• Journal of Ecology and Environment
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• v.46 no.3
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• pp.204-217
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• 2022

Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m² ha^-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g^-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g^-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.183-190
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• 2018

Backgrounds: The main purpose of this research was to assess changes in vegetation structure, wetland index, and diversity index for a 15-year-old created wetland in Jincheon, South Korea. The created wetland consists of four sub-wetlands: a kidney-shaped wetland, a ditch, an ecological pond, and a square wetland. Vegetation and water depth data were collected at each site in 1999 and 2013, and Shannon diversity and wetland indices were calculated. Results: The total number of plant species increased from 18 in 1999 to 50 in 2013, and the ecological pond in 1999 and the ditch in 2013 presented the highest diversity indices (2.5 and 3.2, respectively). Plant species were less diverse in 1999 than in 2013, presumably because these initial wetlands were managed periodically for water purification and installation of test beds. The proportion of wetland plants, including obligate wetland and facultative wetland species, decreased from 83 to 56%, whereas upland plants, including obligate upland and facultative upland species, increased from 17 to 44%. After ceasing water supply, water depth in all four sub-wetlands declined in 2013. Thus, upland plants established more readily at these sites, resulting in higher diversity and lower wetland indices than in 1999. Conclusions: The major floristic differences between 1999 and 2013 were an increase in the number of upland plants and a decrease in wetland species. Although wetland indices were lower in 2013, the created wetland performed important ecosystem functions by providing habitats for wetland and upland plants, and the overall species diversity was high.

• Journal of Soil and Groundwater Environment
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• v.19 no.1
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• pp.26-33
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• 2014

Uncertainty associated with a sampling method is very high in evaluating the degree of site contamination; therefore, such uncertainty affects the reliability of precise investigation and remediation verification. In particular, in evaluating a site for a small-sized filling station, underground utilities, such as connection pipes and oil storage tanks, make grid-unit sampling impossible and the resulting increase in uncertainty is inevitable. Accordingly, this study quantified the uncertainty related to the evaluation of the degree of contamination by total petroleum hydrocarbon and by benzene, toluene, ethylene, and xylene. When planning a grid aimed at detecting a hot spot, major factors that influence the increase in uncertainty include grid interval and the size and shape of the hot spot. The current guideline for soil sampling prescribes that the grid interval increase in proportion to the area of the evaluated site, but this heightens the possibility that a hot spot will not be detected. In evaluating a site, therefore, it is crucial to estimate the size and shape of the hot spot in advance and to establish a sampling plan considering a diversity of scenarios.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1007-1021
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• 2018

Community dynamics of benthic macroinvertebrates and biological evaluation of water quality were investigated at Gigyecheon of Pohang and Gyeongju, Korea. The survey was carried out at 8 sites from May to October, 2017. As a result, total of 104 species under 54 families, 15 orders, 8 classes in 4 phyla with 5,052 individuals were revealed. The number of species was the most abundantly identified in aquatic insects, 76 species under 34 families, 6 orders. Among them, the order Odonata was the most abundant taxon as 21 species(20.2%). The most abundant individuals were collected in the phylum Mollusca as 1,453 individuals(28.8%). Various species appeared dominantly at each site by season, and the most dominant species was Caridina denticulata denticulata belonging to the class Malacostraca with 0.08 of dominance index. According to the results of community structure analyses, the diversity and richness indices were the highest at site II, the evenness index was the highest at site I, and the dominance index was the highest at site IV. The number of species and individuals of gathering collectors were the highest among functional feeding groups. Those of sprawlers were the highest among habitat orientation groups. The ESB showed a tendency to change according to season and site, and it was the highest in May at most surveyed sites. The KSI was also somewhat fluctuated according to season and site. From these indices, average biological water quality was evaluated as class II.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.2
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• pp.13-35
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• 2017

