• The Korean Journal of Ecology
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• v.21 no.5_1
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• pp.457.2-486
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• 1998

Ecological success of introduced species is frequently attributed to the reproductive characters of those species. We examined the relationship between both flowering season and plant size and reproductive characters in two introduced species of Taraxacum, e.g., T. officinale and T.laevigatum. Seventy six plants of T. officinale and 23 plants of T. laevigatum were randomly tagged from a population at the sungshin Women's University in April of 1997. The size and number of vegetative characters such as rosette diameter, leaf number, and the largest leaf length and width were measured for each plant at the onset of flowering. The infructescence was collected continually from each plant before seed dispersal from April to August of 1997. The number of infructescence per plant, and seed number and total seed weight per infructescence were measured. Mean individual seed weight per infructescence was also obtained. T. officinale possessed larger sized, but smaller number of, leaves than T. laevigatum, thereby resulting in no significant difference in total leaf area. There was a trend that vegetatively larger plants in both of these species produced reproductive characters larger in size or greater in number, except for seed number and total seed weight per infructescence in T. laevigatum. All reproductive characters examined in T. officinale decreased toward the end of flowering season. In T. laevigatum, infructescence number per plant also declined during a flowering season: however, mean seed number per infructescence increaed toward the end of flowering season with no significant seasonal change in the total seed weight per infructescence. T. officinale produced on average about twice as many seeds per plant as T. laevigatum during a growing season. These two Taraxacum species produced quite small seeds in size compared to the endemic species, exhibiting a far better dispersal ability of introduced species. These data demonstrate that most reproductive characters decline in size and number in both species during a long flowering period, but the two species appear to employ different strategies to achieve reproductive success in disturbed habitats.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.1
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• pp.16-27
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• 2023

Primary succession on bare rocks is a challenge for invaders, including one of which was plants. The invasion of bare rock by exotic species raises the question of whether their presence hinders or facilitates succession. This study aimed to determine the role of exotic species in primary succession in six overburden (OB) coal mines using a chronosequence approach. Vegetation analysis was undertaken using line transects. Measurements were carried out on the absolute and relative coverage of each species. Native and exotic species were identified and grouped using information from local communities, identification books, and websites. The relationship between time and number of species, time, and relative dominance of exotic and native species was analyzed using Pearson's correlation. Species number and dominance data were analyzed descriptively. The number of native species from the six OB heaps was higher (57) than that from exotic heaps (50). Neither the number of species nor the coverage showed a significant relationship with time. Exotic species predominated throughout the age of the embankment but tended to decrease over time. Temporary dominance by exotic species plays a role in assisting primary succession in the OB. This process might be prolonged without the temporary dominance of exotic species during early primary succession.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.907-923
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• 2018

The aim of this study was to determine the appropriate stockpiling methods for revegetation by comparing the germination status of seed banks before and after preservation for 2 years. Soil temperature in stockpiled topsoil was higher in open treatment and at 1.5 m, whereas soil water content was maintained at lower levels (14.06-19.08%), than those in the control group. The seed banks in stockpiled topsoil had 48 species and 1,559 individuals, among which perennials showed the highest number in terms of life forms, whereas Compositae and Gramineae were dominant in terms of families. Based on seed bank type, persistent seed banks had the highest number of species, while transient seed banks had the highest number of individuals. By stockpiling period, the number of species in the seed bank started to increase after 24 months, while the number of individuals began increasing after 12 months and exceeded that of the control group after 24 months. Regarding the treatment of stockpiling methods, the number of species and individuals in open treatment were closer to those of the control group. When analyzed by height, the number of species and individuals were higher at 0 m, but still lower than those of the control group. A multivariate analysis of variance (MANOVA ) showed that the optimal combination was obtained in open treatment and the number of individuals increased with the lengthening of the stockpiling period.

