Flora characteristics of vascular plants in the Geomun Oreum, UNESCO World Natural Heritage Site in Jeju Island, Korea

A study on the flora of Geomun Oreum, designated as a UNESCO World Natural Heritage Site, was surveyed in 2019. Vascular plants in this area revealed 310 taxa belonging to 90 families, 210 genera, 279 species, one subspecies, 27 varieties, and three formas. The Geomun Oreum showed low mean annual temperature, but it was confirmed that the emergence of warm-temperate plant species and evergreen broad-leaved forests was prominent. These results were interpreted to be due to a great deal of precipitation, many frost-free days, and the difference between the highest and lowest temperatures depending on the geographical characteristics of Geomun Oreum. Geomun Oreum is evaluated as a relatively natural habitat given the limited access of visitors and management, but it was confirmed that Sedum tosaense, a critically endangered species of the rare plants designated by the International Union for Conservation of Nature, requires conservation plans in the area.