• Title/Summary/Keyword: evenness index

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Tree Diversity, Distribution and Population Structure of a Riparian Forest from Certain Zones along the Dikhu River in Nagaland, India

  • Leishangthem, Devlin;Singh, Maibam Romeo
    • Journal of Forest and Environmental Science
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    • 제34권1호
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    • pp.31-45
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    • 2018
  • At present the biodiversity of the riparian forest is under threat due to various anthropogenic pressures. Hence study was conducted along the three unprotected zones of riparian forest in Dikhu river, Nagaland, north-east India in order to compared the diversity, distribution and population structure of riparian trees. In each zone $100{\times}100m^2$ plot were marked and subdivided into 20 plots of $10{\times}10m^2$. 10 plots on each side of the river were taken randomly covering 0.02 ha. Only tree with dbh ${\geq}10cm$ and dbh above 1.5 m above ground level were recorded as individual species. A total of 29 tree species belonging to 18 families were recorded from the three zones of the river. Tree species richness was highest at the middle zone (19) followed by upper (14) and lower zone (7). The most abundant species and family recorded at upper, middle and lower zones were Melia azaderach of Euphorbiaceae ($380\;stems\;ha^{-1}$), Terminalia chebula of Euphorbiaceae ($432.5\;stems\;ha^{-1}$) and Duabanga grandiflora of Lythraceae ($365\;stems\;ha^{-1}$) respectively. The ranges of diversity indices observed in the three zones were: Shannon-Wiener index (1.25-0.73), Simpson diversity index (0.42-0.93), Evenness index (0.47-0.37) and Index of co-dominance (0.75-0.94). Rest of other indices were also estimated and compared. Distribution of trees shows the contagious pattern common in the upper and middle zones and regular in the lower zone. The girth size class analysis demonstrated that the riparian forest is in less mature succession stage. This study emphasize the need for management and conservation of riparian forest by developing policy to declare the riparian zone as protected area to prevent further degradation and loss of biodiversity from these unregulated zones along the river.

월성원자력발전소 온배수가 해조류 종조성 및 군집구조에 미치는 영향 (Effects of Thermal Effluents from Wolseong Nuclear Power Plant on Macroalgal Composition and Community Structure)

  • 최한길
    • ALGAE
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    • 제23권2호
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    • pp.151-162
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    • 2008
  • Marine algal flora and community structure were seasonally examined at three sites in the vicinity of the Wolseong nuclear power plant in Korea from February to November 2006. A total of 126 seaweeds including 25 green, 31 brown, 70 red algae, and 1 marine plant were identified. The greatest number of species occurred at Jeonchonri (101 species) followed by intake (88 species) and discharge (29 species) during the study period. Of 126 seaweeds, 76 annuals and 13 warm tolerance species were recorded. Dominant species based on important value (IV > 10) were Ulva pertusa and Enteromorpha linza at intake, U. pertusa and Padina arborescens at discharge, and Sargassum horneri and Corallina pilulifera at Jeonchonri shore. Annual average biomass exhibited a wide range of variations, from 40.67g m-2 in dry weight at discharge to 133.69g m-2 at Jeonchonri. Among six functional groups, dominant group was coarsely-branched form at intake and Jeonchonri, but it was different at discharge site as filamentous form. Seaweed community structures of discharge site were distinguishable in decreasing species richness, biomass, species diversity index (H’), richness index (R), and evenness index (J’). Also, the ratios of green algae, warm tolerance species, annual algae, filamentous form and dominance index (DI) remarkably increased. Such phenomenons of discharge site are usually found under environmentally stressful conditions such as high disturbance. Thus, I can conclude that the heated effluents of nuclear power plant act as environmental stress influencing seaweed community structures and it can be detected with various community indices.

