• Journal of Ecology and Environment
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• 제30권3호
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• pp.251-255
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• 2007

Self-thinning was measured in Salix communities on Bam Island in Seoul at various age stages. $D^2H$ was used to estimate tree biomass, where D is stem diameter at breast height or 10 cm height for plants with height <1.5 m, and H is height. A log-log plot of density versus $D^2H$ and correlation analysis indicated a significant relationship between density and biomass with equation 'log $D^2H$ = -1.27 log N + 7.06'. This indicates that self-thinning affects biomass in the Salix community with -1.27 as the thinning coefficient. If we assume a thinning exponent -3/2, then the allometric coefficient of the equation, log w = a log $D^2H$ + b, is 1.18. This is much higher than that for any other species studied in Korea. There were statistically significant relationships between age and density and between age and basal area and these relationships suggest guidelines for transplantation of willows and for the assessment of Salix community restoration projects in riverine wetlands based on standard density, basal area, and age. The results of this study may also increase understanding of succession processes in Salix community restoration in riverine wetlands.

• 한국환경생태학회지
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• 제20권2호
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• pp.103-113
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• 2006

월출산국립공원 묵동지역에 대해 30개 조사지(단위면적 $100m^2$)를 설정하여 식생구조를 파악하였다. TWINSPAN을 이용하여 군락분리를 시도한 결과, 굴참나무-신갈나무군락, 굴참나무군락, 굴참나무-소나무군락, 소나무군락 그리고 상수리나무군락의 5개 군락으로 최종 분리되었다. 각각의 군락은 상대우점치를 이용하여 군락구조를 밝혔다. 이상의 결과를 통해 월출산국립공원 묵동지역의 식생천이는 소나무림에서 참나무림으로 진행될 것으로 예상된다.

• 한국물환경학회지
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• 제27권4호
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• pp.413-424
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• 2011

The study was aimed to evaluate the applicability of a three-dimensional (3D) hydrodynamic and water quality model, ELCOM-CAEDYM for Yongdam Reservoir, Korea. The model was applied for the simulations of hydrodynamics, thermal stratification processes, stream density flow propagation, and water quality parameters including dissolved oxygen, nutrients, organic materials, and algal biomass (chl-a) for the period of June to December, 2006. The field data observed at four monitoring stations (ST1~ST4) within the reservoir were used to validate the models performance. The model showed reasonable performance nevertheless low frequency boundary forcing data were provided, and well replicated the physical, chemical, and biological processes of the system. Simulated spatial and temporal variations of water temperature, nutrients, and chl-a concentrations were moderately consistent with the field observations. In particular, the model rationally reproduced the succession of different algal species; i.e., diatom dominant during spring and early summer, after then cyanobacteria dominant under warm and stratified conditions. ELCOM-CAEDYM is recommendable as a suitable coupled 3D hydrodynamic and water quality model that can be effectively used for the advanced water quality management of large stratified reservoirs in Korea.

• 한국해양학회지:바다
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• 제24권1호
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• pp.92-105
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• 2019

제주 연안 식물플랑크톤 군집의 시공간적 특성을 파악하기 위해 2015년 3월부터 2016년 2월까지 10개의 정점 0, 30 m 수심에서 수온, 염분, 용존산소 등 환경 요인과 현존량 및 출현종 등을 매월 조사하였다. 조사기간 동안 제주 연안의 평균 수온은 0 m 13.7~25.9, 30 m $13.6{\sim}20.8^{\circ}C$의 범위로써 3월에 최소값, 8월에 최대값을 보였다. 평균 염분은 0 m 31.51~34.47, 30 m 33.03~34.47psu의 범위였으며, 7월에 최소값, 2월에 최대값을 보였다. 평균 용존산소는 0 m 6.12~8.10, 30 m $5.73{\sim}7.88mg\;L^{-1}$의 범위를 보였으며, 평균 Chl-a 량은 0 m 0.28~2.48, 30 m $0.44{\sim}1.01{\mu}g\;L^{-1}$ 범위를 보였고 식물플랑크톤 현존량은 연중 $5,300{\sim}639,900cells\;L^{-1}$ 범위로써 현존량은 전 정점에서 2월에 최소, 북부와 서부해역은7월, 남부와 동부해역은 8월에 최대를 보였다. 조사기간 중 출현한 총 종수는 362종으로써 규조류(Bacillariophyta) 181종, 와편모조류(Dinophyta) 147종, 그리고 기타 식물편모조류(phytoflagellates) 34종으로 구성되었다. 20%이상의 현존량 점유율 차지한 우점종을 계절별로 보면, 춘계(3월)와 추계(10월)에 Paralia sulcata와 Skeletonema costatum 두 종이었으며, 하계(8월)에는 Chaetoceros 속 6종류, 그리고 동계(12월)에는 Chaetoceros 속 2종류와 Thalassionema frauenfeldii가 우점하여, 각 우점종의 계절적 분포가 뚜렷하였다. 해역별 식물플랑크톤 군집 동태를 보면, 북부와 서부해역의 현존량 월변화가 비슷한 경향성을 보였으며, 남부와 동부해역이 유사한 경향성을 보였다. 이상의 종조성과 우점종의 천이는 이전 조사와 다른 특징을 보이고 있으며 이러한 식물플랑크톤 군집 동태 변화는 수온과 염분, 그리고 해류 등의 물리적 환경 변화에 기인된다고 생각된다.

