Ashe juniper and land development

David Bamberger hugging an Ashe juniper tree
Photo Copyright © 2003 Greg Pasztor

City Council recently slashed preservation standards for Ashe juniper in order to conserve water. But does removing these trees for land development help the aquifer?

More importantly, does destroying the trees benefit the overall health of our city? Here, we sort out the myths and facts, not only about water usage but about how the trees serve sustainable development.

First, look beyond the narrow focus of water consumption and consider the benefits these trees provide:

• air pollution removal
• stormwater management
• erosion prevention and slope stabilization
• air cooling
• endangered Golden-Cheeked Warbler habitat.

Then, read below and decide for yourself if the "water wasting" argument "holds water".

Myths and facts about Ashe juniper

Myth: Destroying cedars for land development results in less water usage

Fact: It requires large amounts of water to establish and maintain the new trees and grass typically planted after houses are built. Conversely, preserving drought-adapted vegetation requires little water.

Myth: Eliminating Ashe juniper from the tree ordinance will help the aquifer

Fact: Eliminating junipers will harm water quality and reduce aquifer recharge. Trees serve as placeholders for naturally vegetated land. If they are eliminated, the land they stand on will be paved over, especially on commercial projects.

When impervious cover such as pavement increases, contamination in stormwater runoff also increases. When land is paved over, aquifer recharge features are covered up, thereby blocking water from recharging the aquifer.

Furthermore, tree require space. They occupy large volumes, both above and below ground. If junipers are eliminated, green space will be eliminated along with them.

In an urban setting like this one in Northwest San Antonio
there is no rationale for eliminating Ashe juniper

Myth: Clear-cutting cedar for land development increases aquifer recharge

Fact: There are no scientific studies showing that replacing cedars with asphalt, concrete, and buildings increases aquifer recharge. Land development is radically different from cattle ranch management, therefore existing "cedar clearing" studies cannot be relied on to justify exempting cedars from the tree ordinance.

Cedar clearing symposium report

Many cedar clearing studies are performed for the benefit of the cattle industry. Cattle ranchers often seek government subsidies for cedar clearing to make way for grass-covered pastures. Ironically, overgrazing is responsible for much of the damage that nature tries to repair with Ashe juniper.

Moreover, the effectiveness of Ashe juniper control depends on a lot of factors that vary from site to site. A study at Seco Creek, in Uvalde County, showed that initial removal of brush led to increased water yields. But three years later, after re-vegetation with native grasses, there was less aquifer recharge than on a control site that remained covered by Junipers. Other field studies in Texas found that any increase in water yield after clearing was substantially diminished once the site was planted with grass.

Click image to read biologist Fred Wills' perspective

These resources have more information:

• Shrub Control and Water Yield on Texas Rangelands: CURRENT STATE OF KNOWLEDGE, a 2005 research report by A&M's Texas Agricultural Experiment Station (1.9 Mb file)
• Brush Management Myths and Facts by environmental defense
• Gregg Eckhardt's Brush Management webpage
• Elizabeth McGreevy Seiler's website (Click on Untwisting the Cedar at the bottom of her webpage)
• The War on Cedar; Texas Monthly story by Joe Nick Patoski

Myth: Nobody wants Ashe juniper on their property, hence we are doing homeowners a favor by getting rid of them.

Fact: It is important to know that developers are not required to preserve any particular species of tree, and that the vast majority of trees can be destroyed without triggering any requirement for mitigation. On many tracts, preservation requirements can be met by preserving only oaks. Furthermore, the tree ordinance gives developers the option of exceeding allowable cedar removal by providing mitigation. This is accomplished by planting small replacement trees, by paying into the City's tree planting fund, or by preserving existing trees too small to be protected by the ordinance.

In reality, developers are seeking only to pave the way for damaging, high-density development. Many people have junipers in their yard and consider them a valuable addition to their property. Regardless, homeowners are free to remove the trees, since the tree ordinance does not apply to property on which construction of houses has been completed.
Several years ago, the president of the Greater San Antonio Builders Association wrote an opinion piece encouraging preservation of junipers. See Keeping Cedars Around May Not Be a Bad Idea.