• Korean journal of applied entomology
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• v.46 no.3
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• pp.363-373
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• 2007

To evaluate environment of farm lands using indicator insects and evaluation indices, the insect abundance of which is one of the major criteria for the evaluation of agricultural environment of farm land in urban areas and industrial complex, three sites (Ansan, Daesan, Suncheon) were designated and monitored from 2004 to 2006. The flora of agricultural land was more than urban areas and industrial complex of that in three sites. Soil, water and air pollution of urban areas and industrial complex were more serious than those of agricultural land in three sites. Overall population of insects were high from June to August in the surveyed three sites. Collected insects in agricultural land were 12 order, 106 family and 166 species, those in urban areas were 11 order, 102 family and 148 species, and in industrial complex were 11 order, 100 family and 152 species. Species and population belonging to Coleoptera was dominant in the surveyed sites. The insect diversity indices of farm land were 2.36 in agricultural land, 1.92 urban areas and industrial complex. And agricultural environment of agricultural land was good, urban areas was common and industrial complex was poor. Based on the major criteria of evaluation items, the criteria were selected as diversity index over 2.1, insect indicator Pheropsophus javanus in agricultural land, diversity index 1.5-2.0, insect indicator Nephotettix cincticeps in urban areas, diversity index below 1.5, insect indicator Pagria signata in industrial complex.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.393-401
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• 2013

The objectives of this study were to analyze structures of fish community and the ecological health using a multi-metric fish model, the Index of Biological Integrity (IBI) in the Backje Weir of Geum River during two periods namely before-the-fishkill ($B_f$) and after-the-fishkill ($A_f$). The total number of fish species observed were 32 and among them 10 species (35%) were Korean endemic species. The exotic species observed were 3 which decreased by 0.4% after-the-fishkill ($A_f$). The dominant species were Opsariichthys uncirostris amurensis (13%) at the Bf period and Squalidus japonicus coreanus (17%) at the Af period in the Backje Weir. At after the fishkill ($A_{f-I}$) total biomass was about 10 times lower than the biomass before-the-fishkill ($B_f$). The biomass of Carassius auratus decreased 98% after-the-fishkill and as time passed by the biomass recovered to nearly 100%. Similar decrease in the biomass occurred in the population of Opsariichthys uncirostris amurensis, while Rhinogobius brunneus population increased. According to the structure analysis of fish community, species richness index, evenness index and species diversity index were high but after-the fishkill, the values of indices decreased. Tolerant species (64%) dominated the fish community, and the sensitive species (2%) were rare, indicating the degradation of the ecosystem. According to analysis of the multi-metric model (IBI), the mean model value of the fish community in Backje Weir was estimated as 17.5 indicating a "fair condition".

• Korean Journal of Environment and Ecology
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• v.35 no.4
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• pp.377-386
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• 2021

This study was conducted to provide basic data for habitat management and preservation of Jeongmaek. A total of 18 priority research areas were selected with consideration to terrain and habitat environment, and 54 fixed plots were selected for three types of habits: development, valley, and forest road and ridge. The survey was conducted in each season (May, August, and October), excluding the winter season, from 2016 to 2018. The distribution analysis of birds observed in each habitat type using a self-organizing map (SOM) classified them into a total of four groups (MRPP, A=0.12, and p <0.005). The comparative analysis of the number of species, the number of individuals, and the species diversity index for each SOM group showed that they were all the highest in group III (Kruskal-Wallis, the number species: x² = 13.436, P <0.005; the number of individuals: x² = 8.229, P <0.05; the species diversity index: x² = 17.115, P <0.005). Moreover, the analysis by applying the land cover map to the random forest model to examine the index species of each group and identify the characteristics of the habitat environment showed a difference in the ratio of the habitat environment and the indicator species among the four groups. The index species analysis identified a total of 18 bird species as the indicator species in three groups except for group II. When applying the random forest model and indicator species analysis to the results of classification into four groups using the SOM, the composition of the indicator species by the group showed a correlation with the habitat characteristics of each group. Moreover, the distribution patterns and densities of observed species were clearly distinguished according to the dominant habitat for each group. The results of the analysis that applied the SOM, indicator species, and random forest model together can derive useful results for the characterization of bird habitats according to the habitat environment.

