• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.151-160
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• 2019

The study of spiders that function as predators in agroecosystem can broaden the understanding of agroecosystems. This study investigated the effect of heterogeneity at different spatial scales on richness and abundance of spiders in upland and paddy fields. We collected 48 samples using pitfall traps at upland and paddy fields, respectively. The total species richness of spiders estimated by sample- and coverage-based rarefaction and extrapolation curves. The total species richness was high in the upland fields at the total study sites, whereas the average species richness per study site was high in the paddy fields. We confirmed that the diversity enhancement of spiders was influenced by the structural complexity of habitat at field-scale, and crop diversity at broader scale.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.456-456
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• 2021

하상 변화는 유량이나 유사의 흐름에 따라 침식, 운반, 퇴적되어 변화하며, 하상변동에 의한 결과는 하천의 형태 (직렬,복렬, 곡렬 등)나 서식처의 구조 (여울과 소, 웅덩이, 습지 등) 형성 로 나타난다. 이어서 서식처 구조의 다양성은 생물다양성에 긍정적인 영향을 미친다. 본 연구에서는 수리 (유량이나 유사량)-지형(서식처 구조)-생태 (생물다양성)을 연계하여 관리하기 위한 생태적인 하천관리 프레임을 제시하기 위하여, 지형과 생물상의 관계를 우선 파악하고자 한다. 국내 하천은 수생태 건강성 평가 중 서식 및 수변환경 지수(HRI, Habitat and Riparian Index)를 활용하여 하천의 형상 및 자연성을 평가한다. 해당 지수는 하천의 자연성을 판단할 수 있으나 유량이나 유사량 등과 같이 수리적 조건과 연계하여 하천환경 변화를 예측하기 어렵기 때문에, 본 연구에서는 하천의 자연성을 판단하는 지형변수들을 제안하고, 생물상과 상관관계를 분석한다. 수질 변화가 급격하지 않는(년간 변화폭이 일정한) 금강 유역의 지천 (갑천, 미호천, 논산천, 유구천 등) 중 생태계 건강성 평가 지수가 산정되어 있는 지점을 기준으로 상·하류 약 5 km 구간들을 대상으로 한다. 지형 변수로는 (항공사진을 이용한)사주 비율(사주면적/제방 내 홍수터 면적), 사주 식생비율(식생면적/사주면적)과 사주 변동량(연간 사주 이동량), 서식처 구조의 다양성(여울, 소, 웅덩이 등), 기존의 서식 및 수변환경 지수 등을 활용하고, 생물 변수로는 저서동물지수(BMI, Benthic Macroinvertebrate Index), 저서동물의 우점도, 어류생물지수(FAI, Fish Assessment Index), 어류생물지수에 활용하는 국내종의 총 종수, 여울성 저서종수, 민감종수 등을 활용한다.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.341-348
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• 2002

Correlations among the island area, distance to mainland, latitude, longitude, human impacts, diversity and composition of vascular plants were investigated by analyzing data on 261 islands(10.3% of total number of islands in Korea) selected from the annual reports for 'the natural evironment survey of the uninhabited islands in Korea' published by 'Ministry of Environment' during three years from 1999. The area of surveyed 261 islands ranged 1,100 to 961,000㎡(average of 75,000㎡), and the distance to mainland ranged 0.15 to 51.5km (average of 14.9km). Total number of plant species recorded in those islands was 1,109 species throughout 30 families, and mean mumber of plant species of each island was 98.7 species. Native species were 1,003 species (90.4%), and exotic species were 106 species(9.6%). The families with the largest number of species was the Compositae with 114 species, and followed in the order of Gramineae(90), Leguminosae(54), and Rosaceae(53). The result of multi-dimensional scaling analysis based on the plant species composition showed that 261 islands were distinctly divided into two groups, western sea group(131 islands) and southern sea group(130 islands). The islands of western sea group(average area of 93,000㎡) had greatly larger area than them of southern sea group(average area of 57,000㎡), but the average number of species (average species of 192) per island were less than in southern sea group (average species of 233). And, the partitioning into two groups was responsible for the species restricted to southern than to western sea group. Therefore, this results suggest that the distribution pattern and the composition of plant species could be also affected by the latitude of the island. When the species-area model was applied to total island and plant species, these results indicate that the island area was the most significant predictor of plant species diversity, and the distance to mainland and the human impacts were also shown to be significant predictors of plant species richness. But when applied to both groups of islands by the stepwise selection method, the result showed that islands of southern sea group were greatly affected by the factors such as human impacts, distance to mainland and longitude than western sea group. For the purpose of conservation of natural ecosystem on the uninhabited islands in Korea, we will also examine how the human impacts and the invasion of exotic plant species will disturb the native species diversity.

