• ALGAE
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• 제23권3호
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• pp.241-250
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• 2008

Since seagrasses in the coastal and estuarine ecosystems achieve high levels of production, they require high inorganic carbon and nutrient incorporation. Thus, seagrasses may play a significant role in carbon and nutrient cycling in the coastal and estuarine ecosystems. To examine growth dynamics of Zostera marina L. environmental factors such as underwater irradiance, water temperature, and salinity, and biological parameters such as shoot density, biomass, shoot morphology, and leaf productivity were measured in two bay systems (Jindong Bay and Gamak Bay) on the southern coast of Korea. While underwater irradiance did not show distinct seasonal trend, water temperature at both sites exhibited clear seasonal trend throughout the experimental period. Shoot density increased dramatically during winter due to the increased seedlings through germination of seeds in Jindong Bay and due to the increased lateral shoots in Gamak Bay. Eelgrass biomass increased during winter and decreased during summer. Maximum biomass in Jindong Bay and Gamak Bay was 250.2 and 232.3 g dry weight m–a2, respectively. Carbon incorporation into the eelgrass leaf tissues was estimated from productivity and leaf tissues carbon content. The calculated annual carbon incorporations at the Jindong Bay and Gamak Bay sites were 163 and 295 g C m–`2 y–`1, respectively. This high carbon incorporation into seagrass tissues suggests that seagrass habitats play an important role as a carbon absorber in the coastal and estuarine ecosystems.

• Journal of Plant Biology
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• 제28권2호
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• pp.119-126
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• 1985

Sargassum confusum을 대상으로 동해안 오호리 지역에서 1983년 3월 부더 1984년 4월까지 이 종의 생장 및 일차생산력을 조사하였다. S. confusum은 2월에 생장하기 시작하여 여름에 최대생장을 나타낸 후 빠른 속도로 쇠퇴하는 생육주기를 가진다. 생식활동은 6월에 주로 이루어 진다. 이러한 생장양상은 수온과 밀접한 관제를 갖는다. 최대성장율은 5월의 1.3cm/day이며 최대길이는 8월의 120cm이다. 산소명암병법으로 측정된 S. confusum의 일순생산력은 6월에 11.2 gC/dry wt/day이며 이를 기초로 추정한 연생산력은 745 gC/$m^2$/yr이다. 한편 현존량의 변화에만 의존하여 추정된 연생산력은 745 gC/$m^2$/yr로서 탈락에 의한 손실이 약 60%에 달하고 있다.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.73-78
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• 2018

본 연구는 혼합영양 배양 조건에서 acetate의 주입이 Anabena azollae의 성장에 미치는 영향을 파악하기 위해 수행되었다. 4가지 종류의 acetate 중 ethyle acetate가 Anabena azollae의 성장에 가장 효과적이라고 밝혀졌으며, 주입한 ethyle acetate의 농도가 증가할수록 성장속도는 증가하는 것을 확인하였다. 40 mM의 ethyl acetate의 경우 비성장속도는 $0.979day^{-1}$, 최대바이오매스 생산성은 $0.293g\;L^{-1}\;d^{-1}$로 본 연구에서 배양속도가 가장 빠른 것으로 판명되었다. Acetic acid와 butyl acetate의 경우 Anabena azollae 성장을 방해하는 것으로 나타났다. Aetration의 경우 0.54 vvm에서 성장속도가 가장 빨랐다. 반연속배양에서는 aeration 실험이 끝난 후 연속하여 ethyle acetate 주입을 하여 배양을 하였다. 회분식실험에 비해 반연속배양에서의 비성장속도와 최대바이오매스 생산성은 모두 감소하였지만 최대 농도는 5.91 g/L로 가장 큰 값을 나타내었다.

• 미생물학회지
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• 제32권3호
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• pp.238-244
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• 1994

