• Title/Summary/Keyword: richness index

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Seasonal Variation in Macroalgal Community Structure around the Byeonsan Peninsula, Korea (변산반도 해조류 군집구조의 계절적 변동)

  • Han, Su Jin;Lee, Ji Hee;Jeon, Da Vine;Oh, Ji Chul;Kim, Bo Yeon;Park, Seo Kyoung;Choi, Han Gil;Nam, Ki Wan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.47 no.3
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    • pp.274-282
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    • 2014
  • We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

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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    • v.46 no.3
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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.

Species Diversity of Forest Vegetation in Togyusan National Park (덕유산 국립공원 삼림식생의 종 다양성)

  • Kim, Chang-Hwan;Bong-Seop Kil
    • The Korean Journal of Ecology
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    • v.19 no.3
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    • pp.223-230
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    • 1996
  • Five measurements of species diversity (richness index, diversity index, evenness index, dominance index and species sequences-importance curve) and their relationships with sltitude, tree age and community type were studied in $T\v{o}gyusan$ National Park, Korea. Altitude and tree age were the major variables explaining the differences of species diversity in the whole forest. Species richness index, diversity index and evenness index of Quercus mongolica and Pinus densiflora communities were lower than those of Carpinus laxiflora, Q. serrata, Fraxinus mandshurica, Q. mongolica - P. densiflora communities than that in the other communities. The species sequence-importance curve of the forest communities in $T\v{o}gyusan$ coincided with the ideal curve calculated by the lognormal-distribution theory.

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Species richness related to landscape characteristics of uninhabited islands in Korea

  • Rho, Paikho
    • Journal of Ecology and Environment
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    • v.33 no.2
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    • pp.105-114
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    • 2010
  • The principal objective of this study was to characterize the relationships between geographical conditions (e.g., island area, distance to mainland) and landscape structures of uninhabited islands, and to evaluate the effects of islands and their landscape structures on species richness. One hundred randomly selected islands and 5,000 m buffered areas derived from the boundaries of each island were used to summarize the number of observed bird species, and landscape pattern indices, particularly patch density, edge density, shape index, and mean nearest neighboring distance. Spatial arrangements of individual patch type at the class level, which are markedly affected by the distance from an island to the mainland, have a superior ability to explain the variances in species richness, as compared to the geographical conditions and landscape pattern indices at the landscape level. The results demonstrate that the patch type landscape structure is the primary factor affecting species richness, as well as the distance to the mainland. In particular, landscape pattern indices of cropland/pasture and woody cover are statistically significant in terms of explaining species richness, which suggests that food resources and appropriate conditions in landscape structures of habitat types are assumed as important elements in attracting bird species. This study also proposes the importance of evaluation on the landscape structure of each island, in order to designate protected areas and to establish a management plan for species conservation in uninhabited islands.

Analysis on the Relationship between Biological Indices and Survey Area of Benthic Macroinvertebrates Using Mathematical Model (수학적 모형을 이용한 저서성 대형무척추동물 군집지수-조사면적 관계 해석)

  • Kong, Dongsoo;Kim, Ah Reum
    • Journal of Korean Society on Water Environment
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    • v.31 no.6
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    • pp.610-618
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    • 2015
  • This study was conducted to find out the influence of sample size (accumulated survey areas) on the seven biological indices of benthic macroinvertebrates. BMI, the index similar to Zeilika-Marvan’s saprobic index, tended to be independent on the variations of sample size. The other indices (Shannon-Weaver’s diversity, Margalef’s richness, Menhinick’s richness, Pielou’s evenness, and Lenat’s EPT index) showed the considerable variations along with the increase of sample size and environmental conditions. To get the appropriate index values, it should be sampled at least 6 replicates more based on 30×30cm Surber sampler. In addition, the habitat heterogeneity index of benthic macroinvertebrates suggested in this study, it will be able to be used for evaluating the heterogeneity of habitats.

