• Journal of Forest and Environmental Science
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• v.29 no.2
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• pp.157-164
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• 2013

The campus of Chittagong University in Bangladesh is rich in forest ecosystem. The campus has large area with vast tract of land planted with valuable timber tree species. The present study identifies and discovers the potential growing stock of the plantations in the campus area. This Growing stock was measured in three parameters viz. volume, biomass and organic carbon stock. Study identified thirty three economically valuable forest tree species in the plantations of Chittagong University. Out of three growing stock parameters, volume of timber was found to be low in indigenous tree species in the plantation sites other than exotic species. This might be due to their slow growth rate and low density in the plantation sites. However, biomass and organic carbon stock of trees per hactre area showed that indigenous species gather and sequester more timber and carbon respectively than introduced species. Plantations of Chittagong University campus can acquire $25.51m^3/ha$ volume of economically important tree species, where biomass and organic carbon stock is 222.33 tonne/ha and 107.48 tonne/ha respectively. This result shows a positive impression on the plantation site to be considered as good forest reserve.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.506-515
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• 2009

This study was carried out to investigate the distribution status and UI(urbanization index) of the naturalized plants and exotic plants. For this purpose 7 cities and counties in the northern South Jeolla Province were selected and investigations were conducted on a total of 14 sites, two sites from each city or county, during the period of March to November 2006. The exotic plants were identified as 111 taxa; 26 families, 79 genera, 105 species, and 6 varieties. As for urbanization index, Hampyeong County had the highest level of urbanization(21.95%) and Gokseong County the lowest level of urbanization(16.38%). Naturalized plants classified as family were as follows: Compositae was 36 kinds(32.43%) Graminae 17 kinds(15.31%) and Leguminosae 7 kinds(6.31%). Major communities of naturalized plants consisted of 21 communities including Robinia pseudoacacia-Amorpha fruticosa community, Erigeron annuus community, Erigeron canadensis community etc. Invasive naturalized plants consisted of 7 taxa: Paspalum disticum var. indutum, Paspalum distichum, Rumex acetocella, Solanum carolinense, Aster pilosus, Ambrosia artemisiifolia var. elatior and Ambrosia trifida. The study shows that the integrated management of exotic plants on a national scale is needed. It also recommend that a systematic and integrated management of exotic plants in the northern South Jeolla Province is crucial to preserve and protect natural species.

• Weed & Turfgrass Science
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• v.4 no.1
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• pp.1-9
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• 2015

Many irrigated and drainage canals, reservoirs, lakes, and rivers are choked by the explosive growth of aquatic weeds, resulting in enormous direct loss in Korea. Distribution of aquatic weeds and exotic invasive plant species in irrigation and drainage waterways, and riparian wetlands was reviewed to provide basic information for management of aquatic weeds and invasive plant species in wetlands. Dominant emergent weeds in canals, reservoirs and lakes were Phragmites communis, Leersia japonica, Zizania latifolia, Conyza canadensis, C. annuus, Rumex crispus, Panicum dichotomiflorum, Bidens frondosa, and Oenothera odorata. Dominant emergent weeds in wetlands of rivers include Digitaria sanguinalis, P. communis, R. crispus, Artemisia princeps, Humulus japonicus, Echinochloa crusgalli, B. frondosa, and Persicaria thunbergii. In irrigation and drainage canals and lakes, dominant submersed weeds were Hydrilla verticillata, Najas minor, Potamogeton malaianus, P. crispus, Ceratophyllum demersum, Myriophyllum verticillatum, Salvinia natans, and Trapa natans. Dominant exotic weeds in wetlands include Trifolium repens, O. odorata, C. annuus, B. frondosa, Avena fatua, Ambrosia artemisiifolia, X. strumarium, and P. dichotomiflorum. Approaches to aquatic weed control were mechanical, chemical and biological control techniques. Periodic monitoring of aquatic weeds and exotic weeds, and their integrated management studies are needed in waterways and riparian wetlands in Korea.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.177-187
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• 2005

