Vegetation Structure and Site Environment of Natural Habitat of an Endangered Plant, Viola websterl

摘要

This study was performed to obtain basic data about vegetation structure and site environment of rare and endangered plant, viola websteri in five natural habitats. The dominant species of Hongcheon habitat were Pyrus pyrifolia (tree layer), Morus bombycis (subtree layer), Pyrus pyrifolia (shrub layer) and Isodon inflexus (herb layer). Mt. Yeonin habitat were dominated by Quercus mongolica (tree layer), Morus bombycis (subtree layer), Philadelphus schrenckii (shrub layer) and Viola websteri (herb layer). Mt. Yumyung habitat were dominated by Cornus controversa (tree layer), Morus bombycis (subtree layer), Fraxinus rhynchophylla (shrub layer) and Adenocaulon himalaicum (herb layer). Mt. Daebu habitat were dominated by Acer mono (tree layer), Staphylea bumalda (subtree layer), Staphylea bumalda(shrub layer) and Dryopteris crassirhizoma (herb layer). And the dominant species of Mt. Worak habitat were Larix leptolepis (tree layer), Fraxinus rhynchophylla (subtree layer), Alangium platanifolium var. macrophylum (shrub layer) and Adenocaulon himalaicum (herb layer). It was found out that the average acidity of soil pH was 5.23; 0.30ds/m for electron conductivity; 12.6% for organic matter content; 0.68% for total nitrogen; 21.66 ppm for available phosphorous; and 23.45 cmol(+)/ kg for CEC. Interchangeable cation was decreased in order of Ca~(2+)> Mg~(2+)> K~+. Viola websteri had positive association with Polygonatum odoratum var. pluriflorum and Geranium thunbergii but negative association with Poa sphondylodes. Species diversity index (H'), maximum Species diversity index (H' max), evenness (J') and dominance (1-J'), of investigated sites ranged 0.6816 (Mt. Worak) approx 0.9656 (Mt. Daebu), 1.0000 (Mt. Yeonin) approx l.3010 (Hongcheon, Gangwon), 0.5330 (Mt. Worak) approx 0.8947 (Mt. Daebu) and 0.1053 (Mt. Daebu) approx 0.4670 (Mt. Worak) in woody layer and 1.0414 (Mt. Yumyung) approx 1.3295 (Mt. Worak), 1.4314 (Mt. Yumyung) approx 1.6435 (Mt. Daebu), 0.6984 (Hongcheon, Gangwon) 0.8356 (Mt. Worak) and0.1644 (Mt. Worak) approx 0.3016 (Hongcheon, Gangwon) in herb layer, respectively.