• Title/Summary/Keyword: 서식이용 밀도

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Distribution Characteristics of Largemouth Bass (Micropterus salmoides) as an Exotic Species, in Some Medium-to-Large Size Korean Reservoirs and Physico-chemical Water Quality in the Habitats (국내 중대형 인공호에서 외래종인 배스(Micropterus salmoides)의 분포 특성 및 서식지의 이화학적 수질)

  • Kim, Hyun-Mac;Kil, Ji-Hyon;Lee, Eui-Haeng;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.46 no.4
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    • pp.541-550
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    • 2013
  • The objective of this study was to understand the distribution characteristics of largemouth bass as an exotic species in relation to water chemistry. The survey was conducted in 10 reservoirs in Korea that showed different properties in size, location and eutrophic state. Total number of fish species observed in the artificial reservoirs was 52 (13 family) and the relative abundance of the bass was 13% of the total, which is the third dominant species in the whole sample. The relative abundance of bass was the highest in the Pyungtak reservoir (60%), whereas the Daechung reservoir showed the lowest abundance (only 3%). Although no significance difference statistically were founded in the relationship between bass abundance and water quality parameters. The reservoir trophic state showed some relationships. As result, the higher abundance was observed in hypertrophic reservoirs that located in the esturine regions compared to other large and medium reservoirs classified as meso- or eutrphic state. In conclusion, bass distribution in the reservoir ecosystem can not be directly explained by water chemistry only but other environmental factors should be considered.

Assessment of benthic environment conditions of oyster and mussel farms based on macrobenthos in Jinhae bay (저서생물상을 이용한 진해만 수하식 양식장의 저서환경 평가)

  • Park Heung-Sik;Yi Soon-Kil
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.5 no.1
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    • pp.68-75
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    • 2002
  • This study were observed to the conditions of organic pollution applying to tile environmental assessments based on macrobenthos around the raft culture ground which became an issue by organic matter input in Jinhae Bay. Three stations, mussel farm, oyster farm and the control station on which rarely culture activities were fixed and have analyzed to the sediment characteristics and macrobenthic communities. Muddy substrates between 6.0 and 6.60 on mean grain size have prevailed to the bottom layer in all stations. The highest organic matter content of 2.8% was observed to the mussel farm while the lowest one of 1.5% was recorded on the control area. As a total, 79 species from seven phyla were identified. Comparing to shell farms, the control station have composed to more diversified community structure. In the mussel and the oyster farm, opportunistic species, living in high organic contents area, Lumbrineris longifolia, Heteromastus. filiformis in polychaetes and Corophium sinense in amphipod were dominated. As results on environmental assessment, in spite of changing to the species composition and densities seasonally, the mussel farm have recorded only to moderately polluted condition.

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Predicting the Goshawk's habitat area using Species Distribution Modeling: Case Study area Chungcheongbuk-do, South Korea (종분포모형을 이용한 참매의 서식지 예측 -충청북도를 대상으로-)

  • Cho, Hae-Jin;Kim, Dal-Ho;Shin, Man-Seok;Kang, Tehan;Lee, Myungwoo
    • Korean Journal of Environment and Ecology
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    • v.29 no.3
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    • pp.333-343
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    • 2015
  • This research aims at identifying the goshawk's possible and replaceable breeding ground by using the MaxEnt prediction model which has so far been insufficiently used in Korea, and providing evidence to expand possible protection areas for the goshawk's breeding for the future. The field research identified 10 goshawk's nests, and 23 appearance points confirmed during the 3rd round of environmental research were used for analysis. 4 geomorphic, 3 environmental, 7 distance, and 9 weather factors were used as model variables. The final environmental variables were selected through non-parametric verification between appearance and non-appearance coordinates identified by random sampling. The final predictive model (MaxEnt) was structured using 10 factors related to breeding ground and 7 factors related to appearance area selected by statistics verification. According to the results of the study, the factor that affected breeding point structure model the most was temperature seasonality, followed by distance from mixforest, density-class on the forest map and relief energy. The factor that affected appearance point structure model the most was temperature seasonality, followed by distance from rivers and ponds, distance from agricultural land and gradient. The nature of the goshawk's breeding environment and habit to breed inside forests were reflected in this modeling that targets breeding points. The northern central area which is about $189.5 km^2$(2.55 %) is expected to be suitable breeding ground. Large cities such as Cheongju and Chungju are located in the southern part of Chungcheongbuk-do whereas the northern part of Chungcheongbuk-do has evenly distributed forests and farmlands, which helps goshawks have a scope of influence and food source to breed. Appearance point modeling predicted an area of $3,071 km^2$(41.38 %) showing a wider ranging habitat than that of the breeding point modeling due to some limitations such as limited moving observation and non-consideration of seasonal changes. When targeting the breeding points, a specific predictive area can be deduced but it is difficult to check the points of nests and it is impossible to reflect the goshawk's behavioral area. On the other hand, when targeting appearance points, a wider ranging area can be covered but it is less accurate compared to predictive breeding point since simple movements and constant use status are not reflected. However, with these results, the goshawk's habitat can be predicted with reasonable accuracy. In particular, it is necessary to apply precise predictive breeding area data based on habitat modeling results when enforcing an environmental evaluation or establishing a development plan.

