• 한국습지학회지
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• 제5권2호
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• pp.33-42
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• 2003

Habitat pattern and distribution of the water birds were analyzed along the Hyungsan River on nine sites during fifteen months from January 2001 to March 2002. Water birds including 16,186 individuals and 86 species in total were observed from all the surveyed sites at the downstream of the Hyungsan river. Site 5, which has been observed 4,669 individuals and 60 species of the birds, was the most favorite habitat for the water birds in the Hyungsan River. And the diversity of water birds from the Hyungsan river showed the fewest species and individual numbers of the water birds at the site 2 located at the estuary of the river and site 3, the small reservoir for filtering of the draining water from the industrial area. The similarity between habitats in the Hyungsan river was divided of three groups by the cluster analysis with the bird species and individual numbers such as coastal area, estuary sites, and rice paddy field areas.

• Korean Journal of Radiology
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• 제24권3호
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• pp.235-246
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• 2023

Objective: It is difficult to predict the treatment response of tissue after stereotactic radiosurgery (SRS) because radiation necrosis (RN) and tumor recurrence can coexist. Our study aimed to predict tumor recurrence, including the recurrence site, after SRS of brain metastasis by performing a longitudinal tumor habitat analysis. Materials and Methods: Two consecutive multiparametric MRI examinations were performed for 83 adults (mean age, 59.0 years; range, 27-82 years; 44 male and 39 female) with 103 SRS-treated brain metastases. Tumor habitats based on contrast-enhanced T1- and T2-weighted images (structural habitats) and those based on the apparent diffusion coefficient (ADC) and cerebral blood volume (CBV) images (physiological habitats) were defined using k-means voxel-wise clustering. The reference standard was based on the pathology or Response Assessment in Neuro-Oncologycriteria for brain metastases (RANO-BM). The association between parameters of single-time or longitudinal tumor habitat and the time to recurrence and the site of recurrence were evaluated using the Cox proportional hazards regression analysis and Dice similarity coefficient, respectively. Results: The mean interval between the two MRI examinations was 99 days. The longitudinal analysis showed that an increase in the hypovascular cellular habitat (low ADC and low CBV) was associated with the risk of recurrence (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.46-4.91; P = 0.001). During the single-time analysis, a solid low-enhancing habitat (low T2 and low contrast-enhanced T1 signal) was associated with the risk of recurrence (HR, 1.54; 95% CI, 1.01-2.35; P = 0.045). A hypovascular cellular habitat was indicative of the future recurrence site (Dice similarity coefficient = 0.423). Conclusion: After SRS of brain metastases, an increased hypovascular cellular habitat observed using a longitudinal MRI analysis was associated with the risk of recurrence (i.e., treatment resistance) and was indicative of recurrence site. A tumor habitat analysis may help guide future treatments for patients with brain metastases.

• 한국환경과학회지
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• 제28권11호
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• pp.917-925
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• 2019

All of the animals and the plants in ecosystem are intimately connected to one another and the changes of forests and surroundings affect directly wild animals. This study was conducted at Hangyeong-myeon Cheongsu-ri located in the western part of Jeju Island belonging to Hangyeong Andeok Gotjawal Zone and Jocheon-eup Seonheul-ri located in the eastern part of Jeju Island belonging to Jocheon Hamdeok Gotjawal Zone. The survey on advent of birds was carried out twice a month from January 2014 to December 2015. We divided habitat environments into three survey sites such as a forest, a shrub forest and a farmland. A total of 65 species and 4,802 individuals were observed during the survey period. In a forest, 36 species and 1,287 individuals were observed while A shrub forest had 40 species and 1,554 individuals. And in a farmland, 41 species and 1,961 individuals were observed. The only 10 species were observed in forest and the only 7 species in shrub forest and the only 10 species in farmland. The species diversity and the evenness of a farmland were the highest, and the species richness was the highest in a shrub forest, and the dominance of a forest was the highest among the three areas. The similarity index between a shurb forest and a farmland was high while that between a forest and a farmland was low. The similarity index related with breeding appeared that a forest and a farmland was different from each other.

