• Korean Journal of Environment and Ecology
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• v.28 no.4
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• pp.432-441
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• 2014

April, 2005 to October, 2013. The collected species during the survey period were 17 species belonging to 6 families. Dominant species was Zacco koreanus(Relative abundance 59.9%) and subdominant species Pungtungia herzi(8.5%). Korea endemic species were 12, including Coreoleuciscus splendidus. The species of Hemibarbus mylodon was identified as natural monument, and Pseudopungtungia tenuicorpa and Gobiobotia brevibarba were endangered species. Water quality assessment of Gapyeong Stream, had lately maintained the rating of "very good" for nine years, based on the Ministry of the Environment standards notice. It was found that there was a tendency for populations which is Coreoperca herzi carnivorous species decreases, increases omnivorous species Zacco platypus. As a result of community analysis, dominant index was 0.58~0.86, diversity index was 0.94~1.77 and richness index was 0.99~2.39. As a result of using the Rarefaction curve, were analyzed occurrence species expected each year, number of species is estimated from a sample of 151 individuals, up to 12(2005) was at least 5(2007) species. The regression coefficient (b) in relation to length-weight on Z. koreanus population were annual average $3.29{\pm}1.11$, condition factor slope $0.0034{\pm}0.0021$, which maintained good growth condition and stabilized population.

• Korean Journal of Environmental Biology
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• v.36 no.3
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• pp.400-411
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• 2018

This study was a survey of the Wonju stream in Wonju city from May 2015 to September 2016. A total of three sites were selected from the upstream area Gwanseol-dong to the downstream area Hojeo-myeon. Physicochemical analysis, aquatic insect changes, cluster analysis, functional group analysis, rarefaction curve, and statistical analysis were compared between 2004 and 2016. A total of 19 species (38.78%) in 2004 and 22 species (36.67%) in 2016 were analyzed, with the largest number belonging to ephemeroptera. The individual ratio ranged from 27,759.2 (ind. $m^{-2}$, 84.30%) in 2004 to 4,573.2 (ind. $m^{-2}$, 41.64%) in 2016, with the highest number involving diptera. As a result of the community analysis, significant differences were detected in the indices of dominance, diversity, evenness, and richness in 2004 and 2016 (p<0.05). Burrowers of the habitat orientation groups showed the greatest variation with an average of -68.00% (${\pm}2.15$) and the collector-gatherers of the functional feeding groups showed the highest variation of -40.12% (${\pm}1.77$). The rarefaction curve analysis suggested that the species was the poorest in the midstream regions in 2004 and 2016. Physical factors and water quality showed a significant correlation with diversity index, evenness index, and the number of individuals. MDS analysis of the similarity of upstream and downstream regions was high in 2004, and low in 2016. The differences were attributed to physicochemical changes such as increase in flow velocity due to improvement of small dams and changes in bottom structure.

• Korean Journal of Environmental Biology
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• v.40 no.2
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• pp.148-156
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• 2022

Ecological occupation in irrigation ponds is a well-acknowledged fact that is essential for biodiversity conservation in agricultural ecosystems. However, there are few studies on the ecological functions and relationship between a paddy field and irrigation using macroinvertebrates in an environmentally friendly paddy field. The objective of this study is to identify the community and distribution characteristics of macroinvertebrates in an agricultural paddy field and irrigation pond ecosystems, and to provide basic data on the ecological function of an environmentally friendly paddy field. Macroinvertebrate sampling was conducted from May to September in an agricultural paddy field and irrigation pond in an environment-friendly paddy field in Boryeong city. We conducted a study to identify the distribution characteristics using macroinvertebrate species analysis, such as Functional Feeding Groups (FFGs), Habitat Oriented Groups (HOGs), rarefaction curve, and a two-way dendrogram. A total of 37 species of macroinvertebrates in 28 families, 13 orders were collected study during the period of the investigation. Dominant taxa of macroinvertebrates included Coleoptera, Hemiptera, and Odonata. In terms of FFGs, predators and gathering collectors accounted for approximately 70%, in relation to HOGs, and climbers and swimmers occupied more than 50% from both the paddy field and irrigation pond. With respect to the rarefaction curve, the irrigation pond (July) was high as E (S, 141)=18 species, while the paddy field (May) was comparatively low as E (S, 141)=9 species. In conclusion, our results revealed that macroinvertebrates, such as Notonecta triguttata, Peltodytes intermedius, Appasus major, Laccotrephes japonensis, Appasus japonicus, Sigara substriata, Enochrus simulans, and Sternolophus rufipes, were used as a habitat and spawning ground in both paddy field and irrigation pond. The irrigation pond appears to be a very important spawning ground for macroinvertebrates.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.151-160
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• 2019

The study of spiders that function as predators in agroecosystem can broaden the understanding of agroecosystems. This study investigated the effect of heterogeneity at different spatial scales on richness and abundance of spiders in upland and paddy fields. We collected 48 samples using pitfall traps at upland and paddy fields, respectively. The total species richness of spiders estimated by sample- and coverage-based rarefaction and extrapolation curves. The total species richness was high in the upland fields at the total study sites, whereas the average species richness per study site was high in the paddy fields. We confirmed that the diversity enhancement of spiders was influenced by the structural complexity of habitat at field-scale, and crop diversity at broader scale.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.274-284
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• 2022

