• 제목/요약/키워드: habitat density

검색결과 356건 처리시간 0.032초

먹이 밀도와 수심에 따른 황새(Ciconia boyciana)의 섭식 행동에 대한 사례연구 (A Case Study on Foraging Behavior of Oriental White Storks (Ciconia boyciana) in the Variation of Prey Density and Water Depth)

  • 성하철;김정희;정석환;김수경;조지연;정미라;최유성;박시룡
    • 환경생물
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    • 제27권2호
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    • pp.155-163
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    • 2009
  • 멸종위기종 황새의 야생 방사를 위한 먹이 서식지 조성 시 필요한 정보를 제공하고 야생 황새의 먹이 서식지 보호와 보존을 위한 기초 자료를 제공하고자 연구를 시작하였다. 이를 위하여 충북 청원군 미원면 화원리에 있는 산지형 습지 일부에 울타리를 치고 황새 암수의 한 쪽 날개의 첫째날개깃 일부를 잘라 방사하여, 6월 20일부터 8월 16일까지 서식지 먹이 밀도와 수심 변화에 따른 서식지 이용률 및 섭식행동 특성을 파악하였다. 황새는 밀도가 높은 서식지에서 오랫동안 머물며 섭식시도와 섭식량을 증가시켰으며 수심에 따라 암컷은 수심이 얕은 서식지에서 그리고 수컷은 중간 깊이의 서식지에서 섭식시간과 섭식량을 증가시켰다. 그러나 섭식효율성은 밀도와 수심과 관련없이 의미있는 차이가 없었다. 단지 암수 간의 섭식효율성이 밀도에 따라 그리고 수심이 다른 서식지에서 섭식행동에 따라 다르게 나타났다. 따라서 본 연구를 통하여 반자연적 환경에 방사된 황새가 먹이 밀도에 따라 섭식 지역을 선택할 수 있음을 보여주었고 섭식효율성은 개체에 따라 혹은 섭식 방법에 따라 다르게 나타날 수 있음을 보여주었다.

삼지구엽초(三枝九葉草) 자생지(生地生) 환경(環境) 특성(特性) (Habitat Environment of Epimedium koreanum Nakai)

  • 박경열;최병열;이은섭;김순재;박철호
    • 한국약용작물학회지
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    • 제6권1호
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    • pp.51-56
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    • 1998
  • 본 연구는 1995년부터 1997년까지 경기도와 강원도 5개군 7개소를 중심으로 자생하는 삼지구엽초의 환경특성을 구명하여 삼지구엽초 작물화재 배연구의 기초자료로 제공하고자 수행하였던 바 그 결과를 요약하면 다음과 같다. 1. 조사된 자생지는 대체로 북서 사면에 표고 $60{\sim}400m$, 경사도 $2{\sim}20%$인 곳의 냇가에서 $5{\sim}80m$ 주위로 물줄기를 따라 장타원으로 위치하고 있었다. 2. 자생지 토양은 잔자갈이 있는 양토 또는 사양토로서 가비중이 $0.74{\sim}1.26g/cm^3$, 공극율 $52.5{\sim}72.1%$로 나타났다. 3. 토양화학성은 pH $4.1{\sim}5.8$, 유기물함량 $4.9{\sim}6.6%$, 유효인산 $21{\sim}125\;ppm$, 치환성양이온 (me/100g)은 $K^+\;0.35{\sim}1.09,\;Ca^{++}5.42{\sim}18.73,\;Mg^{++}\;0.99{\sim}1.53$, CEC는 $14.8{\sim}34.3me/100g$이었다. 4. 자생지는 주로 개암나무, 떡갈나무, 참나무 등 낙엽광엽활엽수에 의하여 차광되어 취, 둥굴레, 삽주, 뱀딸기, 제비꽃 등 반음지식물과 함께 자생하고 있었다. 5. 삼지구엽초 군락에 도달하는 광투과 정도는 노지 대비 relative photon flux density $3.5{\sim}13.1%$ 상대조도는 $3.3{\sim}11.9%$ 였으며 기온은 $4.3{\sim}6.5^{\circ}C$낮았다. 또한 지온은 5월에서 8월까지 $17.5{\sim}20.1^{\circ}C$로 경과되어 외기기온의 $25.1{\sim}30.8^{\circ}C$에 비하여 낮았으나 변화폭이 작았다.