시루봉의 산불 이후 식생회복 (Vegetation Recovery of Burned Area after Forest Fire from Mt. Sirubong)

  • 허만규;최주수;정영기;허홍욱;문성기
    • 생명과학회지
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    • 제15권1호
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    • pp.27-32
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    • 2005
  • 경상남도 진주시 수곡면 시루봉에서 산불이 난 1994년부터 2000년까지 식생회복에 따른 종조성을 조사하였다. 소나무를 비롯한 목본과 풍산포 종자를 가진 초본류는 산불 이후 3년 이내에 왕성한 성장을 보였다. 산화지의 생활형 조성은 H-Dl-R5-e로 다른 산화지와 크게 다를 바 없었다. 산화지 6지점의 평균 종다양도지수는 2.135(1996년), 2.784(1998년), 2.948(2000년)이였다. 6지점의 균등성지수는 1.816(1996년), 2.641(1998년), 1.925(2000년)였다. 천이 분석에서 식생의 회복과 더불어 종수는 증가하여 산화 3년 후에는 주변지역과 거의 유사하거나 약간 높은 지점도 나타났다. 우점도지수 등의 결과에서 추정되는 바는 산불 후 수목의 식재시 산불 후 3년 이전에 실시하는 것이 적합할 것으로 사료된다

서해안 태안반도 해조군집의 종조성과 수직분포 (Species Composition and Vertical Distribution of Marine Algal Communities at the Taean Peninsula of the West Coast of Korea)

  • 안중관;유경동;오지철;이재일;윤희동;김영환
    • 한국수산과학회지
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    • 제50권1호
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    • pp.55-64
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    • 2017
  • Seasonal variability in algal community structure was examined at the intertidal zones of five study sites on the Taean Peninsula, on the western coast of Korea, from February 2014 to November 2015. A total of 118 species of marine algae, comprising 17 green, 24 brown and 77 red algae, were identified. The maximum number of species was observed at the Mohang site (75 species), and the minimum at the Yeonpo site (46 species). The seaweed biomass was $160.24g\;dry\;wt./m^2$ on average, and was maximal at Uihang ($519.04g\;dry\;wt./m^2$) and minimal at Yeonpo ($19.03g\;dry\;wt./m^2$). Based on biomass, the dominant seaweeds at Taean peninsula were Sargassum thunbergii and Corallina pilulifera. Community indices were as follows: richness index (R), 3.21-5.01; evenness index (J'), 0.33-0.38; and diversity index (H'), 0.90-1.12. Based on evaluation of the environmental states by the community indices, the ecological evaluation index (EEI) of Taean peninsula was "moderate". The overall species and biomass of seaweeds decreased after the oil spill. However, Hakampo previously showed a similar algal community structure. In conclusion, the algal community was temporarily affected by the oil spill, but rapidly recovered.

지리산국립공원 저서성 대형무척추동물의 섭식기능군 분포 특성과 생물학적 수질평가 (Distribution Characteristics of Functional Feeding Groups of Benthic Macroinvertebrates and Biological Evaluation of Water Quality in Jirisan National Park)

  • 방기준;김형곤;윤춘식;정선우
    • 한국환경과학회지
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    • 제25권5호
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    • pp.655-671
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    • 2016
  • The distribution characteristics of functional feeding groups and biological evaluation of water quality with benthic macroinvertebrates were investigated from 2013 to 2014 in the mountain streams of Jirisan National Park. Both quantitative and qualitative collection had been performed six times during study periods in twelve sites located at upstream, midstream and downstream of four valleys, Chilsungol, Baemsagol, Daesunggol and Piagol of freshwater ecosystem in Jirisan National Park. As results, the total collected benthic macroinvertebrates were 3 phyla, 4 classes, 11 orders, 37 families, 107 species and 4,028 individuals. In 2013, 3 phyla, 4 classes, 10 orders, 32 families, 89 species and 1,829 individuals were collected. And in 2014, 3 phyla, 4 classes, 9 orders, 31 families, 80 species and 2,199 individuals were identified. The total dominant species was Ecdyonurus kibumensis, and EPT groups occupied 80.39% of total species number. Biotic indices were also compared to site and to season. The dominant index (DI) was highest at the downstream of Baemsagol in the spring of 2013, and the evenness index (J') was highest at the downstream of Daesunggol in the summer of 2013. Both diversity index (H') and richness index (RI) were highest at the upstream of Baemsagol in the summer of 2014. The correlation between altitude above sea level and functional feeding groups of benthic macroinvertebrates was also researched in this study. As a result, the species number of shredders and predators have significantly increased according to the increase of the altitude of their habitat. On the other hand, individuals of gathering collectors have increased according to the increase of altitude. The biological water quality was evaluated and compared with several methods in this study, and we suggest that ESB and GPI are more appropriate than KSI and BMI to evaluate biological water quality of mountain stream water.