• 대한토목학회논문집
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• 제29권3B호
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• pp.311-317
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• 2009

원주천 수환경과 어류군의 조사연구를 기초로 하여 표본 집단 사이의 유사지수를 파악하고 UPGMA 분류법을 사용한 어류군집의 cluster분석을 실시하였다. 원주천의 상류, 중류, 하류의 복원을 위한 지표어종으로 독중개, 갈겨니, 피라미를 선택하였다. 서식환경 향상으로 하수관거의 재정비와 유역관리를 분석을 통한 갈수유량 증대와 그에 따른 수질향상을 분석하였다. 원주천 중류의 복원목표 어종으로 갈겨니를 선택하여 복합 서식적합도를 분석하였다. 갈수유량의 증가는 서식적합도 향상에 매우 중요한 것으로 나타났다. 저수로의 변경에 따른 수심과 유속의 변화가 복합서식적합도의 향상을 가져오지만 지배적인 변수는 아닌 것을 확인하였다. 갈수유량의 증가와 더불어 저수로 폭을 10%씩 줄인 결과는 초기 복합서식적합도 0.1~ 0.25에서 0.37~ 0.78로 약 3배 이상의 향상을 가져와, 이를 원주천 어류군집의 서식 적합한 하천구조 개선방안으로 제시하였다.

• Journal of Ecology and Environment
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• 제47권4호
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• pp.250-260
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• 2023

Background: Crabgrass (Digitaria ciliaris, Poaceae) is a globally distributed weed, including in Afro-Eurasia, America, and Australia. As a highly gregarious plant, crabgrass is an important habitat for a diverse array of insects, and a potential habitat for agricultural pests. To compare the insect communities associated with the crabgrass community, insects were sampled using sweep sampling (100 sweeps per sample) at five sites, including Daejeon (Daejeon and Gap rivers), Anseong, Namhae, and Inje, with a focus on the Daejeon River. Results: A total of 5,888 individual insects belonging to eight orders, 42 families, and 115 species were collected from the five sites. Both the number of species and individuals of Hemiptera were the highest at all of the sites. In the present study, 73% of the insect population fed on D. ciliaris as a host plant. The dominant species in the D. ciliaris community was Laodelphax striatellus (Delphacidae), being ubiquitous at all the sites which showed a high abundance of rice pests in the communities and the suitability of D. ciliaris as an alternative host plant for them. The Shannon-Wiener diversity index was highest in Inje on 17 September (2.88), and the Chao1-bc diversity index was highest in the Gap River on 5 September (80). The sampling efficiency of 100 sweep samples (sample coverage) was calculated to be as high as 90%. The results of the samples taken from September to November in the Daejeon River showed that the number of species and individuals decreased gradually over time, and the number of dominant species decreased sharply between September and October. Similarity analysis indicated that sampling dates that were closer together yielded sampled assemblages with higher faunal similarity. In addition, in each sampling, the difference in the minimum temperature during the two-week period prior to sampling and faunal similarities were negatively correlated. Conclusions: This study provides foundational data that could enhance our understanding of insect diversity in D. ciliaris. The data can facilitate ecological conservation and management of Korean grasslands generally, as well as identification of potential pests that may disperse from D. ciliaris communities to nearby farmland.

• 환경생물
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• 제38권4호
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• pp.714-723
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• 2020

