RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      • 좁혀본 항목

      • 좁혀본 항목 보기순서

        • 원문유무
        • 음성지원유무
          • 원문제공처
          • 등재정보
          • 학술지명
          • 주제분류
          • 발행연도
          • 작성언어
          • 저자

        오늘 본 자료

        • 오늘 본 자료가 없습니다.
        더보기
        • 무료
        • 기관 내 무료
        • 유료
        • SCOPUSKCI등재

          미국 알라바마에서 지질학적으로 다른 두 하천의 Alkaline Phosphatase 활성도

          Joo,,Gea-Jae,Ward,,Amelia,K. The Ecological Society of Korea 1995 Journal of Ecology and Environment Vol.18 No.1

          Alakline phosphatase activity (AP A) as a phosphorus deficiency measurement in flowing waters and of microhabitats (rocks, wood, leaves, and sediments) was measured and its relationship to flux of nutrients and response to rainfall events were determined for two geologically different streams in west Alabama from August to November. Results indicated water column AP A in both streams had a low correlation with levels of orthophosphate, total organic phosphorus, nitrate, ammonia, dissolved organic carbon, and discharge (r=0.075-0.583; n=g-IU. Communities on rock surfaces showed a higher AP A level than those on wood and leaves. Sediment passed through a $106{\mu}m$ sieve showed 2-9 times higher AP A level than material passed through $425{\mu}m$ sieve. The first storm after drought at Yellow Creek introduced substantial quantities of DOC (2.5 times baseflow concentrations) and $N0_3-N$ (5.8 times baseflow concentrations) which did not affect AP A significantly. The second storm at Little Schultz Creek caused minor changes in nutrient cocentrations; however $N0_3-N$ levels and AP A were drastically lower due to the dilution effect. Retention of stream water AP A at Yellow Creek and Little Schultz Creek on $0.45{\mu}m$ filter (54 and 43%, respectively) and $0.22{\mu}m$ (83 and 77% of total APA. respectively) indicated more free dissolved portion of the enzyme was present at Little Schultz Creek. Little Schultz Creek (with carbonate and with a higher productivity and biomass) showed a consistantly greater AP A activity $(132{\pm}54\;{\mu}M{\cdot}1^{-1}{\cdot}min^{-I};\;n=g)$ than Yellow Creek $(41{\pm}23\;{\mu}M{\cdot}1^{-I}{\cdot}min^{-I}$, with a sandstone substrate; n=l1, $p{\leq}O.OO1)$. Overall, a greater APA on all microhabitats and the presence of more dissolved enzyme in Little Schultz Creek during the study period may indicates it is more P deficient than Yellow Creek.

        • KCI등재
        • KCI등재

          Vertical Distribution of Zooplankton in the Regulated River(Nakdong River)

          Joo,,Gea-Jae,Jeong,,Kwang-Seuk,Kim,,Hyun-Woo,Chang,,Kwang-Hyeon 한국육수학회 2002 생태와 환경 Vol.35 No.4

          본 연구에서는 조절 강생태계인 낙동강 하류(물금, 하구둑에서 약 27㎞)에서 1999년 5월에서 10월 사이 동물플랑크톤의 수직분포를 조사하였다. 낙동강에서 동물플랑크톤 종들의 밀도는 수심별로 차이를 보였다. 윤충류인 Polyarthra와 Keratella의 경우 수심 0.5m와 2m지점에 집중되는 경향을 보였다. 같은 윤충류인 Asplanchna의 경우 3.5m지점에서 높은 밀도를 나타냈다. 지각류와 요각류의 경우도 수심별로 다른 밀도를 나타냈으나 수직분포경향은 계절적으로 달랐다. 본 연구결과, 저수지화 성향을 띤 강에서의 동물플랑크톤의 연구에 있어 이들의 수직분포가 고려되어야 할 것으로 사료된다. Vertical distribution of zooplankton was studied in a regulated river system. Monthly samples were collected at the lower Nakdong River(Mulgum, above 27㎞ from the estuary barrage) from May to September in 1999. Zooplankton species and abundances were unevenly distributed in the water column. Among small rotifers, Polyarthra and Keratella were densely distributed at upper(0.5m) and mid layer(2m) while the density of Asplanchna was often higher at lower layer(3.5n). Cladocerans also showed heterogeneous vertical distribution patterns and their distribution was seasonally different. The occurrence of zooplankton patches was noted as similar to those commonly reported from lakes and reservoirs. The factors leading to the establishment of such distribution patterns was briefly discussed.

