• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.195-202
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• 2011

This study analyzed and modeled the relationships between the probabilities of two exotic species occurrence (i.e. largemouth bass and blue gill) and environmental factors such as climatic and geographical variables using Generalized Additive Models (GAM), Generalized Liner Models and Classification Tree Analysis (CTA). The most moderate occurrence probability of largemouth bass was predicted using GAM with an area under the curve (ADC) of 0.88 and Kappa of 0.42, while those of blue gill was suggested by using CTA with an AUC of 0.92 and Kappa of 0.44. The most significant environmental variable in terms of changes in deviance for both species was the annual air temperature for the occurrence probability. Dams had stronger effect on the occurrence of largemouth bass than blue gill. Model development and prediction for the occurrence probability of fish species and richness are necessary to prevent further spread of exotic fishes such as largemouth bass and blue gill because they can threaten habitats of native river ecosystem through various mechanisms.

• Journal of architectural history
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• v.15 no.2
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• pp.23-38
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• 2006

During the repair and restoration of the Daewoongjeon Hall of Youngguksa Temple, species identification and tree-ring dating for both present wood elements and charred ones excavated under the Hall, were conducted. The species of 74 wood elements of Daewoongjeon Hall, were identified as Pinus densiflora Sieb. et Zucc. and only 1 was identified as exotic Pinus species. The latter wood, which was used in the laths, seems to have been replaced during past repairs. Many documentary records and various artifacts pertaining to Youngguksa Temple are being excavated, but none described precisely the construction date of the present Daewoongjeon Hall. Also, from beneath the Daewoongjeon Hall, cornerstone and foundation of previous building and several charred wood elements were excavated. In comparing the direction of the stone columns of foundation of the previous structure and the existing Daewoongjeon Hall, the previous structure was rotated in an angle of approximately $15^{\circ}$. Therefore, in order to find the association of the previous structure with the present Daewoongjeon Hall, tree-ring dating was conducted. The dating of 41 original timbers and 14 roof-filling timbers of the present construction elements revealed that the last annual ring was of A. D. 1703 with complete latewood, indicating that those woods was cut some time between the autumn of 1703 and spring of 1704, and the building was erected in 1704 when we assume no period of wood storage. The year of the last annual ring of the charred elements, which were excavated from beneath the Daewoongjeon Hall, was analyzed as 1674. The cutting year of the woods used for the present building began in 1698, therefore, it can be presumed that the Daewoongjeon Hall before the fire was a structure that was elected shortly after 1674 and that a catastrophic fire occurred some time between 1674 and 1698.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.202-211
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• 2019

Oceanic islands are biologically important for their unique assemblages of species and high levels of endemism and are sensitive to environmental change because of their isolation and small species source pools. Habitat destruction caused by human landscape development is generally accepted as the main cause of extinction on islands, with exotic species invasion a secondary cause of extinction, especially on tropical islands. However, secondary impacts of human development (e.g., general degradation through resource use and exotic species introduction) are understudied on temperate islands. To determine secondary impacts of human development on the understory vegetation community, 90 field sites on Ulleung Island, South Korea, were sampled during the summer of 2016. Understory vegetation was chosen as it is a proxy for ecosystem health. Diversity and percent cover of introduced, native, and endemic species were tested against proximity to developed areas and trail usage using a model selection approach. Diversity was also tested against percent cover of three naturalized species commonly found in survey plots. The main finding was that distance to development, distance to town, and trail usage have limited negative impacts on the understory vegetation community within best-supported models predicting native and introduced cover and diversity. However, endemic species cover was significantly lower on high usage trails. While there are no apparent locally invasive plant species on the island at the time of this study, percent cover of Robinia pseudoacacia, a naturalized tree species, negatively correlated with plot diversity. These findings indicate that forests on Ulleung Island are not experiencing a noticeable invasion of understory vegetation, and conservation efforts can be best spent preventing future invasions.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.107-113
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• 2002

This study was performed to obtain the information on fruit set, propagation and flowering habits of the exotic ornamental bottle brush tree (Callistemon citrinus). Trees have fruit capsules for four years since the fruit set and they have enlarged for three years. While 2 and 3-year-old capsules have similar seeds in number and size, 1-year-old ones have fewer and smaller seeds. Most dried capsules open when they have 75％ relative water contents. Two year old seeds which they were dried at 30％ germinated better than others. Removal of capsule bearing twigs resulted in greatly increased subsequent flower numbers (an average of 14 flowers per tree) compared with twigs where seed capsule were allowed to remain. In cutting for propagation, semi-hard wood branches dipped in 100mgι$^{-1}$ IBA for 24 hours rooted at 86.4 ％ and had an average of 12.6 primary roots.

