• ALGAE
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• v.23 no.4
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• pp.301-310
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• 2008

The marine benthic algal flora and biomass of Chuja Island, southern coast of Korea, was investigated. The collections of intertidal marine algae were made at two sites, Yecho of Hachujado and Hupo of Sangchujado, from October 2006 to July 2007. A total of 162 species, including 15 green, 47 brown and 100 red algae, were identified in this study. The occurrence of species according to season was abundant during spring to summer and less in autumn. The vertical distribution of intertidal zone in Chujado was characterized by Gloiopeltis spp., Myelophycus simplex, Ishige okamurae, Chondrus ocellatus, Grateloupia elliptica, Hizikia fusiformis and Sargassum spp. The average biomass of macroalgae was measured as 400 g wet wt m$^{-2}$. The dominant species based on the biomass were Sargassum yezoense, S. coreanum and Hizikia fusiformis. ESG II (ecological state group) as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, occurred 85.8% in the intertidal seaweeds. These results provide a baseline for future monitoring studies in the Chuja Island.

• Journal of Ecology and Environment
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• v.29 no.1
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• pp.1-16
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• 2006

Environmental variables, fishing and biological data of the common squid, Todarodes pacificus were used to describe changes in structure, migration and abundance of the squid population in relation to ocean climate shifts. It was possible to consider the main groups of the squid (autumn and winter-spawned groups) as a single population to aid conservation in the waters around Korea and Japan (TWC and KOC regions). The patterns of yearly fluctuations in abundance of the squid population in the two regions were the same during 52 years of $1952{\sim}2003$. The abundance of the squid began to decrease in both regions in the early 1970s, remained low in the 1980s and the main squid groups synchronously increased in the 1990s coincident with favorable changes of thermal conditions and plankton production in those ecosystems. The mechanisms of changes in the structure, distribution and abundance of common squid population in relation to current-mediated migration circuits are explained on the basis of phenological variables responding to climate shifts.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.273-280
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• 2001

We investigated the flora and vegetation structure of exotic plants along stream geomorphology and disturbance factors in the riparian zone of Seunggi stream, Incheon. Total 53 exotic plant species were found in the riparian corridors of Seunggi stream. The percentage of exotics ranged from 25% to 33% of total species richness, and its mean value was 24% in the whole riparian area. The percentage of exotics reflected the vulnerability of riparian zones to plant invasions by disturbances, and it could be used as an indicator of riparian system dysfunction. The distinct distribution patterns of exotic plants did not found in the lateral topographic features of the stream. Invasion and proliferation of the exotic plants were somewhat remarkable at terraces and bank slopes of the stream. Among various disturbance factors, plowing and trampling were important on the invasion of exotic plant species of Seunggi stream.

• Journal of Environmental Science International
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• v.16 no.12
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• pp.1369-1382
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• 2007

To find proper water quality management strategy for oxygen consumption organic matters in Jinhae bay, the physical process and net supply/decomposition in terms of COD was estimated by three-dimensional eco-hydrodynamic modeling. The estimation results of physical process in terms of COD showed that transportation of COD was dominant in loading area from land to sea, while accumulation of COD was dominant in $middle{\sim}bottom$ level. In case of surface level, the net supply rate of COD was $0{\sim}60\;mg/m^2/day$. The net decomposition rate of COD was $0{\sim}-0.05\;mg/m^2/day$($-5{\sim}-10$ m, in depth) to 2 level, and $-0.05{\sim}-0.20\;mg/m^2/day(10m{\sim})$ to bottom level. These results indicate that the biological decomposition and physical accumulation of COD are occurred for the most part of Jinhae Bay bottom. The variation of net supply or net decomposition rate of COD as reducing land based input loading is also remarkable. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters to improve the water quality of Jinhae Bay.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.368-378
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• 2005

