• Title/Summary/Keyword: habitat properties

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Effect of phosphorus application on appearance of algal water bloom and rice yield in rice-barley double cropping system

  • Hwang, Jae-Bok;Bae, Hee-Soo;Park, Tae-Seon;Choi, In-Bae
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.233-233
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    • 2017
  • Algal communities are important to maintain the aquatic ecosystems function. Algae have short life cycles, they respond quickly to environmental change and their diversity and density can indicate and the quality of their habitat. The bloom forms before the rice seedings have emerged, it may present a physical barrier that prevents the seedlings from penetrating the floodwater. Wind may also move the algal bloom, pushing the young plants beneath the surface. Another harmful action develops when the water dries up and the algae form a layer at the bottom of the field. The layer envelops the seedlings, which are not yet deeply rooted, and drag them to the surface when the water is let in again. Soil utilization pattern can be the mail facter affecting soil physico-chemical properties, especially in soil phosphorus (P). Solid content of the algae culture solution increased with the increase in the nitrogen rather the phosphors concentration. Phosphoric acid was treated with conventional treatments (100-0%, before transplanting time-tillering stage), 50-50%, 0-100%, and un-treated. The herbicide was treated on the 7 DAT (day after transplanting). Green algae samples were collected 20 DAT. Total phosphoric acid was the highest at 0.06 in 50-50% treatment in 20 DAT. The amount of green algae was about twice (9.8 mg/20ml) that of un-treated. Total number of green algae was 54 species(Green algae 35 species, Euglena 9 species, Stone wheel 10 species). Among the phosphoric acid treatment methods, the number of occurrences of green algae were the highest with 39 species in 0-100%, followed by 50-50%, 28 species, conventional treatments, 22 species, non-treatment, 18 species, respectively. Rice Yield was not significantly different by phosphoric treatment time, but slightly higher than un-treated. The maximal algal biomass was observed about 2weeks or 1 month after transplanting; the subsequent decrease of the biomass was related to the consumption by grazers and to a deficient light under the rice canopy. Maximal algal growth was observed just before tillering. To estimate the suitable method of phosphorus application in puddled-soil drill seeding of rice, available phosphorus appearance of algal water bloom, and rice yield were investigated in paddy soil of rice-barley double cropping system.

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Vegetation Structure and Conservation of the Jeongdori Windbreak Forests on Wando Island in Dadohaehaesang National Park (다도해해상국립공원 완도 정도리 방풍림의 식생구조와 보전)

  • Lim, Dong-Ok;Choi, Hyun-Woo;Jang, Jong-Jae
    • Korean Journal of Environment and Ecology
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    • v.24 no.1
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    • pp.69-77
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    • 2010
  • The Jeongdori windbreak forests of Wando island, located between the sea and the land, are very important as ecological succession areas that protect cultivated lands and fishing villages. Among the Jeongdori windbreak forests, the rocky seashore areas are occupied by Sageretia theezans mantle community, and their inner sections by sub-tree layers such as Ligustrum japonicum and Ligustrum obtusifolium. More specifically, the inner sections of the rocky seashore areas were found to be the habitat of Ligustrum japonicum-Quercus variabilis community, Ligustrum jarponicum-Viburnum erosum community, Ligustrum japonicum-Cinnamomum japonicum community, Cinnamomum japonicum-Carpinus tschonoskii community, and Pinus densiflora-Viburnum erosum community. The average height of tree layers of the Jeongdori windbreak forests is 10.3m, and the average diameter at breath height are 30.3cm. Though the windbreak forests was artificially made, it is now virtually natural forest and deserves protection for ecological reasons. Designated as a scenic spot 3, it is always in the danger of being damaged by frequent tourist visits. So the Jeongdori windbreak forest needs to be continuous maintenance and management by the National Park Service. Considering of the precious cultural treasures of the famous pebble stones covering Gugyedeung and the naturality of the Jeongdori windbreak forests, the Jeongdori windbreak forests as a scenic spot have to designated as the national monument in future and will preserve by the Cultural Properties Administration.