Zooplankton Community Distribution in Aquatic Plants Zone: Influence of Epiphytic Rotifers and Cladocerans in Accordance with Aquatic Plants Cover and Types (수생식물이 발달된 습지에서 동물플랑크톤 군집 분포: 수생식물의 밀도 및 종류가 부착성 윤충류와 지각류에게 미치는 영향)

  • Choi, Jong-Yun;La, Geung-Hwan;Kim, Seong-Ki;Jeong, Kwang-Seuk;Joo, Gea-Jae
    • Korean Journal of Ecology and Environment
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    • v.46 no.1
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    • pp.86-93
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    • 2013
  • We monitored 32 wetlands in order to investigate the influence of aquatic plants on zooplankton density and diversity in the littoral zone in Gyeongsangnam-do from May to June in 2011. A total of 65 zooplankton species were identified in the study sites. Among them, the diversity of epiphytic zooplankton were higher (40 species) than planktonic zooplankton. Littoral zones of all wetlands were covered by various aquatic plants, and influenced the epiphytic zooplankton assemblages. Based on the data from $1{\times}1$ (m) quadrat sampling, epiphytic and planktonic rotifer density showed no significant relationships with macrophyte cover. However, the epiphytic cladocerans density significantly increased under high aquatic plant cover ($r^2=0.39$, p<0.05, n=32). Types of aquatic plants strongly influenced epiphytic zooplankton density. Upo and Jangcheok are locations which have well developed Phragmites communis and Ceratophyllum demersum communities in the littoral zone, and a higher density of epiphytic zooplankton was recorded on the surface of C. demersum. Especially, rotifers such as Lepadella, Monostyla and Testudinella showed obvious differences (One-way ANOVA, p<0.05 for all three species). This result suggests that epiphytic zooplankton have a substrate preference for larger surface areas, likely for adherence, on C. dimersum. In conclusion, the complex structure of the littoral plant community is expected to provide diverse refuge and microhabitats to epiphytic zooplankton.

Leaf Spray Control Efficacy of the Entomopathogenic Nematode, Steinernema carpocapsae Weiser, Supplemented with the Selected Antidesiccant, Keltrol-F, on the Beet Armyworm, Spodoptera exigua(Hubner) (선발 내건제 Keltrol-F를 이용한 곤충병원선충(Steinernema carpocapsae Weiser)의 파밤나방(Spodoptera exigua(Hubner))에 대한 엽면살포 방제 효과)

  • 이성섭;김용균;한상찬
    • Korean journal of applied entomology
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    • v.39 no.3
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    • pp.199-205
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    • 2000
  • The field control efficacy of entomopathogenic nematode, Steinernema carpocapsae Weiser, was evaluated on the beet armyworm, Spodoptera exigua (Hiibner). The insect pest has been known to be a defoliator at the aerial part of the crop and difficult to be controlled effectively with most commercial chemical insecticides due to its insecticide resistance. To overcome the susceptibility of the nematodes to desiccation when they were applied by leaf spray in field condition, we screened several commercial antidesiccants (alkyl glucoside, CMC, glycerol, Keltrol-F, Kunipia-G, and Laponite LXG) optimal for survival of the nematodes. Keltrol-F (0.1 %) was selected as a candidate supplement for field application of the nematodes. Leaf spray of the nematodes at 5,000 infective juveniles/ml of distilled water containing 0.1 % Keltrol-F resulted in 87.7% control efficacy on the 3rd instar larvae of Sp. exigua.

