Distributional Characters of Warm-Temperate Evergreen Broadleaf Tree Species Growing in Urban Park -Focused on Duryu Urban Park in Daegu

摘要

Present study aims to find out how evergreen tree species planted in urban parks spread to nearby wild areas. We accomplished field investigation at the Duryu Park area, Daegu, where located a transitional zone between the warm-temperate and the cool-temperate zones. From 2018 to 2019, a total of 32 floristic-sociological releves were made. Distribution patterns of tree species connected into habitat conditions were explored by canonical correspondence analysis (CCA). 10 tree species dispersed spontaneously in the study area were recognized; Nandina domestica, Euonymus fortunei, E. japonicus, Quercus acuta, Q. glauca, Q. phillyraeoides, Elaeagnus pungens, Ligustrum japonicum, Osmanthus heterophyllus, and Ilex cornuta. Most of these trees were the preferentially ornamental plants introduced in the park since 1977 and mainly bird dispersal seeds. Q. glauca and L. japonicum appeared the most predominant dispersion. Their micro-habitats are the much humid and warmer stands of the deciduous broad-leaved forests mainly. We concluded that urban gardening has been also an important agent to recover the native vegetation if introducing potential natural vegetation (PNV). The habitat-based PNV in the Daegu area arose as a critical issue for further understanding.