Abstract

Background: We developed a habitat suitability index (HSI) model for Pedicularis hallaisanensis, a Grade II Endangered Species in South Korea. To determine the habitat variables, we conducted a literature review on P. hallaisanensis with a specific focus on the associated spatial factors, climate, topography, threats, and soil factors to derive five environmental factors that influence P. hallaisanensis habitats. The specific variables were defined based on the collected data and consultations with experts in the field, with the validity of each variable tested through field studies. Results: Mt. Seorak had a suitable habitat area of 2.48 km2 for sites with a score of 1 (0.62% of total area) and 0.01 km2 for sites with a score of 0.9. Mt. Bangtae had a suitable habitat area of 0.03 km2 for sites with a score of 1 (0.02% of total area) and 0 km2 for sites with a score of 0.9. Mt. Gaya showed 0.13 km2 of suitable habitat for sites with a score of 1 (0.17% of total area) and 0 km2 for sites with a score of 0.9. Lastly, Mt. Halla showed 3.12 km2 of suitable habitat related to sites with a score of 1 (2.04% of total area) and 4.08 km2 of sites with a score of 0.9 (2.66% of total area). Mt. Halla accounts for 73.1% of the total core habitat area. Considering the climatic, soil, and forest conditions together with standardized collection sites, our results indicate that Mt. Halla should be viewed as a core habitat of P. hallaisanensis. Conclusions: The findings in this study provide useful data for the identification of core habitat areas and potential alternative habitats to prevent the extinction of the endangered species, P. hallaisanensis. Furthermore, the developed HSI model allows for the prediction of suitable habitats based on the ecological niche of a given species to identify its unique distribution and causal factors.