Fish fauna of mountain streams in the Odaesan National Park area was investigated from May to October 2004. A total of 2,580 individuals were collected and classified into 26 species belonging to 9 families at the 25 sites. There were 8 Korea endemic species $(30.77\%)$, including Pseudopungtungia tenuicorpa, Silurus microdorsalis, Coreoperca herzi. Exotic species, Oncorhynchus mykiss was collected in this survey. Dominant species were Rhynchocypris kumgangensis $(37.17\%)$, and subdominant species was Rhynchocypris steindachneri$(23.02\%)$. Also Zacco platypus, Zacco temmincki, Oncorhynchus masou masou, Brachymystax lenok tsinlingensis, and Ladislavia tazanowskii were numerous. In spite of the geographical isolation by Taebaek-sanmaek, 8 species were introduced from the Han River systems to eastern water systems in Odaesan National Park.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.274-288
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• 2018

This study investigated the environmental factors and fish assemblage in 42 wetlands between spring and autumn of 2017 to evaluate the fish distribution and deduce the management strategy for improving biodiversity in created wetlands located at the Nakdong River basin. The investigation identified a total of 30 fish species and found that the most of wetlands were dominated by exotic fishes such as Micropterus salmoides and Lepomis macrochirus. Fish species such as Rhinogobius brunneus, Opsariichthys uncirostris amurensis, Zacco platypus were less abundant in the area with high density of Micropterus salmoides (static area) because they preferred the environment with active water flow. The pattern analysis of fish distribution in each wetland using the self-organizing map (SOM) showed a total of 24 variables (14 fish species and 10 environmental variables). The comparison of variables indicated that the distribution of fish species varied according to water depth and plant cover rate and was less affected by water temperature, pH, and dissolved oxygen. The plant cover rate was strongly associated with high fish density and species diversity. However, wetlands with low plant biomass had diversity and density of fish species. The results showed that the microhabitat structure, created by macrophytes, was an important factor in determining the diversity and abundance of fish communities because the different species compositions of macrophytes supported diverse fish species in these habitats. Based on the results of this study, we conclude that macrophytes are the key components of lentic freshwater ecosystem heterogeneity, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.543-550
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• 2020

This study aimed to identify the characteristics of fish inhabiting Hapcheon Dam and surrounding rivers and the Bluegill population, an invasive species, and provide basic data. The survey of fish living in Hapcheon Dam and surrounding tributaries in the Ulsan area from 2016 to 2017 identified a total of 1,785 individuals of 30 species of 10 families and identified 8 Korea's endemic species (21.8% indigenization rate), 3 exotic species, and 2 ecosystem disturbance species. The comparison of this study with the past survey showed that 36 species of 12 families were reported in the past survey, but 14 species of them were not found in this study. We believe that a more detailed survey of Lake Hapcheon should identify most of them. The analysis of the length-weight relationship for the Bluegill population, identified as the dominant species in the Hapcheon Lake, showed that a large number of populations was in the stage of rapid growth as a large number of populations aged 1 to 2 years was found. Since the obesity level and the length-weight relationship were confirmed to be in good condition, it was necessary to prepare a plan to control the Bluegill population. We expect that this study's results can be useful data for understanding the growth and trends of the Bluegill population inhabiting the Hapcheon Dam and surrounding rivers.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.265-276
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• 2021