Ecological Attributes of Species Composition by Topographical Positions in the Natural Deciduous Forest

  • Kim, Ji-Hong;Lee, Hye-Seon;Hwang, Gwang-Mo
    • Journal of Forest and Environmental Science
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    • v.27 no.1
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    • pp.17-22
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    • 2011
  • Based upon the vegetation data of woody plants by plot sampling method in the natural deciduous forest of Mt. Jeombong, the study was carried out to examine importance value, rank abundance curve, and species abundance curve, and comparatively evaluate seven different species diversity indices for Shannon-Wiener index, Simpson index, McIntosh index, Log series, Margalef index, Berger-Parker index, and species richness, according to topographic positions. The minimal area which meant only few more species were increased was 3.48 ha in total. The dominant species of valley were Carpinus cordata, Acer pseudo-sieboldianum, Quercus mongolica, Acer mono, and Abies holophylla, and the dominant species of mid-slope were Quercus mongolica, Acer pseudo-sieboldianum, Carpinus cordata, Tilia amurensis, and Fraxinus rhynchophylla. Moreover, the dominant species of ridge were Quercus mongolica, Acer pseudo-sieboldianum, Tilia amurensis, Fraxinus rhynchophylla, and Acer mono. According to rank abundance curve and species abundance curve, species evenness was also low. All of Log series, species richness, Margalef, and Shannon-Wiener index discriminated that valley had the highest diversity, and ridge had the lowest diversity; but, Simpson index, McIntosh index, and Berger-Parker index represented that mid-slope had the highest diversity, and ridge had the lowest diversity. Uniquely, in Berger-Parker index, mid-slope was the higher value than total.

An Ecological study on the Sanchon-tideland and Doma-tideland (도마간석지와 산촌간석지에 대한 생태학적 연구)

  • Kim, In-Taek;Cheong, Seon-Woo;Seo, Jeoung-Yoon;Park, Joong-Suk;Oh, Kyung-Hwan;Lee, Chan-Won
    • Journal of Wetlands Research
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    • v.5 no.2
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    • pp.57-65
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    • 2003
  • This study was corried out to provide basic data for water analysis biodiversity, Actual vegetation map, flora and fauna on the Sanchon-tideland(Geojaesi), Doma-tideland(Namhaegun) in Kyungsangnamdo from august 2002 to February 2003. This tidelands was very broad and was being reclaimed. Therefore, it was anxious about destroying the habitat of the water birds. Since the water temperature was influenced by the surrounding air, it was highest in summer and lowest in winter. pH value and DO concentration of the water was highest in winter in the Sanchon-tideland and in surmmer in the Doma-tideland. COD concentration was lowest in winter in two tidelands. SS concentration was highest in summer. T-P and T-N concentration were very low but decreased with the seasonal change from summer to winter. Vascular plants of this area consist of 11 varieties, 67 species, 64 genera, 29 families(Sanchon-tideland) and 1 forma, 11varieties, 62 species, 64 genera, 30 families(Doma-tideland). The predominant community of this area, Phragmites communis Community were found on the seashore. The total insect specimens were classified into 120 species, 48 families, 10 orders(Sanchon-tideland) and perdominant species were Gabala argentata(Dominance 18.78%, Diversity index 1.75, Richness index 45.78). And 91 species, 40 families, 8 orders(Doma-tideland) and perdominant species were Sternolophus (Sternolophus) rufipes(Dominance 15.47%, Diversity index 1.47, Richness index 33.66). The total Fishes were classified into 3 species, 2 families, 1 order and Amphibia were 3 species, 2 families, 1 order. And Salicomia herbacea should be worthwhile species to conserve in this area. Because the water birds lived in The Tideland Sanchon and Doma, it was considered that it was necessary to preserve them.

