• Journal of Korean Society of Rural Planning
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• v.15 no.2
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• pp.81-96
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• 2009

This study has found out the status of the environment ecology(topography structure. land-use, flora, plant community structure, wildbird) in 10 uninhabited islands(i.e. Kei island, Hadon island, Sangdon island, Daewa island, Hwanggang island, Naebi island, Oebi island, Prickly castor-oil tree island, Tongin island, Yuk island), Namhae-gun, Gyeongsangnam-do. Moreover, It has suggested ways of improving the environment ecology status by classifying the type of environment ecology about the degree of use and damage that based on the results of environment ecology survey. According to the results of topography structure survey, the survey site altitude was ranged within 1m$\sim$25m, otherwise, the radient was classified the rock area(.i.e. slope of less than $5^{\circ}$ the dead level) and the slope area where is steep slope. Moreover, there was showed evenly a variety of aspect. Land-use were divided the field(Kei island), dry native grasslands(Hadon island), naturalized grasslands(Sangdon island), Pinus thunbergii community(Dacwa island, Hwanggang island, Naebi island, Yuk island), the rock area(Oebi island, Prickly castor-oil tree island, Tongin island). As the results of flora survey, the number of plant species were 30$\sim$115 species and the naturalized species were found 2$\sim$12 species in each site. The results of plant community structure analysis, The dominant species were Pinus thunbergii and Pinus densiflora were in upper tree layer, furthermore, it were Pinus thunbergii, Eurya japonica, Prunus sargentii, Celtis sinensis, Morus bombycis, ect. in cannopy tree layer. In shrub layer, the dominant species were Rosa multiflora, Rubus crataegifolius, Parthenocissus tricuspidata, etc. The status of wildbird bird, had been found 42 species 938 individuals, especially, there were Bubo bubo kiautschensis(natural monument No. 324) and Haematopus ostralegus osculans(natural monument No. 326). According to these synthetic results, we are able to classify the 5 types of environment ecology such as the natural coast forest that composed of Pinus thunbergii and Pinus densiflora(Daewa island, Hwanggang island, Naebi island, Oebi island, Tongin island, Yuk island), the field in vegetation area(Kei island), vegetation succession area of fallow field type(Hadon island), vegetation damage area by the forest fire and disturbance elements(Prickly castor-oil tree island), dominant naturalized species grassland by grazing cattle(Sangdon island).

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.312-322
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• 2010

In Korea, Torreya nucifera (L.) Siebold & Zuccarini is widely distributed in the warm temperate zone of South coastal area and Jeju island, mainly as preserved forest in the vicinity of the Buddhist temple and Confucian temple. The objective of this study is in order to develop the conservation method and comprehension of vegetation community by current vegetation structure analysis of Torreya nucifera stand. As the results, the number of surveyed species in Torreya nucifera stand were total 148 species with 28 species of tree layer, 38 species of subtree layer, and 82 species of shrub layer. The appearance of the common species were Ligustrum obtusifolium Siebold & Zucc., Hedera rhombea Bean, and Trachelospermum asiaticum Nakai var. asiaticum. All the story of the surveyed region, Torreya nucifera maintained the current dominant species, but the subtree layer and shrub layer was decreased dominant rate because of the development of the crown of tree layer and biased growth of the subtree layer. Most of the tree layer and subtree layer in Torreya nucifera stands are composed of the sprout forest. Therefore, these results suggest that in order to maintain the healthy stand it is demanded for the application of selection thinning method for reducing crown competition in Torreya nucifera forests.