부영양화된 낙동강 하구역에서 세균에 의한 용존 유기물의 이용능을 조사하고 이에 미치는 환경요인의 영향을 파악하기 위하여 미생물학적 요인과 물리화학적 환경요인의 연중 변화를 분석하였다. 총세균수는 0.33 ~ $2.09{\times}10^7$ cells/ml의 변화폭을 나타냈으며, 오염부하량이 큰 정점에서 종속영양세균의 개체수와 비례하였다. 세균이 체적과 생물량은 각각 0.064~0.156 ${\mu}m^3$/cell, 0.163~1.036 ${\mu}g$-C/ml을 나타냈다. 세균의 이차생산성은 0.24~60.86 ${\mu}g$-C/l/h의 범위로 측정되었으며, 부영양화 지표로 사용되는 환경인자와 밀접한 관계를 보였다. 담수역에 속하는 정점에서의 세균생산성의 계절별 변화는 동계에 최고치를, 하계에 최저치를 나타내어 갈수기의 오염부하량 증가와 밀접한 상관성을 보였다. 해수역에 속하는 다대의 경우 동계에 낮은 값을, 하계에 높은 값을 나타내고, 환경요인 중 엽록소 a, 수은 등과 밀접한 상관성을 보였다 (r>0.5, p<0.05). 이로 미루어 낙동강 하구의 하구언 상류역에서는 주위에서 유입되는 유기물이, 하구언 하류역에서는 식물성 플랑크톤의 광합성 산무링 세균의 이차생산성에 미치는 주 영양물질임을 암시하고 있다.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2015년도 하계 학술발표논문집
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• pp.18-28
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• 2015

Apple is cultivated under various climatic conditions in many parts of the world. Better understanding of how climate, genotype, soil, and management factors interact to determine crop productivity will improve our ability to optimize crop selection, management strategies, and resource use efficiencies. We developed and applied a physiology-based apple canopy model to evaluate how climatic factors and crop phenotypes interact to determine biomass accumulation, radiation use efficiency (RUE), and water use efficiency (WUE) at multiple production sites between western and eastern states of the US including WA, CA, NY, WV, and PA. Our results indicate that solar radiation is a dominant factor limiting biomass production in the eastern states while VPD is the primary factor governing crop water use across eastern and western states during the peak growing season. Crop RUE and WUE were strongly correlated in the western states but not in the eastern states while VPD showed highly negative correlation with both RUE and WUE across all locations. The RUE improved with increasing fraction of diffuse radiation ($f_{df}$) and the $RUE-f_{df}$ relationships revealed distinctive responses between western and eastern states. Overall, the eastern locations exhibited slightly higher RUE and WUE than the western locations. However, overall productivity and total water use were greater in the western states. A clear decline of productivity with increasing temperature and afternoon VPD past an optimum was predicted in the western locations but this pattern was less clear in the eastern locations. We also discuss potential phenotypes with specific physiological and morphological traits that are differentially suitable for western and eastern locations. Our results provide plausible, spatially explicit explanations and insights to disentangle the complex relationships between crop productivity, resource use efficiencies, phenotype, and climate drivers in apple grown in the US.

• 한국해양바이오학회지
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• 제9권1호
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• pp.14-21
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• 2017

The purpose of this study was to inhibit biofouling on a selectively permeable membrane (SPM) and increase biomass productivity in marine photobioreactors (PBRs) for microalgal cultivation by chemical treatment. Surfaces of a SPM, composed of polyethylene terephthalate (PET), was sulfonated to decrease hydrophobicity through attaching negatively charged sulfonic groups. Reaction time of sulfonation was varied from 0 min to 60 min. As the reaction time increased, the water contact angle value of SPM surface was decreased from $75.5^{\circ}$ to $44.5^{\circ}$, indicating decrease of surface hydrophobicity. Furthermore, the water permeability of sulfonated SPM was increased from $5.42mL/m^2/s$ to $10.58mL/m^2/s$, which reflects higher nutrients transfer rates through the membranes, due to decreased hydrophobicity. When cultivating Tetraselmis sp. using 100-mL floating PBRs with sulfonated SPMs, biomass productivity was improved by 34% compared with the control group (non-reacted SPMs). In addition, scanning electron microscopic observation of SPMs used for cultivation clearly revealed lower degree of cell attachment on the sulfonated SPMs. These results suggest that sulfornation of a PET SPM could improve microalgal biomass productivity by increasing nutrients transfer rates and inhibiting biofouling by algal cells.

• 한국해양바이오학회지
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• 제15권2호
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• pp.41-48
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• 2023

The objective of the present study was to improve the biomass productivity of newly isolated freshwater green microalga Parachlorella sp. This was accomplished by culture conditions optimization, including CO₂ concentration, superficial gas velocity, and light intensity, in 0.5 L bubble column photobioreactors. The supplied CO₂ concentration and gas velocity varied from 0.032% (air) to 10% and 0.02 m/s - 0.11 m/s, respectively, to evaluate their effects on growth kinetics. Next, to maximize the production rate of Parachlorella sp., a lumostatic operation based on a specific light uptake rate (q_e) was applied. From these results, the optimal CO₂ concentration in the supplied gas and the gas velocity were determined to be 5% and 0.064 m/s, respectively. For the lumostatic operation at 10.2 µmol/g/s, biomass productivity and photon yield showed significant increases of 83% and 66%, respectively, relative to cultures under constant light intensity. These results indicate that the biomass productivity of Parachlorella sp. can be improved by optimizing gas properties and light control as cell concentrations vary over time.

