• Title/Summary/Keyword: ecological change

Search Result 1,329, Processing Time 0.026 seconds

Environmental Impact Analysis on Fish Stocks caused by Environmental Change in the Coastal Fishing Ground (연안어장의 환경변화가 수산자원량에 미치는 영향평가)

  • ;MASAHIKO SEKINE
    • Journal of Ocean Engineering and Technology
    • /
    • v.15 no.1
    • /
    • pp.36-44
    • /
    • 2001
  • To predict the influence on fish stocks which were caused by environmental change in the fishing ground of shallow sea areas, we have developed the Shallow-Sea Ecological Model(SSEM) which that focuses on living organisms, especially fish and benthos. By applying the SSEM in the Seto-Inland Sea of Japan, we have simulated another aspect of influence on fish stocks that was caused by oxygen deficient water mass and nutrient loads. From the simulated result of the fish stocks, it was indicated that the stock of fish and benthos has shown a relative difference between the western sea and the eastern sea in the Seto-Inland Sea. According the to prediction, results of fish stocks that were caused by oxygen deficient water mass, it was estimated that the pelagicfish stock increases about 6 %, whereas the stocks of demersalfish and benthos decreases about 30% and 70%, respectively. On the other hand, it seemed that there was an increased in the fish stocks of demersalfish and benthos in the eastern sea of Seto-Inland Sea by nutrient loads reduction.

  • PDF

Assessing the EPIC Model for Estimation of Future Crops Yield in South Korea (미래 작물생산량 추정을 위한 EPIC 모형의 국내 적용과 평가)

  • Lim, Chul-Hee;Lee, Woo-Kyun;Song, Yongho;Eom, Ki-Cheol
    • Journal of Climate Change Research
    • /
    • v.6 no.1
    • /
    • pp.21-31
    • /
    • 2015
  • Various crop models have been extensively used for estimation of the crop yields. Compared to the other models, the EPIC model uses a unified approach to simulate more than 100 types of crops. It has been successfully applied in simulating crop yields for various combinations of weather conditions, soil properties, crops, and management schemes in many countries. The objective of this study was to estimate the rice and maize yield in South Korea using the EPIC model. The input datasets for the 30 types in the 11 categories were created for the EPIC model. The EPIC model simulated rice and maize yields. The performance of the EPIC model was evaluated with the goodness-of-fit measures including Root Mean Square Error (RMSE), Relative Error (RE), Nash-Sutcliffe Efficiency Coefficient (NSEC), Mean Absolute Error (MAE), and Pearson Correelation Coefficient (r). The rice yield showed to more high accuracy than maize yield on four type of method without NSEC. Theses results showed that the EPIC model better simulated rice yields than maize yields. The results suggest that the EPIC crop model can be useful to estimate crop yield in South Korea.

High ranavirus infection rates at low and extreme temperatures in the tadpoles of Japanese treefrogs (Dryophytes japonicus) that breed in rice paddies in the summer

  • Nam-Ho Roh;Jongsun Kim;Jaejin Park;Daesik Park
    • Journal of Ecology and Environment
    • /
    • v.47 no.2
    • /
    • pp.35-41
    • /
    • 2023
  • Background: Several species of amphibians in agricultural areas are often infected with ranaviruses; however, the biological or ecological factors that cause this infection are not well understood. In this study, we investigated whether local tadpole density, Gosner developmental stage, and weather conditions affected ranavirus infection in Dryophytes japonicus tadpoles in rice paddies over three months. Results: During the study, eight samplings were undertaken between June 6 and August 21, 2022. No die-off of tadpoles occurred, but 20 of 110 tadpoles (18.8%) were found to be infected with ranavirus. The tadpole density at the sampling site and Gosner stage of the sampled tadpoles were not related to the daily ranavirus infection rate. The mean daily highest temperature during the two weeks prior to the sampling date and the mean daily lowest and highest temperatures during the week prior to the sampling date were negatively related to the daily infection rate. Conclusions: Our results suggest that low and extreme temperatures caused by flooding and draining of paddy fields or climate change in summer could be a significant risk factor for ranavirus infection in summer-breeding frogs in agricultural areas.

