Victoria L. Sork
Distinguished Professor, Department of Ecology & Evolutionary Biology
Director, UCLA Mathias Botanical Garden and Herbarium
University of California, Los Angeles
Title: 21st Century common garden study of oaks demonstrate evolutionary and conservation applications
Abstract:
Provenance studies and common gardens are valuable tools for evolutionary biologisits, foresters, and restoration biologists to document the extent to which individuals distributed across a species’ range are genetically differentiated due to local adaptation. In California, predicted warmer temperatures and reduced precipitation combined with increased fire frequency create urgency to develop strategies for restoration and conservation of tree populations. The overarching goal of this talk is to use the findings of a long-term provenance study of valley oak (Quercus lobata), a foundational and iconic oak of California ecosystems, to demonstrate how climate-associated traits and current levels of maladaptation can inform restoration practices.Using 5- and 12-year-old progeny from range-wide distribution of 600+families, we modeled growth rates and performance measures (height * survival) and found that the relative fitness of these individuals is greatest at temperatures much cooler than where they are growing. In other words, current populations are maladapted to current climate environments. We utilize this information to test three seed source strategies for planting oaks: local seed sources, seed sources from matching climates, and empirically derived climate-adapted seed sources. In one study, the use of genomic information associated with growth in warmer climates reveals that climate-adapted seed sources will produce better growing trees under predicted warmer climates. In a second study, the use of climate-adapted phenotypes based on the provenance study findings will produce better growing genotypes. The study provides compelling evidence of the value of long-term common garden experiments to address 21st C. problems.