State tree may be doomed

RENO -- A new study by researchers at the University of Arizona suggests that a combination of global warming and drought could prove exceptionally deadly to pinion pine, Nevada's state tree.

Scientists at the school's Biosphere 2 research station found that pinions could die five times faster during droughts of common duration if the climate warms by 7 degrees.

Half the pinions studied were kept in normal temperatures, the others in an environment 7 degrees warmer. Some trees in each group were then deprived of water to simulate droughts common in the past.

Trees subjected to higher temperatures died far faster than the other trees, suggesting that even short droughts can produce widespread tree mortality in a warmer climate.

"What this highlights is that together, drought and temperature can kind of provide a double whammy," researcher David Breshears told the Reno Gazette-Journal.

The study focused on double-needle pinions common in the Southwest, not the single-needle pinion that is Nevada's state tree. But the results, scientists said, probably would apply to many species of pinions.