Effects of reforestation approaches, agroforestry and woodlot, on plant community composition, diversity and soil properties in Madhupur Sal forest, Bangladesh

  • Hasan, Mohammad Kamrul;Islam, Md. Tariqul;Akter, Rojina;Roshni, Nasima Akther
    • Journal of Ecology and Environment
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    • 제46권3호
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    • pp.204-217
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    • 2022
  • Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m2 ha-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.

제주도 북부 북촌리 연안에서 어획된 어류군집의 장기변화(2012~2022) (Long term variations of fish assemblage in the coastal waters Bukchon-ri, northern part of Jeju Island from 2012 to 2022)

  • 고준철;김보연;한송헌;김민선;곽정현
    • 수산해양기술연구
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    • 제59권4호
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    • pp.301-314
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    • 2023
  • Long term variations of fish assemblage in the coastal waters of Bukchon-ri were determined using samples collected by trammel net from 2012 to 2022. Water temperature increased by 0.4℃ in 2022 that was less then 2012. During the survey period, a total of 95 species (53 families and 15 orders) of fishes were identified, Scorpaeniformes (five families and 22 species) and Perciformes (25 families and 39 species) accounted for 73% of the total number. The number of species was higher in summer than winter, showing a peak in summer at 66 species and lower in winter and autumn at 45 species. The number of individuals and the biomass peaked in summer at 1,238 individuals and 280.1 kg, and were the lowest in autumn at 597 individuals and 155.4 kg. The annual diversity index, evenness index and richness index were appeared 2.11-2.80, 0.64-0.80 and 4.70-7.34 at each years. The dominance index were appeared highest in 2014 while 2021 were appeared the lowest in 2017. The subtropical fishes were identified total of 38 species (40.0%) and the number of species was higher in 2022 at 22 (52.4%) species and lower in 2015-2017 at each 10 (31.3-37.0%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), boxfish (Ostracion immaculatus), smallscale blackfish (Girella melanichthys), flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), rock porgy (Oplegnathus punctatus), and bluestriped angelfish (Chaetodontoplus septentrionalis) in study sites.

제주도 남부 사계리 연안에서 삼중자망으로 어획된 어류군집 변화 (A variation of fish assemblage by trammel net in the coastal waters of Sagye-ri, southern Jeju Island)

  • 고준철;김보연;한송헌;김민선;곽정현
    • 수산해양기술연구
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    • 제60권2호
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    • pp.114-127
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    • 2024
  • A variation of fish assemblage in the coastal waters of Sagye-ri, southern Jeju Island was determined using samples collected by trammel net from 2012 to 2022. The total fish species caught by trammel net were identified 88 species, 46 families, 12 orders, and the number of appearance and biomass were 3,479 individuals and 883.6 kg. The annual variation of species was the highest in 2013 at 46 species and the lowest in 2021 at 30 species. The seasonal variation of species was higher in summer at 67 species and lower in winter, autumn at 47 species. The annual diversity index, evenness index, and richness index were appeared 2.42-3.00, 0.69-0.78 and 5.18-7.24 at each years. The dominance index appeared highest in 2013 and the lowest in 2018. Cluster analysis based on the number of individuals of fish was classified into two groups at the dissimilarity level of 57%, and results of SIMPROF analysis revealed significant differences in community structure among the two groups. The subtropical fishes were identified a total of 42 species (47.7%) and the number of species was higher in 2013 at 25 (54.3%) species and lower in 2018 and 2021 at each 17 (54.8~56.7%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), scarbreast tuskfish (Choerodon azurio), bluestriped angelfish (Chaetodontoplus septentrionalis), balloon fish (Diodon holocanthus), and flag fish (Goniistius zonatus) at study sites.

대형댐 하류지역 저서성 대형무척추동물 군집의 생태학적 비교 (An Ecological Comparison of Benthic Macroinvertebrate Community in Downstream Region of Large Dams)

