A Comparison of Cover and Distribution of Corticolous Macro-Epiphytes in Three Woodlots in and North of Columbus, Ohio

Abstract

Three woodlots, one urban, one suburban, and one rural, were studied for cover and frequency of corticolous lichens and bryophytes. Epiphyte cover was measured by fitting aluminum foil over the epiphyte, cutting and weighing the foil. Lichens less than 1 cm in diameter were assumed circular and the diameter measured. Cover and presence were noted only within a cylindrical quadrat 1.3 to 1.6 m high. Trees were chosen by the random pairs method (10 pairs/site). The epiphytes found were the lichens Physcia millegrana, Physcia orbicularis, Parmelia rudecta, Parmelia caperata, and Lepraria sp. and the moss Leskea gracilescens. Only one species was found at the urban site, P. oribuclaris. P. orbicularis, P. millegrana, and L. gracilescens were found at the suburban site. All 6 species were found at the rural site. Percent cover and percent frequency increased from the urban, to suburban, to rural sites for all species except P. millegrana, which was greatest at the suburban site. The probable cause of these differences in cover and frequency of macro-epiphytes is the greater concentration of atmospheric pollution, probably sulfur dioxide, in and near the city.