San Antonio: ripples of change; armed with new information on the benefits of their urban trees, officials plan for a greener and more ecologically based future. (Perspectives).San Antonio San Antonio (săn ăntō`nēō, əntōn`), city (1990 pop. 935,933), seat of Bexar co., S central Tex., at the source of the San Antonio River; inc. 1837. successfully straddles the line between historic relic and modern city. Tourists flock by the thousands to visit the Alamo Alamo Eighteenth-century mission in San Antonio, Texas, site of a historic siege of a small group of Texans by a Mexican army (1836) during the Texas war for independence from Mexico. , site of the decisive 1836 battle for Texas independence, or to stroll the banks of the San Antonio River
The San Antonio River is a major waterway that originates in central Texas near San Antonio and follows a roughly southeastern path through the state. along downtown's commercially successful River Walk. The city is ringed by springs, creeks, and rivers that arise from fault lines along one of the nation's largest limestone aquifers. The lush and varied vegetation that results attracts an array of migratory birds--and nature lovers. These natural and manmade attractions have brought the city and its surrounding area impressive population growth and urban expansion. Now the greater San Antonio area is trying to meet the clean air, clean water, and energy needs of its many residents. Looking to improve environmental quality, the Alamo Forest Partnership turned to AMERICAN FORESTS American Forests is a nonprofit conservation organization that promotes healthy forests and urban tree planting. The organization was established in 1875 as the American Forestry Association, by physician/horticulturist John Aston Warder and a group of like-minded citizens for assistance in evaluating the area's tree canopy cover. The Alamo Forest Partnership is a consortium of governmental and environmental organizations spearheaded by the city's publicly owned Publicly owned can refer to:
WHAT'S A COMMUNITY TO DO? To do that, AMERICAN FORESTS conducted an Urban Ecosystem Urban ecosytems are the cities, towns and urban strips constructed by humans. This growth in the urban population and the supporting built infrastructure has impacted on both urban environments and also on areas which surround urban areas. Analysis (UEA UEA University of East Anglia (UK) UEA Universala Esperanto-Asocio (World Esperanto Association) UEA Utah Education Association UEA Urban Exploration Alberta UEA United Earth Alliance ) of the greater San Antonio area. The analysis--which encompassed 788,000 acres of Bexar County, including the city of San Antonio--reevaluated the area's assets to include the environmental benefits provided by trees. The first phase determines landscape changes over time and assesses the impact those changes have had on air and water quality and on residential energy consumption. Using satellite and aerial imagery along with Geographic Information Systems (GIS) technology, changes in land cover were measured between 1985 and 2001. In autumn, AMERICAN FORESTS will complete the second phase of the study: creating a "green data layer" of information about urban forest ecology Forest ecology is the scientific study of patterns and processes in forests. The management of forests is known as forestry. Forest Ecosystem Scope of Forest Ecology that the local community can use when making planning and management decisions. Municipalities increasingly are turning to the analysis to make the powerful point that trees are an integral and money-saving part of the urban infrastructure. "Although we have acknowledged the benefits of tree cover in reducing air conditioning air conditioning, mechanical process for controlling the humidity, temperature, cleanliness, and circulation of air in buildings and rooms. Indoor air is conditioned and regulated to maintain the temperature-humidity ratio that is most comfortable and healthful. costs and improving air quality for some time," says Milton B. Lee, CPS's CEO (1) (Chief Executive Officer) The highest individual in command of an organization. Typically the president of the company, the CEO reports to the Chairman of the Board. and general manager, "prior to the study, we didn't have any scientific data that measured the extent of our tree canopy or the values it provided." ECOLOGICAL ISSUES Bexar County, in south-central Texas, sits at the edge of a wave of urbanization spreading north into the Hill Country and onto the Edwards Aquifer The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of Edwards Plateau in the U.S. state of Texas, it discharges about 900,000 acre feet (1.1 km³) of water a year and directly serves about two million people. Recharge Zone. The recharge zone, home to endangered bird and aquatic species, is where rain and streamwater enter San Antonio's primary source of drinking water drinking water supply of water available to animals for drinking supplied via nipples, in troughs, dams, ponds and larger natural water sources; an insufficient