TWO-DIMENSIONAL HABITAT MODELING USING HABITAT SUITABILITY INDEX FOR TWO COREOPERCA SPECIES

초록

Coreoperca kawamebari and C. herzi are distributed in South Korea and the two species were known to be allopatric, but a recent study has reported that the two species are sympatric in the Boseong River. Habitat suitability index (HSI) of the two species at a coexistence reach of the river was developed and two-dimensional hydraulic modeling (River2D) and physical habitat simulation (PHABSIM) were applied to predict and evaluate their distribution. The important environmental variables for C. kawamebari were water velocity, substrate and vegetation cover: habitats of C. kawamebari were pool areas covered with fine substrate and emergent vegetation. In contrast, substrate size was a critical factor for C. herzi: its habitats were covered by large substrate size with a wide range of water velocity. The result of River2D with physical habitat simulation was matching with field measurement data: habitat suitability index for the two species effectively explained the distribution of both species. Thus, PHABSIM results at the coexisting reach suggested that the two species occupied separate areas with different environments, which enabled them to coexist.