• 제목/요약/키워드: physiological ecology

검색결과 245건 처리시간 0.03초

Photosynthetic characteristics and chlorophyll of Vitex rotundifolia in coastal sand dune

  • Byoung-Jun Kim;Sung-Hwan Yim;Young-Seok Sim;Yeon-Sik Choo
    • Journal of Ecology and Environment
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    • 제47권3호
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    • pp.103-116
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    • 2023
  • Background: This study analyzed the physiological adaptations of a woody plant, Vitex rotundifolia, in Goraebul coastal sand dunes from May to September 2022. Environmental factors and physiological of plants growing under field and controlled (pot) conditions were compared. Results: Photosynthesis in plants growing in the coastal sand dunes and pots was the highest in June 2022 and July 2022, respectively. Chlorophyll fluorescence indicated the presence of stress in the coastal sand dune environment. The net photosynthesis rate (PN) and Y(II) were highest in June in the coastal sand dune environment and July in the pot environment. In August and September, Y(NPQ) increased in the plants in the coastal sand dune environment, showing their photoprotective mechanism. Chlorophyll a and b contents in the pot plant leaves were higher than those in the coastal sand dune plant leaves; however, chlorophyll-a/b ratio was higher in the coastal sand dune plant leaves than in the pot plant leaves, suggesting a relatively high photosynthetic efficiency. Carotenoid content in the coastal sand dune plant leaves was higher in August and September 2022 than that in the pot plant leaves. Leaf water and soluble carbohydrate contents of the coastal sand dune plant leaves decreased in September 2022, leading to rapid leaf abscission. Diurnal variations in photosynthesis and chlorophyll fluorescence in both environments showed peak activity at 12:00 hour; however, the coastal sand dune plants had lower growth rates and Y(II) than the pot plants. Plants in the coastal sand dunes had higher leaf water and ion contents, indicating that they adapted to water stress through osmotic adjustments. However, plants growing in the coastal sand dunes exhibited reduced photosynthetic activity and accelerated decline due to seasonal temperature decreases. These findings demonstrate the adaptation mechanisms of V. rotundifolia to water stress, poor soils, and high temperature conditions in coastal sand dunes. Conclusions: The observed variations indicate the responses of the V. rotundifolia to environmental stress, and may reveal its survival strategies and adaptation mechanisms to stress. The results provide insights into the ecophysiological characteristics of V. rotundifolia and a basis for the conservation and restoration of damaged coastal sand dunes.

Effects of Turbid Water on Fish Ecology in Streams and Dam Reservoirs

  • Seo, Jin-Won;Lee, Jong-Eun
    • 생태와환경
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    • 제41권4호
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    • pp.431-440
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    • 2008
  • Turbid water or suspended sediment is associated with negative effects on aquatic organisms; fish, aquatic invertebrate, and periphyton. Effects of turbid water on fish differ depending on their developmental stage and a level of turbidity. Low turbid water may cause feeding and predation rates, reaction distance, and avoidance in fish, and it could make fish to die under high turbidity and long period. Therefore, it is very important to find out how turbid water or suspended sediment can affect fish in domestic watersheds. The objectives of this study were 1) to introduce international case studies and their standards to deal with suspended sediment, 2) to determine acute toxicity in 4 major freshwater fishes, and 3) to determine in relation to adverse effect of macroinvertebrates and fish. Impacts of turbid water on fish can be categorized into direct and indirect effects, and some factors such as duration and frequency of exposure, toxicity, temperature, life stage of fish, size of particle, time of occurrence, availability of and access to refugia, etc, play important role to decide magnitude of effect. A review of turbidity standard in USA, Canada, and Europe indicated that each standard varied with natural condition, and Alaska allowed liberal increase of turbidity over natural conditions in streams. Even though acute toxicity with four different species did not show any fatal effect, it should be considered to conduct a chronic test (long-term) for more detailed assessment. Compared to the control, dominance index of macroinvertebrates was greater in the turbid site, whereas biotic index, species diversity index, species richness index, and ecological score were smaller in the turbid site. According to histopathological analysis with gills of macroinvertebrate and fishes, morphological and physiological modification of gills due to suspended sediments can cause disturbance of respiration, excretion and secretion. In conclusion, in order to maintain good and healthy aquatic ecosystem, it is the best to minimize or prevent impact by occurrence of turbid water in stream and reservoir. We must make every effort to maintain and manage healthy aquatic ecosystem with additional investigation using various assessment tools and periodic biomonitoring of fish.

