Flora and Vegetation Characteristics of the Natural Habitat of the Endangered Plant <i>Pterygopleurum neurophyllum</i>

This study analyzed the flora, life form, and vegetation of the Nakdong River wetland. Vegetation analysis was performed on 37 plots using the phytosociological method of the Zürich-Montpellier School. PCA analysis was conducted by using the vegetation data (ground cover of class; 1~9) of 37 plots surveyed by phytosociological method. PCA (Principal Component Analysis) was used to statistically analyze the objectivity of the community classification and the character species. The traditional classification and mathematical statistic methods were used. A total of 82 taxa belonging to 28 families, 65 genera, 72 species, 2 subspecies, and 8 varieties were present in the vegetation of the survey area. The life form was analyzed to be the Th-R₅-D₄-e type. The communities were classified into seven communities: <i>Miscanthus sacchariflorus</i> community, <i>Phragmites communis</i> community, <i>Phragmites communis–Carex dispalata</i> community, <i>Ulmus parvifolia</i> community, <i>Zizania latifolia</i> community, <i>Setaria viridis</i> community, and <i>Salix koriyanagi–Salix chaenomeloides</i> community. As a result of PCA analysis, it was classified into seven communities. Seven communities were analyzed, where the most dominant species (<i>M. sacchariflorus</i>, <i>P. communis</i>, <i>C. dispalata</i>, <i>U. parvifolia</i>, <i>Z. latifolia</i>, <i>S. viridis</i>, <i>S. koriyanagi</i>, <i>S. chaenomeloides</i>) of each community were examined as character species. Another species is analyzed as <i>Salix koreensis</i>. Of the sixteen <i>M. sacchariflorus</i> communities, <i>Pterygopleurum neurophyllum</i> was present in six plots (A-2 group) but not in ten plots (A-1 group). These two groups showed differences in coverage and the number of occurring species. As for the relative net contribution degree (r-NCD) in the A-2 group, most species showed low r-NCD except for <i>M. sacchariflorus</i>, which showed an r-NCD of 100. The r-NCDs in the A-1 group were as follows: <i>Miscanthus sacchariflorus</i> (100), <i>P. neurophyllum</i> (21.74), and <i>Persicaria perfoliata</i> (10.14). Therefore, <i>P. neurophyllum</i> is difficult to grow in the A-1 group. As a result, it is thought that the high density of <i>M. sacchariflorus</i> affects the growth and distribution of <i>P. neurophyllum.</i> In order to expand and maintain <i>P. neurophyllum,</i> the habitat environment needs to be altered by adjusting the density of <i>M. sacchariflorus.</i>