This study was carried out to analyze vegetation structure and change of the disturbed area in forest ecosystem(FE), riparian ecosystem(RE) and coastal ecosystem(CE) related to Regional Ecological Network at Chungnam province through constancy and dominance analysis, species diversity index, similarity index and canonical correlation analysis. Data were collected from April to October in 2015. As a result of constancy and dominance analysis of forest disturbed area, non-effective species(NES) was 30 species(17.0%), exported species(ES) was 98 species(55.7%) and imported species(IS) was 48 species(27.3%) among the total 176 species, respectively. In riparian disturbed area with total 139 species, there were 16 NES(11.5%), 98 ES(70.5%) and 25 IS(18.0%) respectively. In coastal disturbed area with 140 species, there were 20 NES(14.3%), 88 ES(62.9%) and 32 IS(22.9%) respectively. In all types of disturbed areas, the ratio of ES was higher than IS. As a result of species diversity, species richness and shannon's diversity index of disturbed area decreased in all kinds of crown strata such as tree, subtree, shrub and herb layer compared to the control area. As a result of similarity index, that of each type between control site and disturbed site was 0.374 in FE, 0.329 in CE and 0.259 in RE in the order. As a result of the CCA analysis, the number of present species, vine plants ratio and exported species ratio in disturbed area of FE and RE were decreased, and the naturalized plant ratio, imported species ratio and herb ratio were increased. But environmental factors of CE were not shown any clear tendency. In conclusion, many species occupied in control site disappeared into the disturbed area, and the naturalized plants and herb species were abundantly imported in the area. Therefore, it was considered that this study could be applied to the development of long-term and short-term ecological restoration techniques in view of vegetation changes.

• Journal of Environmental Impact Assessment
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• v.30 no.3
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• pp.164-174
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• 2021

Information on biodiversity plays an important role in conservation planning for ecosystem. As existing biodiversity indices are calculated and predicted only based on the number of individuals and species, it is difficult to explain aspects of genetic and ecological diversity. Phylogenetic diversity can indirectly evaluate ecological diversity as well as genetic diversity overlooked by existing biodiversity assessments. In this study, typical metrics of biodiversity (e.g., species diversity, species richness, etc.) and phylogenetic diversity were evaluated together using a long-term monitoring data of winter birds in Jungrang, Cheonggye and Anyang stream where are designated as Seoul migratory bird reserves. Then discussed the meaning of each assessmentresult. In Jungrang and Anyang stream, the number of individuals generally decreased overtime, whereas in Cheonggye stream, there was no significant change. In addition, species abundance increased over time slightly in Cheonggye stream, while there was no significant change in Jungrang and Anyang stream. Species diversity temporally increased in Jungrang and Cheonggye stream, excluding Anyang stream, but phylogenetic diversity showed a tendency to increase only in Cheonggye stream. These changes in the biodiversity assessment indices are thought to be due to anthropogenic disturbances such as construction that occurred within each site, and it was shown that species diversity and phylogenetic diversity do not always lead to the same assessment results. Therefore, this study suggests that biodiversity assessment needs to be considered from various contexts such as genetic and ecological perspectives.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.65-82
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• 2011

In order to evaluate the weed suppressing effect of Solanum viarum Dunal. In this study species diversity in patch of S. viarum and allelopathic effects of the aqueous extracts on S. viarum were investigated. Number of species and species diversity in site close to patch of S. viarum were decreased gradually 1site ($7.7{\pm}2.0,\;1.5{\pm}0.2$), 2site ($5.3{\pm}1.2,\;1.2{\pm}0.2$) and 3site ($4.0{\pm}1.7,\;0.9{\pm}0.1$). And total phenolic compounds of soil in survey area were increased gradually site1 ($0.16{\pm}0.01mg\;g^{-1}$), site2 ($0.17{\pm}0.01mg\;g^{-1}$) and site3 ($0.22{\pm}0.02mg\;g^{-1}$). So the number of species and species diversity (r=-0.692, P<0.05) were negatively correlated with increased total phenolic compounds of soil in the survey area. The relative germination ratio, the mean germination time, the relative elongation ratio, the fresh weight and the dry weight of receptor plants are generally getting decreased while the concentration of the aqueous extracts from S. viarum escalate. But every ratio was various depending on the growing regions, the kind of receptor plants and the treatment of the aqueous extracts. Especially, the radicle by injection of the aqueous extracts concentration of S. viarum was influenced more than the shoot on the same condition. The total phenolic compounds on region of S. viarum was gradually increased in stems (fresh $0.56{\pm}0.02mg\;g^{-1}$, dry $1.58{\pm}0.08mg\;g^{-1}$), roots (fresh $1.77{\pm}0.07mg\;g^{-1}$, dry $2.64{\pm}0.06mg\;g^{-1}$), leaves (fresh $6.01{\pm}0.14mg\;g^{-1}$, dry $7.04{\pm}0.29mg\;g^{-1}$), seeds (fresh $6.21{\pm}0.17mg\;g^{-1}$, dry $9.08{\pm}0.73mg\;g^{-1}$) in order. On the contrary, the negative correlation on germination and growth of receptor plants was shown by total phenolic compounds on the each parts of S. viarum. We think that the aqueous extracts of S. viarum showed allelopathic effects on other plants. Therefore, S. viarum holds the higher competitiveness in plant community in Jeju Island and makes possibility of application as natural herbicide.

