• Ocean and Polar Research
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• 제45권3호
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• pp.173-183
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• 2023

The barren ground phenomenon in Korea began to occur and spread in the southern coast region and in Jeju Island in the 1980s, and since the 1990s, the damage has become serious in the east coast region as well. Korea has enacted the fisheries resource management act to manage such barren ground through the installation of sea forests among projects for the creation of fishery resources. Until now, projects related to the identification of the cause of barren ground have focused on the density of crustose coralline algae, sea urchins and seaweed, so the original cause of barren ground has not yet been identified. In order to manage barren ground, it is necessary to identify the cause of barren ground. To identify these causes, it is necessary to comprehensively consider i) studies on spatial characteristics such as rock mass distribution, slope and water depth, ii) studies on ecological and oceanographic characteristics such as water temperature, salinity, El Niño, and typhoons etc, iii) studies on organisms such as crustose coralline algae, macroalgae, and sea urchins, and iv) studies on coastal use such as living and industrial sewage inflow. Next, as with regard to legislative policy proposals , it is necessary to prepare self-management measures by the government, local governments, and fishermen as well as address management problems related to the use of sea forests by fishermen after their creation . In addition, when creating a sea forest, a management model for each resource management plan is required, and evaluation indicators and indexes that can diagnose the cause of barren ground and guidelines for barren ground measures should be developed.

• 한국지반공학회논문집
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• 제21권5호
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• pp.45-50
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• 2005

최근에 샌드드레인공법이나 샌드콤팩션파일공법 등과 같이 모래말뚝을 이용한 연약점토지반 개량공법의 적용이 증가하고 있다. 이러한 공법들로 개량된 연약점토지반에서는 모래말뚝에 의한 압밀촉진효과를 기대 할 수 있는데 실무에서는 보통 Barren의 이론해 등과 같은 이론식을 이용하여 그 효과를 평가하고 있다. 그러나 이러한 이론식들은 복합지반의 비선형 체적압축거동과 압밀중의 투수계수 변화 현상을 고려할 수 없으며, 따라서 그 평가결과가 합리적 이라고 판단하기 힘들다. 본 연구에서는 일련의 수치해석을 실시하여 Barren의 이론해에 적용되는 복합지반의 압밀정수 결정법에 대하여 고찰하였다. 수치해석 결과의 분석을 통하여 압밀 중에 변화하는 점토부의 체적압축거동특성과 투수성의 변화특성을 고려한 압밀정수의 결정방법을 제안하였다.

• 한국수산과학회지
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• 제45권3호
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• pp.262-270
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• 2012

Seaweeds provide habitats in which marine animals can spawn and develop, and serve as a food supply for algaegrazing species such as sea urchins and abalone. Recently, seaweed species have disappeared from coastal ecosystems, leaving barren ground, defined as habitats that have lost their algae forests and where coralline algae containing calcium carbonate components have become encrusted on rocks. The biological causes of barren ground include grazing by herbivores and excessive seaweed harvest. The environmental harm caused by the spread of barren ground includes accelerated eutrophication following the reduction in seaweed, which plays an important role in oceanic purification. In the present study, we identified the relationships between various seaweed species and the occurrence of barren ground. Subtidal benthic macroalgal flora and community structure were observed seasonally on barren ground along vertical transects of rocky shores of Bihwa, Samchuck, and the east coast of Korea from February to November 2006. Fifty-eight seaweed species were identified, including 7 green, 15 brown, and 36 red algae species. There were between 6 and 28 species among seasons. Over the whole study period, average seaweed biomass (g wet wt $m^{-2}$) was 241.90 g, with a seasonal range of 25.26 to 760.34 g. Seaweed biomass declined with increasing seawater depth and ranged between 91.26 and 422.08 g. The vertical distribution of algae was characterized by Undaria pinnatifida and Sargassum honeri at 5 m, S. honeri and U. pinnatifida at 10 m, and U. pinnatifida and Agarum clathratum at 15 m depth. Seasonal patterns in community indices were not found. Community indices showed different patterns along vertical shoreline gradients; the dominance index increased but the richness, evenness, and diversity indices decreased with seawater depth. Sea urchin density was 8 to 24 individ. $m^{-2}$ in Bihwa. These urchin populations had significantly aggregated spatial patterns and recurrent destructive grazing appeared to be occurring.