대추씨(Zizyphus jujuba Seed)의 무기질, 구성 총 아미노산, 유리 아미노산 및 지질 구성 지방산조성에 관한 연구 (Studies on the Compositions of Mineral Components, Total Amino Acid, Free Amino Acid and Fatty Acid of Zizyphus jujuba Seed)

  • 김한수
    • 한국가정과학회지
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    • 제8권1호
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    • pp.25-31
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    • 2005
  • Chemical components of the physiological activity substance in Zizyphus jujuba seed were analyzed for the use as an functional processed products. The proximate compositions of Zizyphus jujuba seed were carbohydrate 89.40%, moisture 8.23%, crude protein 1.22%, crude fat 0.65% and crude ash 0.50%, respectively. the richest mineral contained in Zizyphus jujuba seed was Mg(198.3mg/100g), followed by Mn(113.0mg/100g), K(100.2mg/100g), Ca(25.3mg/100g), P(25.6mg/100g_, Fe(23.5mg/100g), Zn(18.7mg/100g), Cu(7.4mg/100g) and Na(5.3mg/100g). Total amino acid contents of Zizyphys jujuba seed were 1103.12mg/100g, and the major amino acids were proline(235.17mg%), aspartic acid(175.941mg%), gltamic acid(101.46mg%), leucine(50.27mg%), serine(47.71mg%), aspartic acid(47.27mg%), glycine(41.60mg%) and lysine (33.78mg%), respectively. The amount of free amino acids in the protein of Zizyphus jujuba seed were 178.62 mg/100g, and the major free amino acids were proline(121.30mg%), alanine(6.01mg%), valine(2.63mg%) and arginine(2.04mg%), respectively. The compositions of major total fatty acid in the lipid Zizyphus jujuba seed were C18:2(n5c) 28.72%, C18:1(n9t) 23.76%, C18:1(n9c) 13.45%, C16:0 13.45% and C20:5(n3) 1.77% in order, respectively.

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원적외선 방사 기능 실내복 착용이 인체 피부혈류량, 온열 심리 및 온열 생리 기능에 미치는 영향 (Influences of Wearing Far-infrared Indoor Clothing on Skin Blood Flow, Perceptual and Thermal Responses)

  • 백윤정;서원지;김형찬;이주영
    • 한국의류학회지
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    • 제44권2호
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    • pp.342-353
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    • 2020
  • The purpose of this study was to evaluate far-infrared clothing (FIR condition) with non-far-infrared clothing (Control condition) to assess the effects of FIR on thermo-physiological responses. Eight young healthy males (23.0±2.3 yr, 176.5±3.7 cm, and 69.0±4.3 kg) participated in this experimental trial, which consisted of a 20 min rest followed by a 40 min walk (4.0 km·hr-1) and a 20 min recovery at 20℃ with 50%RH. The results showed that finger skin blood flow and mean skin temperature were significantly higher for the FIR condition than the control during exercise and recovery (p<.001). Clothing microclimate temperature of the FIR condition was 0.5℃ higher on the back (p=.001) and 0.4℃ higher on the thigh (p=.015) during recovery. Clothing microclimate relative humidity of the FIR condition was 13% higher on the chest (p=.006) and 19% higher on the back (p<.001) during exercise than control. Subjects felt warmer and more comfortable in the FIR condition than in the control (p<.05). Perceived skin wettedness (%BSA) was less in the FIR condition than in the control (p=.001). These results indicate that ceramic-embedded clothing had significant effects on thermoregulatory responses for light activity in an indoor environment.

