Urban ecosystems: breakthroughs for city green.
In the 20 years since that job, I've spent my time trying to revise that scenario by making natural landscapes relevant to people who build big things, like power plants, or make decisions about building even bigger things, like cities. After several national surveys of urban forests and hundreds of conversations with urban foresters, I realized that trees and even existing natural landscapes were not recognized as a valuable community resource. Community leaders must make difficult decisions - often choosing between costs and community benefits - and until now have lacked the information they need to understand the benefits natural resources provide.
As a natural resource expert, I believe it's my job to supply this information, and it's getting easier now to do that. AMERICAN FORESTS is helping communities map, measure, and analyze their local ecosystem using a computerized planning tool, and the results show natural resources are more than pulling their weight. Early estimates suggest the national savings from urban ecology total $40 billion a year.
Let me give you an example to show how far we've come in how we view our natural resources.
That electric utility I worked for decided to standardize the way it built power plants, beginning with one under construction along the Ohio River. The "recipe" called for a couple hundred acres of land to be literally turned upside down to fit the standard design.
I realized the magnitude of the job when the landscape architect asked me to meet him on-site to review landscape plans. Over the next two years we would need to rebuild and stabilize hundreds of acres of land with various grasses and plants. We were to reroute a stream to reduce flood risk, then "reattach" it to the Ohio River. I looked at the stack of plans but couldn't concentrate. That stream thing stuck in my mind.
Those plans were ambitious, but the construction guys were not intimidated; they had a piece of equipment for everything the landscape architect wanted done. Over a few months a ditch became a stream with lush green banks and flowing water. The landscape architect showed me plans for fish habitat, complete with old logs and rocks lowered into place with a crane.
Although I felt better rebuilding the natural landscape - work that put my forestry education to good use and gave me some practical experience - my sense of accomplishment was soon overshadowed by a daunting question: Had we restored the natural landscape or just patched it up to solve a development problem?
I turned my attention to planting large trees on a quarter-mile-long dirt mound that looked like a burial ground for a truck convoy. We mobilized lots of people and big equipment to dig up trees at the nursery and prepare the planting holes. But on planting day only five workers were available, making it impossible to get even half the trees in the ground. Faced with the prospect of trees drying out over the weekend and dying, I turned to the construction manager for help.
When I ex-plained the problem, he changed the subject to insects on his trees at home. He would not help. That's when I realized that what I saw as a critical ecological-restoration project was viewed by the company as a low-priority beauty treatment. Nothing I could say about the trees could be related positively to the bottom line, because though the dollar benefits of electric power could be measured, the dollar value of the landscape could not.
Since then I've made it my No. 1 concern to quantify the costs and benefits of the natural landscape and communicate them to decisionmakers. At the power company I learned that the development was designed independently from existing natural resources. The buildings and properties we created would operate the same regardless; the land would be reworked to fit the project, and my job was to prevent existing resources from causing a problem.
Researchers and practitioners have proven that natural actions - like those of the stream - can be harnessed in a way that retains natural functions and also allows them to contribute to the development. Through measuring and mapping we can now can show how beneficial these natural elements are - in dollar-and-cent terms. These figures show that trying to hamstring existing resources and move the energy they produce to other sites winds up being a poor investment in time and money.
This new technology has changed the way we look at natural resources. We used to merely count the number of trees along streets - only 10 percent of a city's total tree canopy - to conduct an urban forest inventory. Now we look at all the trees in a community and also recognize that they are only part of the ecosystem. We don't just count different elements of the ecosystem - we analyze their value by measuring the work they do. Thanks to the development of high-tech tools, such as computerized land-use planning software, every community can determine the value of its local ecosystem, and use that information for nature-friendly development. New computerized mapping and analyzing software called CityGreen: Measuring Urban Ecosystem Values, developed by AMERICAN FORESTS, not only gives natural resources value, it helps communicate those values. We have entered a new planning dimension where we can not only build better communities by fitting them to the needs of the natural landscape, we can determine how much money we save by doing it right.
This new high-tech system for analyzing urban ecosystems is available to any community that has a high-speed personal computer. The system uses Geographic Information Systems (GIS) software, which is commonly used for land-use planning, to connect ecological resources to the decisionmaking process. This technology is so powerful that it allows information from a wide range of experts to be combined and interpreted on the same map, translating the technical jargon unique to each profession into a common language using visual images, maps, and charts. When you ask critical questions such as how an expanding community will affect the tree canopy, the software analyzes the benefits of the tree canopy and assigns it a value in dollars.
Before this it was impractical, if not impossible, to compile all the information used in the community-development process. And if land-use-planning experts can't get a clear picture of our urban ecosystems, how can we expect an accurate interpretation for community leaders? Those leaders get most of their information from experts, and that information needs to be put into perspective so it can all be compared when decisions have to be made. With this new analysis technique, a standard mapping system produces a picture of what a community or a site actually looks like and provides decisionmakers with a standard measuring system - the American dollar.
The analysis can be done quickly - important because the people who make decisions about our communities need to have the most complete information possible when deciding which course of action to follow. This software allows them to ask questions like, "What happens if we move that road?" and actually see the ramifications of that choice.
Whatever your specific interest in the community-development process, you will be able to see the outcome of different options. If you are a land developer, you can review development options before spending a lot of money creating concept plans. If you are a community's engineer, you can estimate how changes in the landscape will change stormwater management. If your concern is the environment, you can measure potential changes in air or water quality. If you are one of the decisionmakers, you can weigh different options and make adjustments to harness the benefits of the natural system while directing development to the most appropriate places or providing incentives for those that meet high standards of quality.
