• 제목/요약/키워드: nutrient cycle

검색결과 135건 처리시간 0.025초

전 세계 대양 영양염 자료의 상호 비교성 향상을 위한 국제동향 : SCOR Working Group 147 (Towards Comparability of Global Oceanic Nutrient Data, COMPONUT) 활동에 대하여 (International Trend Towards Comparability of Glabal Oceanic Nutrient Data: SCOR Working Group 147 (Towards Comparability of Global Oceanic Nutrient Data, COMPONUT) Activity)

  • 노태근;김은수;강성현;조성록
    • Ocean and Polar Research
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    • 제37권3호
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    • pp.225-233
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    • 2015
  • To understand the fluctuation of global carbon levels caused by the biogeochemical cycle within the ocean interior, it is essential to achieve comparability of global oceanic nutrient data to a fairly high degree. The Scientific Committee on Ocean Research (SCOR) commissioned a working group (WG147) to establish a system for achieving comparability of oceanic nutrient data within 1% among laboratories around the world. The introduction of international activities for improving nutrient comparability will facilitate the use of nutrient reference material of seawater by researchers within Korea, which will help in meeting international standards of nutrient comparability and promote international cooperation.

금강하구역에서 영양염 거동에 대한 조석 및 담수유출의 영향 (The Effect of Tidal Cycle and River Runoff on the Dynamic of Nutrients in Keum river estuary)

  • 김종구;강훈
    • 한국환경과학회지
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    • 제11권6호
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    • pp.519-528
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    • 2002
  • This study was to evaluate the impact of river runoff and salt intrusion by tide on nutrient balance of estuary during a complete tidal cycle. 24 hours time series survey was carried out during a spring tide July 2001 on a tidal estuary in the Keum river. Three stations(A,B,C) were set along a transect line of about 10km, which linked the lower part of estuary dyke to the subtidal zone. Surface water was sampled simultaneously at each station every hours f3r the determination of nutrients. Water temperature, pH and dissolved oxygen were measured in situ. Riverine input of silicate and nitrate during ebb tide significantly increased the concentration of all stations. Conversely, during high tide, nutrient concentration were lowered by the mixing of fresh water with sea water Ammonium nitrogen concentration were higher at intertidal zone(Stn.B) due to sewage inflow to Kyeongpo stream and ammonium release under anaerobic conditions. Also, these results was discussed as a biological component that influences the processes of nutrient regeneration within the estuary. Best correlations were found at lower part of estuary dyke(Stn.A) for salinity against DIN(Y=0.121 Sal.+4.97, r2=0.956) and silicate(Y=0.040 Sal.+2.62, r2=0.785). But no significant correlation was found between salinity and ammonium. Unbalanced elemental ratio(N/P, Si/N and Si/P) depended significantly on the import of nutrients (silicate & nitrate nitrogen) from river and stream. The effect of the tidal cycle and river runoff is important that in determining the extend of the variations in nutrient concentrations at all station.

Role of litter production and its decomposition, and factors affecting the processes in a tropical forest ecosystem: a review

  • Giweta, Mekonnen
    • Journal of Ecology and Environment
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    • 제44권2호
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    • pp.81-89
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    • 2020
  • In the forest ecosystems, litterfall is an important component of the nutrient cycle that regulates the accumulation of soil organic matter (SOM), the input and output of the nutrients, nutrient replenishment, biodiversity conservation, and other ecosystem functions. Therefore, a profound understanding of the major processes (litterfall production and its decomposition rate) in the cycle is vital for sustainable forest management (SFM). Despite these facts, there is still a limited knowledge in tropical forest ecosystems, and further researches are highly needed. This shortfall of research-based knowledge, especially in tropical forest ecosystems, may be a contributing factor to the lack of understanding of the role of plant litter in the forest ecosystem function for sustainable forest management, particularly in the tropical forest landscapes. Therefore, in this paper, I review the role of plant litter in tropical forest ecosystems with the aims of assessing the importance of plant litter in forest ecosystems for the biogeochemical cycle. Then, the major factors that affect the plant litter production and decomposition were identified, which could direct and contribute to future research. The small set of studies reviewed in this paper demonstrated the potential of plant litter to improve the biogeochemical cycle and nutrients in the forest ecosystems. However, further researches are needed particularly on the effect of species, forest structures, seasons, and climate factors on the plant litter production and decomposition in various types of forest ecosystems.