A Study on Surface Landscape Change and Sedimentary Environment of the Dongcheon Estuary through Aerial Photographs and Sediment Analysis (항공사진 및 퇴적물 분석을 통한 순천 동천하구의 지표경관 변화 및 퇴적환경 연구)

  • Lee, Ye-Seul;Lim, Jeong-Cheol;Jang, Dong-Ho
    • Journal of The Geomorphological Association of Korea
    • /
    • v.28 no.1
    • /
    • pp.35-50
    • /
    • 2021
  • In this study, we analyzed the changes in the topographical landscape and the sedimentary environment to evaluate the ecological value of the Dongcheon Estuary and protect the wetland, and presented the conservation management method of the Dongcheon Estuary. Based on the result of topographical landscape analysis, agricultural land tended to decrease continuously, and artificial structures gradually increased. Moreover, in sediment analysis, the Dongcheon Estuary showed both the characteristics of river sediments and coastal sediments, and in some areas problems such as acidification and nutritional imbalance appeared. Therefore, in order to protect and manage the Dongcheon Estuary with high ecological value, it is necessary to limit the development around micro topography and minimize the artificial damage in the Dongcheon Estuary. In addition, efforts such as securing facilities for reducing pollutants and freshwater wetlands for pollutants, that flow in from nonpoint pollutants are required.

A Review on Environmental Impact Assessment of Offshore Wind Farms Related to the life-history of Marine Birds on the Korean Peninsula (한반도 해양성 조류의 생활사적 특성을 고려한 해상풍력발전 환경영향평가에 대한 고찰)

  • Seungyeon Lee;Who-Seung Lee
    • Journal of Wind Energy
    • /
    • v.14 no.3
    • /
    • pp.69-82
    • /
    • 2023
  • Offshore wind farms (OWFs) should be promoted as part of global efforts to respond to climate change, and efforts to preserve biodiversity in terms of climate change adaptation should also be considered. However, the ecological status of marine birds related to OWFs on the Korean Peninsula, such as habitat and reproduction, are not well known. In this study, ecological reasons for the reproductive status of Black-tailed gulls in Korea and representation related to OWFs, the evaluation direction of marine birds related to OWFs was presented. In a review of the techniques for monitoring marine birds, it was confirmed that Korea also needs to provide basic status information on marine birds at the national level. In addition, this study analyzed the reproductive status and related research status of Black-tailed gulls, an important indicator and dominant species on the Korean Peninsula, in relation to marine development projects including OWFs. Furthermore, the direction of environmental impact assessment preparation and impact prediction for various development projects promoted in the ocean, such as OWFs, was considered.

A Review of Ecological Niche Theory from the Early 1900s to the Present (생태적 지위(Ecological Niche) 이론에 대한 검토 및 제언)

  • Koo, Kyung Ah;Park, Seon-Uk
    • Korean Journal of Environment and Ecology
    • /
    • v.35 no.4
    • /
    • pp.316-335
    • /
    • 2021
  • This study reviewed the change of theory of ecological niche(concepts and definitions) over time to provide a theoretical basis for habitat-related studies of animals and plants. Accordingly, it analyzed and summarized the major discussion trends of ecological niche worldwide in each period from the 1900s to the present. Countries advanced in ecological studies, such as the EU and the USA, have conducted theoretical and empirical studies on the ecological niche since the early 1990s. The concept of the ecological niche was introduced in the early 1900s, developed in the mid-1900s, and advanced from the mid-1900s to the late 1900s. Since the 2000s, the advanced concept has diversified with new developments in technologies and research methods. The factors suggested by theoretical and empirical studies in defining the ecological niche of a species include 1) population dynamics of the target species, 2) all biotic conditions to sustain a population (food relationship and material flow in the food chain), 3) all non-biotic conditions to sustain a population (physical environmental conditions), 4) all direct and indirect interactions between these environmental factors, and 5) response and adaptation mechanisms that include the migratory ability of the target species or genetic diversity and adaptability to change. Unlike such international advancement, there have not been sufficient theoretical, philosophical, and empirical studies of ecological niche in Korea. The concepts and definitions by Greennell, Elton, and Hutchinson were selectively and partially borrowed for empirical studies without full description. Considering that the theory of ecological niche becomes the foundation for habitat-based species conservation and restoration, it is necessary to seek diversification and advancement of theoretical and empirical research and research methods and technological development. It will provide an important foundation for the academic advancement of ecology and for establishing and implementing policies to preserve and restore ecology and biodiversity effectively and successfully in Korea.

Assessment of Forest Degradation and Carbon Storage for REDD+ Project in North Korea (북한에서의 REDD+ 사업을 위한 산림황폐화 및 탄소저장량 평가)

  • Piao, Dongfan;Lee, Woo-Kyun;Zhu, Yongyan;Kim, Moonil;Song, Cholho
    • Korean Journal of Environmental Biology
    • /
    • v.34 no.1
    • /
    • pp.1-7
    • /
    • 2016
  • As the deforestation in North Korea gets severed, the interest for REDD+ is also increasing. This study analyzed historical land cover changes of the study area which is 10,000 ha in Hwanghaebukdo of North Korea for assessing change in landcover and carbon storage. The result showed that the forest area had decreased from 7,035 ha to 4,293 ha which is approximately 39% of total forest area between 1989 and 2013. The deforestation caused that forest carbon storage had decreased approximately $284,399tCO_2$. Set the baseline and analysed the potential reduction amount of carbon emission, it was estimated that REDD+ project could store approximately $364,704tCO_2$ for next 30 years. This study still has limitations such as lacking in direct field survey and the data of stand volume of each tree species which was replaced with the data of stand volume in South Korea. But, study can be applied for future REDD+ projects in North Korea.