• 생태와환경
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• 제37권1호통권106호
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• pp.47-56
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• 2004

영양염 (N, P, Si, Fe) 결핍이 팔당호내 서로 다른 3개지점의 식물플랑크톤 군집(>10 ${\mu}m$)에 어떠한 영향을 미치는지 파악하기 위하여 채수한 현장수를 결핍배지에서 일정시간 배양한 후 대조군과 비교 조사하였다. 조사결과, 현장수는 공히 영양물질과 현장수 증류에 따라 서로 다른 종 천이 및 생물량을 나타냈다. 영양염 결핍에 따른 천이는 N, P, Si 결핍군에서는 속(genus)수준에서, Fe결핍에서는 종(species) 수준에서 일어났다. 특히 Fe결핍에서 남조 Microcystis aeruginosa, N 결핍에서 Anabaena의 발달은 매우 흥미로운 결과이다. 또한 모든 결핍군에서 뚜렷한 성장저해 현상을 보였으나 Si 결핍군에서는 생물량 변동이 거의 없었다. 식물플랑크톤 군집은 영양염결핍과 채수지점에 따라 차이를 보였는데, 전체적으로 N,P 결핍군에서는 우점도 감소 및 다양도 증가를 보였으며,Si,Fe 결핍군과는 반대 결과를 보였다. 따라서 영양염 결핍은 조사지점에 따라 다소 차이를 보였으나 식물플랑크톤 종 천이, 생물량 변동 등의 뚜렷한 군집변화를 유도함으로서 수계내 문제조류의 근본적 해결의 가능성을 시사해 주었다.

• 한국산림과학회지
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• 제81권4호
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• pp.325-336
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• 1992

본 연구는 오대산(五臺山) 국립공원내(國立公園內)의 활엽수(闊葉樹)-젓나무속(屬) 혼효림(混淆林)에서 삼림천이(森林遷移) 경향과 잠재(潛在) 삼림식생(森林植生)을 검토 분석한 것이다. 88개의 $5m{\times}50m$ 대상표본구(帶狀標本區)를 설치하여 상층(上層) 우세목(優勢木)의 아래에서 생육하는 하층목(下層木)에 의해서 세대(世代) 교체(交替)되는 과정을 바탕으로 천이(遷移) 경향을 평가하였다. 조사 대상 삼림(森林)의 천이(遷移) 경향 분석은 Markov chain의 수학적(數學的) 이론에서 변형된 추이행렬(推移行列) 모델을 사용하였다. 본 연구 결과가 암시하는 바에 의하면 조사 삼림(森林)은 천이(遷移)의 중간단계(中間段階)에 있으며, 수종(樹種) 구성상(構成上) 극성상림(極盛相林)에 도달하려면 700년(年) 이상의 기간이 소요될 것으로 나타났다. 현재 28%와 13%의 높은 상대밀도(相對密度)를 유지하고 있는 신갈나무와 피나무는 극성상(極盛相)의 안정상태(安定狀態)가 되면 각각 3%와 5% 이하로 수종(樹種) 구성비율(構成比率)이 감소하리라 예상된다. 반면에, 젓나무, 당단풍, 까치박달, 그리고 잣나무의 구성비율(構成比率)은 증가할 것으로 사료되며, 현재 활엽수(闊葉樹)와 침엽수(針葉樹)의 혼효율(混淆率)이 6.5 : 3.5에서 5.0 : 5.0로 변화할 것이다. 신갈나무의 천이계열상(遷移系列上)의 문제점을 고찰한 바, 신갈나무는 천이(遷移) 중반단계의 우세종(優勢種)으로써 역할을 하며 극성상(極盛相) 수종(樹種)은 아닌 것으로 추정한다. 추이행렬(推移行列) 모델의 실제 상황에 대한 적용성을 평가하기 위하여 연구 모델의 단정(假定)과 민감도(敏感度) 역시 고찰하였다. 전반적인 연구 결과가 지적하는 바에 의하면 조사 삼림의 현재 생태적(生態的) 동태(動態)는 인간에 의한 방해와 교란(攪亂)이 있은후 천이가 진행 중임을 반영(反映)한다.

