Phenotypic variation in California populations of valley oak (Quercus lobata Née) sampled along elevational gradients

Abstract

California oaks exhibit tremendous phenotypic variation throughout their range. This variation reflects phenotypic plasticity in tree response to local environmental conditions as well as genetic differences underlying those phenotypes. In this study, we analyze phenotypic variation in leaf traits for valley oak adults sampled along three elevational transects and in young seedlings grown from their acorns in greenhouse conditions. This project represents the early phase of a long-term provenance study of valley oak (see Delfino Mix and others, Establishing a range-wide provenance test in valley oak (Quercus lobata Née) at two California sites, these proceedings) where we subsample the maternal families sampled along elevation gradients to assess the extent to which selection may be shaping geographical variation in leaf phenotypes of valley oak. We find that leaf thickness is the trait that shows correlations in adult populations in the field and significant variation in the greenhouse. For this trait, we also found significant differentiation across maternal families, providing preliminary evidence that this trait experiences differential selection across natural populations with different environments. This study, part of a large-scale provenance/genomic study of the genetic basis of phenotypic variation, provides an early analysis of leaf traits that may play an important role in local adaptation to climate environments and provide background for management and restoration of California oak forests.

Parent Publication

• Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world

Citation

Albarrán-Lara, Ana L.; Wright, Jessica W.; Gugger, Paul F.; Delfino-Mix, Annette; Peñaloza-Ramírez, Juan Manuel; Sork, Victoria L. 2015. Phenotypic variation in California populations of valley oak (Quercus lobata Née) sampled along elevational gradients. In: Standiford, Richard B.; Purcell, Kathryn L., tech. cords. Proceedings of the seventh California oak symposium: managing oak woodlands in a dynamic world. Gen. Tech. Rep. PSW-GTR-251. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 433-445.