25시간 연속관측을 통한 섬진강 하구에서 시공간적 해양환경 변화 조절 요인 (Factors Controlling Temporal-Spatial Variations of Marine Environment in the Seomjin River Estuary Through 25-hour Continuous Monitoring)

  • 박미옥;김성수;김성길;권지남;이석모;이용우
    • 한국해양환경ㆍ에너지학회지
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    • 제15권4호
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    • pp.314-322
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    • 2012
  • 섬진강 하구에서 수온, 염분, pH, 용존산소, 부유입자물질, 영양염류, 엽록소 a의 시간에 따른 변화 양상을 파악하기 위해서 2006년 3월(건기)과 7월(우기)에 각각 25시간 연속관측을 실시하였다. 또한 공간적인 분포특성을 파악하기 위해서 염분경사에 따라 해양환경 조사를 실시하였다. 섬진강 하구에서 염분의 변화는 건기에는 조석주기, 우기에는 강물 유출량에 영향을 받는 것으로 나타났다. 용존무기영양염류(질산염, 아질산염, 규산염) 농도의 시공간적 분포는 건기에는 염분의 변화와 좋은 상관관계를 보였다. 반면 우기에는 시간에 따라 농도 변화가 작았다. 우기시 영양염류의 평균 농도는 건기에 비해 용존무기질산염의 경우 약 6배, 용존무기인의 경우 약 4배, 용존무기규산염의 경우 약 43배 높게 나타났다. 엽록소 a 농도는 용존무기영양염류의 농도가 높은 우기에 비해 건기에 높게 나타났다. 이 연구결과, 우기와 건기에 해양환경인자의 시공간적 분포는 조석과 강물유출량의 영향에 의해 결정되며, 엽록소 a의 분포는 용존무기영양염류의 분포보다는 담수의 유출량 변화와 연관성이 있는 것으로 판단된다.

The role of diuretic hormones (DHs) and their receptors in Drosophila

  • Gahbien Lee;Heejin Jang;Yangkyun Oh
    • BMB Reports
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    • 제56권4호
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    • pp.209-215
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    • 2023
  • Maintaining internal homeostasis and regulating innate behaviors are essential for animal survival. In various animal species, a highly conserved neuroendocrine system integrates sensory inputs and regulates physiological responses to environmental and internal changes. Diuretic hormones 44 and 31, which are homologs of mammalian corticotropin-releasing factor (CRF) and calcitonin gene-related peptide (CGRP), respectively, control body fluid secretion in Drosophila. These neuropeptides and their receptors have multiple physiological roles, including the regulation of body-fluid secretion, sleep:wake cycle, internal nutrient-sensing, and CO2-dependent response. This review discusses the physiological and behavioral roles of DH44 and DH31 signaling pathways, consisting of neuroendocrine cells that secrete DH44 or DH31 peptides and their receptor-expressing organs. Further research is needed to understand the regulatory mechanisms of the behavioral processes mediated by these neuroendocrine systems.

연안해역의 환경변화에 따른 저차 생태계 Pulsing Simulation 예비 진단 (Preliminary Diagnosis for Pulsing Simulation of Low Trophic Ecosystem by Environmental Changes in Coastal Area)

  • 이대인
    • 환경영향평가
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    • 제21권3호
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    • pp.461-468
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    • 2012
  • In general, long-term changes of ecological factors take a pulse form in which they interact with other factors and go through a repeated increasing and decreasing cycle. The coupling of the two approaches the grid model and the box model in ecological modeling can lead to an in-depth understanding of the environment. The study analyzes temporal variations of major storages with an energy system model that formulizes effectively the relationships among nutrients, phytoplankton, and zooplankton in the Yellow Sea and the East China Sea. An increase of light intensity and standing stock of nutrient increase the magnitude and frequency of pulsing. Also, an immense reduction of nutrient concentration can cause extinction of the pulsing and bring about a steady state. It is concluded that the nutrient loads in freshwater discharge from the Yangtze affect the cycles of major ecological components as well as water quality variables and play an important role in the marine ecosystem.

Phosphorus and Base Cation Inputs through Litterfall Components in Pine Forests after Tree Removal Due to Pine Wilt Disease Disturbance

  • Baek, Gyeongwon;Kim, Seongjun;Kim, Choonsig
    • 한국산림과학회지
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    • 제108권3호
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    • pp.296-301
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    • 2019
  • This study was conducted to measure litterfall and nutrient (P, K, Ca, Mg) inputs under varying degrees of disturbance by pine wilt disease in pine forests in southern Korea. Litterfall was collected to evaluate nutrient responses at different intensities of disturbance (various levels of basal area) by pine wilt disease across 2 years. Phosphorus, Ca, and Mg concentrations in needle litterfall were positively correlated (p < 0.05) with decreased disturbance intensities (increased basal area) depending on the time of sampling, whereas the nutrient concentrations in other litterfall components (branches, bark, reproductive organs, and miscellaneous litterfall) were not significantly correlated (p > 0.05) with the intensity of pine wilt disease disturbance. Dry weight and nutrient inputs through litterfall components decreased linearly with increasing intensity of disturbance by pine wilt disease (p < 0.05), except for the nutrient inputs of branch (K, Ca, Mg) and reproductive organ (K, Ca) litterfall. These results indicate that decreased litterfall across different levels of disturbance may be related to the reduced soil nutrients in pine wilt disease forests.

