"The incredible diversity of native plants in the coastal prairies is gone within 30 years after the Chinese tallow tree invades the area," said Siemann, assistant professor of ecology and evolutionary biology. "By studying how this tree has been able to thrive, we should be able to learn more about the rules that govern a biological community and the interactions among species within that community."

Known for its heart-shaped leaves and white fruits, the Chinese tallow tree originated in Asia. The U.S. government brought it to the Gulf Coast area around 1900 in hope of using the wax-covered seeds as an agricultural crop. That project was unsuccessful, and the trees escaped from cultivation. Siemann is concerned about the spread of Chinese tallow trees, because once they replace bluestem grasses, sunflowers, blazing stars and other plants found in the prairies, those species and their associated animal fauna will not come back.

One of the reasons this tree has been able to grow so well is that insects have left it alone and munched on other foliage. Siemann said this is particularly peculiar because unlike the slow-growing tallow tree found in China, the American variety lets its defenses down. The Chinese variety has chemicals in its leaves that makes them hard to digest. The American variety does not produce this substance; instead, it appears to use that energy to grow quickly, which promotes the development of forests.

Siemann is testing various methods of controlling the tallow trees using land in Galveston County owned by the University of Houston Coastal Center. "If you knock down the tallow trees, they just sprout from roots like crazy," he said.
'"/>

Contact: B.J. Almond
balmond@rice.edu
713-348-6770
Rice University
22-Feb-2002