        • KCI등재

          Limnological Characteristics and Influences of Free-floating Plants on the Woopo Wetland during the Summer

          Joo,,Gea,Jae,Kim,,Gu,Yeon,Park,,Sung,Bae,Lee,,Chan,Woo,Choi,,Sang,Ho 한국육수학회 2002 생태와 환경 Vol.35 No.4

          본 연구는 하계동안 습지 수면을 덮고 있는 부유성 수생식물이 습지생태계에 미치는 영향을 알기 위하여 1998년 1월부터 1999년 10월까지 우포습지의 이·화학적 변화를 파악하고 하계에 부유수생식물 및 저토가 수질에 미치는 영향을 현장실험을 통하여 평가하였다. 우포습지의 수위는 홍수발생 시 낙동강의 범람으로 2-3m 정도의 변화를 보였다. 대부분이 이·화학적 요인들 및 동·식물플랑크톤의 밀도는 여름동안의 홍수와 6월에서 10월까지 습지 수표면을 거의 덮고 있는 수생 식물에 의해 많은 영향을 받는 것으로 나타났다. 용존산소(Jun.-Sept., 4.5±2.5 ㎎/ℓ; Oct.-May, 8.1±4.0 ㎎/ℓ)와 pH(Jun.-Sept., 6.9±0.4; Oct.-May, 7.4±0.8)는 다른 계절에 비해 여름철에 현저히 낮았다. 여름철에 번성하는 부유성 수생식물(개구리밥, 생이가래, 좀개구리밥)과 수중의 저토가 하계의 육수학적 특성이 미치는 영향을 파악하기 위하여 수표면에 enclosure(100 L, 6개)를 설치하고 부유식물, 천 그리고 노출 상태의 처리군을 부유식물의 유·무, 수중 저토의 유·무에 대해 실험한 결과, 부유식물이 있는 처리군이 다른 경우에 비하여 DO, pH가 낮게 나타났고, 노출된 대조구에서 상대적으로 식물플랑크톤(chl. a)의 생체량이 높았다. 또한 각 처리군에서 수중 저토가 있는 경우 영양염류농도가 높았고, 특히 부유식물이 있는 처리구에서 높은 영양염류의 농도를 보였다. 동물플랑크톤 군집의 변화는 부유식물에 의한 뚜렷한 영향은 보이지 않았지만, 초기에 rotifer가 우점하였고, 이후 cladoceran과 copepoda의 증가로 rotifer의 밀도가 급격히 감소하였다. 결과적으로, 조사기간 중 하계에 지속적으로 관찰된 DO와 pH가 감소하는 것은 수생부유식물의 번성과 수중 퇴적물의 분해에 따른 영향인 것으로 나타났다. During January 1998-October 1999, the impact of free-floating plants(FFP) on limnology of the wetland ecosystem was evaluated through the investigation of physico-chemical characteristics of the Woopo Wetland along with in situ manipulation experiments of aquatic plants. Flooding events occurred in the wetland during the summer period(Jun.-Aug.) and water levels rose to 2-3m due to precipitation from the catchment and inflow from the main channel of th Nakdong River. Physico-chemical parameters and plankton dynamics in the wetland during the summer were greatly influenced by floods and growth of free-floating plants. Dissolved oxygen(Jun.-Sept., 4.5±2.5 ㎎/ℓ; Oct.-May, 8.1±4.0 ㎎/ℓ) and pH(Jun.-Sept., 6.9±0.4; Oct.-May, 7.4±0.8) levels were significantly lower during the summer than any other seasons. Three types of enclosure experiments(100 L, treatments with floating plants, screened and opened) were conducted under the presence and absence of sediment for 15 days in the 1999 summer. The treatments with sediment had higher levels of nutrient concentrations than those of the others. Among the treatments with sediment, nutrient concentrations in the treatments with free-floating plants were higher than the others. Zooplankton communities in each treatment showed a similar variation, although the scale of zooplankton densities differed. Rotifer community dominated the zooplankton at the initial phase of the experiment, but decreased drastically along with an increase of cladoceran and copepod communities. In conclusion, low levels of dissolved oxygen and pH in the Woopo Wetland during the summer seemed to be caused by a proliferation of free-floating plants and active decomposition process at the bottom of the sediment.