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안면도 소나무림 내 미세지형구분을 통한 하층식생구조와 소나무 천연갱신 양상 (Vegetation Structure of Lower Stratum and Pinus densiflora Natural Regeneration Features from Micro-topography Classification in Pinus densiflora Forest of Anmyeon-do Island)

  • 변성엽;김현섭;윤충원
    • 한국산림과학회지
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    • 제108권2호
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    • pp.189-199
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    • 2019
  • 최근 수입 생산을 목표로 한 산림관리에서 생태계 관리를 목표로 하는 산림관리로 패러다임 전환이 진행되고 있으며, 이에 따라 자연 친화력이 높은 천연갱신법이 근래에 들어 주목을 받고 있다. 본 연구는 소나무림을 대상으로 각종 환경인자와 하층식생, 갱신 치수와의 상관관계를 구명하고자 수행하였다. 조사구의 설치는 선상조사법을 이용하여 총 50개소를 설치하였으며, 조사된 자료를 갱신치수량과 밀접한 관계성을 보인 토양습도에 따라 습지(19개소), 건조지(31개소)로 구분하여 분석하였다. 그 결과, 높은 갱신량을 보인 건조지(157,419본/ha)에서는 졸참나무, 초피나무, 청미래덩굴, 칡 등이 주요 종으로 나타났으며, 낮은 갱신량을 보인 습지(57,895본/ha)에서는 국수나무, 밤나무, 조록싸리, 까치수염, 두릅나무, 때죽나무 등이 주요종으로 나타났다. 치수고와 근원경 발달의 분석결과 습지가 건조지에 비해 생장속도가 빨랐으며, 근원경 대비 수고 생장속도는 건조지가 습지에 비해 빠른 것으로 나타났다. 습지에서 갱신치수는 발아한 후 5년이 경과했을 때 급격한 생장량을 나타내는 것으로 확인되었다. 이는 갱신 치수가 주변 식생과의 경쟁 등 생육환경에 적응할 수 있는 능력을 갖추게 되면 급격한 생장을 이루는 것으로 판단되므로, 습한 지역에서의 천연갱신 시업 초기에는 건조한 지역에 비하여 풀베기 작업 등의 관리를 보다 집약적으로 수행하여야 할 것으로 판단되었다.

Application of Statistical and Machine Learning Techniques for Habitat Potential Mapping of Siberian Roe Deer in South Korea

  • Lee, Saro;Rezaie, Fatemeh
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • 제2권1호
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    • pp.1-14
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    • 2021
  • The study has been carried out with an objective to prepare Siberian roe deer habitat potential maps in South Korea based on three geographic information system-based models including frequency ratio (FR) as a bivariate statistical approach as well as convolutional neural network (CNN) and long short-term memory (LSTM) as machine learning algorithms. According to field observations, 741 locations were reported as roe deer's habitat preferences. The dataset were divided with a proportion of 70:30 for constructing models and validation purposes. Through FR model, a total of 10 influential factors were opted for the modelling process, namely altitude, valley depth, slope height, topographic position index (TPI), topographic wetness index (TWI), normalized difference water index, drainage density, road density, radar intensity, and morphological feature. The results of variable importance analysis determined that TPI, TWI, altitude and valley depth have higher impact on predicting. Furthermore, the area under the receiver operating characteristic (ROC) curve was applied to assess the prediction accuracies of three models. The results showed that all the models almost have similar performances, but LSTM model had relatively higher prediction ability in comparison to FR and CNN models with the accuracy of 76% and 73% during the training and validation process. The obtained map of LSTM model was categorized into five classes of potentiality including very low, low, moderate, high and very high with proportions of 19.70%, 19.81%, 19.31%, 19.86%, and 21.31%, respectively. The resultant potential maps may be valuable to monitor and preserve the Siberian roe deer habitats.

