by HR McCarthy, DE Pataki, GD Jenerette
Ecological Applications 21(8):3115-31272011
In arid or semi-arid regions, the benefits that trees provide must be considered in light of the amount of water they require. This study aimed to provide a method for determining which urban tree species offered the best trade-off in terms of water use and growth. The leaf-level gas exchange, sap flux density, leaf 13C, and stem growth measurements of eight common, non-native species of the LA Basin were studied to determine the water-use efficiency (WUE). There was considerable variation in annual whole-tree WUE (a factor of ~200), indicating that this characteristic may be valuable in optimizing species choices. The species with the highest WUE did not necessarily have the lowest growth rates; they did tend to originate from regions with a high water-vapor deficit.