Saturday, April 20, 2002
Submitted by Calvin Finch, Ph.D., Manager, Conservation Division, Water Resources & Conservation Department, SAWS, and Horticulturist

TREES, ONE OF THE KEYS TO PROTECTING AND IMPROVING THE ENVIRONMENT

Urban areas have much to offer: economic opportunity, education, and the arts but there are special challenges as well. When you place so many people, buildings, roads, and automobiles so close together, there is a potential for environmental problems. Some obvious areas where environmental problems arise are air pollution, noise pollution, pollution from runoff, and temperature sinks (hot area). San Antonio has some problems in all those areas but, thankfully, not as much as most big cities. A coalition of environmentally-conscious agencies and organizations have identified trees as one of the keys to protecting and improving the San Antonio environment. The organization is called Alamo Forest Partnership.

Alamo Forest Partnership is led by City Public Service (CPS). Other Steering Committee members include the San Antonio Water System (SAWS), City of San Antonio, U.S. Department of Defense, San Antonio Trees, Texas Forest Service, University of Texas at San Antonio (UTSA), Alamo Area Council of Governments, San Antonio Forests, American Forests, Texas Parks & Wildlife, Bexar Audobon Society, National Park Service, and the Neighborhood Resource Center.

CPS is taking a lead role because the state of the urban forest is so closely related to energy conservation. A city with trees uses less air-conditioning energy. SAWS and the City are involved because of water runoff. The more runoff that occurs, the more potential there is for pollution and erosion. Storm runoff costs cities millions of dollars. Landscape watering is even affected by the urban forest. The more shade there is, the less water is required for lawn irrigation.

The Alamo Forest Partnership is now in the midst of a tree survey of 30, 2-acre sites spaced around the city in all habitat types. The survey will establish a baseline determination of the state of our forest in Bexar County so we can monitor the number of trees, their health, and their size in the future. With that data we can calculate what impact the trees are having on watershed protection, water conservation, energy use, air quality, and wildlife habitat.

If you lived in Stone Oak or shopped at HEB at 281 and 1604, you may have seen me and a group of volunteers last week measuring and recording trees. This weekend we complete our part of the survey by working with wildlife biologist Rufus Stephens (Texas Parks and Wildlife, Urban Programs) on a 2-acre patch of woods in the Applewhite area.

After the survey is complete the data collected will be analyzed by American Forest to produce an evaluation of where we are now. The Partnership will use the analysis to organize a tree planting program to insure that future San Antonians will have a better environment than we have now. The goal will be to have more and healthier trees. For more information on the Alamo Forest Partnership call Jenna Terrez (CPS) at 210-353-2792.

As we wait for the analysis of the state of our tree resources, all of us can plant more trees in our landscapes. Containerized trees can be planted anytime in the San Antonio area. Dig the hole as deep as the container and 2 to 4 times as wide. Place the native soil back in the hole and water the tree in well. The soaking will help insure that all of the air pockets will be filled with soil. Put three to four inches of mulch over the wet root system. Feel the soil under the mulch every week; if it is dry to one inch, water again. Expect to water every week through the summer if trees are planted now. Do not waste your money on root stimulator and do not add organic material, potting soil, or sand to the planting hole. The planting hole can become a well where water gets in more easily than it drains, drowning the roots. This phenomenon is especially likely in heavy clay soils that cover much of the San Antonio area.

            Consider live oak, Texas red oak, bur oak, Mexican white oak, cedar elm, Montezuma cypress, Chinese pistache, Lacey oak, chinkapin oak, and Mexican sycamore for large shade trees. Consider your tastes on tree selection and also consider the idea that a diverse planting is more desirable than a tree cover dominated by one or two species. To learn more about the recommended trees, visit plantanswers.com on the internet or visit the San Antonio Botanical Garden (555 Funston) where all of the species are growing.