Classification of Unit Ecosystems in Damyang Riverine Wetland (담양 하천습지 내 단위 생태계의 분류)

  • Son, Myoung Won;Chang, Mun Gi;Yoon, Kwang Sung;Choi, Tae Bong
    • Journal of the Korean association of regional geographers
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    • v.19 no.1
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    • pp.1-13
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    • 2013
  • Damyang Wetland Reserve with $980,575m^2$ area is located in Damyang-gun, Jeonlanam-do and Buk-gu, Gwangju Metropolitan City. The purpose of this paper is to divide Damyang riverine wetland into several geomorphic units, to analyze their sediments, and to categorize small ecosystem units composing riverine wetland. Riverine wetlands are classified into three types such as riverbed-, floodplain-, and abandoned-channel-wetland, and Damyang riverine wetland belongs to riverbed-wetland type. In this paper to categorize small geomorphic units of riverine wetland, we divide small geomorphic units from aircraft images analysis, and modify and supplement them following field survey results. Damyang Wetland Reserve is categorized into 22 ecosystem units. That physical and chemical properties of their sediments are different spatially, implicate that inorganic environment of Damyang riverine wetland ecosystem is very extensive. On the basis of the results of this study, policymakers will be able to design a strategy which manage Damyang Riverine Wetland Reserve more effectively, and for them interdisciplinary researches on relationships between various fluvial landforms and various lifeforms inhabiting them in Damyang Riverine Wetland Reserve are required.

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Characterization of Ecological Networks on Wetland Complexes by Dispersal Models (분산 모형에 따른 습지경관의 생태 네트워크 특성 분석)

  • Kim, Bin;Park, Jeryang
    • Journal of Wetlands Research
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    • v.21 no.1
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    • pp.16-26
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    • 2019
  • Wetlands that provide diverse ecosystem services, such as habitat provision and hydrological control of flora and fauna, constitute ecosystems through interaction between wetlands existing in a wetlandscape. Therefore, to evaluate the wetland functions such as resilience, it is necessary to analyze the ecological connectivity that is formed between wetlands which also show hydrologically dynamic behaviors. In this study, by defining wetlands as ecological nodes, we generated ecological networks through the connection of wetlands according to the dispersal model of wetland species. The characteristics of these networks were then analyzed using various network metrics. In the case of the dispersal based on a threshold distance, while a high local clustering is observed compared to the exponential dispersal kernel and heavy-tailed dispersal model, it showed a low efficiency in the movement between wetlands. On the other hand, in the case of the stochastic dispersion model, a low local clustering with high efficiency in the movement was observed. Our results confirmed that the ecological network characteristics are completely different depending on which dispersal model is chosen, and one should be careful on selecting the appropriate model for identifying network properties which highly affect the interpretation of network structure and function.

Fishes distribution and their connection to artificial reefs off Bukchon, Jeju Island using geographic information system (지리정보시스템을 활용한 제주도 북촌의 인공어초해역에서 어류 분포와 어초와의 관계)

  • KANG, Myounghee;FAJARYANTI, Rina;JUNG, Bongkyu;YOON, Eun-A;MIN, Eunbi;LEE, Kyounghoon;OH, Woo-Seok;PARK, Geunchang;SHIN, Young-Jae;CHOI, Yong-Suk;YI, Byung-Ho;HWANG, Doojin
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.121-128
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    • 2019
  • Various artificial reefs provide the fish habitat and nursery, and contribute the improvement of fisheries productivity. The evaluation methods of fishery resources in the artificial reefs have been done by fishing, scuba diving, underwater camera, and scientific echo sounder/sonar. There are a number of studies using echosounders on the quantitative and qualitative evaluations of artificial reefs in various seas around the world. This study focused on the spatial distribution of fishes around artificial reefs and the influential area of reefs off Bukchon, Jeju Island. Not only acoustic data but also various properties of artificial reefs were used in the geographic information system to extract relevant results. As a result, the major material of reefs on this study site was concrete and the number of reefs with that material was the most. The volume of reefs consisted of steel only and steel with riprap was considerably large compared to other reefs. The average NASC in the vertical distribution of fishes in artificial reefs was $31.6m^2/nm^2$ in April, and that was $61.3m^2/nm^2$ in June. The distance between the fish school and their nearest reef in June morning had a wide range from 750 to 3250 m. On the basis of the influence ray of artificial reefs, it had a tendancy of NASC to decrease with distance from the reef in the June morning. It is a preliminary study to present the geospatial analysis example to understand a better way of comprehensive artificial reef environments.

A Study on the Implement of AI-based Integrated Smart Fire Safety (ISFS) System in Public Facility

