• Journal of Wetlands Research
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• v.15 no.1
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• pp.25-34
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• 2013

The purpose of this study is to investigate the properties of Menyanthes trifoliata habitat in coastal lagoons. To characterize plant composition in the habitats in the lagoon, the plot sampling method was applied. The depths of water and floating mat were measured. Surface water quality factors including pH, electrical conductivity (EC), dissolved oxygen (DO), and total dissolved solids (TDS) were measured in the sites. Phosphate, nitrate, ammonium, and major cations were measured in laboratory. The wetland has 78 taxa of wetland plants. The average coverage and density of M. trifoliata was 62.6% and $71.2/m^2$, respectively and Phragmites australis is important associate in Sunyoodam lagoon. The average depths of floating mats were 26.5cm in M. trifoliata and 68.9cm in the P. australis-M. trifoliata communities, and the water depth below the mat was 106.5cm and 17.7cm, respectively. The values of pH, DO, EC and TDS in the water were 5.06, 46.1%, 59.4 ${\mu}s/cm$, and 29.3 mg/L, respectively. The concentrations of phosphate, nitrate, and ammonium showed 47.2, 9321, and 15.9 ${\mu}g/L$, respectively. The concentrations of Ca, K, Na, and Mg had 11.1, 1.5, 15.1, and 11.3 mg/L, respectively. The habitats of M. trifoliata in the lagoon corresponds to a kind of lowland communities in Hewett's classification. To conserve the habitats of M. trifoliata in Sunyoodam lagoon, the supply of open water area, the construction of observation deck, and the block of inflow from the surrounding paddy fields are needed in the future.

• Korean Journal of Ecology and Environment
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• v.37 no.3 s.108
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• pp.319-331
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• 2004

This study was conducted to evaluate the ecological impact of freshwater bivalve (Corbiculidae) on plankton communities in experimental enclosure systems (2 m ${\times}$ 2 m ${\times}$ 2 m). During the acclamation period of one month, cyanobacteria, including Microcystis viridis and Microcystis aeruginosa, dominated in both control and treatment enclosures with no noticeable density difference. After the addition of 100 mussels, dominant species of phytoplankton shifted from Microcystis to Scenedesmus in concert with slight decrease in the cell density and the increase of N/P ratio. However, cell density in the control quickly increased, accompanied with changes of dominant species to Oscillatoria spp. With the introduction of additional 500 musseles in the treatment enclosure, dominant phytoplankton species in both enclosures were replaced with Selenastrum spp. and Cryptomonas sp. In the initial stage, the total zooplankton abundance in the control was higher than that of treatment, but it was reversed after the addition 100 mussels. After mussel density increased up to 600 indivisuals, zooplankton density in the treatment decreased with dominance of small taxa, such as rotifers and nauplius. However, abundance and carbon biomass of large zooplankton, such as Bosmina longirostris and Diacyclops thomasi were maintained in a high level compared with those of control. During the study period, Chl. a concentration in mussel treatment and control increased with DIP and $NH_3-N$, respectively. Due to the increase of $NH_3-N$, especially after the introduction of additional 500 mussels, nitrogen limitation did not occur in the treatment enclosure in contrast with strong nutrient limitation occurred in the control. These results indicate that filter-feeding Corbicula could exert important impact on nutrient recycling and plankton community structure in a freshwater ecosystem, through direct feeding and competition for the same food resource as zooplankton on one hand, and through alteration of nutrient availability on the other.

• Korean Journal of Plant Taxonomy
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• v.32 no.3
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• pp.339-362
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• 2002

Pollen morphology of 13 species of Korean Euphorbia was re-examined by means of LM and SEM. Taxonomic evaluation of palynological characters and relationships among taxa were also discussed based on the analysis of polar length, equatorial diameter, aperture size and exine thickness. Korean Euphorbia species were classified into three groups based on the mean size of polar length (P) and equatorial diameter (E) as follows:Group 1. sect. Tulocarpa and Tithymalus of subgenus Esula; $(P){\times}(E)=(54.88-67.17{\mu}m){\times}(44.30-64.75{\mu}m)$, Group 2. sect. Esula and Helioscpiae of subgenus Esula; $(P){\times}(E)=(39.98-47.24{\mu}m){\times}(36.07-38.83{\mu}m)$, Group 3. sect. Chamaesyce and Hypericifoliae of subgenus Chamaesyce; $(P){\times}(E)=(30.32-32.51{\mu}m){\times}(21.71-26.23{\mu}m)$. Various features of surface sculpturing were also grouped into 8 types by the characteristics of perporation size and distance of perporations as well as connection state of it. Pollen size and surface sculpturing were comparatively available in the levels of subgenus and section. Especially subgenus Chamaesyce was distinctly different from subgenus Esula by having compactly distributed perporations on exine surface as well as its small size of pollen grains. Because of the great variations in pollen size and the occurrence of various types of surface sculpturing according to the local poulations of each species, it was evaluated that they were unsuitable in classifying each species of Euphorbia. But such cases, that is, E. hylonoma being more familiar with E. ebracteolata than E. Pallasii, and E. pekinensis and E. fauriei as well as E. pallasii being strongly related with each other based on the similarity of surface sculpturing, reflected its usefulness in the classification of some Euphorbia species.