What exactly does the software do? Many planning departments have detailed information on buildings, streets, and utilities but don't have access to ecological information. The Urban Ecological Analysis maps ecological features so they can be included in the standard land-use-planning process and analyzed together with the built structures. This new technique provides a more complete picture of the existing environment than is currently available to any planning agency in the country.
Consider the scale of data commonly used for land-use maps. These base maps often are created from satellite data in which the smallest area a viewer can see, called a pixel, is 90 meters. Because the area each pixel encompasses is so large, trees and other natural-resource elements get lost - literally.
Look at the figure on page 26 that shows a section of Atlanta called Midtown. In conducting an analysis for the city, we compared the satellite data used for regional planning with photos taken from much lower levels and found that a site with 16 percent tree canopy was registering as 0 on the planning map. Such discrepancies can make a big difference in planning decisions and development choices.
To help determine the value of the landscape, AMERICAN FORESTS established an urban ecological classification system that combines standard land-use-planning categories and vegetative cover to determine an ecological structure, or eco-structure, for specific areas. Mathematical models we've developed use research data and other technical information to determine how each eco-structure will respond to various natural events, for example, how stormwater flow rates change with each eco-structure. The value of each structure can be analyzed based on how it reacts to a natural event such as a rainstorm or heat wave. For example, let's take an area of single-family housing with a dense tree canopy. Specific dollar benefits can be associated with the function of this eco-structure including energy conservation, stormwater management, and air quality.
In our analysis for the city of Atlanta we recorded 105 different eco-structures. For planning presentations, these classifications are simplified to about 10 categories. The resulting map provides community leaders with all the information they need for discussions and visual presentations. This level of detail also gives them a more accurate analysis for addressing development issues.
Once a city is classified into eco-structures, costs and benefits are calculated by tallying the values of natural-resource features for stormwater management, erosion control, wildlife, carbon reduction, air quality, and others. Then the relationships between natural and cultural features are examined, along with their overall impact on air, water, and nutrient cycles. These costs and benefits are summarized for each urban eco-structure so planners can see the financial advantages.
The Urban Ecological Analysis makes the ecosystem a part of the planning process without pitting development against environment. Instead, it provides dozens of development options for a specific site. For instance, the analysis can compare the stormwater management costs and benefits of an undeveloped forested property vs. one completely cleared of trees and covered with dense housing. It can also calculate the benefits of various development options between these two extremes.
AMERICAN FORESTS is currently conducting urban ecological analyses in five cities across the U.S. - Atlanta, Georgia; Austin, Texas; Baltimore, Maryland; Miami, Florida; and Milwaukee, Wisconsin. The results can be used to estimate benefits provided by urban ecosystems in other cities. Using GIS, cities similar in size and structure to those already analyzed are assigned equal benefits. For larger or smaller cities, the values are estimated. When combined, the information becomes a summary of the value of our nation's urban ecosystems - and a basis for public policy discussions.
Existing tree cover in cities around the country provides an estimated $4 billion in energy savings annually. According to our calculations, those savings could double if trees were planted in vacant strategic locations. Judging from the information already collected on summer energy conservation, comprehensive benefits could be much larger than expected when you factor in the added value other ecological elements would produce. We predict the national savings from urban ecology to be in the $40 billion range.
High-tech wizardry like AMERICAN FORESTS' Urban Ecological Analysis gives community leaders a chance to increase the value of their existing ecosystems. Make no mistake - these precious natural resources will begin to decline if we don't integrate development with the environment. City leaders now can reverse this trend and gather the information they need to make the best decisions for their communities' environmental health and quality of life.
I'm proud to say our Urban Ecological Analysis provides a tool I wish I'd had when I started my career - it can prove that environmental conservation doesn't cost, it saves. And it makes the last-minute restoration work I did 20 years ago truly a thing of the past.
This is the last in a series of five articles exploring our urban ecosystems, from the meaning of the term to how natural and built elements can coexist successfully. The entire set of magazines is available from AMERICAN FORESTS for $10 plus $3 shipping and handling. The four previous articles were: "The Urban Ecosystem: Putting Nature Back in the Picture" (October/November Urban Forests), "The Megafauna: People of the Urban Ecosystem" (December/January Urban Forests), "Inside Ecosystems" (March/April American Forests), and "The Sustainable City" (May/June American Forests).
RELATED ARTICLE: MEASURING THE VALUE OF URBAN ECOSYSTEMS
For the last five years. AMERICAN FORESTS has looked for a way to help, community leaders utilize local natural resources in community planning, development, and management. Now we have one - new software that measures, maps, and analyzes urban ecosystems using GIS technology and cutting-edge scientific findings about the functional values of natural resources.
The GIS software - called CityGreen: Measuring Urban Ecosystem Values - is designed for use on personal computers as an application program of ArcView II. ArcView was developed by Environmental Systems Research Institute (ESRI) to give personal computer users an affordable but comprehensive GIS software program. ArcView II makes this possible by using data prepared by a more-sophisticated system called ArcInfo. ArcInfo is a high-tech Unix-based system commonly used by city management programs.
The CityGreen/ArcView combination allows planners, engineers, local citizen groups, and natural-resource managers to map local ecosystems and analyze their values. The analysis produced by this program provides community leaders with the information they need to balance the value of natural resources with other elements of a city's urban infrastructure.
If your community needs to know how to make the best use of its natural resources in the community-development process, you'll want to try AMERICAN FORESTS' CityGreen for ArcView. Contact Linda Mallet at 202/667-3300 ext. 236. - GARY MOLL
GARY MOLL - is AMERICAN FORESTS' vice president for urban forestry. He has more than 20 years experience as an urban forester and has worked for industry, government, and nonprofit organizations.
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|Title Annotation:||Special Focus: Urban Forests; includes related articles|
|Date:||Sep 22, 1995|
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