Inorganic matters originated from stone quarries and manufacturing plants could alter the ecological characteristics of adjacent aquatic systems, especially the structure and function of benthic macroinvertebrate community. In such situation, the locality of stone quarry and the quantity of inorganic matters would be important factors that determined the disturbing strength to the benthic macroinvertebrate community. Locality patterns of stone quarries were classified into 3 types in relation to the stream ecosystem; stream-proximity, upstream-inclusion and tributary-inclusion type. In the result of species:abundance analysis, stone quarry B (upstream-inclusion type) showed geometric distribution, while others showed broken-stick distribution pattern. The benthic macroinvertebrate communities closer to stone quarries showed smaller species numbers and standing crops among all types of stone quarries. However the values of species evenness index were not seriously different between controls and directly affected sites. These results indicated that the effect of inorganic disturbance would differ from those of organic pollution that induced the highly dominant state occupied by tolerant species. Number of occurred species, standing crops, community indices and biotic indices indicated that the community of upstream-inclusion type was the most seriously damaged from the inorganic disturbance, and the community would be very simple and unstable. Tributary-inclusion stone quarry heavily damaged to tributary system in biologically, but influence to the main stream seemed to be depended on the scale of main stream. Among 3 types of stone quarry localities, stream-proximity type induced the least damages to benthic macroinvertebrate community, though the degrees of damage were different along with distances between stream and stone quarry.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.1-16
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• 2024

Most wetlands worldwide have suffered from extensive human exploitation. Unfortunately they have been less explored compared to river and lake ecosystems despite their ecological importance and economic values. This is the same case in Korea. This study was aimed to estimate the assemblage attributes and distribution characteristics of benthic macroinvertebrates for fifty wetlands distributed throughout subtropical Jeju Island in 2021. A total of 133 taxa were identified during survey periods belonging to 53 families, 19 orders, 5 classes and 3 phyla. Taxa richness ranged from 4 to 31 taxa per wetland with an average of 17.5 taxa. Taxa richness and abundance of predatory insect groups such as Odonata, Hemiptera and Coleoptera respectively accounted for 67.7% and 68.2% of the total. Among them Coleoptera were the most diverse and abundant. Taxa richness and abundance did not significantly differ from each wetland type classified in accordance with the National Wetland Classification System. There were three endangered species (Clithon retropictum, Lethocerus deyrolli and Cybister (Cybister) chinensis) and several restrictively distributed species only in Jeju Island. Cluster analysis based on the similarity in the benthic macroinvertebrate composition largely classified 50 wetlands into two major clusters: small wetlands located in lowland areas and medium-sized wetlands in middle mountainous regions. All cluster groups displayed significant differences in wetland area, long axis, percentage of fine particles and macrophyte composition ratio. Indicator Species Analysis selected 19 important indicators with the highest indicator value of Ceriagrion melanurum at 63%, followed by Noterus japonicus (59%) and Polypylis hemisphaerula (58%). Our results are expected to provide fundamental information on the biodiversity and habitat environments for benthic macroinvertebrates in wetland ecosystems, consequently helping to establish conservation and restoration plans for small wetlands relatively vulnerable to human disturbance.

• KIEAE Journal
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• v.15 no.5
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• pp.107-112
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• 2015

Purpose: This study desires to investigate an effect of indoor temperature, humidity, and illuminance targeting a planting system of double-skin facade and cavity space adjacent to the outside within a certain period of winter. Through this, the study suggests a basic material about an energy conservation effect of double window system using planting to reduce heating load of a building in winter, so desires to contribute to indoor thermal comfort effect and illuminance correction study of double window and indoor plant. Method: Considering effects such as day and night climatic elements and air conditions in winter, illuminance measurement was conducted through a double-skin facade of space, a subject of the measurement, on the basis of practical residence time of a resident, and this study analyzed characteristics of indoor illuminance about this. The study measured and compared a change of insolation, dry-bulb temperature, and relative humidity at each indoor-outdoor measuring point, so measured and compared characteristics of an indoor temperature effect by elements of double-skin facade and indoor plant. Result: Through this study, the researcher could determine that indoor plant within double window in winter not only blocks solar radiation but also photosynthesizes, so is somewhat disadvantageous to winter thermal comfort reducing heating load. In addition, solar radiation going through interior plays a role to bring down somewhat high humidity to about 50% of reasonable humidity, so plays a direct role of maintenance of comfortable indoor space. Although there are effects such as blocking of solar radiation and temperature reduction, this has a positive influence on humidity control and proper illuminance distribution. The researcher could determine that illuminance, temperature, and humidity by solar radiation penetration for the whole measuring time play a role to supplement indoor environment mutually.