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.197-201
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• 1996

A mixed forest community of Abies holophylla and broad-leaved trees in Odaesan National Park was studied to determine the adequate number of plots of shrub stratum for investigating forest community structure. Thirty 5m*5m plots were set up in the shrub stratum, and species-area curve and performance curve were made out. The minimum number of plots where a given percentage increase in number of plots produce in number of plots produced less than the same percentage increase in number of species was six. The minimum number of plots where a given percentage increase in number of plots produced less than the half of the percentage increase in number of plots was eleven. The minimum number of plots where the dominant species was distinguished from the subdominant species was five. The minimum numver of plots where the first subdominant species was distinguished from other subdominant species was ten. The diffrence of species diversity(H') between five or more plots and total thirty plots was less than 0.05. Similarity index was more than 70% between five or more plots and total thirty plots, and more than 80% between ten or more plots and total thirty plots. The conclusion is that the adequate number of 5m*5m plots for the shrub stratum was about 5 in general case and about 10 in case of requiring more accuracy.

• Korean Journal of Environment and Ecology
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• v.8 no.2
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• pp.150-153
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• 1995

A Pinus densiflora forest in Chuwangsan was studied to determine the adequate plot area of shrub stratum for investigating forest community structure. Nineteen nested plots were set up in the studied forest, and species-area curve and performance curve were established. According to species-area curve, the minimum plot area where a given percentage increase in plot area produced less than the same percentage increase in number of species was 900$m^2$. The minimum plot area where a given percentage increase in plot area produced less than the half of the percent-age increase in number of species was 1,500$m^2$. According to performance curve of the importance values of the major species, the minimum plot area where the importance value of the major species was distinguished from each other was 1,400$m^2$. According to performance curve of species diversity, the minimum plot area was 750-1,500$m^2$. Similarity indices between plot area above 900$m^2$ and total plot area were more than 90% and similarity indices between plot area above 625$m^2$ and total plot area were more than 85%. It may be given as a conclusion that minimum plot area was about 1,500$m^2$ in case of requiring more accuracy.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.10-22
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• 1992

Oribatid mites communities at plantations of the Korean white pine (Pinus koraiensis) were investigated for the composition and distribution at the Sudong area, Namyangju-gun, Kyung-gido, Korea. Oribatid mites collected were classified into 38 families, 64 genera, and 109 species. Among them the eurysphere, stenosphere, and sporosphere species were 35, 49, and 25 species, respectively. The species diversity of oribatid mites increased at sites from 3 years after to 5 years after transplanting and then decreased by afforested years. The dominant species of oribated mites at the surveyed areas were 6 species including Ceratozetes japonicus. Number of dominent species and recessive species decreased by afforested years. However, influential species increased. According to the MGP analysis I, type G was found in all sites. The eurysphere and the sporosphere species were type G. The stenosphere species were type P at an earlier planting stage, type G at a middle planting stage, type M at a latter planting stage. The semieurysphere species were type M. According to the MGP analysis II, site 1, 2, and 4 were type G, but site 3, 5, and 6 were type P.

