San Antonio’s Tree Deficit
June 25, 2009

A recently published report from American Forests shows that San Antonio has a steadily growing deficit of 455,000 trees. This deficit is the difference between scientific recommendations for the city's tree canopy cover and the current state of San Antonio's urban forest.

Despite increasing public awareness of trees’ health and aesthetic benefits, San Antonio continues to rapidly lose trees. Over a 5-year period (2001-2006), the Edwards Aquifer recharge and transition zones lost 7,600 acres of trees and natural open space.

Satellite image of San Antonio in 2003,
classified according to land cover

Previously, San Antonio was thought to have a 1.4 million tree deficit, but improvements in imaging technology revealed trees that were overlooked by older instruments. In its May, 2009 Urban Ecosystem Analysis for San Antonio, American Forests recommends 55% tree canopy cover for the Edwards Aquifer recharge and transition zones. Within the City limits, 40% tree canopy cover is recommended.

These recommendations strike a balance between environmental health and development density by suggesting lower canopy cover in the downtown area and progressively higher levels in suburban and aquifer recharge zone areas. By basing canopy cover recommendations on a national assessment of urban forests, San Antonio's goals were placed in context with similar U.S. cities.

Attempts by the City to enforce tree preservation rules have helped slow tree loss, even though many large development projects are exempt. The data show that local tree planting efforts are clearly inadequate, and that City and County programs need to ramp up by orders of magnitude.