Analyses of tree rings of large, canopy loblolly pines (Pinus taeda L.,) growing near a drainage ditch in the Great Dismal Swamp have indicated that the tree rings are datable and hydrologically (climatically) sensitive. Climatic and prior growth factors in regression explained 87 and 71 percent of the variance of the preditching and postditching earlywood widths, respectively, and 82 and 7O percent of the latewood widths for the same time periods. Early summer precipitation was significantly, and positively, correlated with preditching latewood growth. When pre and postditching records were merged into a single record, regression analysis explained less growth variation than when the two time periods were considered individually, implying a change in growth response following ditching. Prior to ditching, growth was most limited by dry summers which followed dry summers. After ditching, growth was less strongly linked with precipitation and more strongly linked with temperature. Regression results are compatible with the contention that growing season water levels in the proximity of the collection site have been lower since ditching.