남조류 Anabaena 휴면포자의 연구 동향 및 방향 (Current Status and Perspectives in the Akinete Study of the Blue-green Algal Genus Anabaena)

  • 강필구;이송지;변명섭;윤성애;김헌년;이재관;황순진
    • 생태와환경
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    • 제47권1호
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    • pp.1-12
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    • 2014
  • 남조류는 겨울철에 휴면포자의 형태로 퇴적층에서 존재하다가 적합한 환경조건이 되었을 때 다시 영양세포로 전환된다. 이렇게 전환된 영양세포는 성장에 적합한 환경이 되었을 때 대량증식 하게 되어 수체 내에서 우점한다. 이전까지의 국내 대부분의 연구는 수체 내 영양세포의 변동과 환경인자와의 관계 또는 영양세포에 대한 생리생태적 연구부분에 국한되었다. 하지만, 휴면포자에서 영양세포로 진행되는 부분에 대한 연구가 조류 대량증식의 궁극적인 기작이 되므로 휴면포자에 대한 연구는 조류의 생활사를 이해하는 데에도 매우 중요하다. 또한 다른 조류들간의 변동 및 천이의 연구를 위해서도 필수적이다.

Interactions of nitrogen supplying level and elevated CO2 on Growth and Photosynthesis of Picea koraiensis Nakai seedlings

  • Wang Y.J.;Mao Z.J.;Park K.W.
    • 한국생물환경조절학회:학술대회논문집
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    • 한국생물환경조절학회 2004년도 추계학술대회 논문집
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    • pp.139-143
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    • 2004
  • To evaluate the biological and physiological response of Picea koraiensis Nakai to elevated $CO_2$ and nitrogen.3-year old seedlings were planted in an ambient and 700 ppm $CO_2$ at low (2mM $NH_4NO_3$) or high nitrogen (16mM $NH_4NO_3$) supplying treatments for 3 months. Photosynthetic parameters were measured monthly. Seedlings were harvested at monthly intervals and growth parameters of root system, stem and needle fractions were evaluated. The result showed that height of the seedlings grown at both of elevated $CO_2Xhigh$ nitrogen and elevated CO2×low nitrogen supplying treatments increased significantly more than that of at ambient CO2 treatments. Seedlings grown at elevated $CO_2Xhigh$ nitrogen produced more root biomass than at elevated $CO_2Xlow$ nitrogen and ambient $CO_2Xhigh$ nitrogen treatments. This result suggested that the root growth response of Picea koraiensis seedlings was greater in elevated $CO_2{\times}high$ nitrogen regime, which is very important for carbon sequestration in soil. $A_{max}$ of the seedlings grown at elevated $CO_2Xhigh$ nitrogen increased during the three months significantly, and $A_{max}$ of the seedlings grown at the other three treatments decreased significantly, suggesting that the interaction between elevated $CO_2$ and high nitrogen supplying stimulates the $A_{max}$ of Picea koraiensis. $A_{max}$ of the seedlings grown at elevated $CO_2Xlow$ nitrogen showed higher than other three treatments in the first month of the experiment, but decreased in succedent two months, suggesting that elevated $CO_2$ promotes the photosynthesis of the seedlings. However long term growth in elevated $CO_2Xlow$ nitrogen supplying condition resulted in an acclimatory decreased in leaf photosynthesis.

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생강 근경부패병의 발생 생태 및 토성 , 토양화학성 및 토양 생물성과의 관계 (Ecology of Rhizome Rot Incidence of Ginger and Relation of Soil Texture, Chemistry and Biology)

  • 이왕휴;이두구
    • 한국환경농학회지
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    • 제17권1호
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    • pp.1-4
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    • 1998
  • 충남 서산과 전북 봉동지방의 생강 근경부패병의 발생생태를 조사하였다. 서산지방의 근경부패병 발병율은 봉동보다 낮았다. 서산의 생강 수확량은 평균 1,140Kg였고, 봉동은 818Kg/10a 였다. 발병후 살균제는 서산에서 많이 사용하였다. 포장간 토양물리성은 약간의 차이가 있었다. 발병율이 낮은 은하리는 23%의 점토를 함유하고 있다. 반면에 병발생이 많은 유소리는 미사함량이 60%이상이었다. 생강 재배 지역의 토양화학성은 적정 농도 범위였으나, 인산은 적정농도 450-500ppm(mg/Kg)보다 모두 높았다. 이것은 하천의 오염원이 되므로 인산시비를 줄여야 할것을 추정하였다. 재배 중기인 8월에 사상균수가 최고치를 나타내는 경향이었고, 세균과 방선균수도 사상균수과 비슷한 경향이었다. 세균수/진균수는 포장간 큰차이를 나타냈다.

