• Journal of Life Science
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• v.18 no.10
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• pp.1400-1409
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• 2008

This study was carried out to offer the forensic entomological evidence to estimate the postmortem interval (PMI) based on the decomposing state of the pig carrion and the arthropod succession in exposed carrion. A total of 48 species of 28 families belonging to 7 orders were collected, and dominant insect varied with season, i. e., the Calliphoridae in March, May and October, both of the Calliphoridae and the Staphylinidae in July, and the Staphylinidae in September. The Calliphoridae was the first visiting insect throughout all the seasons as well as the index insect dominant in the early decomposing stage. The index insect in the later decomposing stage, however, was the Staphylinidae throughout all the seasons except in March. In March, the Muscidae was dominant, presumably because the flies consistently arrived throughout the extended period of decomposition of the carrion owing to the low ambient temperature of the season. In this connection, it is known that not only the decomposition stage of the carrion and the carrion-associated insect but also the climatological condition of the region have to be taken into consideration to estimate the PMI.

• The Korean Journal of Ecology
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• v.22 no.6
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• pp.325-335
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• 1999

Empetrum nigrum dominant community or Rhododendron mucronulatum and R. yedoense var. poukhanense dominant shrub community are developing above l,500m on Mt. Halla in Cheju Island, Korea. These communities were formed as a result of the forest of Abies koreana regression by grazing or erosion over a long period of time. This study was conducted using the phytosociological method and it clarified the floristic composition of the community in Cheju Island by comparing with a similar community in Japan. Also this study interpreted the development data of these communities and considered community succession. As a result of our interpretation, shrub community of Cheju Island is recognized as two associations, Festuco obinae-Empetretum nigrum ass. nov and Rhododendretum mucronulatum ass. nov. Each association of Cheju Island is composed of endemic species of Cheju Island. related to the Korean peninsula and to Japan. The two associations are divided into 8 sub-units but each community development has been created with longtime grazing and prescribed fire. Maybe the location stability by stoppage of interference and grazing will process community transition Quickly. Comparing the shrub communities of Cheju Island with Maianthemo-Rhododendretum in Kyushu, Japan, which is close geographically, both areas have the species of Miscanthetea sinesis and Ericaceae in common. But Cheju Island has more abundant species and has higher ratio of appearance of alpine plants. The shrub communities of Cheju Island and Kyushu. Japan are identified as having a different rank over Alliance.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• Journal of Ecology and Environment
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• v.31 no.4
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• pp.269-276
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• 2008

In order to understand the role of seed banks for restoration, seed banks in abandoned rice fields in the Gwangneung National Arboretum, central Korea were investigated using the seedling emergence method. The study sites represented three stages: an initial stage dominated by forbs such as Persicaria thunbergii and Juncus effuses var. decipiens, a middle stage dominated by Salix, and a late stage dominated by Quercus aliena and Prunus padus (in nearby riparian forest chosen as a reference stand). DCA ordination arranged the stands according to the number of years since abandonment. CCA ordination identified the dominant environmental variables correlated most closely with Axes 1 and 2 as $Mg^{2+}$ (intraset correlation was 0.827) and $K^+$ (intraset correlation was -0.677), respectively. Species richness and diversity decreased from the initial stage (H'=2.61) to the middle (H'=1.79) and late (H'=0.75) stages. A total of 49 species $(/m^2)$ and 18,620 seedlings $(/m^2)$ emerged out of the seed bank samples. The DCA ordination and similarity analysis detected a large discrepancy between the composition of the actual vegetation and the seed bank. We conclude that the contribution of seed bank to restoration is low. However, seed bank may help the recovery of forbs after disturbance. Some of our results are consistent with the tolerance model of succession whereas others follow the trajectory of the facilitation model. More research on succession will be required to understand the underlying mechanisms.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1029-1034
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• 2010

In this paper, we present the roundness profile and run-out error measurement for a rotating shaft. The devices for measuring the roundness require a precision rotation table which is used as a reference to obtain the circular profile. Therefore, the roundness measuring system is expensive and requires precision manufacturing. The two-point method for succession measurement has been used to obtain a linear profile or used in straightness measurement using two displacement measuring devices. In this paper, the method is used for measuring the circular profile of a rotating shaft. A method to remove the vibration of the shaft, i.e., the run-out, is used, and the original circular profile is obtained from the measured raw data that excludes the run-out error of the rotating shaft. This method will be useful for obtaining the precise circular profile without using a precision reference circular artifact.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1053-1064
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• 2010