• 한국수산과학회지
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• 제40권5호
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• pp.323-331
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• 2007

Barren ground is an abnormal phenomenon in coastal ecosystems where seaweeds are destroyed and largely replaced by coralline algae containing calcium carbonate components. To restore the seaweed forest, we attempted reconstruction in an area of Samcheok, Korea, where barrenness is extensive. We developed two methods of seaforest construction underwater longline and seed transplantation for the brown seaweed Laminaria japonica, a fast-growing edible seaweed. The blade length of L. japonica attached to an underwater long line was $93.9{\pm}38.2cm$ and blade weight $7.6{\pm}2.1g$ in February 2004. Seaweed size declined after August 2004. A Similar pattern was observed using the transplantation method with maxima of $179.3{\pm}40.3cm\;and\;14.9{\pm}3.2g$ for blade length and weight, respectively in July 2004. The transplanted seaweeds matured in October as did a wild population. These results indicate that transplanted seaweed acclimate to new environments.

• 해양환경안전학회지
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• 제25권2호
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• pp.212-219
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• 2019

본 연구는 우리나라 제주 해역의 여름철 해조 군집 특성과 갯녹음 현황을 파악하고자 수행하였다. 연구는 2017년 7월부터 9월까지 스쿠버 다이빙(SCUBA Diving)을 이용하여 정량 조사 및 정성 조사를 시행하였다. 연구 결과 녹조류 11종(9.1 %), 갈조류 24종(19.8 %), 홍조류 86종(71.1 %) 등 총 121종의 해조류가 확인되었다. 지역별로는 형제섬이 60종으로 출현종수가 가장 많았으며, 하례가 18종으로 가장 적었다. 연구 지역의 평균 생물량은 $1,503.0g{\cdot}m^{-2}$이며, 주변 도서의 평균 생물량($3,268.7g{\cdot}m^{-2}$)이 본섬의 평균 생물량($914.7g{\cdot}m^{-2}$)보다 높았다. 우점종은 주변 도서에서 Sargassum macrocarpum, 본섬에서 Ecklonia cava로 나타나 생물량뿐만 아니라 종 조성에서도 차이를 보였다. 해조 군집 특성(종 조성, 생물량, 대형 갈조류의 생물량 비율), 무절산호말류의 피복도, 조식동물의 밀도 등을 토대로 연구 지역의 여름철 해조 군집 상태를 평가한 결과, 형제섬과 마라도 두 지역은 우수한 해조 군집을 유지하고 있는 것으로 판단되어 보전 및 지속적인 관리가 요구되며, 다른 6개 지역은 각 지역별로 해조 군집의 조성 내지 복원이 필요한 실정이다. 갯녹음 현상이 가속화됨에 따라 모니터링뿐만 아니라 현재 해조 군집의 현황 파악이 제대로 이루어지지 않은 지역을 대상으로 해양 생태계의 실태를 파악하는 일도 시급한 것으로 판단된다.

• 생명과학회지
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• 제16권6호
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• pp.1044-1051
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• 2006

The barren ground is an abnormal phenomenon of coastal ecosystem in which seaweeds, are destroyed and mostly replaced by the coralline algae containing the calcium carbonate components. To restore the seaweed forest, We have exerted an effort in the local areas, Samchuck, Korea, where barren phenomena are profound. Two methods of seaweed forest construction developed in the present study are underwater longline and seed transplantation for the brown seaweed Costaria costata, a fast growing edible seaweed. The sizes of C. costata attached on the underwater longline were $96.7{\pm}2.2mm$ of blade length and $83.6{\pm}7.7g$ of blade weight in April. Thereafter the sizes declined from May. Similar pattern was obtained from in the transplantation method with maxima of $90.4{\pm}15.8mm$ and $70.1{\pm}31.7g$ for blade length and weight, respectively in April. It appeared totality maturation from two methods in May. This maturation time is the same like that of wild C. costata.

