• 생태와환경
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• 제43권1호
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• pp.19-23
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• 2010

Life cycle and secondary production of Nymphs of Nemoura gemma Ham and Lee were estimated by using specimens collected from a stream in Mt. Jumbong in the central Korean peninsula. N. gemma in the study stream was univoltine. Youngest nymphs were collected in April. They appeared to grow continuously until the emergence in early spring next year. The cohort production interval for the species was estimated as 399 days. The annual secondary production (ash free dry weight) estimated by removal-summation and the size-frequency methods were 582 and $786\;mg\;m^{-2}\;yr^{-1}$, respectively. Gut content analysis showed that N. gemma was a shredder.

• 생태와환경
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• 제52권1호
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• pp.28-39
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• 2019

This study was conducted to elucidate microplastics detection of freshwater ecosystems in Geum river. Samples are collected at 6 points in freshwater, 5 points in fishes. Freshwater was sampled 100 L per each points and fish species were Opsariichthys uncirostris amurensis, Hemibarbus labeo, Pseudogobio esocinus, Zacco platypus, Micropterus salmoides and Cyprinus carpio. FTIR analyis was adopted to identify microplastic types. Extracted microplastics were PES (polyester), PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), PVC(Polyvinyl chloride) in freshwater, and PES, PE, PP, PET, PVC in fishes. Our results were expected to be used basic research information for further study in microplastics of freshwater ecosystems.

• 생태와환경
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• 제53권4호
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• pp.336-343
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• 2020

Large-scale cultivation of Microcystis aeruginosa in different light conditions was conducted for verifying the cell growth in a greenhouse system. Environmental and chemical parameters of the large-scale culture medium were measured for analyzing the interaction between M. aeruginosa and its symbiotic bacteria. During cultivation, a difference in cell growth pattern was observed between control (natural light) and light-limited groups (reduction of blue, green, and blue/green light, respectively). Comparing the control group, the light reduced groups showed slow and delayed cell growth through the cultivation period. Also, there is differences in the consuming pattern of total nitrogen and total phosphorus which indicated that the possibility of interaction between M. aeruginosa and symbiotic bacteria.

• 생태와환경
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• 제54권2호
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• pp.102-107
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• 2021

The distribution pattern of species richness was determined by temperature. To examine the relationship between hemipteran richness and temperature, hemipteran species were collected using pitfall traps at six different oak forest sites with different annual mean temperatures in South Korea. Multiple linear regression analyses were conducted with mean annual temperature (MAT) and plant richness to evaluate differences in hemipteran richness. The influences of MAT and plant richness of study sites on hemipteran richness were examined by comparing three models (plant richness+MAT+MAT², plant richness+MAT, and MAT) or two models (plant richness+MAT and MAT). Hemipteran richness showed an inverse diversity pattern as a function of temperature, with higher species richness at lower temperature sites. Meanwhile, Aphididae showed a bell-shaped diversity pattern with the highest value at low medium temperatures. The regression analysis showed that hemipteran richness was affected by temperature and plant richness in their habitats.

• 생태와환경
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• 제54권2호
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• pp.125-129
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• 2021

Chironomids are a large group of invertebrates that live in various aquatic habitats. The distribution range of these invertebrates has become varied due to anthropogenic impacts; as such, their distribution can be used as an indicator of environmental health. Adult chironomids are well known in South Korea; however, the larvae have rarely been studied due to difficulties associated with morphological classification. To address this lack of information, we collected larvae from four important rivers in South Korea and summarized their taxonomic morphological characteristics. The antennae, mandible, and mentum were used for larval taxonomic characterization. In this study, we describe the basic morphological features and key pictorial features of 20 species of chironomids, representing 16 genera.

• 생태와환경
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• 제55권4호
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• pp.415-420
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• 2022

It is essential that continual assessments of the impact of mine-derived water as a long-lasting burden on freshwater environments. Abundance-based evaluations of benthic macroinvertebrates have been conducted to evaluate anthropogenic disturbances and devise policies to reduce their impact. In this study, the status of a stream habitat was evaluated based on the body length and biomass weight of benthic macroinvertebrates of the family Baetidae. Following the renewal of the mining water treatment plant, the abundance of Baetidae assemblages recovered to a level comparable to that of a reference site. However, relatively low values were found for both body length and biomass weight in Baetidae species inhabiting the reddened streambed area, suggesting that the habitat has not yet been completely recovered despite the recovery of the abundance of the Baetidae assemblages. Therefore, continuous investigation and evaluation of this disturbed stream are necessary until their growth conditions of the habitat have functionally recovered.