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제주산 진피를 이용한 단일 침출차의 가공 특성 및 항산화성 (Antioxidant Activity and Physicochemical Characteristics of Tangerine Peel Tea Prepared with Citrus unshiu Cultivated in Cheju)

  • 유경미;김채은;김동일;허담;황인경
    • 한국식품조리과학회지
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    • 제21권3호
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    • pp.354-359
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    • 2005
  • To investigate the physiological activities and development of tangerine peel tea, we examined the antioxidant effect of tangerine peel tea and determined the physicochernical characteristics including proximate composition, mineral contents, color values and sensory evaluation. The wet weight composition of tangerine peel tea was $61.6\pm0.3mg$ of crude carbohydrate, $15.0\pm20mg$ of crude lipid, $8.3\pm2.1mg$ of crude Protein and $7.6\pm0.1mg$ of crude ash. The pH of tnagerine peel tea decreased with increasing preparation temperature. The Hunter color values (L and a values) generally increased with increasing preparation temperature. Total phenolic contents of tangerine peel tea were $16.0 mg\%\;at\;60^{\circ}\;18.9mg\%\;at\;80^{\circ}C\;and\;20.9m\%\;at\;100^{\circ}C$. As the preparation temperature of tangerine peel tea increased, the radical scavenging activity (DPPH) also increased obviously. In the sensory evaluation, the tangerine peel tea prepared with 1 g at $80^{\circ}C$ obtained the best result with high scores in overall acceptability.

임분의 광환경이 활엽수 3수종의 광합성율 및 엽록소 함양에 미치는 영향 (Effects of Light Enviroment on Photosynthetic Rate and Chlorophyll Contents of Three Broad-leaved Species Growing in the Forest)

  • 김갑태
    • 한국환경생태학회지
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    • 제19권2호
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    • pp.188-192
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    • 2005
  • 이 연구는 큰 나무 아래 어린 나무를 심어 (수하식재) 새로운 숲을 가꾸는 방법 (임분갱신법)을 찾고자 낙엽송 간벌지에 음나무, 물푸레나무 및 층층나무 묘목을 1998년 봄에 수하식 재 한 것과 이웃에 위치 한 동일한 묘령의 임간포지에서 생육하는 개체들과의 엽록소항량과 광합성율을 2000년 7월에 측정$\cdot$비교하였다. 이는 식물종에 따른 광량에 대한 적응력 차이 (내음성)를 생리학적으로 확인하고자 시도하였다. 낮은 광도에 적응하기 위하여 음나무 잎은 다른 수종들에 비하여 보다 많은 엽록소함량과 광합성능을 증가시 키는 반응을 보였다고 판단된다. 이러한 결과로 보아 내음성은 음나무, 물푸레나무, 층층나무의 순으로 낮아지는 것이라 판단된다.

생육조건에 따른 산수국의 엽생장 및 생리적 특성 (Physiological Characteristics and Leaf Growth of Hydrangea macrophylla var. acuminata Growing in Different Environmental Conditions)

  • 김갑태
    • 한국환경생태학회지
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    • 제20권1호
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    • pp.70-74
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    • 2006
  • 이 연구는 관상용이나 천연감미료, 생리활성물질의 원료로 활용되는 산수국의 적정 생육조건을 구명하고자 수행하였다. 2년생 산수국의 삽목묘를 대상으로 광, 수분 및 시비처리를 실시한 후 8월과 9월에 광합성, 엽록소 함량, 엽생장을 조사 비교하였다. 광도처리별 광합성율의 유의차는 8월에는 유의차가 인정되었으나, 9월에는 유의차가 인정되지 않았다. 관수처리별 광합성율은 주3회 관수처리구에서 높았다. 시비구가 무시비구에 비해 광합성율이 약간 높게 나타났다. 엽록소함량은 광도처리별에 있어서는 8,9월 모두에서 유의차가 인정되었으며, 관수처리별에서는 8월에서만 유의차가 나타났으며 시비처리에서는 모두 유의차가 인정되지 않았다. 엽생장(엽장과 엽폭)은 전광과 주 3회 관수처리 시에 양호하였다.