Ecological comparison of Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) community between Mt. Nam and Mt. Jeombong as a Long Term Ecological Research (LTER) site

Species composition, frequency distribution of diameter classes, species diversity, and stem vitality of woody plantswere analyzed in a Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) forests in permanent quadrates of Mt. Namand Mt. Jeombong, which were installed for Long Term Ecological Research (LTER). The principal objective of this studywas to clarify the ecological characteristics of both sites by comparing the Mongolian oak communities established inMt. Nam surrounded by urban area and in Mt. Jeombong as a natural area, to accumulate the basic data for long-termmonitoring, and furthermore to predict possible changes in vegetation due to climate change. The species compositionof the Mongolian oak community on Mt. Nam differed from that of Mt. Jeombong. Such differences were usuallydue to Sorbus alnifolia, Styrax japonicus, Oplismenus undulatifolius, Ageratina altissima and so on, which appeared inhigher coverage in Mt. Nam. Species diversity of the Mongolian oak community in Mt. Nam was lower than that in Mt.Jeombong. This result was attributed to the fact that the Mongolian oak community in Mt. Nam is under continuousmanagement and was dominated excessively by S. alnifolia, and S. japonicus, which were originated from artificial interferenceand chronic air pollution. As the results of analyses on the frequency distribution of diameter classes of majortree species and the transitional probability model based on Markov chain theory, the Mongolian oak community inMt. Nam showed a possibility of being replaced by a S. alnifolia. Considering that this replacement species is not only asub-tree but is also shade-intolerant, such a successional trend could be interpreted as a sort of retrogressive succession.The Mongolian oak community established in Mt. Jeombong differed from the community in Mt. Nam in terms of itsprobability of being continuously maintained.