supply leads to dehydration; it can be the source of infection, e.g. leptospirosis, salmonellosis, or of poisoning, e.g. , and it needs protection from pollution. The greater San Antonio area has a particularly sensitive ecosystem built upon hard limestone bedrock and thin soils. The limestone's faults and sinkholes allow rainwater to drain directly into the aquifer without the benefit of passing through soil, which naturally filters out sediment and urban runoff pollutants. In addition, because its thin soil doesn't hold water well, the region is prone to flash flooding. These problems have been exacerbated by increased urbanization and a corresponding decrease in tree cover. San Antonio's population has risen 22 percent in 10 years, making it the ninth largest city in the U.S. In the first phase of the analysis AMERICAN FORESTS determined that since 1985 San Antonio has lost 39 percent of its heavy tree cover (canopy coverage greater than 50 percent). The corresponding decrease in greater San Antonio's tree cover is 22 percent. Urbanized areas (less than 20 percent canopy cover) in greater San Antonio increased from 69 percent in 1985 to 77 percent in 2001. The trends in moderate tree density (20 to 49 percent) show that as the area is developing, tree canopy is not being conserved. The region falls short of AMERICAN FORESTS' recommended 25 to 39 percent overall tree canopy for the semi-arid southwestern part of the U.S. The greater San Antonio area and city currently have 20 percent and 14 percent heavy tree cover, respectively. This trend needs to be reversed to tap the natural improvement benefits trees can provide. When population increases, the pressure on the surrounding natural resources increases as well. Reduced tree cover and an increase in impervious surface Impervious surfaces are artificial structures, such as pavements and building roofs, which replace naturally pervious soil with impervious construction materials. They are an environmental concern because, with their construction, a chain of events is initiated that modifies urban area take their toll on a region's air and water quality and energy consumption. The greater San Antonio area has lost 45,000 acres of heavy tree canopy (22 percent) over the last 15 years, costing its citizens $9 million a year for air pollution abatement and $146 million for stormwater management. They also lost $1 7.7 million in residential summer energy savings. The San Antonio region exceeds U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and air quality standards for ozone pollution levels, which could jeopardize federal funding for transportation projects. Officials there recently signed an Early Action Compact, which allows the region to create a local plan to bring down pollution levels and make its air healthy again. Signing the agreement were the EPA EPA eicosapentaenoic acid. EPA abbr. eicosapentaenoic acid EPA, n.pr See acid, eicosapentaenoic. EPA, n. , the Texas Commission on Environmental Quality The Texas Commission for Environmental Quality is the environmental agency for the U.S. state of Texas. External links
Additional tree planting and tree preservation could he an effective part of the overall solution. Trees have proven effective in helping to counter the effects of the urban heat island An urban heat island (UHI) is a metropolitan area which is significantly warmer than its surroundings. The temperature difference usually is larger at night than during the day and larger in winter than in summer, and is most apparent when winds are weak. , a condition in which city centers with greater impervious surfaces and less tree canopy cover generate warmer temperatures and greater air pollution compared to their rural surroundings. In the greater San Antonio area, trees currently remove 17.6 million pounds of pollutants, a benefit valued at $42 million. Trees lost between 1985 and 2001 would have removed an additional 3.7 million pounds of pollutants annually, a savings of approximately $9 million per year. "As nonattainment status for air quality looms over San Antonio, we know it will be necessary to do more to improve air quality," says Scott Smith Scott Smith is the name of:
The members of the Alamo Forest Partnership, which sponsored the UEA, work together to preserve and plant trees. Along with City Public Service, partners include the Texas Forest Service, city of San Antonio, University of Texas at San Antonio The main campus is situated on 600 acres (2.4 km²,) at the intersection of Interstate 10 and Loop 1604 near the northern edge of San Antonio, Texas in Bexar County. The university is also one of the UT System's fastest growing schools, maintaining a 12. , Alamo Area Council of Governments The Alamo Area Council of Governments (AACOG) is a voluntary association of cities, counties and special districts in south-central Texas. Based in San Antonio, the Alamo Area Council of Governments is a member of the Texas Association of Regional Councils. , San Antonio Water System, Texas Parks and Wildlife, U.S. Department of