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한국하천호수학회 / v.38, no.spc, 2005년, pp.31-38 
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( In Situ Measurement of Diel Periodicity in Urea Decomposition in a Reed Zone of Lake Biwa, Japan ) |
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| Diel change in urea decomposition activity of epiphytic algae on Phragmites stems and phytoplankton in a shallow littoral reed zone in the south basin of Lake Biwa was investigated with an in situ technique using $^{14}C$-labelled urea. The daily rates of urea decomposition (sum of urea carbon incorporation rate and $CO_2$ liberation rate) by epiphytic and planktonic algae were calculated as 180 ${mu}$ mole urea surface shoot area $m^{-2};day^{-1}$ and 210 ${mu}$ mole urea $m^{-3};day^{-1}$. The chlorophyll a specific urea decomposition rates of epiphytic and planktonic algae were 4.7 to 6.4 and 4.4 to 6.2 ${mu}$ mole urea mg chl. $a^{-1}$ incubation $time^{-1}$ in daytime and 4.2 to 5.7 and 2.4 to 3.5 ${mu}$ mole urea mg chl. $a^{-1};time^{-1}$ in nighttime, respectively. High values were obtained during 12:00 ${sim}$ 18:00 and low values during 00:00 ${sim}$ 06:00 for both epiphytic and planktonic algal communities. A clear diel periodicity in the urea decomposing activity of the planktonic algae was observed. The activity of the epiphytic algae, on the other hand, showed no destinctive variation during a day. The present results indicate that epiphytic algae are one of the significant urea decomposers in a reed zone, and that the diel patterns are quite difference between both algal communities. |
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| 키워드 |
| urea decomposition;diel periodicity;epiphytic algae;reed zone;Lake Biwa; |
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한국하천호수학회지 / v.38, no.spc, 2005년, pp.31-38
한국하천호수학회
ISSN : 1976-8087
UCI : G100:I100-KOI(KISTI1.1003/JNL.JAKO200518317186000)
언어 : 영어 |
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| 논문 제공 : KISTI 한국과학기술정보연구원 |
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