• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.109-121
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• 2023

Squr dikes in rivers can enhance various ecological environments, contributing to the improvement of the river's environmental functions. However, the alterations in flow caused by squr dikes not only enhance environmental functions but can also have adverse effects. Therefore, this study aimed to analyze the flow changes induced by the installation of squr dikes through flume experiments and assess their impact on fish habitats. Key factors in the fish habitat environment include flow velocity, turbulence kinetic energy, and recirculation zones. Among these, particular emphasis was placed on examining turbulence kinetic energy and recirculation zones. Experimental conditions were set by varying the interval and submergence of the squr dikes, resulting in a total of eight experimental cases. The results revealed that shorter interval and lower submergence of the squr dikes led to increased turbulence kinetic energy and recirculation zone sizes, significantly impacting fish habitats.

• Journal of Environmental Science International
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• v.33 no.7
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• pp.477-487
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• 2024

This study aimed to identify the growth environment of Cudrania tricuspidata by analyzing the site environment, soil characteristics, and vegetation structure of the species habitats and to provide basic data for identifying suitable cultivation sites for mass production. The study was conducted on 17 sites in five cities/counties of Gyeongnam and Jeonnam province. It was found that C. tricuspidata habitats were mainly distributed on gentle slopes in the southeast and southwest, with an average altitude of approximately 290 m. The soil of the C. tricuspidata habitats was sandy loam with a high proportion of sand, averaging 73.9%, 4.6%, and 21.5% sand, silt, and clay, respectively. The soil had a pH value of 5.41 (5.20-5.79), organic matter content of 8.2% (3.6-12.6%), total nitrogen content of 0.36% (0.19-0.54%), available phosphorus content of 3.50 ppm (0.95-7.61 ppm), and cation exchange capacity of 15.9 cmol⁺/kg (10.0-20.7 cmol⁺/kg) on average. The vegetation structure analysis showed that C. tricuspidata appeared in the tree layers of regions A (Jinju) and E (Yeosu), but the importance of C. tricuspidata was found to be high in the subtree and shrub layers in all regions. The ecological niche breadth was widest (0.874) in region B (Hadong) and narrowest (0.480) in region E (Yeosu).

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.3
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• pp.28-37
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• 2016

Through the research and analysis on the hydrological environment and soil environment of habitats through documentary and field studies over 14 habitats of Euryale ferox Salisb. within Jeollabukdo, with the objective of acquiring the basic data for forming an environment based on plantation of reservoirs that are composed with Euryale ferox, the following results were obtained. As a result of analyzing the construction period of the habitats of Euryale ferox from a total of 14 places, the average period of duration after construction of all subject reservoirs appeared to be 71.8 years. Moreover, when examining the relationship between the age of reservoirs and eutrophication, it could be judged that at least the eutrophication of subsoil and water environment is not an obstacle to the growth of Euryale ferox grows in habitats that have a reservoir age of approximately 70 years or more. As a result of analyzing the gardening of soil sediment of the Euryale ferox habitats, the component ingredients appeared to be composed of 80.2% of clay, 16.7% of silt and 3.1% of sand, and the soil class pursuant to such was classified as 'heavy clay'. The organic matter contents of soil sediment appeared to be an average of 36g/kg, and there appeared to be no noticeable difference between the habitats and non-habitats of Euryale ferox. The water quality environment of Euryale ferox habitat appeared to be pH 6.5~7.9, concentration of dissolved oxygen to be $1.8{\sim}8.8mg/{\ell}$, concentration of COD to be $6.8{\sim}74mg/{\ell}$, floating materials to be $2.0{\sim}213mg/{\ell}$, total nitrogen to be $0.422{\sim}10.723mg/{\ell}$, and phosphate to be $0.003{\sim}0.126mg/{\ell}$. The average DO concentration of Aedang Reservoir at Jeongeup, Daejeong Reservoir at Imsil, and Myeongdeokji at Gimje with high vitality and green coverage ratio of Euryale ferox appeared to be $3.5mg/{\ell}$, total nitrogen to be $1.33mg/{\ell}$, and concentration of phosphorus-phosphate to be $0.061mg/{\ell}$. When comparing such with the entire average value, the DO and total nitrogen concentration appeared to be rather low, and the phosphorus-phosphate concentration appeared to be higher by two times or more, thus, an in-depth study on the correlation of the vitality of Euryale ferox Salisb. and concentration of phosphorate-phosphorus will be needed in the future.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.331-341
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• 2012