• Korean Journal of Ecology and Environment
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• v.36 no.1 s.102
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• pp.74-82
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• 2003

This study was carried out to understand how the bird community would change in a stream ecosystem after implementation of close-to-nature river improvement techniques conducted on the Gwacheon, Seocho and Hakyeul reaches in the Yangiae Stream, 'Seoul. At the Gwacheon reach, the number of species and individuals tended to decline. However, at the Seocho reach, the number of species was increased while the number of individuals appeared to be not changed greatly. Especially, density of Dabbling Ducks were rapidly increased. At the Hakyeul reach was both the number of species and the number of individuals were increased. Density of Herons and Dabbling Ducks rose, while density of Wagtails was decreased suddenly. Except the Gwacheon reach, the survey areas were gradually improved in species richness and density after the construction of river improvement. We suggested that the naturally-formed meandering (channel) bar, restoration of riparian vegetation and artificial ponds were helpful for birds habitation, however bicycle path constructed in flood plain was negative.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.5
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• pp.730-743
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• 1997

Community structure and distribution patterns of benthic polychaetes were studied in Aug. 1983 and Feb. 1984 in Kwangyang Bay, Korea. During the study period, the large-scale reclamation and dredging operations were taking place. Polychaetes were composed of 76 species with a mean density of $342\;ind.{\cdot}m^{-2}$ during the summer 1983 and 77 species with a mean density of $437\;ind.{\cdot}m^{-2}$ during the winter 1984. Community structure indices were applied to the seasonal data. The stations influenced by the Seomjin river are characterized by a low species number and low diversity, while the stations located in channel regions represent high species richness and highdiversity. The inner bay stations showed the intermediate level in terms of species richness and diversity. On the basis of taxa composition and abundance in summer, the cluster analysis indicated that the study area was divided into live regions. The main factors that govern the polychaete distributions appeared to be the fresh water run-off and bottom sediment composition. However, a slight difference was observed in winter community, and changes in composition of the dominant species were found from Lagis bocki and Chone teres to Glycinde gurjanovae and Heteromastus filiformis. As a result, the broad scale reclamation and dredging activities may have played a role in changes of the polychaete community structure and the dominant species composition in Kwangyang Bay.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.3
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• pp.180-189
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• 2001

This study was conducted to investigate the macrobenthic community in Ulsan Bay and Onsan Bay, in November of 1997. The density of benthic animals was 535 md./m2, and the number of species was 117. Polychaeta was the most dominant faunal group, comprising a total of 63 species, and its density was 380 md./m2 The most dominant benthic macrofauna was Cirratulrus cirratulas (2.7%), and followed by Tharyx sp. (16.6%), Ruditapes philippinarum (16.1%), Lumbrineris longifolia (10.3%) and so on. The dominant species occupied their distinct unique distribution area. Tharyx sp., R. philippinarum and Grandidierella sp.1 occurred mainly in Ulsan Bay, L. longifolia and Euchone sp. in Onsan Bay, and C. cirratulas and Cirriforimia tentaculata in both bays. By cluster analysis, study area was divided into 4 station groups: Northern Ulsan Bay (Al), the middle area of Ulsan Bay (Bl), offsea area between Ulsan Bay and Onsan Bay (Bll), and Onsan Bay (C). Northern Ulsan Bay was characterized by low species number and high density. The dominant species were C. cirratulas R. philippinarum and Tharyx sp. The middle area of Ulsan Bay was by low species number and density, and its characteristic species was Grandidierella sp.1. The offsea area between Ulsan and Onsan Bay was by high species number and low density. Onsan Bay was by high species number and high density, and its important species were L. longifolia and Euchone sp.

• Korean Journal of Environment and Ecology
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• v.7 no.2
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• pp.187-191
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• 1994

A mixed forest community in Tokyusan was studied to determine the adequate plot area of tree stratum for investigating forest community structure. Nineteen nested plots were set up in the studied forest community, and species-area curve and performance curve were established. According to species-area curve, the minimum plot area where a given percentage increase in plot area produced less than the same percentage increase in number of species was 500$m^2$. The minimum plot area where a given percentage increase in plot area produced less than the half of the percentage increase in number of species was 1,000$m^2$. According to performance curve of the importance values of the major species, the minimum plot area where the importance value of the major species was distinguished from each other was 900$m^2$, and the minimum plot area was 500$m^2$ except for a big tree of Pinus densiflora distributed unexpectedly. According to performance curve of species diversity, the minimum plot area was 400$m^2$. Similarity indices between plot area above 900$m^2$ and total plot area were more than 90% and similarity indices between plot area above 400$m^2$ and total plot area were more than 85%. It may be as a conclusion that minimum plot area was generally about 500$m^2$ and in case of requiring more accuracy, minimum plot area was about 1,000$m^2$.