• Animal Bioscience
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• v.34 no.9
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• pp.1466-1478
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• 2021

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.287-296
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• 2021

This study was conducted to investigate the species composition collected by fyke net and characteristics of the Erythroculter erythropterus population in the Asan Lake and Chungju Lake from June to September, 2021. The collected fish in Asan lake were identified as 4,977 individuals of 13 species from a total of six families and in Chungju lake were identified as 2,436 individuals of 18 species from a total of eight families. The dominant species in Asan lake, both the individuals and biomass were E. erythropterus with 4,470 (89.8%) and 498,424g (84.5%). The dominant species in Chungju lake, both the individuals and biomass were E. erythropterus with 1,327 (54.5%) and 301,818 g (77.5%). The results of the community analysis showed that a dominant index value of Asan lake was 0.93, higher than 0.71 of Chungju lake, and a diversity, evenness, and richness index value of Chungju lake were higher than of Asan lake. The frequency distribution of the total length analysis of the E. erythropterus population showed the appearance rate of 1~2 year olds was high in Asan lake, and the appearance rate of more than 2 years old were high in Chungju lake. The length-weight analysis of E. erythropterus in Asan Lake and Chungju Lake showed a regression coefficient b of 3.06 and 3.04, a condition factor (K) of 0.000128 and 0.000051 with a positive slope. This study could be served as baseline data for assessing habitat characteristics based on the species composition of fishes, and identifying health conditions of E. erythropterus in Asan Lake and Chungju Lake, artificial lakes.

• Ocean and Polar Research
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• v.25 no.2
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• pp.183-200
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• 2003

In order to assess the ecological changes induced by organic pollutants of the Shihwa Lake, BPI (Benthic Pollution Index) based on the benthic faunal community was employed. It was modified from Infaunal Trophic Index (ITI), and recommended as a pollution detecting method for the environmental assessment. The BPI values were calculated from the benthos data, which were collected for three terms: in 1980, before the Shihwa Lake was built up; in 1994-1997, which the Shihwa Lake was completely isolated from the outer seawater; in 1997-1999, after inflow of the outer seawater. Since the Shihwa Dike was constructed in February 1994, the pollution intensity of the lake had been increased from the narrow and inner part of the former Gyeonggi Bay and spread fast along the coast line of the Shihwa Lake. Then, in 1996 it showed the very high BPI levels all around the Lake. This serious polluted condition had been lasted till 1997, when the inflow of the seawater was begun. In 1998, from the nearest part of the Shihwa Gate, the BPI levels gradually became low in most area of the Lake, except its inner and narrow part. These greatly lowered BPI levels mean that the seawater inflow could be assumed to affect positively in the lake. Furthermore, BPI gave the same results from the other environmental assessment based on the abundance and the species richness of macrobenthic community. It shows that BPI could be useful as an effective method to assess the marine environment and evaluate the status of environmental conditions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.4
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• pp.29-41
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• 2015

Abandoned paddy field provides an excellent opportunity to improve the species diversity and habitat quality. Ecological characteristic on the changing of plant communities at different seral stages is a major basis data for ecological restoration. In this study, we investigated changes of the species composition and community indices on the plant community associated with abandonment of cultivated rice paddies. The ecological stability of the habitat was evaluated by using eco-floristic characters(Di; Disturbance index, AUI; Actual urbanization index). Survey sites were grouped into six stages(stageI (${\leq}3years$), stageII(3-5years), stageIII(5-7years), stageIV(7-10years), stageV(10-15years), stageVI(${\geq}20years$). Vegetation investigation was done from May 2009 to October 2012 and carried out phytosociological approach. The total flora were summarized as 176 taxa including 58 families, 127 genera, 157 species, 3 subspecies, 15 varieties and 1 forms. At each of successional stages, 64 taxa in stage I, 34 taxa in stage II, 84 taxa in stage III, 83 taxa in stage IV, 92 taxa in stage V, 23 taxa in stage VI were identified. Of the occurrence plants, the species with the highest r-NCD value were Alopecurus aequalis, Juncus effuusus var. decipiens, Persicaria thunbergii, Artemisia princeps, Salix koreensis and Alnus japonica at each stages. Herbaceous annual plants were dominated in the early stage, but its r-NCD value declined in the middle stage and the late stage. On the other hand, herbaceous perennial plants and Persicaria thunbergii, annual hydrophytes, increases in the middle stage. Woody plant and herbaceous plant which appeared in the forest edge increases in the late stage. Community indices correlate with successional stages. Richness and diversity index increase along the successional gradient. But dominance index decrease along the successional gradient. Evenness index was correlated with lower. In the ecological stability analysis of the habitat that evaluated by eco-floristic characters, stage I was the most unstable habitat. And the stability of the habitat has improved according to the successional stage.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.515-524
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• 2019