• Korean Journal of Environment and Ecology
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• v.38 no.1
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• pp.55-66
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• 2024

This study conducted a survey to investigate the characteristics of fish communities and the inhabiting status of endangered species in the Byekgye Stream, Korea from April to September 2020. A total of 3,415 fish of 9 families and 31 species were collected from 7 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance of 31.2%), and the subdominant species was Z. platypus (15.0%), followed by Pungtungia herzi (11.7%), Acheilognathus yamatsutae (5.4%), A. lanceolata intermedia (4.8%), Rhinogobius brunneus (4.4%), and Pseudopungtungia tenuicorpa (4.3%). Among the fish species collected, 19 (61.3%) were identified as Korean endemic species, and two cold-water fish species sensitive to climate change (Rhynchocypris kumgangensis and Cottus koreanus) were collected. Four species were designated as class II endangered wildlife by the Ministry of Environment: A. signifer, P. tenuicorpa, Rhodeus pseudosericeus, and C. koreanus. A. signifer and P. tenuicorpa mainly inhabited the mid to lower streams, R. pseudosericeus in the midstream, and R. pseudosericeus in the upstream. P. tenuicorpa inhabited in large numbers, and estimating the age by total length-frequency distribution in July, the total length of the 26-35 mm group was estimated as 0 years old, the 54-75 mm group as 1 year old, 82-97 mm group as 2 years old, 104-109 mm group as 3 years or older. The cluster analysis showed that the dominance index decreased from upstream to downstream, but the diversity, evenness, and richness index increased. The water quality of Byekgye Stream was evaluated as good overall since the river health (fish assessment index, FAI) using fish was evaluated as excellent (5 stations) and good (2 stations). Byekgye Stream has relatively well-preserved habitats, but conservation measures are required as habitats are disturbed by river repair work in some parts of the midstream and downstream areas where many endangered species inhabit.

• Korean Journal of Weed Science
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• v.11 no.3
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• pp.178-186
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• 1991

This study was conducted to evaluate the major weeds occurred in direct seeded rice and their compition with rice, and to establish the effective weed control method. The important weeds occurring in dry direct seeded rice were Echinochloa crusgalli, Cyperus amuricus, Rorippa islandica, etc. Among them, Echinochloa crusgalli was the most dominant weed species. In view of the Simpson's dominance index, the maximum number of the weeds was observed at 30 days after seeding, showing 0.26, but decreased as the time passed. In other hand, Simpson's dominance index of weed dry weight increased from 0.09 at 15DAS(days after seeding) to 0.28 at 60DAS indicating that particular weed such as barnyardgrass was dominating the fields. The plant height and the tiller number of rice in the dry direct seeded rice were not greatly affected by the time and duration of competition with weeds, but rice yield was greatly influenced by them. The yield reduction was observed when compition between rice and weeds were initiated at 20 to 40 DAS till the harvesting time. The highest weed control efficacy was observed at the treatment of systematic herbicide application such as soil applied Butachlor followed by Mefenacet/Bensulfuron-methyl/Dymron at 30 DAS after seeding, and soil applied Dimepiperate/Bensulfuron-methyl mixture as a preemergence type gave also an excellent control.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.57-66
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• 2008

