DEPARTMENTS


Drought takes toll on Texas trees



Recent news from the Texas Forest Service is disturbing: The agency estimates that last year's brutal drought cost the state 5.6 million urban trees, representing as much as 10 percent of the total number that compose the urban canopy. Cost to remove the trees is estimated at $560 million. Moreover, the foresters claim that the estimated loss of economic and environmental benefits - something too few people take into account - to be $280 million per year. That accounts for benefits like energy savings (reduction in heating and cooling costs) realized from trees' protective cover, plus urban trees' ability to improve air and water quality. Then there's the increase in property value.


Ips engraver beetles have decimated stands of loblolly pine in Texas, where last year's brutal drought compromised the trees' ability to fight off infestation.
Ronald F. Billings, Texas Forest Service; Bugwood.org

That may be just the beginning, however. Urban foresters with the Texas Forest Service conducted a statewide survey using satellite imagery. Comparing images taken before and after the drought, foresters counted live and dead trees on both public and private land to arrive at the current figure. Lead researcher Pete Smith warns that the count is likely to increase as the effects continue to emerge. "This estimate is preliminary because trees are continuing to die from the drought," he explained. "This means we may be significantly undercounting the number of trees that ultimately will succumb to the drought. That number may not be known until the end of 2012, if ever."


Urban trees in Texas succumbed to damage caused by ips engraver beetles, which attack trees weakened by drought.
Courtesy of Ronald F. Billings, Texas Forest Service; Bugwood.org

Last last year, the agency estimated that as many as 500 million trees statewide may have succumbed to the effects of extreme drought. According to the U.S. Drought Monitor, the moisture some parts of Texas received in February had a remedial effect on some areas experiencing short-term drought impacts, particularly in the eastern part of the state. "Longer-term hydrological remnants" are still there, however, centered primarily in western counties and the Panhandle. Considering the fact that trees may display a delayed response to drought conditions, it looks like the toll will continue to rise.


Much of the Southwest is expected to experience persistent or intensifying drought for the next three months, as indicated by the brown areas on this map. Cross-hatched regions will experience continuing drought, with the possibility of some improvement. (Click to enlarge)
Courtesy of National Weather Service Climate Prediction Center