• Journal of Forest and Environmental Science
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• v.37 no.3
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• pp.193-205
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• 2021

The importance of forests and trees in climate change mitigation and soil nutrient cycling cannot be overemphasized. This study assessed the above-ground carbon stock of two exotic and two indigenous tree species - Gmelina arborea, Tectona grandis, Khaya grandifoliola and Nauclea diderrichii and their litter impact on soil nutrient content of an arboretum within the University of Port Harcourt, Nigeria. Data were collected from equal sample plots from the four species' compartments. Tree growth variables including total height, diameter at breast height, crown height, crown diameter and merchantable height were measured for the estimation of above-ground carbon stock. Soil samples were collected from a depth of 0-30 cm from each compartment and analyzed for particle size distribution, organic carbon, total nitrogen, available phosphorus, exchangeable bases, exchangeable acidity, cation exchange capacity, base saturation, pH, Manganese, Iron, Copper and Zinc. Analysis of Variance (ANOVA) was used to test for significant difference (p<0.05) in the carbon contents of the four species and the soil nutrient contents of the different species' compartments. Pearson correlation was used to assess the relationships between the carbon contents, growth parameters and soil parameters. The highest and lowest carbon stock per hectare was observed for G. arborea (151.52 t.ha^-1) and K. grandifoliola (45.45 t.ha^-1) respectively. Cation exchange capacity and base saturation were highest and lowest for soil under G. arborea and K. grandifoliola respectively. The pH was highest and lowest for soil under G. arborea and T. grandis respectively. Carbon stock correlated positively with dbh, crown diameter, merchantable height and Zn and negatively with base saturation. The study revealed that G. arborea and N. diderrichii can effectively be used for reforestation and afforestation programmes aimed at climate change mitigation across Nigeria. Therefore, policies to encourage and enhance their planting should be encouraged.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.5 s.112
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• pp.57-68
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• 2005

This study surveyed planting areas along streets in Gangwon-do to find out how to improve the planting and use of street trees and herbaceous plants. There were 301,491 trees of 41 species on the streets of Gangwon-do in 2004. The predominant species of street trees were Ginkgo biloba ($40\%$), Prunus spp. (Prunus yedoensis and Prunus sargentii) ($25\%$), Platanus occidentalis ($5\%$), followed by Betula platyphylla var. japonica, Zelkova serrata, Prunus armeniaca var. ansu, Acer palmatum, and Pinus thunbergii. Eighty-four herbaceous plant species were found in the Youngseo district (the southern area of Gangwon-do); the ratio of native species to exotic was 51:33. The predominant species were Cosmos bipinnatus, Petunia hybrida, Tagetes spp., Aster koraiensis, and Fagopyrum esculentum. Eighty-nine herbaceous plant species were found in the Youngdong district (the eastern area of Gangwon-do); the ratio of native species to exotic was 55:33. The predominant herbaceous plants were Aster koraiensis, Tagetes spp., Petunia hybrida, Rudbeckia bicolor, Cosmos bipinnatus, Salvia splendens, Brassica oleraceae var. acephala, Aquilegia buergeriana var. oxysepala, Coreopsis drummondii, Viola tricolor, and Dianthus superbus var. longicalycinus. Appropriate pruning adds to the aesthetic value of trees and prolongs their useful life; it also maintains good health and thereby reduces the need to control insects and diseases. Street trees had not been properly pruned due to the presence of power lines and a shortage of pruning information. The pruning was controlled by Korea Electric Power Company, which has no pruning information. Pruning must be maintained by a professional landscape company in order to maintain good shape, such as that which is done for bonsai. In order to improve the planting, use and maintenance of landscape plants in Gangwon-do, the following recommendations are made: street tree species should be diversified, suitable street trees should be selected for each space, native species should generally be used, trees should be appropriately pruned and properly fertilized, pests and diseases should be controlled, plantings should be done in multiple layers, spatial arrangements should be improved, larger trees should be planted, and drainage and underground electric wires should be considered when planting.

