Threats to Oaks in the Eastern United States: Perceptions and Expectations of Experts

Oaks (Quercus spp.) are keystone species in many ecosystems and are ecologically as well as economically valuable. The objective of this study was to gather and evaluate information from a diverse group of oak experts on current and future biotic and abiotic threats to oaks in the eastern United States. Using a Delphi survey method with three iterative surveys, we found that oak decline and climate change were identified as critical current and future threats, respectively, in this region. Focusing on climate change, experts were asked a series of questions to assess its potential future temporal and spatial impact on oaks. With respect to climate change, the majority of experts surveyed believe climate change will manifest gradually, although they were generally uncertain about the geographical distribution of climate change in the future, i.e., the areas where oaks are likely to be impacted by climate change in the future. New/emerging pests and pathogens were seen as the most critical future threat by the third survey round. Results from this study can be used to better inform management practices and research priorities for ensuring resilient oak resources for the future.