Preserving Oaks and Oak Ecosystems Vulnerable to Climate Change

Victoria L. Sork, Ryan Buck, and Alexander Goetz

Published May 2026 in International Oaks No. 37: 165–174

Abstract

Oaks, like many tree species, are vulnerable to climate change in regions where temperature is predicted to rise quickly and droughts are becoming more common. Oaks experiencing rapid climate change are vulnerable because their long lifespan means selection may favor seedlings adapted to conditions that no longer exist, leaving their genotypes maladapted to future climates. Two types of studies that can detect the risk of maladaptation are common-garden experiments and landscape genomic studies. In this paper, we present evidence from a long-term provenance study of a California endemic oak, Quercus lobata (valley oak), showing that this species is maladapted to both current climate and predicted future climates. Using landscape genomic methods, we also present evidence that another California endemic oak, Q. douglasii (blue oak), found in similar regions as Q. lobata, will also be maladapted to future climates. For both species, we use simulations to demonstrate that deploying seed transfer of climate-adapted genotypes will improve the adaptedness of future stands much more effectively than using local or randomly collected acorns. We recommend that oak restoration projects of lands destroyed by previous tree removal or fire be replanted using climate-adapted genotypes so that these efforts will result in healthy tree populations that can tolerate warmer, drier conditions.

Keywords

Quercus, adaptedness, maladaptedness, local adaptation, conservation genetics, provenance study, common garden, landscape genomics

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