한국의 갯벌 생태등급도 개발을 위한 생물학적 지시자의 검토와 제안 (Review and Proposition of Biological Indicators for a New Ecological Grading System of Tidal Flats in Korea)

  • 유재원;이창근;고병설;이시완;한동욱;최근형;김창수;홍재상
    • Ocean and Polar Research
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    • 제33권1호
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    • pp.85-97
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    • 2011
  • The tidal flats of Korea today have reduced by 40% in size compared to 1964. To manage this important habitat properly, development of well-organized and nationwide-applicable grading systems is required. There have been several assessment systems proposed previously in Korea, but they are critically flawed in that selected biological indicators are not adequate and grading criteria are obscure and arbitrary. We reviewed the indicators used in these previous evaluation systems (e.g., diversity indices, quantity and quality of benthic macrofauna, halophytes, water birds, etc.) and subsequently proposed new indicators and an improved grading scheme. For the quantitative assessment of macrobenthic community, biomass reflecting production and ecosystem function is recommended over density, which is much less discriminatory among habitats. Of biodiversity indices used, within-, between-habitat and regional biodiversity indices that accurately reflect sampling efforts are suggested. In addition, we proposed to include species rarity, ecosystem engineers, and the ecological quality index ISEP (Inverse function of Shannon-Wiener Evenness Proportion). As for halophytes, their low spatial coverage on benthic habitat suggests that their presence can be used as an ecological indicator of benthic habitat, regardless of their protective status. We stress the need to introduce 1) quantile approach for quantitative indicators (e.g., diversity, biomass, etc.) in relation to grading, 2) presence-absence approach for spatial or aggregate indicators (e.g., boundaries of halophytes and feeding ground of water birds) and 3) benthic habitat mapping that combines all of these indicators.

불개미를 이용한 송총의 생물적방제에 관한 연구 (Studies on the Biological Control of Pine Caterpillar (Dendrolimus spectabilis Butler) by Red Wood Ants (Formica rufa truncicola var. yessoensis Forel))

  • 김창효;최진식
    • 한국응용곤충학회지
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    • 제15권1호
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    • pp.7-16
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    • 1976
  • 본 보고는 불개미 (Formica rufa truncicola var. yessoensis Forel: red wood ant, Polydomous ant)가 어떤 일정한 지역의 삼림애 한정되어 서식하기 때문에 그의 서식지에 있어서의 서식의 제한인자인 생태학적 환경요인을 구명함으로서, 다른 지역의 송림에 이식하여, 실제로 송충의 천적으로 이용할 수 있는 기초자료가 될 수 있으므로. 자연서식지(A구)이 있어서의 불개미 집(소)의 분포와 밀도를 조사하는 동시에, 토양의 물리 및 화학적성질, 식물의 분포와 밀도, 소나무의 입목도와 울패도, 조소와 지주식물, 지표면의 습도 그리고 이식시험한 결과 등을 종합한 것이며 그의 결과를 요약하면 다음과 같다. 1. 자연서식지에 있어서 불개미의 집(소)은 주로 산록부와 산복부이 분포하여 서식밀도가 높으나 산정부에는 불개미가 전혀 서식하지 못하였다. 2. 자연서식지(A구)에 있어서의 불개미의 경제밀도는 $2.85/m^2$이고 단위밀도는 $1.95/m^2$로서 실제로 송충의 발새오가 피해를 완전히 억제하고 있으므로 경제적 이용효율이 높은 것으로 사료된다. 3. 불개미의 자연서식지는 10-20년생 소나무가 밀생하여 임목도와 울패도가 높은 송림의 지표면에 임간나지가 많고 쇠풀과 화본과 잡초인 새류가 부분적으로 군생하는 반면에 잔디가 적었다. 4. 불개미는 자연서식지의 산록부가 산복부에서 주로 새류와 소나무 등을 지주식물로 이용하여 조소하였다. 5. 자연서식지에 있어서 습도에 따르는 불개미의 분포한계선은 5월부터 9월까지(활동기)는 산복부의 $76\%$선이고 10-11월(월동기)까지는 $72\%$선이었다. 6. 불개미의 자연서식지는 지표면에 유기물과 수분등의 함량이 많은 반면에 Ca와 Mg의 함량이 적고, 미사와 세사 및 점토가 많은 반면에 조사가 현저히 적었다. 7. 불개미를 자연서식지와 환경조건이 비슷한 비서식지의 송림에 분군이식하면 증식과 정착이 가능하다는 것을 알 수 있었다.

