A Study on the Benthic Macroinvertebrates in the Middle Reaches of Paenae Stream , a Tributary of the Naktong River , Korea 2 . Comparison of Communities and Environments at the Upper and Lower Sites of Levees

배내천 中流의 底棲性 大形無脊椎動物에 대한 硏究

Benthic macroinvertebrate communities and environments at the upper and lower sites of levees in the middle reaches of paenae stream, a tributary of the naktong river,were investigated in four seasons from August 1989 to may 1990. Current velocities were significantly fast at the loer sites than the upper sites of levees. Substratum compositions were also different between these two sites. Abundances of major species of benthic macroinvertebrates occurring in four seasons were primarily dtermined by temperature. in each location of levees, however, current velocities and substratum particle sizrs were important in determining species were generally higher than upper sites of levees. Biological indices were also high at the lower sites of levees. diversity, evenness and dominance indices were positively correlated with the quantity of the middle-sized large pebbles(3∼5cm in diameter) in stream bed.