The purpose of this study is to investigate the effects of artificial disturbance by analyzing and comparing the survey data of the Yeongju dam located in Yeongju-si, Gyeongbuk before and after impoundment. We surveyed four sites between the downstream of sediment control to the downstream of Yeongju Dam four times between April and October 2018. The macroinvertebrate data before the survey were gathered from the literature. The total number of benthic macroinvertebrates we observed was $35,037ind./m^2$, including 77 species, 48 families, 14 orders, 7 classes, and 3 phyla. The result of the community analysis showed that the dominant index increased from 0.44(${\pm}0.11$) before impoundment to 0.62(${\pm}0.16$) after impoundment. The diversity index increased from 2.26(${\pm}0.30$) to 1.75(${\pm}0.45$), the evenness index from 0.75(${\pm}0.10$) to 0.66(${\pm}0.14$), and the richness index from 3.11(${\pm}0.98$) to 2.25(${\pm}0.81$). The most dominant species changed from Hydropsychidae spp. to Chironomidae sp. The result of the Principal Components Analysis (PCA) based on Axis 1 showed that the sites of 2014 and Hydropsychidae spp. had a negative value, while the sites of 2018 and Chironomidae sp. had a positive value. In all study sites, the dominance increased while the diversity decreased. The community change was the largest in St. 2. The results of the functional group analysis showed that the scrapers increased while gathering-collectors increased among the functional feeding group and that the clingers decreased while borrows increased among the habitat oriented group. The Benthic Macroinvertebrate Streambed Index (BMSI) decreased from an average of 57.1(${\pm}8.0$, C class) to an average of 30.0(${\pm}12.1$, C class). St. 3 and St. 4, in particular, showed a high reduction rate.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.187-201
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• 2019

This study examined the physicochemical water quality and evaluated the ecological health in 14 sites of Geum River (upstream, mid-stream, and downstream) using the fish community distribution and guilds and eight multi-variable matrices of FAI (Fish Assessment Index) during June 2008-May 2009. The analysis of the water quality variables showed no significant variation in the upstream and mid-stream but a sharp variation due to the accumulation of organic matter from the point where the treated water of Gap and Miho streams flew. The analysis of physicochemical water properties showed that BOD, COD, TN, TP, Cond, and Chl-a tended to increase while DO decreased to cause eutrophication and algae development from the downstream where Miho and Gap stream merged. The analysis of fish community showed that the species richness index and species diversity index increased in the mid-stream area but decreased in the downstream area, indicating the stable ecosystem in the upper stream and the relatively unstable ecosystem in the downstream. The analysis of the species distribution showed that the dominant species were Zacco platypus that accounted for 20.9% of all fish species and Zacco koreanus that accounted for 13.1%. The analysis of the fish tolerance and feeding guild characteristics showed that the sensitive species, the insectivore species, and the aquatic species were dominant in the mid-stream point. On the other hand, contaminants from the sewage water treatment plant of Miho stream had a profound effect in the downstream to show the dominance of tolerant species, omnivorous species, and lentic species. Therefore, it is necessary to improve water quality by reducing the load of urban pollutants and to pay attention to the conservation and restoration of aquatic ecosystems.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.82-92
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• 2007

In 2003, we evaluated biological water quality at twelve sites of Youngsan River using community analysis, fish compositions, and the Index of Biological Integrity (IBI). Of the twelve, four sites were the controls, which have no point sources in the upstream and the remaining eight sites were the impacted sites, which are influenced by wastewater treatment plant (WTP) and agro-industrial complex. Model values of the IBI, based on 12 sites data, averaged 28 (n=12, range: $18{\sim}44$), indicating fair poor condition according to the criteria of US EP A (1993). In the mean time, mean IBI in the control sites (S3, S5, S6, S11) was 42 (n=4, range: $38{\sim}44$), indicating a good condition, whereas mean IBI in the impacted sites was 21, indicating a poor condition. Mean IBI value in the control, thus, was greater by 2 fold than that in the WTP sites. The spatial pattern of IBI values was similar to the patterns of species diversity index and species richness index, except for Site 11, which was 1st order stream. Similarity analysis indicated that three groups were divided at the similarity level of 80%. One group was the streams influenced by wastewater and the other two groups were the pristine streams as the control, indicating that the stream health conditions are directly influenced by presence or absence of the point sources. Also, Pearson's correlation analysis showed that IBI values had negative correlation (r=0.899, p<0.001) with relative abundance of tolerance species, and had positive relation (r=0.890, p<0.001) with sensitive species. Overall, outcomes suggest that the point sources of the WTP might impact the species composition and ecological health, resulting in degradation of biological water quality.

• Journal of Korean Society on Water Environment
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• v.34 no.2
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• pp.183-201
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• 2018

The tolerance of Korean benthic macroinvertebrates to organic pollution has been analyzed since the early 1990s. However, considering the fact that there have been related studies carried out in some European countries since the early 20th century, the history of the research in Korea is very short and there is still much knowledge to supplement. We revised the saprobic valency, the saprobic value and the indicator weight value of 190 benthic macroinvertebrates taxa through the data of water quality and individual abundance collected from 7,086 sampling units in Korea from 2008 to 2014. The individual abundance of Uracanthella (Ephemeroptera) as a representative, one of the most common and abundant taxa in Korea, showed a typical lognormal distribution to 5-day biochemical oxygen demand (BOD5) concentration, and a normal distribution to the class interval of BOD5 concentration according to saprobic series. The value combining the mean individual abundance and the relative frequency of occurrence was a more efficient indicator value than that of each property alone. Benthic Macroinertebrates Index (BMI) was newly proposed as a modification of the saprobic index of Zelinka and Marvan (1961). BMI showed extremely significant correlation (determination coefficient $r^2$ > 0.6, n = 569 sites) with the concentration of BOD5, and the coefficient was a little higher than those of the previous indices. Until now, there has been very little research on the assessment of biological integrity of benthic macroinvertebrates community in Korea. While continuing researches into improve the reliability of BMI, it is necessary to develop multimetric indices for evaluating the integrity, including the composition of species and functional guilds, and the richness and diversity of the community.