  • 김재성;이황구;최준길
    • 한국환경생태학회지
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    • 제27권1호
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    • pp.52-63
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    • 2013
  • 본 연구는 2011년 6월부터 10월까지 지리적으로 인접하지만 다른 수계로 분류되는 전라북도 무주군 일대의 용담댐 하류역과 경상남도 합천군 일대의 합천댐 하류역에 각각 댐에 의한 방류의 영향을 보기 위하여 대상지점(YE-1, 2, 3; HE-1, 2, 3) 및 대조지점(YC-1, 2; HC-1, 2)을 선정하여 각 지점에서 출현하는 저서성 대형무척추동물의 종구성, 군집분석, 섭식기능군 및 서식기능군, 군집안정성을 분석하였다. 채집은 각 댐의 하류역에서 Surber net($30cm{\times}30cm$)을 이용하여 3회에 걸쳐 정량채집을 실시하였다. 조사결과 용담댐 하류지역에서 총 4문 6강 12목 33과 69종 6,369개체가 출현하였고, 하천의 주요 분류군인 EPT-group(Ephemeroptera, Plecoptera, Trichoptera-group)은 46종(66.7%)을 차지하였다. 합천댐 하류지역에서는 총 4문 5강 13목 44과 81종 5,728개체가 출현하였고, EPT-group은 45종(55.6%)을 차지하였다. 군집분석 결과 용담댐 하류지역에서 우점도지수는 0.27~0.50(Mean${\pm}$SD $0.38{\pm}0.09$), 다양도지수는 2.22~2.97($2.67{\pm}0.29$), 균등도지수는 0.63~0.76($0.72{\pm}0.06$), 풍부도지수는 4.43~7.06($5.69{\pm}0.99$)으로 분석되었고, 합천댐 하류지역에서 우점도지수는 0.40~0.81($0.59{\pm}0.18$), 다양도지수는 1.40~2.39($2.00{\pm}0.43$), 균등도지수는 0.38~0.68($0.56{\pm}0.13$), 풍부도지수는 4.04~5.80($4.95{\pm}0.70$)으로 분석되었다. 섭식기능군은 용담댐과 합천댐 하류지역 모두에서 filtering-collectors와 gathering-collectors가 대부분을 차지하였으며, 서식기능군은 burrowers, clingers, swimmers가 대부분을 차지하였다. 군집안정성 분석 결과 용담댐 유역의 대상하천에서 수환경 변화에 저항력과 회복력이 강한 I특성군에 속하는 집단이 더 많은 것으로 분석되었다. 합천댐 유역은 대조하천에서 수환경 변화에 대한 저항력과 회복력이 약한 III특성군에 속하는 종이 많은 것으로 분석되었다. 대형댐 하류지역의 하천생태계 안정성은 환경 변화 및 오염에 강한 I특성군에 속하는 군집이 좌우하고 있는 것으로 판단된다.

괴산군 지역 농업 생태계의 곤충 다양성 비교 분석 (Comparative Insect Biodiversity Analyses on the Agricultural Ecosystems of Goesan District of Korea)

  • 김훈;순옌;이승민;구본진;구윤모;김태연;문명진
    • 한국유기농업학회지
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    • 제29권4호
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    • pp.539-559
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    • 2021
  • 본 연구는 2016년부터 2018년까지 충청북도 괴산군 일대의 조사지역에서 관행농법 및 유기농법을 시행하는 경작지의 논과 밭을 대상으로 작물 생육 기간 중 출현하는 곤충류(거미류 포함)를 지속적으로 채집하여 농업 생태계의 생물 다양성을 모니터링하였고 농법의 차이에 따른 생물 군집의 변이를 분석하였다. 총 3년간의 조사 기간 동안 25목 219과 1,138종의 곤충류가 채집되었는데, 유기농법을 시행하는 조사지에서 채집된 종 수는 관행농 조사지와 비교하여 논(650종 vs. 426종)과 밭(554종 vs. 404종) 모두에서 높은 종 다양성을 유지한 것으로 확인되었다. 곤충류의 종을 동정하고 채집된 개체 수를 통계 처리하여 목 수준에서 분류군을 비교한 결과, 노린재목에 이어 파리목, 벌목, 딱정벌레목, 거미목 순으로 높은 종 다양성이 관찰되었다. 한편, 현장 모니터링을 통해 채집된 종 및 개체의 정량적 측정을 통해 다양한 생물 다양도 지수를 비교한 결과, 유기농지의 종 다양도 지수(H')와 종균등도 지수(J'), 그리고 종 풍부도 지수(RI) 등이 모두 관행농지에 비해 높은 값을 나타내어, 유기농업이 곤충류 종 다양성에 미치는 긍정적인 효과가 입증되었다. 또한, 우점도 지수(DI)와 유사도 지수(QS) 분석 결과에서도 유기농법을 시행하는 농지의 생물 종 다양성이 관행농지에 비해 간섭받지 않고, 보다 독립적으로 유지됨을 확인할 수 있었다.