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Seasonal species composition and cluster analysis of catches by shrimp beam trawl in the Geum river estuary (새우조망을 이용한 금강 하구역 어획물의 계절별 종조성 및 군집분석)

  • Lee, Sun-Kil;Choi, Moon-Seong;Seo, Yeong-Il;Lee, Jae-Bong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.50 no.4
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    • pp.455-466
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    • 2014
  • Seasonal variations in species composition of catches were explored using seasonal samples caught by shrimp beam trawl in the Geum river estuary in 2011. During the study period, total catches were collected 91 species as fish 47 species, crustacean 28 species, mollusca 4 species, gastropoda 5 species, shellfish 3 species and others 4 species. The dominant species were Exopalaemon carinicauda, Eriocheir leptognathus, Palaemon gravieri, Mugil cephalus, Acanthogobius hasta, Cynoglossus joyneri, Pennahia argentata and Coilia nasus. The amount of species in spring and summer was higher than in autumn. The diversity index (H') was 0.43~0.96, evenness index (EI) was 0.14~0.25, and richness index (RI) was 1.54~4.25. Using cluster analysis 91 species were divided into 4 groups. Group I appeared mainly in spring and summer. Group II appeared only in summer. Group III appeared in winter and spring, and Group IV in spring and autumn.

Mapping Mammalian Species Richness Using a Machine Learning Algorithm (머신러닝 알고리즘을 이용한 포유류 종 풍부도 매핑 구축 연구)

  • Zhiying Jin;Dongkun Lee;Eunsub Kim;Jiyoung Choi;Yoonho Jeon
    • Journal of Environmental Impact Assessment
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    • v.33 no.2
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    • pp.53-63
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    • 2024
  • Biodiversity holds significant importance within the framework of environmental impact assessment, being utilized in site selection for development, understanding the surrounding environment, and assessing the impact on species due to disturbances. The field of environmental impact assessment has seen substantial research exploring new technologies and models to evaluate and predict biodiversity more accurately. While current assessments rely on data from fieldwork and literature surveys to gauge species richness indices, limitations in spatial and temporal coverage underscore the need for high-resolution biodiversity assessments through species richness mapping. In this study, leveraging data from the 4th National Ecosystem Survey and environmental variables, we developed a species distribution model using Random Forest. This model yielded mapping results of 24 mammalian species' distribution, utilizing the species richness index to generate a 100-meter resolution map of species richness. The research findings exhibited a notably high predictive accuracy, with the species distribution model demonstrating an average AUC value of 0.82. In addition, the comparison with National Ecosystem Survey data reveals that the species richness distribution in the high-resolution species richness mapping results conforms to a normal distribution. Hence, it stands as highly reliable foundational data for environmental impact assessment. Such research and analytical outcomes could serve as pivotal new reference materials for future urban development projects, offering insights for biodiversity assessment and habitat preservation endeavors.

Spatial and Temporal Changes of Fish Community in the Cheonggye Stream after the Rehabilitation Project (복원된 청계천에 서식하는 어류군집의 시공간적 변화)

  • Choi, Jun-Kil;Byeon, Hwa-Kun;Kwon, Yong-Su;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.41 no.3
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    • pp.374-381
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    • 2008
  • Spatial and temporal changes of fish communities were studied at four study sites in the Cheonggye Stream from October 2005 to August 2006 after the rehabilitation process. During the survey period, 19 species in 6 families were sampled. Species Rhynchocypris oxycephalus and Zacco platypus were identified as dominant species. Korean endemic species such as Acheilognathus yamatsutae and Zacco koreanus were observed in the sites. Overall, species richness and abundance increased as time passes after the rehabilitation, reflecting colonization process of the fish community. Meanwhile species richness and abundance were higher at the downstream than at the upstream. Community indices such as dominant index, richness index and diversity index showed also similar spatial and temporal pattern. Nonmetric multidimensional scaling (NMDS), multivariate ordination technique, was used to analyze spatial and temporal variation of the fish communities, and the results showed spatial variation of fish communities with high species richness at downstream as well as the temporal variation of fish communities with high values of species richness and diversity index at later part of the study period, presenting colonization process of the fish community after the rehabilitation project.