One of the 84 plant species endemic to Jeju Island, South Korea, is Salix blinii H. Lév. We surveyed its habitat to obtain quantitative information on the population demographics of S. blini, and thus to re-evaluate its conservation status and recommend in situ conservation strategies. We recorded 365 individuals in three valleys, above 1,200 m, on Mt Halla, of which 34 were flowering individuals capable of sexual reproduction. Although the population size is limited, the high proportion of small individuals suggests ongoing recruitment. Vegetative reproduction is presumed to play an important role, as it does for other Salix species that grow in valleys or along intermittent streams. Salix blinii is currently categorized as Vulnerable, based on criterion D2, on the IUCN Red List, but we reassess it as Vulnerable based on criteria D1+2 based on the number of mature individuals recorded. Although Mt Halla is designated as multiple large protected areas, small-scale protected areas within these larger areas need to be designated for more effective in situ conservation of S. blinii.