• Korean Journal of Plant Taxonomy
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• v.34 no.3
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• pp.221-244
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• 2004

Prunus sargentii complex of subgenus Cerasus is an Eastem Asiatic plant group that exhibits a broad range of morphological variation and includes P. takesimensis, P. yedosensis, P. verecunda, and P. sargentii. In this study, a morphological analysis was undertaken to determine whether the observed morphological variation was primarily attributable to morphological discontinuities among the taxa. P. sargentii, which distributed eastem area in Korea, northern area in Japan and far east Russia had umbel like inflorescence and additionally was characterized by sticky bud and leaf twigs, compared with P. serrulata complex. Also, P. verecunda in Korea and Japan was characterized by umbel like inflorescence and presence of hair in leaf, petiole and pedicel, and was treated as a variety of P. sargentii. Evidence obtained from multivariate morphometric analyses indicated that the entity of P. takesimensis formed a cohesive group somewhat distinct from P. sargenti.. Especially, P. takesimensis was characterized by relatively small flowers (26-32mm in diameter) and many flowers [(2)3-5] per umbel inflorescence, compared with P. sargentii (34-48mm and 2(3) per inflorescence) and should be recognized as an independent and endeImic taxon in Korea. Additionally, P. yedosensis, which was known to have umbel inflorescence (short peduncle type) with pubescent style based on the type specimen, was comprised of corymb inflorescence (long peduncle type) as well. The morphological differentiation between these two types of P. yedosensis was not considered sufficient to warrant recognition of specific status because of the putative hybrid origin, no distinctive geographical distribution pattern, and existence of various peduncle length on Island Jeju-do of Korea.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.312-323
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• 1999

External morphology, principal component analysis, cluster analysis, and vegetation were investigated to understand the taxonomic relationships and native environmental characters of Megaleranthis saniculifolia populations in four different habitats. Morphological characters such as calyx length and width, calyx index, presence or absence of serrate in calyx lobe, length of peduncle, branch of peduncle and fruit characters were useful for the identification of four different habitats. But, characters of plant height, bract and seed in four habitats were similar. The results obtained based on the principal component(PC) analysis of treated 96 OTU were divided into two groups by PC 1, 2, 3, and the sums of contributions for the total variance were 66.79%(PC1 31.3%, PC2 20.7%, PC3 15.8%, respectively), and only Mt. Taeki population was distinctly different from populations of other three habitats. In cluster analysis based on average linkage cluster analysis and Ward's method, there were similarities in the composition of clustered taxa, and each populations were not identified. Importance value by relative coverage and frequency appeared in M. saniculifolia(50.81%), Aruncus dioicus(12.64%), Corydalus turtschanovii(11.62%), Veratrum oxysepalum(11.45%), Anemone koraiensis(8.96%), Meehania urticifolia(8.76%), Filipendula palmata(7.06%), Aconitum pseudo-laeve(5.66%), Pseudostellaria palibiniana(5.45%) and Smilacina japonica(5.25%), respectively. These species were considered to be highly similar with M. saniculifolia. The highest importance value in all investigated sites was M. saniculifolia, but specific composition of high level different from each habitat. Average diversity of species was 1.40, and the highest in Mt. Kwangdeok(1.31), lowest in Mt. Jumbong(1.17). Average soil pH was 5.25 and similar in each habitat. Although the lowest content of K ion, but the highest the EC, water capacity, organic compound, Ca content were found in soil of Mt. Sobaek. Soils in Mt. Kwangdeok had the lowest content of EC, organic compound, Ca. Soils of Mt. Jumbong showed the highest of Mg content, but the lowest of water capacity, $P_2O_5$, and K contents.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.361-377
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• 2018

The aim of this study was to examine whether the guideline by the Ministry of Environment (ME) successfully and appropriately applied the IUCN Red List criteria at regional level and the rare and endangered national list considered eligible. A certain number of vascular plants, which are widely distributed in the world or in east Asia, deemed to be ineligible for assessment at a regional level as Not Applicable category (NA), because it occurs at very low numbers in South Korea. Among 377 vascular plant taxa evaluated by the ME, NA included 238 species, which represented 63.1%. The number of synonymized species or illegitimate name species were 13 species, which accounted for 3.4%. 21 species (9.3%) were threatened at global level and 103 species were possibly candidates species list for Red List assessments at regional level in the near future. The proportion of NA or waiting list was 66.6% among the list assessed by the ME. The most common errors involved incorrectly application of species extinction in case of population extinction in South Korea to the assessment and provided incorrect interpretation of the Red List criteria at regional level. The most assessments proposed by ME were not backed up without quantitative data quality, justifications, and sources. It is suggested that the risk of extinction should be reassessed at least in the Korean peninsula within the light of their overall distribution including far eastern Russia and North eastern China in north and for Japan and Taiwan in south for regional assessment. The results obtained here using the IUCN criteria at regional level showed that the list proposed by the ME produced an overestimation of the number of threatened vascular plants. Also, the misapplication of the term 'species extinction' for regional assessment was open to some degree of subjectivity and misinterpretation.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.105-117
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• 2019

