Global Warming Could Kill Drought-Stressed Trees Fast

Washington, DC (April 13, 2009)- The journal Proceedings of the National Academy of Sciences published a study which found that droughts during warmer weather kill the pinon pine, a tree found in southwestern United States, 28 percent faster than it killed the trees at cooler temperatures. In addition to a controlled test, the researchers from the University of Arizona’s Biosphere 2 used a 100-year historical drought record to suggest that future widespread die-off of pinon pine during droughts will occur at least five times faster if the climate warms by 4 degree Celsius over the century.

Lead author Dr. Henry Adams said, “It’s the kind of data that you don’t have to do statistics on, because the numbers don’t overlap. The results say that if the climate is warmer, then it takes a shorter drought to kill the trees. And there are many more shorter droughts than longer droughts in the historical record.”
The study was the first to isolate the impact of just temperature on the survival of trees during drought. The lack of including other potential climate change effects such as worsening drought and insect attack, make this study’s projections fairly conservative. “We don’t want to be overly alarmist, but we don’t want to underplay the results…. This is only one tree species, but it’s the first we’ve documented. It could be the pinon pine is the canary in the coal mine,” said co-author Dr. David D. Breshears.
Related Resources:
Science Daily- Global Warming: Heat Could Kill Drought-stressed Trees Fast
Arizona Republic- Pinon pines in danger, Biosphere study shows
Tucson Citizen- UA: Drought-stricken pines may die five times faster as temps rise