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Small-scale spatial genetic structure of Asarum sieboldii metapopulation in a valley

  • Jeong, Hyeon Jin;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • 제45권3호
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    • pp.97-104
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    • 2021
  • Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m2) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (Gst = 0.548, Nm = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

인공보의 어류생태영향 평가를 위한 Echo-sounder 모니터링 기법 적용 (Application of Echo-Sounder Monitoring Technique as Ecological Impact Assessments of Fish on Artificial Weir Construction)

  • 한정호;이재훈;최지웅;임병진;박종환;안광국
    • 환경영향평가
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    • 제21권6호
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    • pp.859-877
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    • 2012
  • In this study, Echo-sounder($E_s$) monitoring methodology was applied to test environmental impacts of artificial weirs(SCW and JSW) in the Yeongsan River on fish community and habitat structures at first time, and was compared with conventional fish sampling methodologies($C_s$). For the Es monitoring in the fields, parallel transect methods was employed in determining the survey distance interval with every 125 m within the upper-lower 2 km of the weirs. Four different fish sampling gears such as casting nets, kick nets, fyke nets, and gill nets were used for applications of $C_s$ monitoring methodology. According to the Echo-sounder monitoring, fish density, expressed as a number of individuals per square meter, along the longitudinal axis of the weir was significantly greater(JSW, t = 3.506, n = 30, p < 0.001) in the down-river reach of the weir than in the up-river reach. Also, fish density along the vertical water column was highest at mid-depths of Seungchon weir, which has simple habitat substrates, while fish density was highest at hypolimnetic depth of Juksan weir. According to fish sampling by the $C_s$ methodology, the fish compositions decreased as the river goes upward, and significant differences(JSW, t = 0.248, n = 30, p < 0.05) in the compositions of fish species occurred between up-reach and down-reach of the weirs. The dominant species near the two weirs were Opsarichthys uncirostris amurensis, Hemiculter eigenmanni and Coilia nasus. Overall, our fish and habitat data, based on $E_s$ and $C_s$ monitoring methodologies, suggest that the weirs disturbed the rivers due to initial habitat disturbances by the weir constructions as well as the barrier roles of weirs on fish passage and migrations. More long-term scientific and systematic fish impact monitoring and assessments($E_s$ and $C_s$) are required in the future to predict changes of ecological structures and functions on the constructions of the weirs.

Habitat Use of Cranes in Cheolwon Basin, Korea

  • Lee, Won-Shin;Rhim, Shin-Jae;Park, Chan-Ryul
    • The Korean Journal of Ecology
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    • 제24권2호
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    • pp.77-80
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    • 2001
  • We investigated the habitat use of cranes, and suggested the proper way to protect and manage the cranes in Cheolwon Basin, which is the most important wintering ground of cranes in Korea. Field surveys were conducted in the wintering seasons from Nov. 1994 to Feb. 1995, and from Nov. 1997 to Feb. 1998. The habitat loss and environmental changes by the road construction and agricultural field rearrangement might have affected the distribution of the cranes. The distribution of cranes seemed to be related with the density of rice grains remained in rice paddies.

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Habitat Evaluation of Japanese Black Bear using GIS

  • Masuyama, Tetsuo;Yamamoto, Toshiharu;Hara, Keitarou;Yasuda, Yoshizumi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1134-1136
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    • 2003
  • In this research, GIS based evaluation methods were applied to habitats of Japanese black bear (Ursus thibetanus japonicus Schlegel) in northern Honshu. The study area was divided into 828 small watershed units , and five GIS indexes, Vegetation Type(V.T.), Extent of Forest Cover (E.F.C.) Slope Incline (S.I), Average Altitude (A.A.) and Road Density(R.D.), were used to evaluate each watershed unit in terms of suitability as black bear habitat. In addition, Interspersion and Juxtaposition spatial indices were calculated for each watershed unit. The results clearly identified the regions with the most suitable habitats, indicating that this methodology is suitable for application to various environmental planning efforts, such as regional development master plans, project-specific environmental impact assessments, species management plans and biodiversity conservation plans.

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