Comparisons of Nutrient Concentration of Leaves, Roots, and Soils in Three Bamboo Stands

  • Baek, Gyeongwon;Yoon, Jun-Hyuck;Bae, Eun Ji;Lee, Jihyun;Kim, Choonsig
    • 한국산림과학회지
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    • 제111권1호
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    • pp.108-114
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    • 2022
  • In bamboo, the nutrient status of tissues and associated soil is an important indicator of nutrient uptake by various bamboo species. In this study, the nutrient concentrations of leaves, roots, and mineral soil at 0-10 cm depths were examined in three bamboo stands [Phyllostachys bambusoides S ieb. et Zucc, Phyllostachys nigra var. henonis Stapf ex. Rendle, and Phyllostachys pubescens (Mazel) Ohwi] at a broad regional scale in southern Korea. In the three bamboo species, species-specific differences were observed in the carbon (C) and calcium (Ca) concentrations of leaves and in the nitrogen (N) and magnesium (Mg) concentrations of roots. Ca concentrations in leaves were significantly higher in P. bambusoides (11.94 g Ca kg-1) than in P. pubescens (7.83 g Ca kg-1), whereas potassium (K) concentrations were lowest in P. bambusoides among the three bamboo species. N concentrations in the roots were significantly lower in P. pubescens (5.23 g N kg-1) than in P. nigra var. henonis (7.72 g N kg-1). In contrast to bamboo tissues, soil nutrients, such as total N, organic C, exchangeable Ca2+, and Mg2+, did not differ significantly among the bamboo species. These results suggest that species-specific practices will be required for nutrient management of bamboo stands because nutrient concentrations vary considerably in the tissues of the three studied species.

Nutrient dynamics in montane wetlands, emphasizing the relationship between cellulose decomposition and water chemistry

  • Kim, Jae Geun
    • 한국습지학회지
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    • 제7권4호
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    • pp.33-42
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    • 2005
  • Wetlands often function as a nutrient sink. It is well known that increased input of nutrient increases the primary productivity but it is not well understood what is the fate of produced biomass in wetland ecosystem. Water and sediment quality, decomposition rate of cellulose, and sediment accumulation rate in 11 montane marshes in northern Sierra Nevada, California were analyzed to trace the effect of nitrogen and phosphorus content in water on nutrient dynamics. Concentrations of ammonium, nitrate, soluble reactive phosphorus (SRP) in water were in the range of 27 to 607, 8 to 73, and 6 to 109 ppb, respectively. Concentrations of ammonium, calcium, magnesium, sodium, and potassium in water were the highest in Markleeville, which has been impacted by animal farming. Nitrate and SRP concentrations in water were the highest in Snow Creek, which has been impacted by human residence and a golf course. Cellulose decomposition rates ranged from 4 to 75 % per 90 days and the highest values were measured in Snow Creek. Concentrations of total carbon, nitrogen, and phosphorus in sediment ranged from 8.0 to 42.8, 0.5 to 3.0, and 0.076 to 0.162 %, respectively. Accumulation rates of carbon, nitrogen, and phosphorus fluctuated between 32.7 to 97.1, 2.4 to 9.0, and 0.08 to $1.14gm^{-2}yr{-1}$, respectively. Accumulation rates of carbon and nitrogen were highest in Markleeville and that of phosphorus was highest in Lake Van Norden. Correlation analysis showed that decay rate is correlated with ammonium, nitrate, and SRP in water. There was no correlation between element content in sediment and water quality. Nitrogen accumulation rate was correlated with ammonium in water. These results showed that element accumulation rates in montane wetland ecosystems are determined by decomposition rate rather than nutrient input. This study stresses a need for eco-physiological researches on the response of microbial community to increased nutrient input and environmental change because the microbial community is responsible for the decomposition process.

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광 조사 간격이 Chlorella vulgaris의 성장량 및 질소, 인 대사에 미치는 영향 (Effects of light irradiation interval on the metabolism of nitrogen, phosporus and growth rate of Chlorella vulgaris)

  • 황현정;황선진
    • 상하수도학회지
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    • 제31권5호
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    • pp.441-445
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    • 2017
  • This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.