  • Myung Sik Lee;Pill Sun Seo
    • International Journal of High-Rise Buildings
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    • v.12 no.3
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    • pp.225-234
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    • 2023
  • Even at this point in the era of digital transformation, we are still facing many problems in the safety sector that cannot prevent the occurrence or spread of human casualties. When you are in an unexpected emergency, it is often difficult to respond only with human physical ability. Human casualties continue to occur at construction sites, manufacturing plants, and multi-use facilities used by many people in everyday life. If you encounter a situation where normal judgment is impossible in the event of an emergency at a life site where there are still many safety blind spots, it is difficult to cope with the existing manual guidance method. New variable guidance technology, which combines artificial intelligence and digital twin, can make it possible to prevent casualties by processing large amounts of data needed to derive appropriate countermeasures in real time beyond identifying what safety accidents occurred in unexpected crisis situations. When a simple control method that divides and monitors several CCTVs is digitally converted and combined with artificial intelligence and 3D digital twin control technology, intelligence augmentation (IA) effect can be achieved that strengthens the safety decision-making ability required in real time. With the enforcement of the Serious Disaster Enterprise Punishment Act, the importance of distributing a smart location guidance system that urgently solves the decision-making delay that occurs in safety accidents at various industrial sites and strengthens the real-time decision-making ability of field workers and managers is highlighted. The smart location guidance system that combines artificial intelligence and digital twin consists of AIoT HW equipment, wireless communication NW equipment, and intelligent SW platform. The intelligent SW platform consists of Builder that supports digital twin modeling, Watch that meets real-time control based on synchronization between real objects and digital twin models, and Simulator that supports the development and verification of various safety management scenarios using intelligent agents. The smart location guidance system provides on-site monitoring using IoT equipment, CCTV-linked intelligent image analysis, intelligent operating procedures that support workflow modeling to immediately reflect the needs of the site, situational location guidance, and digital twin virtual fencing access control technology. This paper examines the limitations of traditional fixed passive guidance methods, analyzes global technology development trends to overcome them, identifies the digital transformation properties required to switch to intelligent variable smart location guidance methods, explains the characteristics and components of AI-based public facility smart fire safety integrated system (ISFS).

Characteristic of Environmental Factors Related to Outbreak and Decline of Cochlodinium polykrikoides Bloom in the southeast coastal waters of Korea, 2007 (2007년 남해동부해역의 Cochlodinium polykrikoides 적조 발생과 소멸에 미치는 환경 특성)

  • Lim, Weol-Ae;Lee, Young-Sik;Lee, Sam-Geun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.13 no.4
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    • pp.325-332
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    • 2008
  • To characterize the initiation, propagation and termination of Cochlodinium polykrikoides blooms in the southeast coastal waters of Korea, 2007, we have analyzed the data set of phytoplankton composition, physical and chemical water properties, and meterological data. The development of C. polykrikoides bloom in 2007 can be summarized in three steps. The first stage from middle of July to end of August was characterized by an unusually persistent and strong southerly wind. C. polykrikoides blooms established already by the strong wind in the middle of south coastal waters were advected intermittently into the study area. Accordingly, highly variable cell densities of C. polykrikoides were observed. At the second stage a favorable growing conditions for C. polykrikoides was developed, which was directed by changes in wind direction from south to northeast and thus enhanced transportation of offshore waters into inshore (August 8 to 30). C. polykrikoides bloom occurred through typical mechanism and showed high cell density. The last stage was represented by disappearance of C. polykrikoides. Typoon 'Nari' carrying heavy rain brought an unfavorable habitat to C. polykrikoides. Low saline condition formed in coastal water due to typoon effects continuously drove the dominant species to diatoms and flagellates which were prevailing over C. polykrikoides in this circumstances(from the middle of September). These stepwise processes could be the causative mechanism of the extraordinarily persistent C. polykrikoides bloom observed in southeast coastal water of Korea, 2007.

Geomorphology and Spatio-Temporal Land Cover Changes in Sincheon Wetland, Mangyeong River (만경강 신천습지의 지형과 시공간적 토지 피복 변화)

  • Jangsoo Kim;Jeong-Sik Oh
    • The Korean Journal of Quaternary Research
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    • v.34 no.1
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    • pp.41-51
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    • 2024
  • The Sincheon wetland shows a remarkable diversity of fluvial landforms, such as river islands, anastomosing channels, braided channels, and sand-gravel bars, which contribute to its rich ecological habitat. The wetland area is characterized by a ecological diversity of herbaceous and woody plants. Significant changes in land cover within the wetlands were observed from 2008 to 2020. Notably, there was a rapid decrease in agricultural area from 18% to 0.04%, while the vegetation area expanded from 45% to 54%. Concurrently, the water area also experienced a notable increase from 34% to 41%. The surface sediment composition in the studied area displays sandy loam characteristics and exhibits acidic soil properties. Sediment acidity tends to increase downstream and in the central part of channels. Variations in acidity are also observed at nearby collection sites due to the tributaries and local discharge. The presence of dense vegetation in river islands and bars has led to a significant transformation of sediments into soil, with this change being more pronounced downstream, particularly near the weirs. The installation of a weir in Sincheon wetland is believed to have a significant impact on altering flow velocities between upstream and downstream sections, as well as influencing erosion and sediment deposition patterns. However, given the formation of landforms in response to weirs, effective administration and management are essential to address potential risks of catastrophic environmental disruptions, such as the removal of weirs and/or the maintenance of river channels.