본 연구는 길안천의 저서성대형무척추동물 군집구조를 과거와 비교하여 분석하고자, 2018년 총 2회 조사를 실시하여 Lee (2004)의 결과와 비교하였다. 2018년 출현종수는 2003년과 비교하여 총 45종이 증가하였으며, 그중 EPT 분류군이 24종, OCH 분류군이 18종이 추가로 조사되었다. 군집분석 결과, 다양도지수(H')와, 풍부도지수(R')는 증가하였고, 우점도지수(DI)는 감소하는 경향을 보였다. 섭식기능군은 주워먹는무리(GC)에 속하는 종이 과거대비 11종이 추가로 발견되어 가장 높게 나타났고, 서식기능군의 경우 붙는무리(CL)가 41종으로 가장 많은 종이 출현하였다. 군집안정성에서는 특성군 I그룹이 2003년에 57.1%, 2018년에 61.5%로 가장 높은 출현율을 보였다. 생물학적 수질평가 결과, 과거 평균 'II등급'의 수질등급과 '보통'의 환경상태에서 2018년에는 평균 'Ia'등급의 수질과 '매우 양호'한 환경상태를 나타냈다. 2018년의 이화학적 요인과 생물학적 요인과의 상관관계 분석결과, pH 및 BOD는 개체수, 우점도지수(DI), 풍부도지수(R'), 다양도지수(H'), 균등도지수(J')에 유의한 상관관계를 나타냈다. 유사도 분석결과, 각 연도별로 두 개의 유사군으로 분류되었다. 길안천 수계가 취수시설 및 생태공원, 하천정비사업을 진행하면서 발생한 물리적 교란 이후 시간이 지남에 따라 물 흐름 개선과 다양한 미소서식처 형성을 통해 종 다양성 및 풍부도가 높게 나타난 것으로 판단되며, 향후, 제한적인 구간의 하천정비공사로 인한 하상 교란과 수질과의 상관관계가 저서성대형무척추동물의 군집구조와 군집안정성에 미치는 영향에 대해 추가적인 연구가 필요할 것으로 사료된다.

• 한국환경복원기술학회지
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• 제26권3호
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• pp.29-42
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• 2023

As the destruction of habitats due to recent development continues, there is also increasing interest in endangered species. Mankyua chejuense is a vulnerable species that is sensitive to changes in population and habitat, and it has recently been upgraded from Endangered Species II to Endangered Species I, requiring significant management efforts. So in this study, we analyzed the potential habitats of Mankyua chejuense using MaxEnt(Maximum Entropy) modeling. We developed three models: one that considered only environmental characteristics, one that considered artificial factors, and one that reflected the habitat of dominant tree species in the overstory. Based on previous studies, we incorporated environmental and human influence factors for the habitats of Mankyua chejuense into spatial information, and we also used the habitat distribution models of dominant tree species, including Ulmus parvifolia, Maclura tricuspidata, and Ligustrum obtusifolium, that have been previously identified as major overstory species of Mankyua chejuense. Our analysis revealed that rock exposure, elevation, slope, forest type, building density, and soil type were the main factors determining the potential habitat of Mankyua chejuense. Differences among the three models were observed in the edges of the habitats due to human influence factors, and results varied depending on the similarity of the habitats of Mankyua chejuense and the dominant tree species in the overstory. The potential habitats of Mankyua chejuense presented in this study include areas where the species could potentially inhabit in addition to existing habitats. Therefore, these results can be used for the conservation and management planning of Mankyua chejuense.

• 한국환경생태학회지
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• 제25권5호
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• pp.691-709
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• 2011

본 연구는 금강 수계의 환경요인을 이용한 서식지 유형분류와 그에 따른 수서곤충 섭식기능군의 분포특성을 규명하기 위한 것으로 2007년부터 2008년까지 금강 수계에서 총 38개 지점에 대하여 봄과 가을에 걸쳐 년 2회씩 총 4회 조사를 실시하였다. 38개 조사지점별로 15개의 환경요인들을 현장 측정한 후 서식지 유사도 분석을 실시한 결과, 거리 척도값 4를 전후하여 상류구간(HD)은 C1과 C3그룹, 중류구간(MS)은 C2와 C4 그리고 C5그룹, 하류구간(LR)은 C6과 C7그룹으로 서식지 유형이 분류되었다. 서식지 유형분류에 있어 영향을 끼치는 주요한 환경요인은, 물리적 환경요인의 경우 하폭과 고도, 화학적 환경요인의 경우 수온과 전기전도도 그리고 DO, 하상재료의 경우 모래와 실트 그리고 잔자갈의 함량으로 분석되었다. 조사시기 동안 출현한 수서곤충은 총 9목 46과 142종으로 조사되었고, 서식지 유형별 종수 및 개체수 현존량 증감과 높은 상관성을 보인 주요 환경요인은 유속과 모래의 함량으로 나타났다. 또한 섭식기능군과 환경요인 사이의 상관성 분석결과, (1) 걸러먹는 무리(FC)는 유속, 수폭, 실트 (2) 주어먹는 무리(GC)는 유속 (3) 잡아먹는 무리(P)는 고도, 유속, 큰돌, 전기전도도, 모래 (4) 뚫어먹는 무리(PP)는 수폭, 실트 (5) 긁어먹는 무리(SC)는 유속, 전기전도도 (6) 썰어먹는 무리(SH)는 고도, 큰돌, DO, pH, 전기전도도, 수온과 각각 상관성을 보이는 것으로 나타났다. 본 연구의 결과, 단계적 다중회귀분석(SMRA)에 의해 도출된 금강 수계의 환경요인 중 고도, 하폭, 유속, 전기전도도, 수온 그리고 모래 등 6개의 요인은 생물군집의 서식과 상관성($r{\geqq}0.600$, P<0.01)이 있는 것으로 나타나 금강 수계 섭식기능군 분포에 영향을 미치는 주요한 요인으로 제시되었다.