The purpose of this study was to establish biomonitoring method for the assessment of the health of fish species in agricultural reservoirs polluted from various environmental contaminants. The ichthyofauna and fish community were investigated in the AsanHo and NamyangHo from September to November 2007. We measured abundance, size distribution, biomass, the number of fish with external and internal lesions, organosomatic index of the fishes collected in the AsanHo and NamyangHo. Dominant species were Lepomis macrochirus, Carassius auratus and the highest biomass were found in Cyprinus carpio, Carassius auratus in the AsanHo and NamyangHo, respectively. The composition of age in the population of Carassius auratus in the AsanHo and NamyangHo was stabled by size distribution analysis. The sex ratio of Carassius auratus were 1:0.36, 1:0.52 as female: male ratio in AsanHo and NamyangHo, respectively. The GSI of were 4.30, 1.69 of female and 1.45, 1.70 of male in AsanHo and NamyangHo, respectively. Most carp were 10-70 cm long in the AsanHo and 20-50 cm in the NamyangHo. The sex ratio of Cyprinus carpio were 1:0.42, 1:0.59 as female: male ratio in AsanHo and NamyangHo, respectively. The GSI of were 0.16, 3.46 of female and 0.93, 2.37 of male in AsanHo and NamyangHo, respectively. Of the 227 fish examined, 1.8% had some type of external lesion in AsanHo and 10% in NamyangHo. Overall, HAI scores ranged from 10-60 and HAI scores of AsanHo relatively lower than that of NamyangHo.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.1
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• pp.27-41
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• 2016

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Geoje-Hansan Bay, Southern Coast of Korea. Macrobenthos were collected by van Veen grab sampler at May (spring) and August (summer) 2013. The total species number and mean density were 300 species $7.6m^{-2}$ and $1,994ind.\;m^{-2}$, respectively. The major dominant species were the polychaetes Lumbrineris longifolia ($299{\pm}164ind.\;m^{-2}$), Aphelochaeta monilaris ($100{\pm}57ind.\;m^{-2}$), the bivalve Musculista senhousia ($91{\pm}96ind.\;m^{-2}$) and the polychaete Praxillella affinis ($80{\pm}66ind.\;m^{-2}$). From the community statistics [cluster analysis and nonmetric multidimentional scaling (NMDS) ordination], the macrobenthic community was distinguished into two groups of inner bay (farming ground of near Sandal Island) and channel station(from Hansan Island to Chubong Island) group. In this study, the ecological status was assessed by four biotic indices Shannon's H', the ATZI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and the Environment Conservation Index (ECI). The ecological status of the macrobenthic community in Geoje-Hansan Bay were poorer in the inner bay station than in the channel station. The results of the present study showed that three biotic indices (Shannon's H', M-AMBI and ECI) were valid as an index for evaluating the ecological status than the AMBI.

• Korean Journal of Ichthyology
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• v.31 no.4
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• pp.222-234
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• 2019

Fish community characteristics and habitat aspects of endangered species, Pseudopungtungia tenuicorpa and Acheilognathus signifer were investigated in the Hwayangcheon Stream of Songnisan National Park, a tributary of the Hangang River, Korea from April to October 2018. During this period, there were 29 species of 8 families collected from 11 survey stations using kick nets, cast nets long bag set nets. The dominant and subdominant species were Zacco koreanus (38.81%) and Rhynchocypris oxycephalus (16.64%), respectively. The next most abundant species were Z. platypus (14.28%), Pungtungia herzi (6.92%), Hemibarbus longirostris (4.52%), Pseudogobio esocinus (3.51%), A. signifer (2.31%) and P. tenuicorpa (1.90%). Among the fish collected, 18 species (62.1%) were Korean endemic species. Endangered species were A. signifer, P. tenuicorpa and Gobiobotia brevibarba. From upstream to downstream, the dominance index has gradually decreased, but number of species and individuals, diversity and evenness has gradually increased. Also, river health (index of biological integrity) is assessed as good (St. 1~8) and very good (St. 9~11). Fish communities were divided into four sections by the similarity index based on species and their numbers, i.e., upper section (St. 1~2, 4~5), upper-middle section (St. 3, 6), middle section (St. 7~9) and lower section (St. 10~11). Endangered species, Pseudopungtungia tenuicorpa inhabited in mostly lower section (St. 10~11) with rock and boulder bottoms, and age groups in April estimated from total length indicated that the 44~61 mm group is 1 year old, the 66~81 mm group is 2 years old, the 88~99 mm group is 3 years old, and the 104~107 mm group is more than 4 years old. Also, endangered species, A. signifer inhabited in middle-lower section (St. 7~11) with boulder and cobble bottoms and slow velocity, which the place inhabited by water plants. Meanwhile, their age structure in April estimated from total length indicated that the 30~43 mm group is 1 year old, the 48~58 mm group is 2 years old, the 62~77 mm group is 3 years old, and the 84~100 mm group is more than 4 years old. The sex ratio of female (47) to male (42) was 1 : 0.89.