• Journal of Korean Society of Rural Planning
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• v.17 no.2
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• pp.23-32
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• 2011

The purpose of this study is to produce basic planning criteria required in ecological restoration and improvement works of streams in rural area through the application of stream assessment methods (water quality, soil environment, and ecological function assessment) at 6 study sites of Han River basin. The investigation results were as followings; 1) There were the evaluation items like a manure use, salt degree, river peripheral tree, which did not fitted to apply to domestic streams, in the SVAP (Stream Visual Assessment Protocol) and NRCS Riparian Assessment that were evaluation models developed in USDA. The area inhabitants with a little knowledge and education personally seems to utilize the evaluation methods through improvement partly with an aspect that evaluation is slightly easy. 2) From the stream assessment results, the construction of diverse pools, large woody debris and isolated backwater pool are needed to improve a few of problems observed at the mostly study sites. The result of NRCS Riparian Assessment showed that the improvement of stream bank vegetative communities is needed by planting tree with deep-binding root masses, and managing of noxious weeds and exotic undesirable plants. 3) Summing up, the assessment results showed that the assessment scores were higher at upstream than downstream, the stream with totally maintenance than that with partly maintenance, the stream with slope bank than that with vertical bank, and the stream with a flood plain than that without a flood plain. So, the direction of stream maintenance projects must be set by consideration of those results.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.4
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• pp.81-90
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• 2005

This study aimed to address problems and suggest solutions in applying seed mixture design criterior of the slope revegetation works according to "The guidelines of Slope revegetation design and construction" proposed by the Ministry of Construction and Transportation. To do this, the planting thickness was set to be the same 2cm while the composition of seeds was made different, which was planted in artificial slopes and fields. The main results were summarized as follows. In the test, when applying the provisional standards of the plant mixtures proposed by the Ministry of Construction and Transportation, tree seeds and native plants were found poor coverage effect in the early stage in all test plots due to introduced grasses. This was because introduced winter grasses which grew well in the early stage, could grow densely, so it might hamper the growth of other plants. Therefore, it was found desirable that standards for seed mixing should be adjusted down by 10% and the ratio of introduced grasses in the mixture should be lowered to 25% while native plants should increase to 20-25%.

• Journal of Forest and Environmental Science
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• v.28 no.2
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• pp.75-83
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• 2012

An explanatory survey was conducted to assess preference and consumption pattern of horticultural species, their sources, location-wise planting preferences and diversity of these species in the rural homestead forest of the offshore island of Bangladesh. Assessment was done through multistage random sampling. Based on homestead size respondents were categorized into small (<0.05 ha), medium (0.05-0.25 ha) and large (>0.25 ha) and twenty from each category were selected randomly for the study. The study revealed that most of the farmer (75.5%) preferred to plant fruit tree species for future plantation followed by timber species (62.2%). But fruit-bearing plants were being gradually replaced by some exotic timber species such as Swietenia mahagoni, Acacia auriculiformis, Tectona grandis, Eucalyptus spp., etc. Diversity and abundance of fruit species was found higher in almost all homestead. A total of 41 horticultural species were identified and seven horticultural species among them were recognized as the most preferred ones in the study area. Consumption pattern was chiefly to meet the nutritional demand and to gain a quick monetary benefit. Average annual income from horticultural species was 7,183.33 Taka (US$102).

• Journal of Ecology and Environment
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• v.37 no.1
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• pp.21-29
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• 2014

Robinia pseudoacacia has become invasively naturalized in Japan. We investigated the role of sexual reproduction in the development of R. pseudoacacia riparian forests along the Chikumagawa River in Japan, by using five chloroplast (cpSSR) and seven nuclear (nSSR) markers. We identified eight chloroplast haplotypes and 147 nuclear genotypes from 619 R. pseudoacacia trees sampled in three plots (Plots A, B, and C) and along two line transects (Lines D and E). CpSSR analyses showed that multiple maternal lines were distributed along the river, and that some haplotypes from different populations overlapped. In addition, while Plots A and B were separated by a short distance, only these two plots exhibited genetic differentiation in the haplotypes. In the nSSR analysis, all pairwise $F_{ST}$ values among the three plots were significantly different from zero. Kinship analysis based on nSSR markers revealed that kinship connected many individuals to another individual from the same plot. These results indicate that seed dispersal near to mother trees contributes to the fine-scale genetic structure of R. pseudoacacia riparian forests. Our results indicate that sexual reproduction, in addition to asexual reproduction, is a major contributor to the fine-scale formation of R. pseudoacacia forests.