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Planting Plan for Improvement of Buffer Green Space Function in the Vicinity of Railroad in Seashore Reclaimed Land - A Case Study of Buffer Green Space, Ansan City - (해안 매립도시 완충녹지 조성현황과 기능향상을 위한 식재방안 - 안산시 완충녹지를 사례로 -)

  • Lee, Kyong-Jae;Han, Bong-Ho;Park, Hyun-Ae;Choi, Jin-Woo
    • Korean Journal of Environment and Ecology
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    • v.22 no.6
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    • pp.691-706
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    • 2008
  • This study analysed problems of railroadside buffer green space and suggested planting methods according to space function and planting concept in seashore reclaimed land, Ansan city. Planting density of railroadside buffer green zone of Ansan city was $0.04{\sim}0.17tree/m^2$, GVZ was $0.15{\sim}1.65m^3/m^2$ which is represented of deficiency of buffer function. In addition, soil hardness of mounded buffer green zone was $2.72{\sim}15kg/cm^2$. It was examined to have functions in terms of habitat for wildbirds and other organisms, surrounding landuse, urban greens, seasonality, landscape for function improvement of buffer green space. Functions of buffer green space were re-established as habitat for organism, buffer and landscape improvement, landscape and urban park, buffer zone and habitat. It was suggested to select Pinus thunbergii as a dominated species of planting method for buffer function and planting density in canopy and under-canopy layer was $0.4tree/m^2$, $0.5/m^2$ in shrub layer. In terms of landscape improvement function, Zelkova serrata, Prunus sargentii and Prunus armeniaca were selected as major species and it in canopy and under-canopy layer was $0.2tree/m^2$ and $0.5tree/m^2$ in shrub layer. In terms of habitat function Quercus acutissima, Prunus sargentii and Sorbus alnifolia were as major species and it in canopy layer was $0.06tree/m^2$, $0.1tree/m^2$ in under canopy layer, $0.8tree/m^2$ in shrub layer.

Breeding Population and Habitat of Black-tailed Gulls (Larus crassirostris) on Nando Island, Natural Monument (천연기념물 난도에서 번식하는 괭이갈매기 개체군 및 서식 환경)

  • Kim, Miran;Kwon, Young-Soo;Nam, Ki-baek;Lee, Ho;Myeong, Hyeon-Ho;Noh, Hyung Soo
    • Korean Journal of Environmental Biology
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    • v.35 no.2
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    • pp.134-142
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    • 2017
  • Nando Island is reported as one of the biggest breeding colonies of seabirds in South Korea, and is protected as a Natural Monument. This study was conducted between July to November 2015, to investigate the breeding population of Black-tailed gulls and their habitat on Nando Island. We estimated the breeding population of Black-tailed gulls (Larus crassirostris) using nest density. The mean nest density of Black-tailed gulls was $0.51\;per\;1m^2$ ($0.51m^{-2}$), and the breeding population was approximately 26,760 individuals. The dominant vegetation was Echinochloa crusgalli and Agropyron tsukushiense var. transiens, which served as shelter and nest sites to Black-tailed gulls. The diet of Black-tailed gulls was mainly the fish, Japanese Anchovy Engraulis japonicas (48%). Other species which were found to breed on Nando Island were Streaked Sheawater (Calonectris leucomelas), Temminck's Cormorant (Phalacrocorax capillatus), and Swinhoe's storm petrels(Oceanodroma monorhis).

A Management Plan According to the Estimation of Nutria (Myocastorcoypus) Distribution Density and Potential Suitable Habitat (뉴트리아(Myocastor coypus) 분포밀도 및 잠재적 서식가능지역 예측에 따른 관리방향)

  • Kim, Areum;Kim, Young-Chae;Lee, Do-Hun
    • Journal of Environmental Impact Assessment
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    • v.27 no.2
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    • pp.203-214
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    • 2018
  • The purpose of this study is to estimate the concentrated distribution area of nutria (Myocastor coypus) and potential suitable habitat and to provide useful data for the effective management direction setting. Based on the nationwide distribution data of nutria, the cross-validation value was applied to analyze the distribution density. As a result, the concentrated distribution areas thatrequired preferential elimination is found in 14 administrative areas including Busan Metropolitan City, Daegu Metropolitan City, 11 cities and counties in Gyeongsangnam-do and 1 county in Gyeongsangbuk-do. In the potential suitable habitat estimation using a MaxEnt (Maximum Entropy) model, the possibility of emergency was found in the Nakdong River middle and lower stream area and the Seomjin riverlower stream area and Gahwacheon River area. As for the contribution by variables of a model, it showed DEM, precipitation of driest month, min temperature of coldest month and distance from river had contribution from the highest order. In terms of the relation with the probability of appearance, the probability of emergence was higher than the threshold value in areas with less than 34m of altitude, with $-5.7^{\circ}C{\sim}-0.6^{\circ}C$ of min temperature of the coldest month, with 15-30mm of precipitation of the driest month and with less than 1,373m away from the river. Variables that Altitude, existence of water and wintertemperature affected settlement and expansion of nutria, considering the research results and the physiological and ecological characteristics of nutria. Therefore, it is necessary to reflect them as important variables in the future habitable area detection and expansion estimation modeling. It must be essential to distinguish the concentrated distribution area and the management area of invasive alien species such as nutria and to establish and apply a suitable management strategy to the management site for the permanent control. The results in this study can be used as useful data for a strategic management such as rapid management on the preferential management area and preemptive and preventive management on the possible spreading area.