• The Korean Journal of Ecology
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• v.28 no.5
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• pp.327-333
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• 2005

For the first time in Korea, plant size, distribution pattern and root growth form of Tamarix chinensis were surveyed at natural stand in Shiwha Lake, from June to July in 2005. T, chinensis grew in the range of 350 m towards north-south and 270 m in east-west direction. The mean number of stems germinated from same root system was 1.9. On the stem base, the numbers of living and dead plants were 1,398 and 114, respectively. Mean perimeter and height of 1,398 plants were $5.9{\pm}3.2$ cm and $159{\pm}51$ cm, respectively. By dividing into 10 classes based on the perimeter size, the largest number of plants were included in the second smallest class category. However, by dividing into 10 classes on the bases of plant height, variation in the number of plants along the height showed normal distribution curve. The heights of dead plants were small in perimeter but diverse in height. On the root base, the number of plants was the greatest in the smallest size class, and conspicuously decreased with size increment. Distribution of T. chinensis was clumped pattern. Age of the largest plant was 8-year. T. chinensis had two types of root growth. One was horizontal growth in the periphery of soil surface, and the other vertical growth.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.79-88
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• 2015

Preparations need to be made for Korean pine(Pinus koraiensis) in anticipation of climate change because Korean pine is an endemic species of South Korea and the source of timber and pine nut. Therefore, climate change adaptation policy has been established to conduct an impact assessment on the distribution of Korean pine. Our objective was to predict the distribution of Korean pine while taking into account uncertainty and afforestation conditions. We used the 5th forest types map, a forest site map and BIOCLIM variables. The climate scenarios are RCP 4.5 and RCP 8.5 for uncertainty and the climate models are 5 regional climate models (HadGEM3RA, RegCM4, SNURCM, GRIMs, WRF). The base period for this study is 1971 to 2000. The target periods are the mid-21st century (2021-2050) and the end of the 21st century (2071-2100). This study used the MaxEnt model, and 50% of the presences were randomly set as training data. The remaining 50% were used as test data, and 10 cross-validated replicates were run. The selected variables were the annual mean temperature (Bio1), the precipitation of the wettest month (Bio13) and the precipitation of the driest month (Bio14). The test data's ROC curve of Korean pine was 0.689. The distribution of Korean pine in the mid-21st century decreased from 11.9% to 37.8% on RCP 4.5 and RCP 8.5. The area of Korean pine at an artificial plantation occupied from 32.1% to 45.4% on both RCPs. The areas at the end of the 21st century declined by 53.9% on RCP 4.5 and by 86.0% on RCP 8.5. The area of Korean pine at an artificial plantation occupied 23.8% on RCP 4.5 and 7.2% on RCP 8.5. Private forests showed more of a decrease than national forests for all subsequent periods. Our results may contribute to the establishment of climate change adaptation policies for considering various adaptation options.

• KIEAE Journal
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• v.16 no.6
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• pp.69-75
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• 2016

Climate change has resulted in the urban heat island (UHI) effect throughout the globe, contributing to heat-related illness and fatalities. In order to reduce such damage, it is necessary to improve the climate observation network for precise observation of the urban thermal environment and quick UHI forecasting system. Purpose: This study analyzed the effective range of the climate observation network and the distribution of the existing Automatic Weather Stations (AWS) in Seoul to propose optimal locations for additional installment of AWS. Method: First, we performed quality analysis to pinpoint missing values and outliers within the high-density temperature data measured. With the result from the analysis, a spatial autocorrelation structure in the temperature data was tested to draw the effective range and correlation distance for each major time period. Result: As a result, it turned out that the optimal effective range for the climate observation network in Seoul in July was a radius of 2.8 kilometers. Based on this result, population density, and temperature data, we selected the locations for additional installment of AWS. This study is expected to be used to generate urban temperature maps, select and move measurement locations since it is able to suggest valid, specific spatial ranges when the data measured in point is converted into surface data.