This study investigates the Korean loungewear market and the traditional culture values of consumers related to loungewear to examine the preference of Korean traditional details, sewing techniques in loungewear design, and purchasing intentions. A survey method was used in this study. A total of 230 self-administered questionnaires were obtained from female consumers and 214 data sets were used for analysis. For the analysis, factor analysis, cluster analysis, and ANOVA were executed with PASW Statistics 18.0 and a structural equation model was estimated by Amos 18.0. The results are as follows. Traditional culture values were classified into two dimensions, traditional succession value and traditional design preference value. In the structure equation model, the traditional design preference value had a significant effect on the preference and the traditional culture succession value had significant effect on purchase intention. The results proved that the preference on loungewear with Korean traditional elements is closely related to purchase intention. Consumer groups were divided into three groups by traditional culture values factor; traditional culture succession group, traditional design preference group, and traditional culture indifference group. Style preference images showed significant differences in relation to traditional culture groups. This study is for use as fundamental knowledge on traditional loungewear brand development and strategy planning by offering specific traditional culture aspects associated with preference and purchase intentions.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.196-204
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• 2016

In this study, vegetation succession and the rate of consequent topsoil development were investigated in shallow landslide scars of sedimentary rock slopes covered by volcanic ashes and pumice in Kagoshima prefecture, Japan. Seven shallow landslide scars of different ages were selected as study areas. In the initial period after the occurrence of a shallow landslide, deciduous broad-leaved trees such as Mallotus japonicus or Callicarpa mollis were occupied in the areas. Approximately 30 years after the landslide, evergreen broad-leaved trees such as Cinnamomum japonicum invaded in the areas, already existed present deciduous broad-leaved trees. After 50 years, the summit of the canopy comprised evergreen broad-leaved trees such as Castanopsis cuspidata var. sieboldii and Machilus thunbergii. Moreover, the diversity of vegetation invading the site reached the maximum after 15 years, followed by a decrease and stability in the number of trees. The total basal areas under vegetation increased with time. It was concluded that the vegetation community reaches the climax stage approximately 50 years after the occurrence of a shallow landslide in the study areas, in terms of the Fisher-Williams index of diversity (${\alpha}$) and the prevalence of evergreen broad-leaved trees. Moreover, according to the results of topsoil measurement in the study areas, the topsoil was formed at the rate of 0.31 cm/year. The development of topsoil usually functions to improve the multi-faceted functions of a forest. However, when the increased depth of topsoil exceeds the stability threshold, the conditions for a shallow landslide occurrence are satisfied. Therefore, we indicated to control the depth of topsoil and strengthen its resistance by forest management in order to restrain the occurrence of shallow landslides.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.209-214
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• 2003

In order to clarify the successional trend and its characteristics of plant community in abandoned field in Cheju Island, we investigated the seral changes of vegetation height, coverage, growth form, species richness, diversity and dominance index along with the time lapse, and then compared with those of mainland researches. And in order to seek the overall trend of vegetation changes, we used cluster, TWINSPAN and PCA ordination techniques. The succession was characterized by the lower species number, lower vegetation height, longer period of herb dominant and later invasion of tree species. These results may come from that ecological traits of Cheju Island itself, and ecosystem fragmented influences that block a seed (propagule) transport. Sere of the dominant species was shown as follows: Mazus japonicus(0.5∼1 years)→Conyza sumatrensis (2 years)→Artemisia princeps var. orientalis(4 years)→Artemisia princeps var. orientalis, indigofera pseudotinctoria(5 years)→Rosa multiflora, Miscanthus sinensis, etc.(8 years)→Miscanthus sinensis(12 years)→Boehmeria nivea, Pueraria thunbergiana etc.(15 years)→Mallotus japonicus(20 years)→Litsea japonica, Machilus thunbergii (20 years<). Abandoned fields were classified into three groups according to time lapse; earlier stage(0∼1 years), middle stage(2∼8 years) and later stage(8∼20 years).

• Journal of Plant Biology
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• v.28 no.1
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• pp.79-93
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• 1985

Plant succession and subsequent changes of soil properties were studied in sand bars at the Nagdong River estuary in Korea. By old maps, ages of sand bars such as Namusitdeung, Galmaegideung, Baeghapdeung and Ogryudeung were estimated about 10, 15, 25 and 60 years old, respectively. The dominance-diversity curves and plant species diversity indices among the sand bars showed increasing trend of stability from Galmaegideung toward Ogryudeung. The soil acidity, contents of organic matter and total nitrogen of soil increased significantly from Galmaegideung toward Ogryudeung. The order of successional degree among the sand bars on the basis of the number of plant species, the results of vegetation analysis and changes of soil properties almost coincide with the order of age among the sand bars. However, the order of successional degree between Namusitdeung and Galmaegideung was more or less obscured because of cyclic succession driven by allogenic processes.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.158-165
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• 2004

This study concerns the succession process of protozoa populations in two activated sludge pilot plants. Protozoa populations with similar structures developed and succeeded each other in two plants. It was observed that initial sludge inoculum did not influence the protozoan composition but shorten the period of the plant stabilization. It seemed the protozoan in aeration tank was come from the influent. The composition of the influent sewage influenced the structure of protozoa in the pilot plants. The flagellates was very abundant during the initial starting phase. These rapidly decreased after growth peak. Then sarcodina, ciliates were increased in succession. In ciliates, free-swimming forms appeared at first and crawling forms and stalked forms were followed. After 36 days from the start, the sludge stabilization phase was characterized by a populations of ciliates dominated by stalked and crawling type and low value of effluent BOD was achieved.