http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
In Situ Measurement of Diel Periodicity in Urea Decomposition in a Reed Zone of Lake Biwa, Japan
Tachibana, Junji,Kondo, Kunio,Seike, Yasushi,Osamu, Mitamura The Korean Society of Limnology 2005 생태와 환경 Vol.38 No.S
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.
Mitamura, Osamu,Tachibana, Junji,Ishida, Noriko,Seike, Yasushi,Choi, Jun-Kil The Korean Society of Limnology 2009 생태와 환경 Vol.37 No.2
Primary production of epiphytic and planktonic algae in a shallow reed zone of a lagoon Nishinoko was investigated. Concentrations of nutrients varied widely horizontally and locally in the lagoon. It seems that the reed zone has a heterogeneous environment. The photosynthetic rates of epiphytic and planktonic algae were 7 to 14 mg C surface stem $m^{-2}hr^{-1}$ and 12 to $46mg\;Cm^{-3}hr^{-1}$, respectively. The areal primary production of epiphytic algae was estimated as 4 to $13mg\;Cm^{-2}hr^{-1}$ from the stem density of Phragmites and the water depth at each station. The production of phytoplankton, on the other hand, was 5 to $56mg\;Cm^{-2}hr^{-1}$. The contribution of epiphytic algae to total primary production averaged 53%, although the assimilation number was much lower than that of phytoplankton. The present results indicate that the epiphytic algae are one of the significant primary producers in the reed zone.
한강수계 (漢江水系) 인공호에서의(人工湖) 요소분해속도 비교연구
삼전촌서좌무 (三田村緖佐武),귤순치,신곡박지 (神谷博之),김범철,조규송 ( Osamu Mitamura,Junji Tachibana,Hiroyuki Kamitani,Bomchul Kim,Kyu Song Cho ) 한국하천호수학회 1995 생태와 환경 Vol.28 No.2
The in situ rate of urea degradation was measured in the euphotic zone of three reservoirs located in the Han River System, The daily rate of urea degradation(i. e., sum of the incorporation rate of urea carbon into the particulate organic matter and the liberation rate of urea carbon into the water as carbon dioxide) in surface water was 14μmol urea·m^-3.day^-1 in Lake Soyang, 43μmol urea ·m^-3.day^-1 in Lake Chungju and 49μmol urea·m^-3.day^-1 in Lake Paldang. There was no change at various depths. The greater part of urea degradation took place during the the phase of carbon dioxide liberation. In the light, an appreciable amount of urea degradation was incorporated into phytoplankton cells, but this was extremely low in the dark condition. High correlation coefficients were obtained between urea degradation rate and photosynthesis or photosynthetic carbon assimilation rate by unit amount of chlorophyll-a. The residence time of urea in surface water was respectively estimated as 9, 2 and 9 days in Lakes Soyang, Chundu and Paldang. The present results suggest that in reservoirs the urea degradation occurred in connection with photosynthetic activity and that its has an important contribution as one of the nitrogen source for phytoplankton population. The brief residence time of urea indicates that the urea is a rapidly recycled from of biogeochemical parameter.