In order to investigate the characteristics of benthic macroinvertebrate communities in the Gihwa stream, a tributary of the Dong River, we surveyed the community and environmental factors in April and November 2013 at 6 sites. The benthic macroinvertebrate taxa represented total 63 species belonging to 29 families, 12 orders, 5 classes and 4 phyla. Total 48 (10~28 in each site) species were collected in April and 44 (13~24 in each site) in November. The number of individuals increased slightly from $560{\sim}2,290m^{-2}$ in April to $806{\sim}3,674m^{-2}$ in November. Chironomidae spp. was dominant species in April and Stenopsyche bergeri was dominant species in November. In the Functional Feeding Groups, Gathering-collector(53.9%) was dominant in April, while Filtering-collector (44.3%) increased in November. Intolerant order category (i.e. EPT species richness) in St.1, St.5 and St.6 increased in November compared to April due to the increase of Trichoptera. St.2, St.3 and St.4, which were located near the fish farm, were low EPT as a whole, but Benthic macroinvertebrate index (BMI) was good state in November than April due to decrease of Chironomidae spp.. The environmental factors in the survey site showed similar tendency except for St.1 between both seasons, and electrical conductivity, salinity, and water width showed seasonal differences. Cluster analysis and Nonmetric multidimensional scaling (NMDS) based on benthic macroinvertebrate community data were divided into two groups according to season. Electrical conductivity, salinity and substrate composition were the most influential factors determining the distribution patterns of macroinvertebrate communities.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.331-344
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• 2018

Lotic organisms in streams are affected by natural and anthropogenic disturbances such as increase of heavy rainfall event caused by climate change and flow regime change caused by weir constructions. Based on domestic and foreign literature, 157 Korean benthic macroinvertebrate taxa were selected species as potential lotic candidates. Three shoreline sites (total 54 samples) were surveyed consecutively before ('08~'09), during ('10~'12) and after ('13~'16) the construction of the weirs (Gangcheon, Yeoju and Ipo weir) in the Namhan-River for tracing changes of lotic communities. As a result, water flow of the Ipo-wier and water quality variables such as T-N, T-P, BOD5, etc. of the weir section revealed no significant changes. Physical habitat conditions such as the flow velocity and streambed substrate evidently changed. Particulary, flow velocity measured at sampling points along with each microhabitat drastically decreased and particle size of streambed substrate steadily decreased after weir constructions. Lotic organisms also decreased after construction, especially Hydropsychidae (insecta: Trichoptera) acutely decreased from $3,526ind.\;m^{-2}$ to $2ind.\;m^{-2}$ As a result of CCA, lotic species such as Hydropsyche valvata, Hydropsyche kozhantschikovi, Cheumatopsyche brevilineata, Cheumatopsyche KUa, Macrostemum radiatum, etc. correlated with the flow velocity, streambed substrate. Therefore, the decrease of the flow velocity and substrate size after weir construction seemed to be closely related to the decrease of the individual abundances of the lotic organisms independently of water quality. In order to evaluate the influence of the ecosystem on the flow regime change more accurately, it is necessary to study the indicator species based on the resistance or preference of the flow.

• Korean Journal of Environment and Ecology
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• v.33 no.4
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• pp.378-401
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• 2019

This study generated a list of plants in eight sections from the Baekdansa ticket office (874m) to Cheonjedan (1,560m) divided in the interval of 100m above sea level to examine the species diversity patterns and distribution changes of the vascular plants at different altitudes in Taebaeksan National Park. Four site surveys found a total of 385 taxa: 89 families, 240 genera, 345 species, 5 subspecies, 34 varieties, and 1 form. A result of analyzing the change of species diversity along elevational gradients showed that it decreased with increasing elevation and then increased from a certain section. A result of analyzing habitat affinity types showed that the proportion of forest species increased with increasing elevation. On the other hand, the ruderal species appeared at a high rate in the artificial interference section. A result of comparing the proportion of woody and herb plants showed that the woody plants gradually increased with elevation and rapidly decreased in the artificial interference section. On the other hand, the herb plants showed the opposite trend. A result of analyzing the change of distribution of species according to altitude with the DCA technique showed that the vascular plants were divided into three groups according to the elevation in order on the I axis with the boundaries at 900m and 1,300m above sea level. The arrangement of each stand from right to left along the altitude on the I axis with a significant correlation with warmth index (WI) confirmed that the temperature change along the altitude could affect the distribution of vascular plants, composition, and diversity. Therefore, the continuous monitoring is necessary to confirm ecological and environmental characteristics of vegetation, distribution ranges, changes of habitat. We expect that the results of this study will be used as the basic data for establishing the measurement measures related to the preservation of biodiversity and climate change.