• 한국산림과학회지
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• 제85권3호
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• pp.506-512
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• 1996

강원도 횡성(橫城) 압곡리(鴨谷里)의 백로(白鷺)와 왜가리 집단서식(集團棲息)이 삼림생태계(森林生態系)에 미치는 영향을 조사하였다. 이 지역은 1973년부터 천연기념물(天然記念物) 248호로 지정되어 보호되고 있는 곳으로 1995년 조사에 의하면 700개체 이상의 백로(白鷺)와 왜가리가 서식(棲息)하는 것으로 관찰되었다. 조류(鳥類)의 집단서식(集團棲息)으로 교목인 잎갈나무들이 대부분 고사하였고, 실생에 의한 보충은 얼어나지 않았다. 서식처 잎갈나무군락의 토양 영양염류(營養鹽類) 함량은 대조구(對照區) 잎갈나무군락에 비해 현저히 높았다. 이것은 주로 조류의 배설물(排泄物), 수관층(樹冠層)과 둥지에서 떨어진 잎과 가지의 분해에 기인(起因)하는 것으로 판단되었다. 집단서식지(集團棲息地)의 교목이 고사(枯死)함에 따라 임상(林床)에 투과되는 광량이 증가하여 초본층의 식물종이 대조구(對照區)와 현저한 차이가 있었다. 부영양화(富營養化)된 서식지에는 환삼덩굴, 가시여뀌, 며느리배꼽, 닭의장풀, 애기똥풀, 바랭이, 도깨비바늘, 마 등이 우점(優點)하는 것으로 조사되었다. 집단번식지와 대조구 잎갈나무군락의 관목층과 초본층의 유사도 지수는 각각 0.36, 0.07이었다.

• 한국조경학회지
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• 제33권2호
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• pp.16-31
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• 2005

This study was carried out to design a bridge-type ecological corridor plan in a forested neighborhood park affected by road construction in Dongjak-gu, Seoul. In order to study the site conditions, we analyzed topography, ecosystem structure, and user behavior and trail use. Existing vegetation was classified into 12 types. Based on a vegetation analysis, the Populus albaglandulosa and Robinia pseudoacacia communities, where planted species are dominant, were distributed extensively in the southern forest area. Planted areas with a single-layer structure of Korean landscape woody plants and Robinia pseudoacacia communities with a single-layer structure were distributed extensively in the northern forest and water-supply area. Based on a study of 28 quadrats, the similarity index between the multi-layer plant communities distributed in the southern forest and the single-layer planted areas was low. Twenty-four species of wild birds(355 individuals) were found in the survey area, including nine interior species and three urban species. The study of user behavior and numbers showed most users were walkers and few users were observed in the southern forest while most users were observed in the northern forest and water supply area. We selected some wild birds as model species to represent migrating species believed to use this park as an ecological corridor during migration. We suggested the new park plan include the following: improvement of vegetation structure for wildbird migration and habitat, connection of park trails for users and presentation of a landscape linked to nature.