soils, which slow stormwater movement, lower total runoff volume, and reduce costly flooding.
Air quality control costs also grew. The lost tree canopy would have removed about 35 million pounds of pollutants from the atmosphere annually at a value of approximately $95 million. Puget Sound’s urban forest improves air quality by removing nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), and particulate matter 10 microns (PM10) or less.
" One consequence of this loss of tree cover and increase in stormwater runoff is the degradation of streams that are so important for healthy salmon populations," said Moll. "By halting this decline and strategically planting trees – millions of them – stream restoration can be accelerated, improving salmon habitat and providing so many other benefits."
AMERICAN FORESTS used Geographic Information Systems (GIS) technology and its unique CITYgreen software to measure the region’s urban forest and values. The next step is to conduct more detailed, neighborhood-level analyses. Over the past year, the city of Bellevue has used CITYgreen to analyze its urban forest.
AMERICAN FORESTS is now looking for additional community partners to join in the effort.
The regional and neighborhood analyses will assist decisi onmakers in developing information and tools to measure urban ecological values and to better incorporate environmental systems into their planning processes.
"The Puget Sound’s rapid urban growth is the single largest factor affecting its ecosystem," said Deborah Gangloff, AMERICAN FORESTS executive director. "By understanding the value and importance of trees and forests, municipal officials and planners have a great opportunity to use this natural capital to the greatest possible benefit."
The study underpins a major cooperative tree-planting campaign being developed by AMERICAN FORESTS and sponsored by specialty retailer Eddie Bauer. Global ReLeaf for the Puget Sound, part of AMERICAN FORESTS' Global ReLeaf 2000 campaign to plant 20 million trees for the new millennium, will be launched in October. AMERICAN FORESTS' 9th National Urban Forest Conference will be held August 31-September 3, 1999 in Seattle.
The Puget Sound Regional Ecosystem Analysis was funded in part by the U.S. Forest Service. The data prepared for it is available free to city and county governments. Communities can obtain detailed information about their urban forests using CITYgreen software and incorporating the findings into future planning.
REPORTERS & EDITORS:
The satellite images in the Puget Sound Regional Analysis can be downloaded from
AMERICAN FORESTS' FTP site: ftp://207.233.147.4/pub/transfer/puget/
AMERICAN FORESTS, founded in 1875, is the oldest national nonprofit citizen conservation organization. Its three Centers - Global ReLeaf, Urban Forests, and Forest Policy - mobilize people around the world to improve the environment by planting and caring for trees.
AMERICAN FORESTS publishes American Forests magazine. Its website is at http://www.amfor.org/.
DEFORESTATION: Cities are overtaking vegetated areas and affecting storm runoff, a study shows.
By John Dodge
The Olympian
OLYMPIA - Whit Reading's 28-acre tree farm in southeast Olympia is an oasis of sorts from the urban development going on all around him. The farm, which includes 10,000 Christmas trees, is coveted by developers who pester Reading to turn it into a housing development for as many as 12 homes per acre. "We just don't want to develop it," Reading said of his home of the past 38 years. "We love it. I have no obligation to build a subdivision." But, in the Puget Sound region, Reading's attitude toward urban land apparently is the exception. The area covered by dense forests in the 3.9 million-acre Puget Sound basin has shrunk 37 percent since 1972 while areas with few or no trees more than doubled, according to a study released Tuesday by American Forests, a national, nonprofit conservation group. Trees and plants absorb stormwater runoff and reduce flooding that destroys property and salmon habitat in rivers and streams. It would cost $2.4 billion to build enough reservoirs and ponds to capture all the stormwater once controlled by natural vegetation in the Puget Sound area, the study said. The dense forests, which help purify the air and water, are down to I million acres while the sparse and non-forested land has up to 1.9 million acres, the study said. In most cases, trees have given way to homes, roads, parking lots and buildings that accommodate a state population that has swelled from 3.4 million in 1970 to 5.7 million today. "Trees are the first to go," Reading said of the push of urban development. American Forests used satellite imagery from 1972, 1986 and 1996 to chronicle the dramatic change in the urban landscape. The area studied included Lacey and most of Olympia. The results are no surprise to people such as Jeanne Koenings of Olympia, who has spearheaded tree replanting efforts in the Eastside Neighborhood Association. "We have a lot of tree planting in our neighborhood, but I think we are going to face a net loss of trees to population growth and development for years to come," she said. The American Forests study suggests that the loss of trees in the Puget Sound urban area has increased the flow of stormwater during major storms by as much as 29 percent. South Sound cities have tree protection and replacement ordinances that apply to new development. In Olympia, a developer must leave 30 trees per acre. If they are mature trees, they could cover as much as 25 percent of the development, Olympia urban forester Joe Roush said. The American Forests study recommends leaving at least 40 percent of an urban area covered by trees, in part to reduce stormwater runoff . If the region is serious about restoring and protecting salmon, it will require a new approach to development, said Tom Holz, a Lacey-based engineer. Holz advocates "zero runoff " development, which translates into smaller lots with just enough land cleared to build a home, and streets, sidewalks and driveways constructed from porous blocks that allow water to filter into the ground. "Stormwater management is an oxymoron," he said. "We shouldn't be trying to collect and then dispose of runoff." |
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John Dodge covers the environment for The Olympian. He can be reached at 754-5444.
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