As a result of the Four-River Restoration Project in Korea, the habitat of endangered plant species of Aster altaicus
var. uchiyamae and Polygonatum stenophyllum, which had been natively grown in the riparian zone of Namhan
River, was destroyed and artificial replacement habitats were created. In this study, Habitat Suitability Index (HSI)
was used to determine whether the replacement habitats are suitable for each species or not. From October 2015 to
July 2016, Habitat Evaluate Procedures (HEP) were conducted on two replacement habitats of A. altaicus var.
uchiyamae (Gangcheonsum and Sum-River) and on two replacement habitats of P. stenophyllum (Gangcheonsum
and Youngjuk) in the Namhan River watershed. As evaluation parameters for A. altaicus var. uchiyamae habitat,
habitat matrix (ratio of unburied gravel), height above the ordinary water level, soil nutrients, and light conditions
were selected and for P. stenophyllum habitat, soil texture, light conditions, and coverage of companion species were
selected. HSI was applied to evaluate the suitability of each replacement habitat. According to the result of the
evaluation, replacement habitats of A. altaicus var. uchiyamae and P. stenophyllum located in Gangcheonsum have
relatively high HSI values as 0.839 and 0.846, respectively. On the other hand, replacement habitats of A. altaicus var. uchiyamae in Sum-River and P. stenophyllum in Youngjuk zone have HSI value of 0, indicating unsuitable habitats
for these species. This is the first attempt to apply HSI for plant species in Korea and proved the usefulness of HSI on
plants.