A Study on the Data Cleaning and Standardization of National Ecosystem Survey in Korea (전국자연환경조사 데이터 정제와 표준화 방안 연구)

  • Kwon, Yong-Su;Song, Kyohong;Kim, Mokyoung;Kim, Kidong
    • Korean Journal of Ecology and Environment
    • /
    • v.53 no.4
    • /
    • pp.380-389
    • /
    • 2020
  • Research on diagnosing and predicting the response of ecosystems caused by environmental changes such as artificial disturbance and climate change is emerging as the most important issue of biodiversity and ecosystem researches. This study aims to clean, standardize, and provide the results of National Ecosystem Survey which should be considered fundamentally in diagnosing and predicting ecosystem changes in the form of dataset. To refine and clean the dataset we developed a simple verification program based on the fifth National Ecosystem Survey Guideline and applied that program to the data from the second (1997~2005), third (2006~2013) and fourth (2014~2018) National Ecosystem Survey. Data quality control processes were implemented including (1) standardization of terminology, (2) similar data table integration, (3) unnecessary attribute and error elimination, (4) unification of different input items, (5) data arrangement in codes, and (6) code mapping for input items. These approaches and methods are the first attempt propose an option for ecological data standardization in Korea. The standardized dataset of National Ecosystem Survey in Korea will be easily accessible, reusable for both researchers and public. In addition, we expect it will contribute to the establishment of diverse environmental policies concerning environmental assessments, habitat conservation, prediction of endangered species distribution and ecological risks due to climate change. The dataset through this study is open freely online via EcoBank (nie-ecobank.kr) which is the first ecological information portal system in Korea developed by National Institute of Ecology.

Ecological Characteristics of Vascular Plants by Habitat Types of Dry Field in Jeolla-do, Korea (전라도 밭경작지의 서식처 유형별 식물상 특성)

  • Cho, Kwang-Jin;Kim, Myung-Hyun;Kim, Min-Kyeong;Na, Young-Eun;Oh, Young-Ju;Choe, Lak-Jung
    • Korean Journal of Environmental Agriculture
    • /
    • v.33 no.2
    • /
    • pp.86-102
    • /
    • 2014
  • BACKGROUND: According to the types of human interference, there are various plants that have strong vitality and ability to breed in the dry field. Recently, climate change alters the geographical distribution and phenology of the plant species. So, we need to understand present occurrence pattern and ecological characteristics of these plants. METHODS AND RESULTS: The plant species data were obtained from 8 regions in Jeolla-do. Flora investigation was done from May 2013 to September 2013. Habitat type of dry field in Jeolla-do was classified into 3 types (inside of dry field: IDF, embankment around the end of a dry field: EDF, levee slope of dry field: LS). The vascular plants of study area were listed 296 taxa which contain 68 families, 203 genera, 244 species, 43 varieties and 9 forms. The vascular plants of three different habitat types were IDF 174 taxa, EDF 249 taxa and LS 136 taxa. The occurrence rate of Therophyte was arranged by the order of IDF(67.6%), EDF(51.9%), LS(54.3%). Naturalized rate was analysed as IDF 27.9%, EDF 21.0%, LS 18.6%. Urbanization index was analysed as IDF 11.8%, EDF 13.7%, LS 10.0%. CONCLUSION: With these results, we found that three habitat types were ecological difference affected by the human impacts. Also, we found environmental indicators through the ecological characteristics of flora for the type of habitat of dry field. These indicators will help assess the agriculture environmental variability and the floral change according to the climate change in dry field.

Consequential Change of Wind Environment in Building Arrangements (건물배치에 따른 풍환경 변화)

  • Lee, Sun-Young;Kim, Sang-Jin
    • KIEAE Journal
    • /
    • v.12 no.2
    • /
    • pp.117-124
    • /
    • 2012
  • The purpose of this study is to investigate the change of wind environment for different building arrangement. In this study, we analyze outdoor wind environment on different building arrangement that take same floor area ratio using the CFD (Computational Fluid Dynamics) method. We do not consider the effect of temperature. Building arrangements of low density, different hight and a lot of green area will change the effect of wind environment. The eight different arrangements of buildings are studied in this paper. In these calculations, we know the different arrangement of buildings change outdoor wind environments. Especially, reducing the number of building and crossing the different height of buildings have a good kind of wind environment at the same floor ratio. We know that these arrangement of buildings to reduce the heat island phenomena on city plan.