• Korean Journal of Environment and Ecology
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• v.29 no.2
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• pp.174-183
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• 2015

We have conducted a verification test of correlation between bird community indices and bird sound recording results in order to use the equipment which deals with the automatic sound collecting system, the song meter. The study areas include four sites which are Gombaeryoung and Zochimryoung in Jeombongsan Mountain and Jookryoung and Gochiryoung in Sobaeksan National Park. We collected the bird sound data five times using a sound recorder and field survey results in the same place of the study site. As a result of the sound recording from the field survey, the species recorded by three researchers of sound analyst include common resident species or species which have a relatively conspicuous call and song. On the contrary, the species recorded by only one researcher are a relatively rare or inconspicuous species or was familiar with the personal experiences of each researcher. The number of species recorded by only one researcher totaled fourteen species (36.8 %), and that of two researchers totaled twelve species (31.6 %), and that of three researchers totaled twelve species (31.6 %). The correlations of the number of species among three researchers was not significant in some results, but the sum or maximum count of the number of species was useful to estimate a significant correlation between the result of researchers and the indices of field surveys. As a result of correlation analysis by using sound recordings, the maximum number of species among the three researchers significantly correlated with the number of species, the species diversity index and the species abundance index in the field survey at the same site, however it did not correlate with the number of individuals and species evenness index. As a result of sound analysis collected from the stationary sound recording system; song meter, the number of frequencies in bird songs and calls correlated with the number of species in the field survey at the same site. The number of calls and songs decreased as time went by. Finally, we could test the active time range and change the activity strength by using a sound recording system. In particular, that sound recording system is able to collect data in same time and site, so it is expected so that the equipment not only replenish a shortage of researchers and survey periods in field research in a short term monitoring survey, but also be able to acquire statistical objectivity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.745-751
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• 2019

Seasonal variation in species composition of fishes in the Sannam reservoir in Changwon, Korea was determined using samples collected by a three-sided fyke net in 2018. During the study period, we collected 2,181 individuals of 9 species, with a total weight of 111,552.2 g. The dominant species were Lepomis macrochirus, Carassius carassius, Erythroculter erythropterus, and Cyprinus carpio. These species accounted for 96.1% of the total number of individuals. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The peak number of fish species occurred in May and August, the biomass of fishes was highest in May. Whereas the number of individuals was highest in February.

• Journal of Forest and Environmental Science
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• v.35 no.1
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• pp.1-5
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• 2019

Species diversity is one of the most important indices that used to evaluate the sustainability of forest communities. In the present study, three variables including number of individuals (frequency of species), basal area and volume of tree species were compared to estimate tree species diversity in broadleaves forests of Iran. Based on systematic random design, 30 plots (circle plot, $1000m^2$) was selected. Type of species, number of species, DBH and height of trees were measured. Simpson (1-D), Hill ($N_2$), Shannon-Wiener (H'), Mc Arthur ($N_1$), Smith-Wilson ($E_{var}$) and Margalef ($R_1$) indices used to estimate tree species diversity. Species diversity was calculated in each plot. ANOVA test showed that there was a significant difference between of three variables used for estimation of species diversity. Number of trees variable has more precision than basal area and volume variables to estimate of species diversity. But Duncan test revealed that there were significant difference between of basal area and volume variables with number of trees. Therefore, basal area and volume variables were selected as more suitable variables in order to estimate of biodiversity indices in northern forests of Iran.

• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.213-230
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• 1996

A study of occurrence and distribution of cellular slime molds(CSMs) in forest soils of central areas of Korea was carried out. Samples for CSMs isolation were collected from 4 study sites; Mt.Kyeryong, Mt. Taebaek, Mt. Sobaek and Mt. Sokri. In Mt. Kyeryong, six species were found. These were Dictyostelium fasciculatum, D.firmibasis, D. mucoroides, D. minutum, D. brefeldianum and Polysphondylium pallidum. The average number of species isolated at one site was 0.75, and average density(clones /g soil) was 292. The results of soil sample analyses were that the concentration of Pb was higher than any other areas. In Mt. Taebaek, seven species were found; D. fasciculatum, D.firmibasis, D. mucoroides, D. miuutum, P.pallidum. P. violaceum, P. candidum. The average number of species isolated at one site was 2.3,and average density was 1,108. Based on importance values calculated from study sites within each of three elevation ranges, several of the more widely distributed and abundant species have distribution patterns that show a response to elevation. In Mt. Sobaek, eleven species were found. These were D. fasciculatum. D.firmibasis, D. mucoroides, D. miuutum, D. brefeldianum, D. crassicaule,D. deminutivum, D. implicatum, P. pallidum. P. violaceum and P. candidum. The average number of species isolated at one site was 3, and average density was 793. Species diversity appeared to be the highest in this area. In Mt. Sokri, six species were found. These were D. fasciculatum. D. mucoroides, D. minutum, D. purpureum, P. pallidum. and P. violaceum. The average number of species isolated at one site was 2.4 and average density was 858. It was noticeable that D.purpureum were much more comrnonly found in this pinus evergreen forest. Key words: Cellular slime molds(CSMs), Importance value, Elevation, Average number of species, Average density.

• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.375-382
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• 2004

This study is conducted to investigate number of species in various habitat size in the area of urban biotope in Seoul from October to November in 2001 and from May to June in 2002. It is established that habitat size does not significantly affect the number of species in urban biotope. Thirty-two bird species were observed in 54 sites. Thirteen species of birds used sites of up to 1㏊, 29 species from 1 to 10 ㏊, and 8 species in the sites larger than 10㏊. We find that most of species appeared in size (1-10㏊), rather than in size (<1㏊, >10㏊). The cumulative number of species for a given cumulative area was consistently higher when small sites were added first. We think that this habitat size is the actual area to promote number of species within the urban area. Also, there was significant increase of number of species at biotope with water source and multiple vegetation structure. Therefore, if water resources and multiple vegetation structure is maintained, even small area can be helpful to the bird species promotion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.503-509
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• 2010

The seasonal and interannual variation in the species composition and abundance of the decapod assemblage (shrimps, crabs, and hermit crabs) collected using pots in the coastal waters off Gori were studied between 2005 and 2008. During the study period, 49 decapod species belonging to 19 families were collected. The dominant species were Crangon hakodatei, Pandalus gracilis, Carcinoplax longimana, Charybdis bimaculata, Carcinoplax vestita, Diogenes edwardsii, and Dardanus arrosor. These seven species accounted for 95.46% of the total number of individuals collected. The number of species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number and biomass of individuals occurred in July 2006. The number and biomass of individuals were higher in summer and lower in winter, and the diversity indices were lower in summer than in the other seasons. The abundance of dominant species showed some seasonal and interannual change; in particular, those of C. hakodatei and P. gracilis corresponded with the bottom water temperature.

• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.394-400
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• 2002

A mixed forest community of broad-leaved trees in Guryongsan area was studied to determine the adequate number of plots of tree and shrub strata for investigating forest community structure. Fifteen 10m$\times$10m plots were set up in the tree stratum and fifteen 5m$\times$5m plots were set up in the shrub stratum. Species-area curves and performance curves were made from vegetation analysis of the plots. In tree stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five. In tree stratum, minimum number of plots where a given percentage increase in nuts her of plots produced less than the half of the percentage increase in number of species was ten. In tree stratum, minimum number of plots where the dominant species was distinguished from the subdominant species was four In tree stratum. minimum number of plots where the subdominant species were distinguished from each other was eight. In tree stratum, the difference of species diversity(H') between seven or more plots and total fifteen plots was less than 0.05 Similarity index was more than 80% between aye or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five . In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the half of the percentage increase in number of species was twelve. In shrub stratum. minimum number of plots where the dominant species was distinguished from the subdominant species was four. In shrub stratum, the minimum number of plots where the subdominant species were distinguished from each other was thirteen. In shrub stratum, the difference of species diversity(H') between six or more plots and total fifteen plots was less than 0.05. Similarity index was more than 80% between five or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. It may be given as a conclusion that adequate number of 10m$\times$10m plots for the tree stratnm was about 5 in general acse and 10 in case of requiring more accuracy, and that the adequate number of 5m$\times$5m plots for ahrub stratum was about 5 in general case and 13 in case of requiring more accuracy.