• Korean Journal of Environment and Ecology
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• v.26 no.4
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• pp.593-603
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• 2012

This study was carried out to investigate the ecological succession sere and conservative value, and to provide the basic data for the planning of the Provincial Park Management in Seonamsagol(Valley), Jogyesan(Mt.) Provincial Park(altitude 884m), Suncheon City, Korea by analysing the structure of the plant community. Twenty plots(size is $20m{\times}20m$) were set up at an altitude of range from 315m to 480m. As a result of analysis of TWINSPAN which is one of the ordination technique, the plant communities were divided into four groups which are community I(Quercus variabilis community), community II(Q. serrata community), community III(Decideous broad-leaved plant community), and community IV(Carpinus tschonoskii community). The warmth index is $104^{\circ}C{\cdot}month$ based on the data of monthly mean temperature during the past thirty years(1981~2010), so we found out that the vegetation of the study site located in the South Temperate Climate Zone. We supposed that the ecological succession sere of the study site is in the early stage of developing from Q. serrata community to Carpinus tshonoskii community, however we should do a long-term monitoring to investigate the changes of the ecological succession each plant community, meanwhile Sasa borealis was dominant species in the shrub layer. The diameter at breast height of specimen tree is range from 20 to 55cm(average 36cm) and the height of that is range from 14 to 35m(average 23cm). The age of community I was 64 years old, that of community II was from 59 to 64 years old, that of community III was from 51 to 62 years old, and that of community IV was from 41 to 68 years old, thus the age of the study site is about from 38 to 72 years old. According to the index of Shnnon's diversity(unit: $400m^2$), community IV was ranged from 0.8452 to 1.2312, community III was ranged from 0.8044 to 1.1404, community II was ranged from 0.8221 to 0.9971, and community I was 0.8324.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.657-679
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• 2010

Mushroom fruiting was investigated in pine and oak dominated forest stands in Songni National Park located in central Korea for six years from 2003 to 2008, in order to understand the relationship between mushroom diversity and the environmental factors, precipitation, temperature, soil moisture and vegetation. The most frequent fruiting families were those of ectomycorrhizal mushrooms, Tricholomataceae, Amanitaceae, Russulaceae, Cortinariaceae, and Boletaceae. The frequency of mushroom fruiting varied from 94 to 167 species per year, with July and August having the highest(13~90 species). Mushroom fruiting was positively correlated to precipitation(r=0.897), using Palmer Drought Severity Index for the long term period and Standard Precipitation Index for short term period. Soil moisture content also affected mushroom fruiting, with Lactarius chrysorrheus and Russula virescens fruiting only at soil moisture content higher than 20%. Positive correlation between mushroom fruiting and temperature was also noted(r=0.77), with optimum rates at $21{\sim}25^{\circ}C$. Tricholoma flayayirens, Amanita gymnopus, Lactarius piperatus, Inocybe asteropora and Xerocomus chrysenteron were able to fruit at temperatures higher than $25^{\circ}C$. However, Laccaria amethystea, Amanita virosa and Russula mariae fruited at relatively wide temperature range. The influence of vegetation on mushroom fruiting was likewise noted, with 38 species, including Suillus bovinus and Boletopsis leucomelas being specific to pine dominated stands, while 42 species, including Polyporus arcularius and Hericium erinaceum were specific to oak dominated stands. On the other hand, around 50 species, including Laccaria laccata and Lycoperdon parlatum, were able to fruit in both types of vegetation. In conclusion, mushroom fruiting greatly varies with changes in precipitation, soil moisture, temperature and vegetation.