Dendroclimatological Analysis of Oak Species in the Southern Appalachian Mountains

White, Philip

Bachelor's Honors Thesis ABSTRACT: A dendroclimatological study was performed on oak species from three sites in the southern Appalachian Mountains. Tree-ring chronologies were developed for Griffith Knob and Little Walker Mountain in the Jefferson National Forest, Virginia, and for Gold Mine Trail in the Great Smoky Mountains National Park, Tennessee. The longest of these chronologies extended from 1836 to 2005, and the oldest tree sampled had a minimum age of 170 years. We statistically compared the three chronologies with monthly precipitation, temperature, PDSI, and PHDI data from local NCDC climatic divisions for the years 1930 to 2005. Oak tree growth correlated significantly and positively (highest r = 0.50, p < 0.0001) with precipitation for each site during one or more summer months (May–July). Temperature correlated significantly and negatively (lowest r = –0.36, p < 0.002) at each site during the same period. PDSI and PHDI each correlated positively and significantly (highest r = 0.57, p < 0.0001) with growth throughout the growing season, with correlations extending into the previous fall at lower elevation sites. Macroclimate factors were similar at each site, yet microclimate differences influenced the duration of the climate signal. The results of this study suggest that oak species in southern Appalachia require a cool, moist summer for maximum growth to occur, while fall moisture availability is important for oaks in a warmer and drier climate. These climatic analyses yield valuable information for the feasibility of climate reconstruction from forest interior trees and the assessment of oak forest health.