Defense, U.S. National Park Service, local nonprofits San Antonio Forest and San Antonio Trees, Bexar Audubon, and the Neighborhood Resource Center. Other partners include Texas Department of Transportation; Keep San Antonio Beautiful, Inc.; Texas Master Naturalist; San Antonio River Authority; Bexar County Environmental Services The various combinations of scientific, technical, and advisory activities (including modification processes, i.e., the influence of manmade and natural factors) required to acquire, produce, and supply information on the past, present, and future states of space, atmospheric, ; and the Open Space Advisory Board. RIPPLES OF CHANGE The study findings have sent promising ripples of change across the community. The UEA results got the attention of the Bexar County Commissioners and the support of San Antonio Mayor Ed Garza and some members of City Council, especially Councilwoman Bonnie bon·ny also bon·nie adj. bon·ni·er, bon·ni·est Scots 1. Physically attractive or appealing; pretty. 2. Excellent. Connor. Connor saw the report as a good source of scientific data for decision making, calling it very useful in preparing an upcoming city watershed management plan. Most dramatically, the UEA revitalized the need for San Antonio to finalize and pass a revised Tree Preservation Ordinance, a controversial process that had been intensively reviewed and negotiated for three years. The Citizens' Tree Coalition, a collection of ecological organizations and neighborhood associations, used the UEA to show the importance of a tree ordinance. The revised ordinance recognizes the value of San Antonio's urban forest and provides greater protection of its desirable trees. A key provision for the protection of tree cover offers developers an incentive to use tree stand delineation, a holistic approach holistic approach A term used in alternative health for a philosophical approach to health care, in which the entire Pt is evaluated and treated. See Alternative medicine, Holistic medicine. to documenting trees by their canopy cover, roots, and associated growing space rather than the more narrowly defined tree stem count. This method for documenting tree-save areas allows developers to reduce "unanticipated expenses and delay..." and to be "excused from the individual tree surveys and construction measures..." The end result is a means for developers to fast-track their projects through review. Other new provisions clarify that protected trees will be preserved in 100-year floodplains, give clusters of trees greater value than individual trees, award variances to preserve trees in residential setbacks, and preserve any species having a trunk at least 30 inches in diameter. Setting aside their differences, both developers and environmentalists wholeheartedly whole·heart·ed adj. Marked by unconditional commitment, unstinting devotion, or unreserved enthusiasm: wholehearted approval. whole supported a new provision requiring all municipal agencies to adhere to adhere to verb 1. follow, keep, maintain, respect, observe, be true, fulfil, obey, heed, keep to, abide by, be loyal, mind, be constant, be faithful 2. the tree ordinance. City Council is expected to pass the ordinance this spring. Armed with this new information, community leaders are reversing the tree-loss trends. "Based on compelling business reasons cited in the study, CPS is developing a comprehensive tree planting and preservation program. This program will help improve air quality in San Antonio and save CPS customers on air conditioning costs," says Milton B. Lee, of City Public Service. Jenna Terrez is an environmental analyst for City Public Service and chair of the Alamo Forest Partnership. The analysis, she says, "will help us identify priority planting areas for CPS's new Green Shade Program." While the program is still in its formative stages, she plans to work with neighborhood associations to plant appropriate species in residential yards, placing them to maximize energy conservation. "I plan to run an analysis of every tree-planting project, documenting the benefits of their neighborhoods with before, after, and 20-year growth projection analyses," Terrez says. "People need to see how their tree planting efforts impact the environment in real and tangible savings." BUILDING A GREEN DATA LAYER With the momentum building, the greater San Antonio area is poised to create a greener plan for future development. In the second phase of its Urban Ecosystem Analysis, AMERICAN FORESTS will provide the tools to do just that. By turning high-resolution satellite imagery Satellite imagery consists of photographs of Earth or other planets made from artificial satellites. History The first satellite photographs of Earth were made August 14, 1959 by the US satellite Explorer 6. into detailed digital data, AMERICAN FORESTS will, in essence, create a green data layer that is rich with technical information, based on scientific and engineering models. San Antonio City Council's Open Space Advisory Board has endorsed this next phase, recognizing