Temporal Patterns of Ozone Pollution in West Virginia: Implications for High-Elevation Hardwood Forests

Abstract

Hourly ozone (O₃) data from one rural and four urban sites throughout West Virginia were analyzed for a three-year period (1987-1989) focusing on seasonal and diurnal patterns of O₃ concentrations. Based on maximum hourly O₃ concentrations (highest 1-hr maximum value per month), there were definite seasonal patterns with highest values from May to August and lowest values from December to February for all years and sites. High O₃ exposures (defined in this study as concentrations ≥0.080 ppm) for the study period were greater in Greenbrier County (a distinctly rural region) and Wood County (an industrialized area). Of these two sites, O₃ concentrations remained high with little diurnal variation in June and July (1988) in the rural area; in contrast, there was large diurnal fluctuation in the urban area. Considering the high O₃ concentrations found at our rural site, the seasonal coincidence of high O₃ with the growing season, and a low diurnal fluctuation of high summer O₃ concentrations at the rural high-elevation site, tropospheric O₃ pollution could represent a distinct threat to the high-elevation hardwood forests of West Virginia. Ozone concentrations presented in this study are well within the range of values which were found by studies in the literature to be damaging to physiological processes and growth parameters in trees.