• Korean Journal of Environment and Ecology
• /
• v.27 no.3
• /
• pp.327-343
• /
• 2013

The aim of this study is to perform community analysis and biological assessment of water quality using benthic macroinvertebrate from Wangpi-cheon watershed which is defined as conservation areas of ecosystem and landscape by ministry of environment in Korea. Field survey of the study area was carried out 2 times from June to September in 2012. As a result of the field survey, total 155 species of benthic macroinvertebrates in 74 families, 15 orders, 7 classes and 5 phyla were collected. The findings of community analysis using the classified species and individuals showed relatively low DI(Dominant Index) value of 0.22 and very high value of average H'(Diversity index) as 4.24. And the analyzed results of SI(Similarity Index) according to habitat types using functional feeding groups showed higher values of 94.51% and 93.19% respectively to tributary and main stream after the designation of conservation areas of ecosystem and landscape. These results infer that various species and lots of individual are widely distributed at Wangpi-cheon watershed and stream ecosystem of the study area is healthy and well maintained after the designation of conservation areas. And also, the calculated EPT value was 62.9% as high enough to explain the cleanness of Wangpi-cheon watershed. We evaluated environmental condition and biological water quality by using ESB(Ecological Score of Benthic macroinvertebrate community) and KSI(Korean Saprobic Index). The average evaluated ESB shows very high value of 208.2, therefore Wangpi-cheon watershed is designated as 'First priority protection waters' area and the value of KSI is 0.32 which meets the saprobic water quality standard as 'First class'.

• Korean Journal of Environment and Ecology
• /
• v.31 no.4
• /
• pp.365-380
• /
• 2017

Rapid changes in the flora of exotic species are ecological problems that cause the alteration of national and regional biota. The purpose of this study is to identify the reality of neophyte flora currently inhabiting in Korea. Having analyzed a total of 151 studies published up until 2016, we found the qualitative and quantitative gaps among the preceding studies due to the lack of rigorousness on the application of the spatial and temporal level of exotic species and academic terminology. In this study, the neophyte is defined as the flora introduced temporarily after the Enlightenment in Korea (late 19th century) and spatially in the Eastern Asiatic Province of the Takhtajan's floral region instead of a country boundary. A total of 326 taxa of 184 genera of 39 families were identified and analyzed for their distributional origin and habitat characteristics. Approximately 87% (285 taxa) was a component of the single-layered herb vegetation, and a total of 211 taxa originated from Europe and North America which are the same temperate biome as Korea. The wetland vegetation components were much fewer with 21 taxa, but they included a large number of invasive alien species that caused critical deterioration in the habitat structure and function of aquatic ecosystems. Ecological approaches to exotic species categories such as Ephemerophyten and Apophyten have emerged.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.9 no.2
• /
• pp.149-160
• /
• 2007

KoFlux Gwangneung Supersite comprises complex topography and diverse vegetation types (and structures), which necessitate complementary multi-disciplinary measurements to understand energy and matter exchange. Here, we report the results of this ongoing research with special focuses on carbon/water budgets in Gwangneung forest, implications of inter-dependency between water and carbon cycles, and the importance of hydrology in carbon cycling under monsoon climate. Comprehensive biometric and chamber measurements indicated the mean annual net ecosystem productivity (NEP) of this forest to be ${\sim}2.6\;t\;C\;ha^{-1}y^{-1}$. In conjunction with the tower flux measurement, the preliminary carbon budget suggests the Gwangneung forest to be an important sink for atmospheric $CO_2$. The catchment scale water budget indicated that $30\sim40%$ of annual precipitation was apportioned to evapotranspiration (ET). The growing season average of the water use efficiency (WUE), determined from leaf carbon isotope ratios of representative tree species, was about $12{\mu}mol\;CO_2/mmol\;H_2O$ with noticeable seasonal variations. Such information on ET and WUE can be used to constrain the catchment scale carbon uptake. Inter-annual variations in tree ring growth and soil respiration rates correlated with the magnitude and the pattern of precipitation during the growing season, which requires further investigation of the effect of a monsoon climate on the catchment carbon cycle. Additionally, we examine whether structural and functional units exist in this catchment by characterizing the spatial heterogeneity of the study site, which will provide the linkage between different spatial and temporal scale measurements.

• Korean Journal of Ecology and Environment
• /
• v.39 no.4 s.118
• /
• pp.508-515
• /
• 2006

This study was conducted from July to December 2004, in order to find measures to improve the water quality and the function of pond ecosystems which are often negatively affected by phytoplankton and suspended particle matters. Most of the time, the management of ponds in Korea does not consider the ecological concepts such as self-purification and nutrient recycling. Instead, conventional methods depend on other factors such as fish farming and the function of fountains and waterfalls. Sustainability of pond ecosystems must be studied with the highest emphasis given to water quality. Water discharges of inflow and outflow as well as balance adjustment for different factors must be thoroughly studied. There is a great need for studies on sustainability because it can be realized through the horizontal or vertical balances of an ecosystem. Our current research offers useful information to the academia and public on maintaining sustainability in terms of structure and function of the pond.

• Korean Journal of Organic Agriculture
• /
• v.21 no.4
• /
• pp.601-615
• /
• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• Journal of Wetlands Research
• /
• v.13 no.3
• /
• pp.665-675
• /
• 2011

Dam as a Wetland can provide functions of ecological conservation, water quality improvement, landscape, and so on as well as. Dam's own various functions. Here we tried to assess function and value of Yongdam dam as a wetland by Hydrogeomorphic(HGM) Method which was developed by U.S. Army Corps of Engineers. In this study, the Upo wetland and Boryeong dam were selected as reference wetlands to assess the functional index of the Yongdam dam. As the results, we obtained the functional index values over 0.6 for total index of the Yongdam dam. It describes that Yong dam dam-wetland is providing over 60% functions of the Upo wetland and Boryung dam-wetland. This result suggests that dam-wetland can provide good wetland functions efficiently if we conserve and manage well.

