9520679 The blue oak is a keystone species in a water limiting environment, and over much of its range in California, this tree is not regenerating. This research is aimed at understanding the role that water relations play in determining the success of this tree. The research will compare vulnerability to drought-induced cavitation in oaks of different ages. It will determine the amount of genetic variation that exists in this trait, by comparing responses of seedlings produced by different parent trees. Finally, it will ascertain the importance of phenotypic plasticity in modifying response to different levels of moisture stress. The research will increase understanding of the mechanisms and variability of response to drought induced cavitation in woody plants. Understanding of the phenotypic expression of water-use traits, and knowledge of variation on temporal and spatial scales should be of considerable value in developing management plans for the conservation of an ecologically important species.
