Invasive plants researched at Austin center

By MONETTE TAYLOR | South Central Texas Edition

A summer burn treatment of KR bluestem is performed on a research plot at the LBJ National Historic Park site. -- Courtesy photo

July 21, 2005 - With temperatures hovering around the 100-degree mark for most of the past month, many ranchers are just happy to have any kind of grass left in the pastures for grazing! However, professionals at the Lady Bird Johnson Wildflower Center have been conducting a number of research programs meant to assist Texas producers make the most of their land, animals and crops.

According to Damon Waitt, senior botanist, they are focusing on "invasive plant species initiatives" that are threatening native plants and destroying habitats for small animals, too. One of the problems being addressed is the "scientific eradication study on King Ranch Bluestem grass."

Along with the U.S. Fish and Wildlife Service, the National Parks Service, Texas Agricultural Experiment Station and the Robert J. Jr. and Helen Klegerg Foundation, the Wildflower Center in Austin has been conducting experiments, headed by Mark Simmons, ecologist, who has been at the center for the past five years.

For the past 18 months, the Wildflower Center ecologists have "determined that summer fires can control the invasive, non-native grass, King Ranch bluestem, without eradicating native vegetation."'

While some ranchers in the area don't mind having the King Ranch bluestem in their pastures, Simmons said most cattle will eat the native grasses until they are gone, before they will eat the bluestem. "It's not especially nutritious," explained Simmons. "Original, native grasses are considered the 'ice cream' plant by cattle."

Although cattle will eat the bluestem in a pinch, ecologists and producers have seen a big reduction in the quail and dove populations, due to the "classic example of invasive species (bluestem)."

At first, producers and scientists tried "prescribed burning" during the cooler, dormant seasons; they have discovered that it failed to get rid of the invasive bluestem. During the past 18 months, researchers have found that summer fires "can control the invasive, non-native grass, King Ranch bluestem without eradicating native vegetation."

Other studies include a roadside re-vegetation study, along with the Federal Highway Administration and the Texas Department of Transportation (TxDOT). While the "recommended" seed mix of the TxDOT contains mainly non-native species, the native seed mix was found to grow more quickly and was more "prolific" than the mix currently used by TxDOT.

This study has received more funding from the Federal Highway Administration, and the study will continue in the fall and winter, in order to provide an alternative to the use of "non-native, invasive species of grass." These "non-native" grasses are threatening to "crowd out native cottonwoods, pecan and cypress trees," explained the Wildflower Center ecologists.

Finally, the Wildflower Center, along with the Town Lake Trail Foundation, City of Austin, Temple-Inland Foundation, Austin Community Foundation and Michael and Susan Dell Foundation, has begun a "comprehensive woodland management plan" for Town Lake Trail in Austin.

Due to the "re-sprouting vines, such as the mustang grape and non-native species, such as Nandina, Chinaberry, Privet and Chinese Tallow, and along with poison ivy and poison oak, the trail has become harder to travel, and needs to be "cleaned up."

On Nov. 17-19, there will be an "Invasive Plant Conference" at the Wildflower Center. It will be the first, statewide conference on non-native plant species. The third day will be "devoted to public education and awareness. For more information on the conference, visit www.texasinvasives.org or www.wildflower.org.