        • KCI등재

          The Application of an Algal Fence for the Reduction of Algal Intake into the Water Intake Facility

          Joo,,Gea-Jae,Jang,,Min-Ho,Park,,Sung-Bae,Jung,,Jong-Mun,Roh,,Jae-Soon,Jeong,,Kwang-Seuk 한국육수학회 2003 생태와 환경 Vol.36 No.4

          본 연구에서는 상수원수 취수장의 취수구로 유입되는 조류 군체의 양을 물리적으로 억제할 수 있는 조류 펜스를 개발하고, 현장에 적용 및 평가하였다(2001년 6-9월). 펜스를 설치한 후 펜스 안팎의 식물플랑크톤 생체량은 통계적으로 유의한 차이를 나타내었다. 분산 분석의 결과 설치 1일 후의 chl.α는 모든 수심(0,1,2m)에서 유의한 차이를 보였으며(모든 수심에서 0.001>p, 각 수심별 n=16), 특히 표층과 수심 1m에서 가장 큰 차이를 보였다. 하지만 조류 저감 효과는 설치 후 3-5일이 지나면서 감소하였다. 조류 펜스의 물리적 유입 저감 효과의 지속성 유지를 위해서는 효과적인 설치 및 유지관리 방안(예, 기계적인 설치 및 주기적인 역세척 등)이 모색되어야 하며, 생태 모형을 이용하여 대번성 시기 예측이 가능할 경우 훨씬 효과적으로 조류의 유입 차단이 가능할 것으로 보인다. In this study, an algal fence was developed and applied to reduce the input of algal scum into the water intake facility. The effectiveness of vertical algal fences (overlapped three types of meshes, (312㎛×375㎛, 390㎛×450㎛, and 0.7㎝×1㎝; vertical depth, 1.5m; length of fence, about 120m)) was experimentally tested at a water intake facility(Mulgum, lower Nakdong River). The application of the fence resulted in the statistically significant difference of algal biomass between inside and outside of the fence. According to ANOVA test, chl. a concentration in day-1 showed large difference at each depth of 0, 1, 2m(0.001>p at each depth, n=16 respectively). Especially large difference was observed at 0 and 1 m depth. However, the fence was only effective for a short period and its efficency declined by D-5 after the installation. When better maintenance options for the fence are prepared, e.g. mechanical installation and periodic backwashing of the fence, the performance of algal fence may be sustained. In addition, reliable models for bloom prediction are required to provide an advanced indication of the optimal timing for the installation so that effective operation would be achieved.

        • KCI등재

          낙동강 중 , 하류에서 식물플랑크톤과 세균의 계절적 동태

          박재림,하경,손연주,주기재 한국환경과학회 2001 한국환경과학회지 Vol.10 No.4

          Investigations were carried out to observe the seasonal succession of phytoplankton, and viable counts of bacteria from the mid to lower reaches of Nakdong River. An intensive monitoring was conducted from May to December 1999 biweekly at 6 sites in a main channel and 3 tributaries. Although there are several sites with high nutrient loading from the basin, all of study sites showed mesotrophic states owing to high discharge(June∼September). Relatively low algal biomass and CFUs(mean of chl. a, 12.3±11.5 ㎍/ℓ, CFUs : 1.8×10 exp (7)) were observed during the rainy season. The diatom population was dominant(over 85% of total community) year-long with peaks (Stephanodiscus hantzschii) in the fall and winter. Dominance of blue-green algal groups during the summer was not observed in the summer. Microorganisms peaked in the summer and fall (June∼September), affected mainly by the inputs of phytoplankton and nutrients. Biomass of phytoplankton and CFU counts were higher in the Kumho River than the other tributaries and main channel.

        맨 위로 스크롤 이동