Using data sets for Japan as a whole, as arranged with approximately $10{\times}10$ km squares (a secondary grid), we investigated the relationship between population density and the habitats of threatened vascular plants listed in the Japanese Red Data Book; depopulated areas in the present and future, areas where under-use may be serious, and those with a predominance of elderly people; and the present state of the habitats in terms of a characteristic land use pattern. Regarding the habitats of threatened vascular plants, the progress of deterioration [$(N_{CR}+N_{EN})/(N_{CR}+N_{EN}+N_{VU})$] in depopulated areas has been confirmed, where $N_{CR}$, $N_{EN}$, and $N_{VU}$ are the numbers of species classified as critically endangered, endangered, and vulnerable, respectively. Moreover, in grid squares used by a human such as farmland, the progress of the deterioration simply increases when population density becomes low. However, for many vascular plants, they are particularly endangered in populous areas. Local populations will decrease throughout Japan with the rate of depopulation in and around large cities being relatively slow. We also propose some issues that need further study. The deterioration by human activity may be reduced. On the other hand, some vascular plants may be adversely influenced by depopulation. Additionally, we should keep a close watch on grasslands and water areas in large cities to preserve vascular plants.

• Hwankyungkyoyuk
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• v.10 no.2
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• pp.175-190
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• 1997

The objective of this study is to increase bio-diversity by developing more efficient methods to created habitats and applying them in introducing prototypes of forest, grassland, and marsh which are found in natural ecosystem, to urban environment. In this context, in creating man-made marsh in Seoul Engineering High School, firstly, philosophical framework to create man-made marsh to restore urban nature and conceptual system to create a region considering life and ecosystem were established. Secondly, by applying the philosophical framework and the conceptual system, water quality section, plantation section, and techniques to create habitats to increase bio-diversity were introduced. Lastly, when the creation is completed, maintenance of the marsh will continue with participation and education of students and residents. This study presents how natural environment can be restored and created in urban areas. This may be viewed as modest beginning. I expect this study proves to be effective in increasing bio-diversity, fulfill its role as an experiment station for restoration and creation of natural environment and natural educational center for students and community as well as habitats for wild life, and open a new chapter in developing a society seeking co-existence of humankind and life. Therefore, when technological guideline on restoration and creation of man-made marsh in urban area is developed based on the outcome of this study, expansion of the project to nationwide including metropolitan cities like Seoul is recommended.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.513-513
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• 1995

The central theme of Habital heterogeneity is to provide animals with habital complexity or structural diversity and to allow resource partitioning among individuals. In turn, the leads to population stability because prey can escape more easily with more hiding places causing less population fluctuation. Species diversity is characterized due to more potential niches both horizontally and verticall. Empirically, in homogeneous habitats population was less abundant, reproduction and survival were lower, spacing behavior, competition and dispersal were higher than in heterogeneous habitats. The results imply that diversity and conservation of species can be maintained through providing heterogeneous habitats.

• Journal of Environmental Science International
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• v.19 no.2
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• pp.197-207
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• 2010

This study was carried out to investigate the ecological characteristic of native Parasenecio firmus population in Korea and China. The survey quadrates were located in the middle of the native P. firmus habitats. According to the field survey, the habitats of P. firmus were classified into same Tilia amurensis community in tree layer. The investigation of native habitat in Korea shows that P. firmus inhabited deciduous forest from with T. amurensis, Acer pictum subsp. mono, Carpinus cordata and Acer pseudosieboldianum, which was similar to vegetation structure of Mt. Laoling in China. The result of the cluster analysis which uses SYN-TAX 2000 program, dissimilarity from 53% level was on a large scale divided at 2 units. The research revealed 96 taxa in total, in which 51 families, 81 genera, 21 varieties, 5 forma, 1 sub-species and 67 species were checked in the flora of the native P. firmus habitats.

