• The Korean Journal of Ecology
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• 제21권5_1호
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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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• 제4권1호
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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.

• 한국환경과학회지
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• 제27권10호
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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.

• 한국환경생태학회지
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• 제29권2호
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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.

• 한국수산과학회지
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• 제52권6호
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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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• 제35권1호
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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.

• 아시안잔디학회지
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• 제10권3호
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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.

• 한국환경생태학회지
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• 제17권4호
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• pp.375-382
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• 2004

본 연구는 서울 도시 비오톱(n=54)을 대상으로 서 식지 면적 에 따른 조류 종수를 파악하고자 2001년 가을과 2002년 봄에 실시하였다. 도시 비오톱을 대상으로 조사한 조류종수의 연구에서 비오톱 면적의 크기가 조류종수에 뚜렷한 영향을 미치지 않는다고 생각되어진다. 전체 대상지에서 32종의 조류가 관찰되었으며 1㏊미만에서 는 13종, 1-10㏊에서 는 29종, 10㏊이상의 면적에서는 8종의 조류가 나타났다. 비오톱 면적 크기에 따른 조류종수의 증가에 관한 연구에서, 면적의 크기가1-10㏊인 대상지가 <1㏊ 이거나, > 10㏊인 대상지보다 더욱 많은 조류가 관찰되었다. 또한, 종-면적 축적 곡선에서 는 작은 면적의 서식지가 추가되어졌을때 종수의 증가율이 지속적으로 높아졌다. 이에 도시 지역에서 조류 종수의 증가를 위해 필요한 최소면적은 1-10㏊가 효과적일 것이라 생각된다. 또한, 수자원과 다양한 식생구조를 가진 비오톱에서 조류종의 뚜렷한 증가를 보였다. 따라서 이러한 환경의 조성은 작은 면적의 서식지도 조류종의 증가에 도움이 될 수 있을 것이다.

• 한국수산과학회지
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• 제43권5호
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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.

• 한국환경생태학회지
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• 제15권4호
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• pp.394-400
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• 2002

무작위표본추출법에 의한 산림군집구조 조사시 교목층과 관목층의 적정 조사구수를 파악하기 위하여 혼효율이 비교적 높은 구룡산 상금정계곡 활엽수혼효림군집의 교목층과 관목층을 대상으로 각각 10m$\times$10m, 5m$\times$5m 크기의 조사구를 15개씩 설치한 후 종수-면적 곡선, performance curve 등을 적용하였다. 종수-면적 곡선에의한 교목층의 적정 조사구수는 일반적인 수준에서 5개 이상이었으며, 보다 정확성을 요구할 경우 10개 이상이었다. 교목층의 상대중요치에 의한 performance curve를 작성한 결과 조사구수 4개 이상에서 우점종과 준우점종의 구분이 뚜렷해지며, 조사구수 8개 이상에서는 준우점종의 순위가 일정한 경향이었다 교목충의 종다양도는 조사구수 7개 이상에서 비교적 일정한 경향을 보였으며 조사군집을 대표한다고 할 수 있는 전체 조사구수 15개의 종다양도와 0.05 이내의 차이를 보였다. 교목층 전체 조사구수와의 유사도지수는 조사구수 5개 이상에서 80% 이상, 9개 이상에서 90% 이상이었다 관목층의 경우, 종수-면적 곡선에 의한 적정 조사구수는 일반적인 수준에서 5개 이상이었으며, 보다 정확성을 요구할 경우 12개 이상이었다. 관목충의 상대중요치에 의한 performance curve를 작성한 결과 조사구수 4개 이상에서 우점종과 준우점종의 구분이 뚜렷하였으며, 조사구수 13개 이상에서는 준우점종의 순위가 일정한 경향으로 유지되었다. 관목층 종다양도는 조사구수 6개 이상에서 비교적 일정한 경향을 보였으며, 조사군집을 대표한다고 할 수 있는 전체 조사구수 15개의 종다양도와 0.05이내의 차이를 보였다. 관목층 전체 조사구와의 유사도지수는 조사구수 5개 이상에서 80%, 9개 이상에서 90% 이상이었다. 이상을 종합하면, 우점종과 준우점종이 구분되는 일반적인 수준의 적정 조사구수는 교목층과 관목층 모두 대체로 5개, 준우점종 내에서의 순위까지 구분되는 보다 정화겅을 요구하는 수준의 적정 조사구수는 교목층 10개, 관목층 13개 정도이었다.