that the digital data will be a valuable tool for local planners to have at their fingertips "Fingertips" is a 1963 number-one hit single recorded live by "Little" Stevie Wonder for Motown's Tamla label. Wonder's first hit single, "Fingertips" was the first live, non-studio recording to reach number-one on the Billboard Pop Singles chart in the United States. during daily decision-making. "But there's still a lot of work to be done," cautions Mark Peterson This article is about the American soccer player Mark Peterson. For the Latter-day Saint leader, see Mark E. Petersen. Mark Peterson is a retired U.S. soccer forward. , regional urban forester for the Texas Forest Service. "Changing mindsets and adopting new policies and procedures Policies and Procedures are a set of documents that describe an organization's policies for operation and the procedures necessary to fulfill the policies. They are often initiated because of some external requirement, such as environmental compliance or other governmental that support trees as ecological assets comes more slowly. Some people still have the notion that tree benefits are purely aesthetic." The Texas Forest Service is committed to integrating the green data layer into local planning. Peterson envisions the city's planning department using it for long-range planning and the developmental services department using it for site plan review. This rich layer of green data will also be invaluable in identifying, purchasing, and protecting significant ecological areas within groundwater recharge zones and in determining optimal tree canopy levels during development, he says. At City Public Service, Terrez concurs with Peterson's vision for integrating the green data layer. In fact, Terrez says, ail municipal agencies must comply with the new tree ordinance's aerial image An aerial image is a projected image which is "floating in air", and cannot be viewed normally. It can only be seen from one position in space, often focused by another lens. mapping requirement for capital improvement projects. "Project managers can use the green data layer to see how trees will impact their site plans for new development." While the signs are good, integrating trees into all aspects of community development is just beginning. San Antonio's community leaders must continue to protect their precious source of drinking water while taking steps to comply with EPXs air quality standards, reduce flooding, and find ways to expand urban growth with environmental sensitivity. The Alamo Forest Partnership must find ways to solve these complex problems while fostering a "trees as asset" mindset mind·set or mind-set n. 1. A fixed mental attitude or disposition that predetermines a person's responses to and interpretations of situations. 2. An inclination or a habit. within all levels of decision making. Fortunately, it is armed with facts on tree cover trends and ecological benefits--and soon will have a green data layer--all the tools it will need to make good planning decisions that ultimately will increase tree canopy and improve local ecology. RELATED ARTICLE: MORE TREES, BETTER CITIES DO THE MATH Satellite images show tree canopy changes over time in northern San Antonio (area in box at right) by zooming in to compare the area in 1985 and 2001. Dark green represents heavy tree cover (50 percent or more); black represents urban areas and sparse tree cover (less than 20 percent). There are many benefits to increasing tree canopy. Adding more trees will improve air quality, reduce stormwater runoff, slow soil erosion, and improve water quality and recharge. Planting more trees also will lower carbon dioxide carbon dioxide, chemical compound, CO2, a colorless, odorless, tasteless gas that is about one and one-half times as dense as air under ordinary conditions of temperature and pressure. levels and improve the local climate by reducing the heat island effect, especially in downtown areas. Property owners can save on home energy by strategically planting shade trees. SEE IT FOR YOURSELF See San Antonio's green data layer for yourself during the 2003 National Urban Forest Conference, to be held in the city September 1720. Titled "Engineering Green," the program features more than 100 sessions, workshops, tours, and exhibits that will highlight ways cities can build according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. nature's laws and rise above the financial, ecological, and social tide of urban growth. Details online at: www.americanforests.org You can also call 703/904-7508 or fill out the registration form in this magazine. CURRENT URBAN BENEFITS (MEASURED IN 2001) Location Greater San Antonio Area City of San Antonio Acres 788,000 275,000 Heavy Tree Canopy 20% 14% Stormwoter Management $1.3 billion $431 million Value (one-time) Air Pollution Removal $42 million $12 million Value (annual) Residential Energy $17.6 million $14.4 million Savings (annual) Cheryl Kollin is director of AMERICAN FORESTS' Urban Forest Center. |
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