• Korean journal of applied entomology
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• v.43 no.4 s.137
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• pp.267-273
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• 2004

To select indicator insects, the abundance of which is one of the major criteria for the evaluation of agricultural environment, was designated and monitored in the three sites (Hongcheon A, B, and Yangpyeong) from 2001 to 2003. Characteristics of rice cultivation are usual cultivation with 2 or 3 times sprayed chemical agents per year in Hongcheon A site, duck cultivation with non-sprayed chemical agent, green manure and mowing in Hongcheon B site, and pond snail with non-sprayed chemical agent, green manure and mowing in Yangpyeong site. Dominant floral species are Digitaria ciliaris (Retz.) Koel., Persicaria thunbergii (Siebold & Zuccarini) H. Gross, Echinochioa crus-galli (L.) Beauvois, and Humulus scandens (Lour.) Merr. in Hongcheon A site, Digitaria ciliaris (Retz.) Koel., Persicaria thunbergii (Siebold & Zuccarini) H. Gross, and Echinochloa crus-galli (L.) Beauvois in Hongcheon B site, and Digitaria ciliaris (Retz.) Koel., Setaria viridis (L.) Beauv., and Persicaria langiseta (De Btuyn) Kitagawa in Yangpyeong site. Degree of green naturality (DGN) was higher in Hongcheon B site (2.0) and Yangpyeong site (3.6) than in Hongcheon A site (1.6). Number of species and individual of insects collected in the three sites were abundant on August and September. The species diversity was higher in Hongcheon B and Yangpyeong than in Hongcheon A. And Coleoptera was dominant in the all sites. The dominance index (DI) was the lowest, but diversify index (H'), evenness index (E) and richness index (RI) were the highest in Hongcheon B site. Based on three results, indicator insects for the evaluation of agricultural environment were selected as Dolichus halensis in Hongeheon A site, as Pheropsophus. javanus and Polionemobius mikado in Hongcheon B and Yangpyeong sites.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.46-56
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• 2012

Benthic macroinvertebrates were investigated in Hoeongseong Lake region from March to October 2010, Korea. Macroinvertebrate communities, composition of the functional feeding groups, habitiat oriented groups and the biological water quality were assessed above and below Hoeongseong Dam in the lake region. Six sites, two (St.1~2) above the lake, two (St. 3~4) into the lake, and two (St. 5~6) below the dam, were selected for quantitative (Surber sampler $30cm{\times}30cm$, mesh size 0.2 mm) and qualitative (Hand net) samplings of benthic macroinvertebrates. As a result, a total of 83 species belonging to 43 families, 17 orders, 8 classes, and 5 phyla were recognized. The EPT-group (50 spp. : 60.24%) that is major taxa or EPT-group plus Diptera (61 spp. : 73.49%) occupied most of benthic macroinvertebrates community. Based on quantitative sampling, the number of benthic maroinvertebrates above the lake was 2,399 individuals including 54 species, 28 families, 11 orders, 4 classes, and 4 phyla, whereas 510 individuals including 16 species, 12 families, 7 orders, 4 classes, and 3 phyla in the lake and 626 individuals including 62 species, 33 families, 13 orders, 6 classes, and 4 phyla below the dam were collected respectively. Dominance index was the highest, with 0.82-0.93 ($0.87{\pm}0.05$) in Hoeongseong lake (St. 3-4), diversity index was 3.04-3.16 ($3.10{\pm}0.06$), evenness index was 0.79-0.85 ($0.82{\pm}0.03$), and richness index was 7.27-8.52 ($7.90{\pm}0.63$), which were relatively higher below the dam sites. In the functional feeding groups, collector-gatherers and collector-filterers were the highest in the whole sites, and predators (Micronecta sedula) was appeared highly in the lake. Moreover, swimmers, burrowers, and clingers were considerably occupied in all collecting sites. The result of the DCA, similarity analysis, and MRPP were well reflective of the composition of lake and stream macroinvertebrates. ESB indicate that the lake sites were evaluated heavily polluted under priority improvement waters. Also, Semisulcospira gottschei, Ecdyonurus kibunensis, Epeorus pellucidus, Rhoenanthus coreanus, Stenelmis sp., and Cheumatopsyche brevilineata are considered as an indicator species above and below Hoeongseong Lake, whereas Macrobrachium nipponense and Micronecta sedula are indicated in the lake.