• 환경생물
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• 제21권1호
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• pp.8-17
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• 2003

The spatio-temporal distribution and seasonal fluctuations of phytoplankton community were carried out in the Southwestern parts of Deukryang Bay of the Korean South Sea from July 1997 to January 1998. A total of 60 species of phytoplankton belonging to 41 genera was identified. In the southwestern parts of Deukryang Bay seasonal succession in dominant species; Eucampia zodiacus, and Chaetoceros spp. in summer, Nitzschia longissima, Chaetoceros curvisetus and Bacillaria paxillifera in autumn, Skeletonema costatum and B. paxillifera in winter, were very predominant. The community structure of phytoplankton in the southwestern parts of Deukryang Bay appeared to be diverse in species composition, and diatoms were most dominant through the year. Phytoplankton standing crops fluctuated with an annual mean of $1.2{\times}10^5$ cells $L^{-1}$ between the lowest value of $8.0{\times}10^3$ cells $L^{-1}$ in January and the highest value of $6.9{\times}10^5$cells $L^{-1}$ by Nitzschia longissima in January. Densities of the phytoplankton cell number by the samples of the southwestern parts of Deukryang Bay ranged from $1.1{\times}10^4$ cells $L^{-1}$ to $1.3{\times}10^5$ cells $L^{-1}$ with the mean value of $4.1{\times}10^4$ cells $L^{-1}$ in summer, from $1.0{\times}10^4$ cells $L^{-1}$ to $6.9{\times}10^5$ cells $L^{-1}$ with mean of $1.8{\times}10^5$ cells $L^{-1}$ in autumn, from $8.0{\times}10^3$ cells $L^{-1}$ to $4.6{\times}10^5$ cells $L^{-1}$ with mean $1.6{\times}10^5$ cells $L^{-1}$ in winter. That is to say, phytoplankton standing crops was high in low temperature seasons, while low in high temperature seasons. Chlorophyll a concentration fluctuated between 1.08 mg $m^{-3}$ and 21.6 mg $m^{-3}$ in January. In the southwestern parts of Deukryang Bay temporal change in chl-a concentration was not apparent. But chl-a concentration was high during a year. Therefore, phytoplankton production in the southwestern parts of Deukryang Bay could be very high year-round.

• 한국환경복원기술학회지
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• 제10권3호
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• pp.52-59
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• 2007

This study was carried out to select proper species for early stage replantation in cutting-slope area of the Baekdu Range roadside. In the cutting-slope area and upper forest area of the cutting-slope area, sample plots of 46 were selected and their vegetations and environmental factors were investigated. We found total 90 species in the 46 plots. We found Festuca arundinacea in 27 plots of the 46 plots. We also found Lespedeza bicolor in 26 plots, Eragrostis curvula in 22 plots, Artemisia princeps var. orientalis in 19 plots, Erigeron annuus and Pinus densiflora in 15 plots, Lactuca indica var. laciniata in 14 plots, Miscanthus sinensis in 13 plots, Oenothera odorata, Commelina communis, and Humulus japonicus in 11 plots, Lespedeza cuneata in 10 plots, Salix koreensis and Salix hulteni in 9 plots, Festuca rubra, Youngia denticulata, Aster scaber, and Festuca arundinacea in 8 plots, Chenopodium album var. centrorubrum in 7 plots, Patrinia villosa and Erigeron canadensis in 6 plots, and Setaria viridis, Digitaria sanguinalis, and Dactylis glomerata in 5 plots.The dominancy of Festuca arundinacea, Eragrostis curvula, Lespedeza bicolor, Miscanthus sinensis, Pinus densiflora, Festuca arundinacea, Festuca rubra, Artemisia princeps var. orientalis, Erigeron annuus, Lespedeza cuneata, Dactylis glomerata, Salix koreensis, Alnus hirsuta, Pueraria thunbergiana, Medicago sativa, Lactuca indica var. laciniata, and Digitaria sanguinalis were 13.41% 11.87%, 4.88%, 4.56%, 3.38%, 2.29%, 2.14%, 2.14%, 1.99%, 1.95%, 1.54%, 1.47%, 1.44%, 1.37%, 1.15%, 1.13%, 1.07% in the roadside cutting-slope, respectively. The dominancy of Rhododendron mucronulatum, Lindera obtusiloba, Rhus trichocarpa, Quercus mongolica, Lespedeza bicolor, Rhododendron schlippenbachii, and Quercus serrata 22.15%, 13.36%, 13.14%, 12.03%, 11.74%, 11.20%, and 11.14% in shrub layer of the upper forest area, respectively. The species of Rhododendron mucronulatum, Lindera obtusiloba, Rhus trichocarpa, Rhododendron schlippenbachii, Zanthoxylum schinifolium, Weigela subsessilis, Stephanandra incisa, Rhamnus davurica, Ligustrum obtusifolium, Lindera erythrocarpa, Rosa multiflora, Rubus coreanus, Symplocos chinensis for. pilosa, Smilax china, Prunus sargentii, and Staphylea bumalda may be more helpful in stabilizing of the cutting-slope area and making harmony with the surrounding forest area.