MCP, Kernel Density Estimation and LoCoH Analysis for the Core Area Zoning of the Red-crowned Crane's Feeding Habitat in Cheorwon, Korea (철원지역 두루미 취식지의 핵심지역 설정을 위한 MCP, 커널밀도측정법(KDE)과 국지근린지점외곽연결(LoCoH) 분석)

  • Yoo, Seung-Hwa;Lee, Ki-Sup;Park, Chong-Hwa
    • Korean Journal of Environment and Ecology
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    • v.27 no.1
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    • pp.11-21
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    • 2013
  • We tried to find out the core feeding site of the Red-crowned Crane(Grus japonensis) in Cheorwon, Korea by using analysis techniques which are MCP(minimum convex polygon), KDE(kernel density estimation), LoCoH(local nearest-neighbor convex-hull). And, We discussed the difference and meaning of result among analysis methods. We choose the data of utilization distribution from distribution map of Red-crowned Crane in Cheorwon, Korea at $17^{th}$ February 2012. Extent of the distribution area was $140km^2$ by MCP analysis. Extents of core feeding area of the Red-crowned Crane were $33.3km^2$($KDE_{1000m}$), $25.7km^2$($KDE_{CVh}$), $19.7km^2$($KDE_{LSCVh}$), according to the 1000m, CVh, LSCVh in value of bandwidth. Extent, number and shape complexity of the core area has decreased, and size of each core area have decreased as small as the bandwidth size(default:1000m, CVh: 554.6m, LSCVh: 329.9). We would suggest the CVh value in KDE analysis as a proper bandwidth value for the Red-crowned crane's core area zoning. Extent of the distribution range and core area have increased and merged into the large core area as a increasing of k value in LoCoH analysis. Proper value for the selecting core area of Red-crowned Crane's distribution was k=24, and extent of the core area was $18.2km^2$, 16.5% area of total distribution area. Finally, the result of LoCoH analysis, we selected two core area, and number of selected core area was smaller than selected area of KDE analysis. Exact value of bandwidth have not been used in studies using KDE analysis in most articles and presentations of the Korea. As a result, it is needed to clarify the exact using bandwidth value in KDE studies.

Experimental Transplantation for the Restoration of Seagrass, Zostera marina L. Bed Around Sinyangseopji Beach in Bangdu Bay, Jeju Island (제주 신양섭지해수욕장 주변 방두만 거머리말 군락 복원을 위한 실험적 이식)

  • LEE, HYUNG WOO;KANG, JEONG CHAN;PARK, JUNG-IM;KIM, MYUNG SOOK
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.26 no.4
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    • pp.343-355
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    • 2021
  • Eelgrass, Zostera marina L., was widely distributed around Sinyangseopji Beach in Bangdu Bay, on the eastern coast of Jeju Island, until breakwater construction in the late 1990s resulted in its complete loss. Six experimental sites were identified for restoration of the Z. marina bed in Bangdu Bay. Using the staple method, 500 Z. marina shoots were transplanted at each site in January 2019 and 2020. The transplants, along with environmental parameters, were monitored for 10 months following transplantation. There were significant differences in underwater irradiance, water temperature, and salinity among the sites, but all were suitable for Z. marina growth. The Ulva species, an opportunistic alga, appeared in spring and accumulated during summer at all sites; however, there was no significant effect of Ulva species on the survival and growth of the eelgrass transplants. Most of the transplanted Z. marina survived, and after 3 months, the density increased by 112.5-300% due to vegetative propagation, with a rapid rate of increase observed during spring and early summer at all sites. For 1-2 months after transplanting, the Z. marina shoots showed signs of transplant shock, after which the shoot density increased at all sites, confirming that all transplants adapted well to the new environment. However, in both 2019 and 2020, during late summer to early fall, the sites experienced heavy damage from typoons (twice in 2019 and three times in 2020) that hit Bangdu Bay. The transplants at two sites located in the center of Bangdu Bay were completely destroyed, but those at three sites located to the west of the bay showed a 192-312% increase in density. Thus, we confirmed that the Bangdu Bay Z. marina bed can be restored, with the highest probability of success for Z. marina restoration on the western side of Bangdu Bay, which is protected from typhoons.