• 수산해양기술연구
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• 제38권1호
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• pp.1-10
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• 2002

1. 제주해협에서는 6월에 가장 낮은 생물량 분포를 나타내었고, 가을철(11월)에 가장 높은 생물량 분포를 보이면서 높은 2차 생산력을 보이는 것으로 사료된다. 2. 해황 및 습중량과의 관계에서 가장 높은 분포를 나타내는 정점은 각각 정점 14와 11로 그 출현위치는 해협의 중앙부분이고, 한국남해연안역 및 제주도 북부연안역에는 다소 낮은 생물량분포를 보이고 있으며, 생물량 분포가 높게 나타나는 해역의 특징은 patch의 형태로 분포하였다 반면 한국남해연안역에 비하여 제주도 북부연안역에높은 생물량 분포를 나타냄으로써 제주해협에서의 갈치어장 형성위치와 생물량 분포와의 관계가 밀접하게 나타날 것으로 판단된다. 그리고, 가을 의 해황 특성인 서로 다른 이질수괴의 경계역인 안상부 해황의 중심에 높은 생물량을 나타냈다. 3. 제주해협에서 patch의 형태로 생물량 분포가 높게 나타나는 해역의 외측에 좋은 갈치어장이 형성되었다.

• Ocean and Polar Research
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• 제41권4호
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• pp.311-318
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• 2019

We analyzed the preliminary survey data (2014-2016) of macrobenthic community biomass (n = 112) from the wind farm area located in the southern part of the west coast of Korea and compared this data with data from the entire west coast (n = 369; 2006-2008). Modal classes from frequency distributions were 6 times higher in the latter (5 vs. 32 g/㎡). The mean and median values of the latter were 1.3 and 1.7 times higher (mean, 20.7 vs. 27.8 g/㎡; median, 17.1 vs. 29.5 g/㎡), and the maximum value was 3.4 times higher. Mood's median test showed significant difference at p-value = 0.01. We estimated the biomass-to-depth relationships from each data set by using Akaike Information Criterion and regarded the non-overlap of the 95% confidence intervals as indicating significant difference. The biomass was different from a 10 m depth below, and 3 times higher in the west coast at around 20 m compared with the maximum depth of the wind farm area. A local event of catastrophic sedimentation ranging from 1 to 2 m was observed in the wind farm during winter surveys. This could be a probable source of the lower biomass, but information on biomass seasonality and a natural experimental approach seem to be needed for the conduct of further studies. This study is meaningful in that it provided the background to assess future changes by understanding the lower level of benthic productivity in the area. We expect this study will contribute to the preparation of measures that can remove or mitigate the source of the lower biomass and improve the productivity of fishery resources in the area.

• 한국유기농업학회지
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• 제20권3호
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• pp.369-383
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• 2012

사육밀도를 달리 했을 때 지렁이 개체군의 생체량 증가를 위한 최적 사육밀도를 추정하려고 하였다. 실험결과를 요약하면 다음과 같다. 1. 사육밀도 S-2과 S-3에서 상대증체량, 생체중 증가율과 유기물 전환효율이 높은 값을 나타내어, 지렁이 개체군의 최대 생체량을 얻기 위한 최적 사육밀도로 추정되었다. 이를 지렁이 생체중과 먹이량의 비율로 나타내면 1:32-1:48의 범위였다. 2. 사육밀도 S-1(1:16)에서 모든 조사시기의 분립생산량이 유의하게 많았고 분립비율도 유의하게 높았다($$P{\leq_-}0.05$$). 3. 사육밀도 S-3(1:48)에서 지렁이 생체중당 난포수와 분립생산량이 가장 많았다($$P{\leq_-}0.05$$). 4. 사육밀도가 높아지고 사육기간이 길어짐에 따라 분립의 전 질소함량, 유효인산함량, 양이온치환능력(CEC) 및 양이온 함량이 증가되는 경향이었다. 5. 유기농업에서 지렁이 분립은 상토 재와 토양개량제 및 작물보호를 위한 농자재로서 잠재적 유용성은 매우 높다고 판단된다.