• Ocean and Polar Research
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• v.32 no.3
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• pp.309-319
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• 2010

To assess community structure and diversity of archaea, a clone sequencing analysis based on an archaeal 16S rRNA gene was conducted at three sediment depths of the continental slope and Ulleung Basin in the East Sea. A total of 311 and 342 clones were sequenced at the slope and basin sites, respectively. Marine Group I, which is known as the ammonia oxidizers, appeared to predominate in the surface sediment of both sites (97.3% at slope, 88.5% at basin). In the anoxic subsurface sediment of the slope and basin, the predominant archaeal group differed noticeably. Marine Benthic Group B dominated in the subsurface sediment of the slope. Marine Benthic Group D and Miscellaneous Crenarchaeotal Group were the second largest archaeal group at 8-9 cm and 18-19 cm depth, respectively. Marine Benthic Group C of Crenarchaeota occupied the highest proportion by accounting for more than 60% of total clones in the subsurface sediments of the basin site. While archaeal groups that use metal oxide as an electron acceptor were relatively more abundant at the basin sites with manganese (Mn) oxide-enriched surface sediment, archaeal groups related to the sulfur cycle were more abundant in the sulfidogenic sediments of the slope. Overall results indicate that archaeal communities in the Ulleung Basin show clear spatial variation with depth and sites according to geochemical properties the sediment. Archaeal communities also seem to play a significant role in the biogeochemical carbon (C), nitrogen (N), sulfur (S), and metal cycles at each site.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.100-112
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• 2001

The purpose of this study is to construct the evaluation criteria based on the relative importance and various combination of each evaluation index and then to evaluate urban biotope in terms of conservation of species and habitat. After the standard of evaluation had been developed through the literature review, the relative importance of the evaluation index through expert survey was found out, and the evaluation model of biotope value has been established. The results of this study are as follows; 1) We have constructed the nineteen evaluation criteria through literature reviews, and have provided relative importance to each evaluation index of the diversity of typical species in biotope, afforestation rate, stratification, Hemeroby grads, and the diversity of landscape patterns based on the results of expert survey. and then we have constructed the evaluation system using the relative importance criteria. 2) To evluate urban biotope using the evaluation system constructed, we selected 14 sites. The final evaluation results of each site is as follows; The III grade areas are Seohan and Hwasung high-rise apartment at Beummul-Dong, Korea Men Power /Agency in Sungs 대 industrial zone, the adjacent area of St. Tongil, and Hyomyung elementary school. The II grade areas are the farm land behind the third Anshim Jugong apartment, and Ehyun park. The I grade areas are swampy land in front of Kangchon and Anshim construction site, water space with semi-natural style in front of Gangchon Woobang apartment, forest zone near page Temple at mt. Palgong, the edge area of Jisan and Gosan, and the tendril yard against Anshim middle school. The only grade IV area is the commercial zone near Taegu Department 3) It is highly useful to evaluate urban biotope using the evaluation criteria constructed for this research, the evaluation criteria we developed may be difficult to guarantee the ability for reproduction and recovery, the appearance-number of the rare and endangered species are difficult to estimate urban biotopes. In the future, it is highly useful to evaluate biotope in terms of conservation of species and habitat through its valuation criteria developed in this research and it is necessary to develop the evaluation criteria applicable to estimation of biotope inventory and reproduction of biotope.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.318-327
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• 1987

Taxonomic composition and diversity were wxamined by statistical analysis for bacterial communities in surface waters of the Sudong Stream, a tributary of North Han River. For total 282 isolates, Flavobacterium, Aeromonas and Enterobacteriaceae was identified by the deterministic schemes as a major group above 50% of total isolates in all sampling sites. Morphological, biochemical and physiological characteristics were numerically analyzed for bacterial isolates from each site and clustered into 15-28 groups. Not all statistically clustered groups were identical to the groups derived from deterministic identification. Especially, consistent relationship was not found in dendrograms for the groups with each a single strain which gas peculiar sugar-degrading activity. At a level of 80% similarity, bacterial diversity (H) was ranged as 2.37-3.14, and it was suggested that the research area was oligotrophic-mesotrophic status. Regional distribution of bacterial community was most heterogeneous at the site where large input of allochthonous materials or bacteria were occurred. And that was the significant factor for the compositions of bacterial communities in the Sudong stream.