In the present study, the community distribution, functional feeding groups, and habitat groups of the benthic macroinvertebrates from Gayasan National Park were investigated at eight different sites from 2015 to 2016. The correlation between habitat altitude and each group type was analyzed statistically. Biodiversity indices, including dominance, diversity, richness, and evenness indices, were calculated. The results showed a total of 4,216 individual benthic macroinvertebrates were collected, including 4 phyla, 6 classes, 16 orders, 40 families, and 100 species. Gammarus sobaegensis was dominant with 0.141% dominance, and the subdominant species was Epeorus nipponicus with 0.088% dominance. The EPT group(Ephemeroptera, Plecoptera and Tricoptera) accounted for 71.00% of the total species and 67.69% of the total individuals. The number of scraper species was highest, and the number of gathering collector individuals was highest among functional feeding groups. The individual number of scrapers(r=-0.358, p ˂ 0.05) and gathering collectors(r=-0.343, p ˂ 0.05) decreased with increasing altitude. The numbers of species and individuals of clingers and sprawlers were highest among the habitat groups. The individual number of clingers(r=-0.547, p ˂ 0.01) and burrowers(r=-0.331, p ˂ 0.05) significantly decreased with increasing altitude. The diversity and richness indices were higher in St. 3 than in the other sites. The dominance index was highest in St. 2, and the evenness index was highest in St. 7. We evaluated the biological water quality with several known methods, and concluded that ESB(Ecological score of benthic macrovertebrates community) and GPI(Group polution index) were more suitable than KSI(Korean saprobic index) and BMI (Benthic macrovertebrate index) to assess the biological water quality of Gayasan mountain stream water.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 조사지점 및 개황
  2.2. 조사방법 및 생물분류
  2.3. 생물지수의 산출과 통계분석
  2.4. 생물학적 수질 평가
 3. 결 과
  3.1. 저서성 대형무척추동물의 서식현황
  3.2. 생물지수
  3.3. 생물학적 수질평가
  3.4. 섭식기능군과 서식습성군의 분포현황
  3.5. 고도에 따른 저서성 대형무척추동물의 분포
 4. 고 찰
 5. 결 론
 REFERENCES

• 문태영(대성기술단) | Tae Young Moon (Daesung Technology Engineering Company)
• 안미순(국립수산과학원) | Mi Soon An (National Institute of Fisheries Science)
• 김형곤(국립수산과학원) | Hyoung Gon Kim (National Institute of Fisheries Science)
• 윤춘식(창원대학교 생물학.화학 융합학부) | Chun Sik Yoon (Department of Biology & Chemistry, Changwon National University)
• 정선우(창원대학교 생물학.화학 융합학부) | Seon Woo Cheong (Department of Biology & Chemistry, Changwon National University) Corresponding author