OZONE EXPOSURES NEAR CLASS-I WILDERNESS AREAS IN NEW-HAMPSHIRE AND VERMONT

Ozone (O-3) is known to cause characteristic injury symptoms on a wide variety of plant species. In response to concern by Federal land mana gers, a comprehensive program was initiated in 1988 to assess the effe cts of O-3 on vegetation in two Class I Wilderness areas in northcentr al New Hampshire and one Class I Wilderness area in southern Vermont. To better quantify the possible risk associated with O-3 exposures aff ecting vegetation in these Wilderness areas, hourly average O-3 concen tration data were characterized, using biologically based exposure ind icators for a site located at Mt. Equinox, Vermont (549 m) and a site al Mt. Washington, New Hampshire (457 m). Mt. Equinox experienced more of a flat diurnal pattern than the Mt. Washington site. The higher am plitude for the Mt, Equinox diurnal patterns in comparison to the Mt. Washington site was indicative of the occurrence of higher hourly aver age concentrations, as well as the infrequent occurrence of hourly ave rage concentrations below 20 ppb. The Mt. Equinox site experienced mor e occurrences of hourly average concentrations greater than or equal t o 80 and 100 ppb than the Mt. Washington site. Similarly, the SUM60 an d W126 integrated exposure values for Mt. Equinox were greater than th e values experienced at Mt. Washington. The lower-elevation Mt. Washin gton site experienced a greater percentage of its O-3 exposure during the daylight hours (0700-1859h) than the Mt. Equinox site.