• ALGAE
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• v.23 no.2
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• pp.91-114
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• 2008

Fifty seven taxa of Cyanobacteria and 15 taxa of Chlorophyta were recorded from the exterior of buildings and rock surfaces of monuments in different regions in India. Four cyanobacteria, e.g. Chroococcidiopsis kashayi, Pseudophormidium indicum, Plectonema puteale and Scytonema geitleri, and the green alga Trentepholia abietina var. tenue occur on the sub-aerial habitats throughout the year. In addition, five other green algae: Chlorococcum infusionum, Scenedesmus arcuatus, Trentepholia aurea, Gloeocystis polydermatica and Printzina effusa, and 18 other cyanobacteria taxa of the genera Chroococcus (5), Asterocapsa (1), Cyanosarcina (2), Gloeocapsa (7), Gloeothece (2) and Scytonema (1) occur on the sub-aerial surfaces enduring extreme temperature and desiccation during summer months of the tropics. During the rainy season, the warm and humid climatic regime coupled with availability of moisture supported an additional ten green algae and 29 cyanobacteria in eight and 17 genera, respectively. The green algal genera Klebsormidium, Stichococcus and Trebouxia, which are dominant in temperate regions, did not occur on the sub-aerial habitats in India, however, species of Gloeocapsa, Chroococcus, Chroococcidiopsis, Phormidium, Leptolyngbya, Nostoc, Scytonema, Chlorella and Trentepholia showed global occurrence in similar habitats.

• Journal of Forest and Environmental Science
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• v.34 no.4
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• pp.275-283
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• 2018

This study created the running water (Bandibooliwon) and lentic water (Sooryunwon) artificial habitats of Luciola lateralis in Hwadamsup, Gwangju-si, Gyunggi-do from April 2014 to February 2016. Through various habitat types, metapopulation was formed, and more sound population was induced to be maintained via interactions between habitats. We investigated coenosite at the habitat creation-target site, and 20 species in the lentic water site and 38 species in running water site were found. After releasing L. lateralis, we checked the status of settlement of L. lateralis larvae through traps and macroscopy, controlled the flow velocity of the habitats in line with the life cycle of L. lateralis (hatching, larva period, landing, pupation, copulation, and oviposition), and shaped gentle slope at water side, and planted moss. We artificially supplied melanian snails (Semisulcospira sp.), the food source, in the running water site and induced stable feeding. Also, We created artificial insectary, bred larvae stably in winter, and secured firefly population for a festival. Through night time observation, the time most suitable for a festival was confirmed to be from 20:30 to 22:00.

• Korean Journal of Ecology and Environment
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• v.53 no.2
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• pp.156-164
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• 2020

The accurate estimation of fish assemblages is highly dependent on the sampling gear used for sampling. We used data from 15 sampling sites along the Nakdong River, which is a large river in South Korea, to identify differences in assemblages and sizes of freshwater fishes collected with either cast nets or gill nets, the two most commonly used sampling gear in South Korea. The two gears differed in the fish assemblages they captured, with more species caught by gill nets. Further, due to its tighter mesh size, the cast net caught significantly smaller fishes than the gill nets(independent t-test, p<0.05). We found the cast net to be appropriate for species that inhabit shallow (less than 2 m) and open water, but inappropriate for deep water, habitats with plant beds, and nocturnal species. Thus, cast net sampling is not efficient in a large river environment, and a combination of sampling methods is more suitable for understanding fish assemblages in such habitats. In general, appropriate selection of fishing methods to specific habitats is necessary to improve data quality and minimize the misrepresentation of environmental conditions.