Tree huggers needed
City staff began taking an ax to the tree ordinance last week, with several contentious recommendations that could undermine tree-coverage goals for San Antonio.
A 2002 urban ecosystem analysis conducted by American Forests for San Antonio showed “the enormous economic value of the City’s urban forest,” according to the Citizens Tree Coalition website. Most important, the analysis “showed an alarming loss of tree canopy cover from 1985 to 2001.”
The environmental value of trees — removing air pollution (they make oxygen) and reducing buildings’ energy usage (they provide shade) amounts to more than $3 billion in the San Antonio metropolitan area, according to the analysis. An average homeowner who has trees on his or her property can benefit as much as $11,000 in environmental and property values.
In 2003, a second phase of the analysis was published, which recommended a 35 percent tree canopy cover for San Antonio, a number the tree coalition uses to set its tree-preservation goals. But the City has fallen short of that goal. City Arborist Debbie Reid estimated San Antonio’s 2003 tree canopy to be 27 percent, but urban forester Mark Peterson disputed that number as being too high because Reid counted trees on land purchased for conservation.
Peterson also noted that by accounting for an average 32-year life cycle for trees, the City should plant 16,000 trees per year for the next 32 years to achieve the optimal coverage.
That does not appear to be happening. Instead, developers are clearing trees, including those over the Edwards Aquifer Recharge and Contributing zones, and City staff is recommending amendments to the tree ordinance that would allow more trees to be bulldozed.
The endangered tree du jour is the ashe juniper (aka mountain cedar) that stuffs up so many noses each year when the tree pollinates. Ashe juniper has earned a reputation as a water guzzler with no appreciable value, and the City Arborist and planning department are recommending that the City lower the standards for preserving them.
| The endangered tree du jour
is the ashe juniper (aka mountain cedar)
that stuffs up so many noses each year
But Peterson says the ashe juniper isn’t as thirsty as it’s reputed to be. “The jury is still out on the overall picture, but it doesn’t use as much water as a citrus tree or other evergreen trees,” he says. “The juniper plays a significant role in the ecosystem.”
Junipers release oxygen into the atmosphere, and drop leaves onto the limestone bedrock, which enhances the thin layer of soil in the Hill Country.
And, Peterson pointed out last week during a City Council work session, massive demolition of juniper trees might trigger the remaining canopy to produce extra pollen to compensate.
“The idea that we’re going to be able to adjust the environment by getting rid of ashe juniper is misguided,” says Richard Alles of CTC, who also works as a City Hall lobbyist for Aquifer Guardians in Urban Areas. “We’re not talking about restoring an ecosystem, we’re talking about replacing ashe junipers with asphalt and buildings, and that is the main point.”
City staff also recommends that a random grid system be used to evaluate the percentage of tree canopy on property to be developed. Instead of counting heritage trees — those that are very old — an amended tree ordinance would allow random sampling of 100 acres, for example, which would be used to represent the entire property. “The question you have to ask,” says Alles, “Is that 10 percent sample of the most valuable trees on a property an accurate representation of the entire piece of property?”
“The point is if you lower the standards so (that) heavily treed land is brought down to what they consider an acceptable level,” he adds, “then there won’t be an adequate level of tree canopy over the entire county area.”
The City is allowing a 30-day comment period on the amendments to the tree ordinance, which are designed to help developers clear their properties and build Wal-Marts and asphalt parking lots without any trees.
For information on how to submit commentary during this 30-day period, call City Arborist Debbie Reid at 207-8053, or the City Clerk’s office at 207-7253. A copy of the tree ordinance is posted at sanantonio.gov. •
By Michael Cary