Spatial and Temporal Patterns of Post Oak’s (Quercus stellata) Radial Growth-Climate Relationship

Abstract

Understanding how tree species will respond to climate change gives insights into future forest composition. Post oak (Quercus stellata) is abundant and dominant throughout the southeastern United States. This study examines the spatial and temporal patterns of the relationship between post oak’s radial growth rates, mean monthly temperature, and monthly precipitation to assess the effect of climate on radial tree growth. Using correlation analysis and moving interval analysis, we tested the relationship between tree-ring chronologies and climate data from nearby weather stations. Maps of significant correlations identify the geographic patterns of post oak’s sensitivity to climate, and moving interval correlation analysis evaluated temporal trends in the relationships. Radial growth was negatively correlated with June and July temperature, particularly along its northwestern geographic range limit. Radial growth was positively correlated with early summer precipitation in the western portion of its range. In the extreme northwest of its range, after 1950, temperature sensitivity disappears or shifts to earlier in the year. Given these responses, predicted future climate conditions suggest that post oak may experience reduced growth rates due to the combined effects of increased summer temperature and drier conditions.