Spatial Distribution of Benthic Macroinvertebrate Assemblages in Odaesan National Park, South Korea

Freshwater ecosystems are among the most threatened ecosystems on Earth and suffer from extensive human exploitation and climate change. Conservation and enhancement of freshwater biodiversity have recently become indispensable for securing ecosystem integrity and sustainability. This study aimed to confirm the biological diversity and distribution characteristics of benthic macroinvertebrates in Odaesan National Park. A total of 133 taxa belonging to 66 families, 18 orders, seven classes, and five phyla were identified during the survey period. Taxa richness ranged from 28 to 63 years with an average of 39.7 taxa. The taxa richness and abundance of Ephemeroptera, Plecoptera, and Trichoptera accounted for 60.3% and 86.0% of the total taxa, respectively. Seven endemic species had restricted spatial distributions and high conservation values. Cluster analysis classified 18 study sites into three major clusters: streams with high heterogeneity in streambeds and high taxa richness, streams located in Gaejanigol (a tributary of the Odae Stream), and three Ramsar wetlands. Indicator species analysis selected 16 important indicators, with the highest indicator value of Pisidium coreanum at 100%. Our results provide useful information on the biodiversity and habitats of benthic macroinvertebrates in the Odaesan National Park, consequently helping to establish conservation and management plans for biological resources.