Forestry experts say diversity with trees is vital to health, abundance.
The live oak, with its stately canopy that spreads shade over a wide area, is easily the most popular tree in Houston. Perhaps a bit too popular.
Surveys of various local neighborhoods consistently show that 60 percent to 70 percent of the trees on public land are live oaks.
Experts say, however, that a diversity of species is essential to keep urban trees healthy and abundant.
“Only 10 percent should be one species,” said Charles Burditt, president of a Conroe-based forestry consulting firm that bears his name. “Otherwise, a disease or other catastrophic event could wipe out a large percentage of your trees.”
Burditt is providing such information and advice through a tree inventory the firm is conducting in Midtown, a redeveloping neighborhood south of downtown.
Experts say a current database of the number, species and condition of trees is an invaluable tool in preserving urban canopies, which are diminishing in Houston and most other cities.
“This is the best practice for urban forestry,” said Kathy Lord, executive director of the nonprofit group Trees For Houston. “If we don’t know what we have in this 680 square miles, how can we take care of it?”
Lord and Burditt said Houston lags behind many other U.S. cities in developing information about its trees. The city did not commission a tree inventory until 1998, when it hired Burditt.
During the next three years, the firm completed inventories in 17 out of Houston’s 88 “super neighborhoods,” all within Loop 610.
Lord said the city parks department is hiring interns from two universities to try and complete the process.
Although Midtown was included in the previous inventories, neighborhood leaders thought they needed more current information as redevelopment continues, said Marlon Marshall, manager of special projects for the Midtown Management District.
The inventory is limited to trees in the public right of way, generally the area between the sidewalk and the street.
Marshall said Midtown leaders also seek cooperation from developers building on private land, asking them to preserve mature trees whenever possible.
After surveying a bit less than half of Midtown, Burditt has counted 1,786 trees on 137 city blocks. About 65 percent are live oaks; crape myrtles, the next most common species, were about 4 percent.
Burditt found that 76 percent of the trees were in good condition, and 70 percent were less than a foot in diameter, indicating they were relatively young.
Marshall said the management district, which collects fees from Midtown property owners to provide services, has already begun caring for trees in response to Burditt’s “prescriptions” for pruning, watering or other maintenance.
Benefits of trees
Gayle Fortson, a Midtown resident for four years, applauded the effort.
“I love my trees. They have a cool, soothing effect,” Fortson said.
Burditt said cities are a stressful environment for trees, a fact borne by a study conducted in 2000 by American Forests, a nonprofit conservation group.
Within a 50-mile radius of Houston, the study found, areas with heavy tree canopy — tree cover of 50 percent or greater — declined from 31 percent of the region in 1972 to 26 percent in 1999.
The group said development and other factors accounted for tree loss in Houston and many other cities.
Aside from their beauty, experts say, trees improve air quality and reduce flooding by absorbing stormwater.
American Forests said the tree canopy lost in Houston would have provided air quality improvements valued at $38 million per year and reduced stormwater flow during a major storm by 360 million cubic feet °X the equivalent of $237 million in drainage systems.
Reporter: M. Snyder
Houston Chronicle (TX)