• ALGAE
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• 제21권4호
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• pp.463-470
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• 2006

Studies have been made of the species composition and variation of benthic marine algae at subtidal zone of Uljin on the east coast of Korea. Destructive method was employed to measure biomass over four seasons (2000-2002). Of 87 marine algae species identified, 11 were Chlorophyta, 29 were Phaeophyta and 47 were Rhodophyta. Dominant species in biomass were Ulva pertusa, Undaria pinnatifida and Sargassum piluliferum in summer, Laminaria religiosa, Sargassum fulvellum and Gigartina tenella in autumn, Codium fragile, Undaria pinnatifida, Sargassum horneri, S. piluliferum and S. ringgoldianum in winter, and Undaria pinnatifida, Dictyopteris divaricata, Sargassum confusum and S. horneri in spring. In general, green algae (Ulva pertusa, Codium fragile) and brown algae (Undaria pinnatifida, Sargassum fulvellum, S. horneri, S. piluliferum) appeared predominantly in the 3, 6 m depths and red algae (Gelidium amansii, Plocamium telfairiae) in the 9, 12 m depths. The barren ground of the rocky shore might provide the decrease of benthic marine algae biomass and species.

• ALGAE
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• 제30권2호
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• pp.139-146
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• 2015

Urchin barrens have been a major issue of rocky coastal ecosystems in temperate regions. In South Korea, the east coast and Jeju Island have especially been a focus because the area of barren ground increases in spite of continual efforts to install artificial reefs. This study approached the urchin barrens issue in South Korea, by focusing on a correlational analysis of urchin and macroalgal abundance. Urchin density and algal species coverage were obtained using a quadrat image analysis. Subtidal sites were then classified into three groups according to the average densities of urchins to evaluate the characterization of the macroalgal community: no urchin (NU) zone; transition (TR) zone, $4inds.\;m^{-2};$ and urchin (UR) zone, ${\geq}8inds.\;m^{-2}$. The average urchin density in the study site was $4.7inds.\;m^{-2}$ and 57 macroalgal species were found in the study site. From the NU zone to UR zone, total species number, species diversity index and evenness gradually decreased, whereas the dominance index increased. The algae species with negative correlations were Grateloupia divaricata, Polysiphonia morrowii, Chondracanthus intermedius, Delesseria violacea, Desmarestia viridis; and those with positive correlations were the crustose corallines, Sargassum horneri. Other species were not significantly correlated with urchin density. The significant correlations indicate that the abundance of some macroalgal species is proportionally regulated by sea urchin density. This study also shows how macroalgal vegetation changes in response to an urchin's density gradient in a natural condition; and there is a TR zone that existed with respect to an intermediate level of algal abundance.

• 한국환경과학회지
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• 제23권1호
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• pp.81-88
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• 2014

In this study, one of the measures for the promotion of the growth of trees planted in poor drainage areas, which functionality pipe supplying oxygen in the soil, and promotes drainage, barren soil and poor drainage areas in planting design was to provide the basic data to compare the impact on the application of functionality pipe. The Zelkova serrata testing materials were selected, planted a total of 12 by three to four individual experiments were conducted. Growth measurements of the items Plot A > Plot C > Plot D > Plot B were excellent in the order of height, number of leaves, leaf width, and chlorophyll content, Plot A > Plot C > Plot D > Plot B was in good order of the growth of the length of the root-collar diameter, Plot C > Plot A > Plot B > Plot D in order rate of variation was good. This has adverse effects on plant growth, poor drainage planting base represents, promote drainage and oxygen supply technique can be applied good to the planting from Zelkova serrata growth based drainage is poor and barren presented as part of research to be done in the future include a means for promoting the growth of plants in soil, the planting design.

• 한국환경복원기술학회지
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• 제5권2호
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• pp.47-52
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• 2002

In this study, in order to find out relationship of green space distribution and lower air temperature effect, observed air temperature distribution in and out green space in the cloudy. On basis of the result, we are analyzed relationship of air temperature distribution in and out green space, of green space distribution and air temperature of, lower air temperature effect and the urban in between the green space by using regression analysis. According to the result, the higher temperature zone formed around urban, and the lower temperature zone was similar to shape of green space. In case of the green space, higher temperature zone is formed around paved surface and barren ground, lower temperature zone is done forest and water area. To compare air temperature of windward and leeward around green space, the windward formed the lower temperature zone and although the wind direction is not the leeward to the green space, air temperature formed lower temperature zone to the urban in between the green space.