• Journal of Wetlands Research
• /
• v.14 no.1
• /
• pp.139-146
• /
• 2012

Stream ecosystems carry out significant functions such as water purification, especially denitrification. However, rapid landuse change since industrialization has altered ecological functions of streams. In this study, we aimed to investigate denitrification rates and their determinant factors in streams with different landuse patterns, and how denitrification rates vary with microtopology within streams. Ten fifth streams of each landuse were selected, and each stream was divided into four microtopological sites within streams - riparian zone, subsoil, and both head and tail parts of sand bars. In situ denitrification rates and physicochemical properties of soil were examined. Denitrification rates of agricultural, urban, and forest streams were $289.62{\pm}70.69$, $157.01{\pm}37.06$, $31.38{\pm}18.65mg$ $N_2O-N\;m^{-2}\;d^{-1}$ respectively. There were no significant differences in denitrification rates depending on microtopology, but the rates in riparian zone were the highest, and the rates in the head parts of sandbars were lower than those of tail parts. The determinant factors for denitrification rates included water temperature, silt and clay contents of soil, inorganic nitrogen, and organic carbon, and these factors all showed positive correlations with denitrification rates. Through this study, we find that landuse pattern in watershed region affects denitrification rates that is one of considerable functions of streams. In addition, estimation of denitrification rates taking into account for microtopology would contribute to developing ecological management and restoration strategy of streams.

• Korean Journal of Environment and Ecology
• /
• v.28 no.6
• /
• pp.613-626
• /
• 2014

Seaweeds were identified after qualitative sampling at 14 stations of Dokdo coasts from May to July 2013 and seaweeds and animals inhabiting 23 Eisenia bicyclis plants were examined to evaluate its ecological role. Biomass was calculated by using regression between stipe length and weight of E. bicyclis. A total of 128 species were identified, including 18 green, 35 brown, and 75 red algae. Coarsely branched form was dominant functional group occupying 47.66% and 91 species (71.09%) were in ESG I group, growing in stable environmental coast. Also, R/P, C/P, and (R+C)/P were 2.14, 0.51, and 2.66, respectively showing temperate and mixed flora. Biomass and density of E.bicyclis were $23.74kg\;m^{-2}$ and 64 fronds $m^{-2}$. Twelve seaweeds and 83 animal species (15 Annelida, 25 Mollusca, 34 Arthropoda, 3 Echinodermata, and 6 others) were observed from 23 holdfasts and Ericthonius pugnax was dominant taxon having 538 (43.11%) of 1,248 animal individuals. These results indicate that E.bicyclis is a keystone species showing very important ecological role. In conclusion, the number of seaweeds increased because of intensive research and dominance of coarsely branched form and ESG I group seaweeds, representing that environmental condition of Dokdo is still intact.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.3-3
• /
• 2020

사회-수문시스템의 인과관계에 대한 보다 상세한 통찰하기 위해서는 현재의 사회-수문시스템의 기능을 이해하고 미래의 사회-수문시스템의 변화 궤적을 예상할 수 있는 모형이 필요하다. 사회-수문학적 관점에서는 수문순환 현상과 더불어 인간 활동과 관련된 인구, 토지이용, 경제성, 환경변화로 연계되는 사회-수문시스템 내 복잡한 관계해석 과정이 중요하다. 본 연구에서는 하천유지유량 결정기준에 따른 사회-수문시스템의 변화과정을 이해하고 가능한 영향궤적을 평가하기 위해 사회수문학적 관점으로 해석하고자 한다. 현재 우리나라에서는 하천유량고시지점 114개 중 각 항목별 고시지점의 비율은 수질(33%), 평균갈수량(33%), 생태(29%), 경관(4%), 수질 및 염해(1%)로 나타났다(2019년 고시 현황). 따라서 사회-수문시스템 내에서 하천유지유량 결정기준 차이에 따라 환경적, 사회적, 경제적 측면으로의 영향을 평가하기 위하여 구조방정식모형을 모델링 한 후, 모형 내 잠재요인(기상, 수문, 환경, 사회·경제)의 상호연관성을 파악하였다. 기상학적 요소로는 기온, 강수량을 선정하였으며, 인간의 활동이 개입된 수문학적 요소는 유량, 하천수이용량으로 선정하였다. 환경적 요소는 BOD, COD, SS를 선정하였으며, 사회·경제적 요소는 인구, 지가변동률을 고려하였다. 이와 같은 사회-수문시스템 내 잠재요인별 요소를 바탕으로 사회-수문학적 영향평가를 위한 가설을 검증하기 위해 통계 프로그램 AMOS를 활용하여 구조방정식모형을 모델링하였다. 향후 사회-수문학 관점에서의 복잡한 영향관계를 정량적으로 평가하고, 다양한 이해관계자 간의 합의를 도출하는 데 있어서 효율적인 의사결정도구로 활용될 수 있을 것으로 기대한다.

• Journal of Wetlands Research
• /
• v.12 no.2
• /
• pp.75-89
• /
• 2010

The purpose of this study is to examine the hydraulic stability of the vegetation mat method on high water revetment. Recently, the river is managed not only for the flood control also for the environmental friendliness. For improving the environmental function of the river, the ecological river restoration projects are being performed. To ensure the stability of flood control, instead of removal of concrete revetment, the vegetation mat method has been widely used on the recovery soil. However, the recovery soil method often failed to be stable against the flood, which has caused the economic loss. In this study, the rate of soil loss is evaluated by the hydraulic experiments. Also, the velocity distribution on high water revetment is analyzed by both the hydraulic and numerical experiments.