In response to climate change, plants must either rapidly adapt to new conditions, acclimate, move, or face the threat of extirpation. Predictions of plant response to climate change generally do not include information on genomic variation, which likely plays a key role in regulating responses to new environmental conditions. In this study, we focus on the California endemic Valley oak (Quercus lobata), which is a keystone species of high ecological and cultural value. We integrate data from two long-term common garden experiments involving > 6,000 trees from 95 populations of Valley oak with genomic data across 10,000 single nucleotide polymorphisms (SNPs) to predict how Valley oak populations will respond under future climate change scenarios. We estimate climate transfer functions (i.e., predicted plant response to a change in climate), how climate transfer functions interact with genomic variation, and generate spatially-explicit predictions of Valley oak responses to increased temperature and drought across the Valley oak range in California predicted under climate change.
Results/Conclusions
Our preliminary results indicate a predicted reduction in growth rates of Valley oak across its range with predicted increases in maximum temperature of the hottest month and climatic water deficit, a metric of drought stress, under medium and extreme climate change scenarios. Importantly the predicted magnitude of these declines in growth rates vary across Valley oak populations and by genetic composition, indicating important within-species variation in response to climate that can be used to guide conservation actions. We identify Valley oak populations and SNPs that may confer resilience to future climate scenarios. In conclusion, we show that climate change is likely to have a negative effect on Valley oak growth and survival if no management or conservation actions are implemented. However, the predicted reductions in growth may be mitigated by selecting provenances or genotypes locally adapted to predicted future climate scenarios in management, reforestation, or restoration projects.