Nutrient Contents of Bracken (Pteridium aquilinum L.) and Soil Chemical Properties of Its Habitat in the Coastal Area (남서해안 고사리 생육지의 토양화학적 특성과 고사리식물체의 무기성분 함량)

  • Lee, Soo-Young;Park, Kang-Yong;Park, Yang-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.5
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    • pp.631-636
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    • 2010
  • One experiment was carried out to investigate the soil chemical properties of bracken growth and the inorganic element contents of plant. To the results of soil analysis in native bracken (Pteridium aquilinum L.) growth, soil pH was 5.2, organic matter was 19 g $kg^{-1}$ and available phosphate was 20 mg $kg^{-1}$, and exchangeable potassium, calcium, magnesium were 0.32, 2.0 and 1.3 $cmol_c\;kg^{-1}$, respectively. In the bracken cultivation soil, pH was 5.7, organic matter was 13 g $kg^{-1}$ and available phosphate 367 mg $kg^{-1}$, and exchangeable potassium, calcium and magnesium were 0.81, 4.0 and 1.4 $cmol_c\;kg^{-1}$, respectively. The soil pH, available phosphate and exchangeable calcium were much lower in bracken native soil than those of cultivation soil, while organic matter was a little higher in native soil than that of cultivation soil. In native bracken plants, three major elements of nitrogen, phosphorus and potassium, were 4.40, 0.55 and 3.40%, calcium and magnesium were 0.22 and 0.32%, and microelements of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron were 126, 210, 23, 75 and 11 mg $kg^{-1}$, respectively. In cultivation bracken, three major elements of nitrogen, phosphorus and potassium, were 5.50, 0.73 and 3.55%, calcium and magnesium were 0.17 and 0.28%, and microelement contents of iron (Fe), manganese (Mn), copper (Cu), zinc (Zn) and boron (B) were 120, 252, 19, 72 and 20 mg $kg^{-1}$, respectively.

Types of Scenic Sites of State-Designated Cultural Property and Relationship between Pal-Kyung and Doncheon-Gugok (국가 지정 문화재 '명승'의 유형과 팔경(八景), 동천구곡(洞天九曲)과의 연관성)

  • Rho, Jae Hyun;Shin, Sang Sup
    • Korean Journal of Heritage: History & Science
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    • v.43 no.1
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    • pp.128-159
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    • 2010
  • In this study, the progress of domestic cultural properties designation, the changes and problems in classification were examined, and the relationship among Traditional Pal-kyung, Dongcheon-gukok, and Modern Pal-kyung were investigated targeting total of 68 cases of state-designated cultural properties of scenic sites in order to show that the traditional significance and value are being inherited today. The major results of this study are as follows. First, increase in scenic site designations with historical, cultural, and scenic characteristics can be viewed as an active intent to embrace the concepts such as cultural utilities, historical characteristics, literary value, and ideological backgrounds, which were specified as the basis for designation in the early Cultural Property Protection Law. Accordingly, it is very encouraging that the concept of cultural attractions such as traditional gardens and observatory points are regarded as an important standard for designation of scenic sites. Second, as for the classification of scenic sites per type, it was found that 'places with excellent natural scenery' were 44.16%(30 cases), followed by 'famous buildings or gardens and places with important legend' occupying 30.9%(21 cases), 'places with famous scenery' occupying 13.2%(9 cases), 'places with outstanding historical cultural and scenic value' that occupying 10.3%(7 cases), and 'animal and vegetation habitat with beautiful scenery' (1 case). Third, according to the current classification standards for scenic sites, there were only 7 cases which could be classified into Pal-kyungs(Famous 8 Sceneries) and 3 cases classified into Dongcheon(beautiful scenery surrounded by mountains and rivers), but there was no Gugok(beautiful valleys). Consequently, in terms of external appearance, the scenic sites among the total scenic sites that could be classified into Palkyung and Gugok were only 14.7%(10 cases). Fourth, the traditional scenic sites based on literal references and Internet analysis occupied 67.7%(46 cases), which were found to be scenic sites related to the traditional Pal-kyung among which 38 cases(55.9% of 46 cases) were included based on the scenery and 8 cases(11.8% of 46 cases) were included due to the scenery at the time. Fifth, there were 8(11.8%) scenic sites which were related to Dongcheon, and 4 cases(5.9%) related to Gugok. Also, it was found that total of 40(48.9%) scenic sites designated as modern scenic sites were playing the role of local scenic sites, and they were used as the tourism advertising contents. Sixth, it was identified that there were 62 cases(91.2%) of scenic sites in total related to traditional and modern Pal-kyung or Dongcheon-gugok, and unlike explicit classifications, most of the designated scenic sites were found to be deeply connected with the historical and cultural significance contained in the scenaries.