Water use efficiency before and after fire suppression and fuels treatments in fire-prone pine forests in the western US
Fuel treatments decreased intrinsic water use efficiency relative to the control in Arizona although the differences were not sufficiently large to reach the threshold of statistical significance. Very dry conditions characterized post-treatment climate in Arizona and treatment decreased competition among trees for water. Decreased competition appears to have led to higher stomatal conductance in surviving trees and thus lower intrinsic water use efficiency, even with post-treatment growth increases as measured by basal area index. The treatment response supports our hypothesis of the expected treatment response.