산지하천에서 빛가 초식에 의한 부착조류의 생체량변화 = Effect of Light and Grazing on Periphyton Biomass Development in a Mountain Stream

다국어 초록 (Multilingual Abstract)

Effects of light and grazing on the biomass development of periphyton were evaluated using natural and artificial substrata (unglazed tile: 3.7×9.5x2cm) in a partially shaded 2nd order mountain stream. In open canopy (relative light input 20∼50%), a relatively high biomass (chl. a: 9.5±3.0 mg/m^2, n=25) was maintained than that of closed canopy(<6% of light input. 3.2±0.9 mg/m^2, n= 17). Due to shading and frequent rainfalls, biomass was lower during the summer than in the spring and winter. During the spring, colonization of periphyton on artificial substrata occurred faster than in winter and it took a minimum of 5∼6 weeks to reach the biomass of natural substrata (8∼9mg/m^2). When snails were allowed to freely enter the chamber (mean density: 114 ind./m^2) with artificial substrata, biomass accumulation (chl. a, AFDW) was low compared to the snail excluded enclosure (50∼90% of ungrazed substrata). It was concluded that the light input on periphyton biomass In a partially shaded stream played a more important role than glazing.