• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.114-126
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• 2013

The purpose of this study was to develop a Korean thermality index (KTI) based on the distribution patterns of benthic macroinvertebrates according to altitude and latitude. Analyzing seasonal data (4,853 sampling units) surveyed and collected during 2007 ~ 2011 at 846 sites in South Korea, we estimated thermal valency, thermal value and indicator weight value of 208 species. Among them, 40 species in 6 orders (Decapoda 1 species, Collembola 1 species, Ephemeroptera 5 species, Plecoptera 17 species, Diptera 3 species, Trichoptera 13 species) were selected as the candidate indicator species sensitive and vulnerable to warmth along with climate change. KTI and Benthic macroinvertebrate index (BMI) were tested at three clean streams (Hangye stream, Buk stream and Bangtae stream). KTI showed significant differences according to altitude and water temperature whereas the saprobity index BMI showed little differences. This result means that KTI can be applicable to assess the impact of water temperature independently of organic pollutants.

• Journal of Korean Society on Water Environment
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• v.39 no.4
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• pp.302-315
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• 2023

Distribution characteristics and altitudinal gradient of four species (E. strigata, E. separigata, E. orientalis-sachalinensis group) of the mayfly genus Ephemera (Order Ephemeroptera) were analyzed with probability distribution models (exponential, normal, lognormal, logistic, Weibull, gamma, beta, Gumbel). Data was collected from 23,846 sampling units of 6,787 sites in Korea from 2010 to 2021. The beta distribution model showed the best fit for positively skewed E. orientalis-sachalinensis and little-skewed E. strigata along with altitudinal gradient. The reversed lognormal distribution model showed the best-fit for negatively skewed E. separigata. E. orientalis-sachalinensis distributed at the range of altitude 1~700 m (mean 251 m, median 226 m, mode 124 m, and standard deviation 161 m), E. strigata distributed at the range of altitude 5~871 m (mean 474 m, median 478 m, mode 492 m, and standard deviation 200 m), E. separigata distributed at the range of altitude 7~846 m (mean 620 m, median 659 m, mode 760 m, and standard deviation 181 m). Altitudinal habitat suitability ranges were estimated to be 42~257 m for E. orientalis-sachalinensis, 335~644 m for E. strigata, and 641~824 m for E. separigata. Based on the altitudinal spectrum of suitability and altitude-related temperature analysis results, E. orientalis-sachalinensis was estimated to be thermophilic, E. strigata to be mesophilic, and E. separigata to be thermophobic. This is the first national-scale evaluation of the altitudinal distribution of Ephemera in Korea. These results will be used in a further research study on altitudinal shift of the species of Ephemera under climate change.