Researchers Work to Stop Ironwood Tree Decline in Guam

With U.S. Department of Agriculture (USDA) grants totaling almost $370,000, researchers from the University of Guam and other institutions are in the process of analyzing termites to assess their role in infecting what is now more than 20 percent of Guam’s ironwood trees with a deadly bacterium.

More than 18 years ago, the ironwood tree, a hearty, salt-resistant species important for soil erosion control and a protector of vegetation from the wind, unexpectedly began dying off in Guam. This condition is now referred to as “ironwood tree decline.” It took another six years to find its main culprit: the bacterial wilt pathogen known as Ralstonia solanacearum

Since then, under a longstanding effort funded by various USDA sources — the Western Sustainable Agriculture Research and Education program, NIFA’s McIntire-Stennis Capacity Grant, the U.S. Forest Service, and the Renewable Resources Extension Act Capacity Grant — University of Guam researchers have been monitoring and surveying the trees to better understand and stop bacterial attacks, planting new trees selectively bred to be resistant to the bacterium and, more recently, pinpointing how termites might spread the wilt bacterium. For more information, read the University of Guam article.