Through sample-size-based rarefaction analyses, we tried to suggest the appropriate degree of sample concentration and sub-sample extraction, as a way to estimate more accurate zooplankton species diversity when assessing biodiversity. When we collected zooplankton from three reservoirs with different environmental characteristics, the estimated species richness (S) and Shannon's H' values showed different changing patterns according to the amount of sub-sample extracted from the whole sample by reservoir. However, consequently, their zooplankton diversity indices were estimated the highest values when analyzed by extracting the largest amount of sub-sample. As a result of rarefaction analysis about sample coverage, in the case of deep eutrophic reservoir (Juam) with high zooplankton species and individual numbers, it was analyzed that 99.8% of the whole samples were represented by only 1 mL of sub-sample based on 100 mL of concentrated samples. On the other hand, in Soyang reservoir, which showed very small species and individual numbers, a relatively low representation at 97% when 10 mL of sub-sample was extracted from the same amount of concentrated sample. As such, the representation of sub-sample for the whole zooplankton sample varies depending on the individual density in the sample collected from the field. If the degree of concentration of samples and the amount of sub-sample extraction are adjusted according to the collected individual density, it is believed that errors that occur when comparing the number of species and diversity indices among different water bodies can be minimized.

• Korean Journal of Plant Resources
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• v.30 no.5
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• pp.481-488
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• 2017

Under circumstances of rapid disappearing of traditional ethnobotanical knowledge, traditional ethnobotanical knowledge surveys are the major step in documenting useful species with a conservation priority. In the ethnobotanical research, the relevance to the survey intensity, ethnobotanical information and plant species richness is the most important research theme. We made up TEK database in south Korea using metadata which had been published by the Korea National Arboretum. We calculated species richness using species richness estimator like ACE, Chao1, Chao2, ICE, Jack 1, Jack 2, and Bootstrap. Species accumulation curves showed each province sampling efforts appeared to be wide range of variance so that Gangwon province need more sampling efforts, and Chungnam province approached a horizontal asymptote earlier. We found heterogeneous patterns in the rarefaction curves of TEK species between gender for each categories of use (medicinal, food and handicrafts). Comparing with regional floral diversities, it was predicted that more diverse species would be found in some provinces by carrying out additional survey.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.701-710
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• 2016

We examined the inter-annual changes in the community structure of fish in the Yeosu coast during the spring fishing period (May June) from 2008 to 2015. Using a both sides fyke net, we collected 74 taxa, of which the dominant species was Trachurus japonicus. In the years 2009-2010 and 2015, when the relative abundance of T. japonicus decreased, the fish species diversity increased, as estimated from the rarefaction curve and beta-diversity, resulting in a significant difference in the fish community structure between two year groups: one comprising 2009-2010 and 2015 and the other comprising 2008 and 2011-2014. T. japonicus may be a keystone species that plays a critical role in temporal changes in the community structure of fish caught by fyke nets along the southern coast of Korea. Obvious modes in the length-frequency of T. japonicus smaller than fork length (FL) 10 cm were observed continually during the study, while the frequency of T. japonicus bigger than FL 15 cm declined rapidly after 2010. The new recruitment of smaller T. japonicus before and after 2010 appeared beginning in June and May, respectively.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.616-624
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• 2008

The ichthyofauna and ecological community analysis in the Dong River, Korea, were investigated from May, 2006 to May, 2007. During the surveyed period, 31 species belonging 9 families were collected. Total of 31 species(primary freshwater: 26 species, peripheral freshwater: 5 species) were found with the primary freshwater fishes being highest. Dominant species was Zacco koreanus(55.73%), and subdominant species was Coreoleuciscus splendidus(7.15%). Also, Microphysogobio longidorsalis (6.12%), Hemibarbus mylodon(4.87%), Iksookimia koreensis(4.49%) were numerous. There were 19 Korean endemic species(61.29%), including Acheilognathus signifer, A. yamatsutae, Pseudopungtungia tenuicorpus, C. splendidus, Squalidus gracilis majimae, H. mylodon. Among them, 1 species was identified as qualifying for possible designation as a natural monument catergory, and 5 species were identified for designation required to protect under a wildlife category. As result of expected number of species according to rarefaction curve, the expected species of the Dong-river ranged from 19(51. 4, 5) to 22(51. 3) and result of similarity analysis ranged from 62.28%(51. 1 and 2) to 84.13%(51. 1 and 5). In conclusions, we could define that the Dong-river has a very good water conditions as habitat of fish, and habitat conditions also are very similar in every survey sites.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.453-462
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• 1998

Macrobenthic community structure was studied at thirteen stations in Taebudo subtidal area, Korea, from July to October 1996. Triple macrobenthos samples were collected using a van Veen grab (0.1 $m^2$) at each station during the study period. A total of 209 species of macrobenthos was sampled with a mean density of 1,093 ind./$m^2$ and biomass of 134,86 g/$m^2$. Of these, there were 72 species of polychaetes ($34.5\%$), 69 crustaceans ($33.0\%$) and 49 molluscs ($23.4\%$). Polyalaetes were represented as a density-dominant faunal group with a mean density of 608 ind./$m^2$, comprising $55.6\%$ of the total benthic animals. It was followed by crustaceans with 307 ind./$m^2$($28.1\%$ of the total density), Echinoderms were represented as a biomass-dominant faunal group with a mean biomass of 54.21 g/$m^2$($40.2\%$ of total biomass). Total number of species and diversity were low in the inner part of the study area with high mud content and high in the offshore stations of mixed sediments. Major dominant species were three polychaetes, Heteromastus filifomis, Scoloplos armiger and Tharyx sp. whose mean densities were 70 ind./$m^2$, 67 ind./$m^2$, and 66 ind./$m^2$, respectively. Cluster analysis showed that the study area could be divided into five stational groups based on the faunal composition, that is, the innermost stations, coastal stations, transitional stations and two offshore station groups. The species diversity of these groups increased from the inner stational group toward the outer groups.