This study investigated the characteristics of fish communities and river health in the Sincheon stream of Imgin River between April and October 2019. The survey collected 3,677 objects in 30 species belonging to 12 families from 23 survey stations. The dominant and subdominant species were Zacco platypus (28.4%) and Oryzias sinensis (13.6%), respectively, followed by Z. koreanus (11.8%), Rhynchocypris oxycephalus (11.7%), Carassius auratus (9.6%), and Pseudorasbora parva (7.9%) in that order. Among the fish species collected, 10 (33.3%) were endemic species in Korea. The exotic species were 5 (16.7%), including Micropterus salmoides, Lepomis macrochirus, Cyprinus carpio (Israeli type), Poecilia reticulata, and Xiphophorus maculatus. The land-locked species included Cottus koreanus and Rhinogobius brunneus, while C. koreanus was a climate change-sensitive species. The dominance of the fish community was low, and the diversity was high in the Sincheon mainstream, Sudongcheon and Cheongdamcheon, whereas Dongducheon and Sangpaecheon showed higher dominance and low diversity. The river health was very good and good in the uppermost and Sudongcheon areas, whereas the upper stream was normal, and the middle and lower streams were poor and very poor, respectively. The water quality was also mostly poor or very poor from the midstream to the downstream, and only Sudongcheon was very good. Therefore, the water quality had a great impact on fish habitat and eventually affected river health significantly. Although the water quality of Shincheon has improved each year, the introduction of several foreign species had a very negative effect. Improvement of river health in Shincheon requires water quality improvement and management of exotic fish species.

• Journal of Korean Society of Forest Science
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• v.10 no.1
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• pp.41-45
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• 1970

This study was carried out to investigate the identification of the woods of commercially important exotic tree species grown in Korea. The test trees used in this study were selected 21 species grown in Kwangyang and Suwon, Korea. The items of macroscopical features were observed and examined principally on the annual rings, transitions spring to the summerwood, pore types and arrangements, sap and heartwoods, wood colors, odor and tastes, resin ducts, parenchymas, and rays etc. The microscopical features observable in the elements, and their compositions such as vessels, tracheids, wood fibers, ray parenchyma cells, and intercellular cannals were observed and measured. The observed and measured results investigated were synthesized, and accordance with these results macroscopical and microscopical keys were prepared for the wood identification as seen in the text.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.40-49
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• 2017

Cultural practices for adzuki bean and the distribution of weed species in the south-west regions of Korea were surveyed to provide information on effective weed management. Approximately 27.5% of the farm households were growing adzuki bean in an area larger than 1 ha while the rest grew the crop in an area smaller than 1 ha. Of all adzuki bean growers, 17.1% seeded in early June, 8.6% in mid June, 34.3% in late June, 17.1% in early July, 20.0% in mid July, and 2.9% in late July. The average planting distance was $71.0{\times}29.5cm$. From the 40 surveys in adzuki bean fields, 35 weed species in 17 families were identified. According to the occurrence frequency, the dominant weed species were Digitaria sanguinalis, Acalypha australis, Cyperus amuricus, Echinochloa crus-galli, and Amaranthus nangostanus in decreasing order of dominance. However, based on dry weight, Chenopodium album (34.4%) was the most dominant followed by Acalypha australis (21.9%), Amaranthus nangostanus (19.1%), Digitaria sanguinalis (7.5%), and Portulaca oleracea (6.1%). The exotic weeds found in the field of adzuki were Ipomoea hederacea, Abutilon avicennae, and Celosia argentea. The plant heights of I. hederacea, A. avicennae, and C. argentea were 259 cm, 98 cm, and 76 cm, respectively, while the fresh weights were 850 g, 66 g, and 101 g, respectively. Integrated weed management systems utilizing mechanical, chemical, and biological control techniques need to be developed for effective weed management in adzuki bean production.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.61-66
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• 1998

The fish fauna and community structure were surveyed at the Naerin Stream of Puk'an River from June 1996 to September 1997. The fishes collected were 36 species, 28 genera belonging to 10 families, in which 16 species were endemic species of Korea. Oncorhynchus mykiss was an exotic fish. The dominant species was Zacco temmincki(relative abundance 42.94%), and subdominant species was Moroco kumgangensis(12.91%). The rare species less than 0.03% of all were Opsariichthys bidens, Squalidus japonicus coreanus, Misgurnus mizolepis, Leiocassis ussuriensis and Siniperca scherzeri. The species diversity, evenness, and dominance index on the fish community were 0.947, 0.609, and 0.218.