| Title |
Assessing Climate Change Vulnerability of Three Hydropsyche Species Using Probability-Based Habitat Suitability and Random Forest Models |
| Authors |
최형식(Choi Hyeongsik) ; 정찬영(Jeong Chanyoung) ; 강보미(Kang Bomi) ; 강성룡(Kang Sung-Ryong) ; 공동수(Kong Dongsoo) |
| DOI |
https://doi.org/10.15681/KSWE.2025.41.6.484 |
| Keywords |
Altitude gradient; Hydropsyche; Random forest; RCP 8.5 scenario; Species distribution modeling |
| Abstract |
Climate change significantly affects freshwater ecosystems by raising air and water temperatures, which in turn influences the physiology and distribution of aquatic organisms. This study evaluated the current and future habitat suitability for three species of Hydropsyche (H. kozhantschikovi, H. valvata, H. formosana) in South Korea, using these species as bioindicators of river health. We estimated equilibrium water temperature through a regression model that accounted for latitude, altitude, and coastal distance, allowing for spatial predictions at a 90-meter resolution. Species occurrence data were categorized into temperature intervals to create probability mass functions, which were fitted using four distribution models. The best model was selected based on normalized root mean square error. We developed habitat suitability index (HSI) curves from these models, and Random Forest classifiers, using elevation and temperature as predictors, achieved high accuracy (ROC?AUC > 0.80). Future distributions were projected under RCP 8.5, which assumes a 2.45 °C increase in water temperature by 2100. The species responded differently: H. kozhantschikovi displayed broad thermal tolerance with moderate habitat loss, H. valvata had narrow tolerance and experienced significant range contraction, while H. formosana showed an extremely limited distribution with slight thermal niche expansion. These findings underscore the species-specific vulnerabilities to warming and emphasize the need to conserve climate refugia in mid- and high-altitude streams. |