• 한국조경학회지
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• 제32권3호
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• pp.1-17
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• 2004

The focus of this study is the promotion of green area volumes and their naturalness, water circulation system, decline of entropy, creation of biological habitats and linkage of separated urban green space. Re-presentative urban biotope survey sites were categorized as urban biotope, semi-natural biotope, and natural forest. In the urban biotope, a residential biotope was constructed near the Han river and in mountain areas. The green-area ratio at the housing complex was about 25%. GVZ(Grunvolumenzahl) was 0.35m$^3$/m$^2$ at the 5∼10-story housing complex, and 1.53m$^3$/m$^2$ over the 11-story. As for the green-area structure of the housing complex, canopy layer, understory layer, and shrub layer were not differentiated and the green-area volume was not high enough. The green-area ratio of school areas as a public area biotope was 5∼20%. GVZ was 1.12m$^3$/m$^2$ at Myungduk High School, and 1.78m$^3$/m$^2$ at Jeonggok Elementary School. In order to convert the urban biotope into an ecological area, green areas around the buildings should be connected to urban buffer green areas, and multi-layer structures should be established with natural plant species. In the semi-natural biotope, neighbor parks were created park in the vicinity of the natural forests. GVZ was 0.28m$^3$/m$^2$, and plantation was established with single layer structure and was definitely insufficient for the area. The urban buffer green areas have been established in strip corridors with the width of 20∼123m. In those areas, GVZ was 0.16∼0.27m$^3$/m$^2$ and had a deficient canopy layer, understory layer, and shrub layer. Soil conditions were not favorable for tree growth. In the natural biotope, GVZ of the plantation was 1.03∼1.5m$^3$/m$^2$ but the high crown closure of this area reduces the chance of species change and succession. GVZ of natural forest was 2.53∼2.57m$^3$/m$^2$. It is desirable to plant diverse plants and the natural forest should be succeeded by broad-leaf deciduous tree species. To improve the value of biotope at Kangseo-Gu, building height needs to be limited to reduce the environmental deterioration in the city. In order to maintain the water circulation system, water-permeable material is recommened when the urban surface areas are paved. The establishment of a water circulation system will improve ground water levels, soil moisture, water quality, and habitats. In order to improve biological diversity, it is desirable to have multi-layer structures in urban green areas with native species.

• 한국환경과학회지
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• 제19권11호
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• pp.1407-1421
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• 2010

This study was carried out to elucidate the relation between water quality and structure of the aquatic ecosystem in the agriculture reservoir Otae-ji from January to December in 2009. The proportion of forest was 46.98%, which means that non-point sources are major contributor of water pollution in this area. The annual mean COD(Chemical Oxygen Demand) in Otae-ji was $3.6mgL^{-1}$, indicating, level II of environmental standards and the trophic state was mesotrophic. Although total phosporus concentration in the reservoir was high in August due to large inflow of nutrients from outside the reservoir during monsoon season, there was no break out of significant algal bloom in the summer. The seasonal succession of phytoplankton showed that the dinophyta dominated in the the spring, chlorophyta in the summer, chrysophyta and chlorophyta in the autumn and chrysophyta in the winter. In case of zooplankton, rotifers dominated in the most seasons, but cladoceran(Bosmina longirostris) dominated in June and copepod(Nauplii) in August. The macrophyte plants showed diverse species compositon consisted of 3 varieties, 24 species, 23 genera, 15 families and 14 orders. The macroinvertebrates also showed various FFG(Functional Feeding Groups) such as GC(Gathering-Collector), P(Predator), SH(Shedder), FC(Filter-Collector) and PP(Plant-Piercer). Ecosystem stability analysis using aquatic insects was classified as Group I, which has high resilience and resistance indices. A total of 14 species of fish was collected but exotic species such as Lepomis macrochirus and Micropterus salmoides were not found in Otae-ji. In conclusion, the preservation of healthy food wed in the reservoir ecosystem is closely related to water quality management as well as effective prevention of algal bloom by helping good material circulation in aquatic ecosystems.