• 생태와환경
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• 제44권3호
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• pp.280-291
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• 2011

생물조절기법(Biomanipulation)을 이용한 수질개선 방법으로서, 인공식물섬을 이용한 부유성 수생식물(I. pseudoacorus)은 그 표면적에 따라서 수층으로의 광량 투과를 제어함으로써 미세조류의 광합성 효율을 저해한다. 또한, 수층에서 영양염을 흡수하여, 미세조류의 성장을 억제함으로서 남조류(M. aeruginosa) 대량발생을 제어할 수 있다는 것을 $^{13}C$, $^{15}N$ 추적자 실험을 통하여 정량적으로 확인하였다. 이와 같이 부유수생식물을 이용하여 저수지내 남조류 번성을 억제함으로서 수질 개선에 중요한 역할을 하지만, 동물플랑크톤의 종 조성 변화를 야기할 수 있다는 것을 고려해야 할 것이다. 본 연구 결과는 향후 인공 식물섬을 사용한 남조류 제어 기법에 중요한 자료로 활용될 것으로 사료된다.

• 생태와환경
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• 제50권3호
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• pp.337-354
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• 2017

남조류 Aphanizomenon속 개체군은 국내외에 널리 분포하고, 독소와 이취물질을 생산함으로써 유해조류로 잘 알려져 있어 육수생태학 분야에서 많은 관심을 갖게 된 분류군 중 하나에 속한다. 본 연구는 보령호에서 동계에 수위가 급격히 강하되면서 Aphanizomenon의 출현빈도, 강도 및 기간이 커지게 되어 이에 대한 시공간적 특성을 수문기상(1998년~2017년) 육수 (2010년~2017년)학의 관점으로 상호 비교하였다. 국내에서 Aphanizomenon은 고온기에 주로 번성하였으며, 저온기에 출현은 총 5회로서 드물었다. 보령호에서 저온기(12월~2월)에 유해조류 Aphanizomenon이 관찰된 것은 2014년부터이었고, 그 후 2017년에 최대값 $2,160cells\;mL^{-1}$를 기록하였다. 그리고 $>1,000cells\;mL^{-1}$를 초과하는 기간은 약 3개월을 넘기기도 하였다. 이것은 다름 아닌 저수온기 ($<10^{\circ}C$)에 비정상적인 수위 강하와 관련성이 컸다. 동계에 수위 강하는 유해조류의 발아 및 발생을 촉진 또는 증폭시킬 수 있는 잠재적 특성을 가지고 있었다. 따라서 후속 수질 생태학적 영향(예, 조류독소 및 이취물질)도 면밀하게 고려되어야 할 필요성이 있었다.

• 생태와환경
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• 제41권4호
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• pp.423-430
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• 2008

As of September 2008,45 Automatic Water Quality Monitoring Systems (AWQMS) have been installed at different sites on the 4 rivers to detect early the presence of pollutants in water and to issue an alarm. We count the number of issuing alarms by AWQMS, however, we will find the alarm has hardly been issued. The reasons for the scarcity of alarm issue are extensively being examined. The National Institute of Environmental Research attributes wrong alarm criteria for each AWQMS station to one the reasons. In this study, a suggestion has been made to modify the current alarm criteria to correspond with characteristics of river water quality. The current system with only two criteria (low and high) should be replaced as four-criteria systems (low, medium, high, and severe) based on cases of other advanced countries and stream conditions of Korea. The highest value of data collected for 5 years was suggested as the alarm criteria for each parameter. Meanwhile the alarm criteria for VOCs, phenol and heavy metals were established as same as drinking water quality criteria.

• 생태와환경
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• 제41권4호
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• pp.554-562
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• 2008

To evaluate the limitation for epiphytic and planktonic algal growth, acid extractable inorganic phosphorus (AP), implying the luxury uptake phosphorus, was measured in five reed zones of Lake Biwa. The AP in epiphytic substances was 0.7 to 1.4 mg P surface stem $m^{-2}$ in summer and 1.2 to 2.8 mg P $m^{-2}$ in winter. On the other hand, the amount in planktonic substances was 1.4 to 5.7 mg P m -3 and 0.8 to 5.4 mg P $m^{-3}$ in both seasons. Contribution of AP in the epiphytic and planktonic phosphorus was 23 to 31% and 8 to 27% in summer, and 17 to 22% and 9 to 17% in winter. It suggests that in summer both epiphytic and planktonic algae had been luxuriously taken up phosphate into cells. The weight ratios of C : N : P were averaged 79 : 20 : 1 for the epiphytic substances and 81 : 12 : 1 for the particulate substances. On the other hand, the ratios without the luxurious phosphorus were 93 : 24 : 1 and 103 : 15 : 1, showing much higher values than the Redfield ratio. High ratio in the epiphytic substances indicates that the phosphorus is the limiting parameter, rather than nitrogen, regulating the growth of epiphytic algal populations.