• Korean Journal of Ichthyology
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• v.20 no.1
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• pp.28-35
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• 2008

Fishes by a set net in the coastal waters off Gwideuk, Jeju Island were studied to determine species composition and catch variation, 2004. The fishing period conducted by a set net in Gwideuk fishing ground were from April to December. A total of 45,473.2 kg including 21 species was caught during the survey period. Most of them consisted of fishes of 17 species and a few were cephalopods of 4 species. Dominant species were Trachurus japonicus and Siganus fuscescens, 44.3% in the total. And sub-dominant species were Sepioteuthis lessoniana, Seriola dumerili, Seriola quinqueradiata, Loligo bleekeri, Seriola lalandi accounting for 54.4%. Although the number of species had a tendency to decreased from July to December, the catch by a set net was higher in summer and autumn than in spring. Such catch variations were closely related to recruitment of dominant species and also the seasonal variation of fishing ground temperature.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.437-448
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• 2013

The ichthyofauna and fish community were studied in Daecheon Stream from April to October 2012. During the survey period a total of 42 species belonging to 13 families were collected. Dominant species by number was Zacco platypus(32.3%) and Tridentiger brevispinis(12.8%). In biomass, the dominant species was Z. platypus(27.7%) and Chelon haematocheilus(11.9%). Also, eight Korean endemic fish species and one endangered species (Rhodeus pseudosericeus) were collected. In addition, two exotic species(Carassius cuvieri and Micropterus salmoides) and migration fish species(Anguila japonica) were observed. Based on the length-weight relationship of Z. platypus, the b value was 3.21~3.29, and the condition factor(K) was 0.89 on average with stable condition. According to similarity analysis, fish communities in Daecheon Stream were divided into three groups; the upper reaches near a reservoir(St. 1), the middle reaches (St. 2 to 4) and the lower reaches near a weir(St. 5). Dominant species at each group were Zacco koreanus(St. 1), Z. platypus(St. 2 to 4) and T. brevispinis(St. 5). This result suggested that artificial structures such as dam and a weir have a marked effect on the distribution of fish communities in Daecheon Stream.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7761-7772
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• 2015

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Jeju Marine Ranching Area (JMRA). A total of 106 species of phytoplankton belonging to 63 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 61% and 35% of total species, respectively. The annual dominant species were Skeletonema costatum-like species(ls) in April, Torodinium teredo, Cylindrotheca closterium, Scrippsiella trochoidea in June, S. costatum - ls, Thalassionema nitzschioides, Pseudo-nitzschia pungens, Ebria tripartita in September and Corethron pennatum, Dictyocha fibura, Neoceratium teres in November. Phytoplankton cell density ranged between $0.6cells{\cdot}mL^{-1}$ in June and $64.0cells{\cdot}mL^{-1}$ in April. It fluctuated with an annual mean of $11.7cells{\cdot}mL^{-1}$ between the lowest value of $0.9cells{\cdot}mL^{-1}$ in November and the highest value of $37.0cells{\cdot}mL^{-1}$ by S. costatum -ls in April. Diversity index in September was higher than diatom blooming seasons in April. According to the phytoplankton community structure, the biological oceanographic characteristics of the JMRA was characterized by nanoplankton during a year. That is, primary production is deemed to have a higher possibility of being adjusted by a reproduction by material cycle in the ecosystems than nutrients supply from the lands.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.155-164
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• 2016

Earworm is very useful animal in soil ecosystem, however it is harmful for golf courses because they introduce many cast on turfgrass that reduces turf uniformity and play quality. However, no information has found on earthworm diversity and seasonal fluctuation in different Korean golf courses. In this study, we focused to carry out earthworm species composition and seasonal population structure in turfgrass of golf courses. During spring and fall season survey with direct digging and tea saponin drenching sampling in 5 different golf courses, 6 species under 3 families of earthworms were collected. Earthworm species composition and density was different among the golf courses. Aporrectodea caliginosa in Lumbricidae was dominant species in Anseong and Dongrae Benest Golf Club; however Amynthas carnosus in Megascolecidae was dominant species in Anyang and Glenrose Golf Club. Ap. caliginosa was collected only aclitellum in July and Am. carnosus was collected aclitellum and clitellum in August in golf courses. Seasonal population of earthworm was different depending on earthworm species (Am. hupeiensis was the highest in August and Ap. caliginosa was in April) however small number of collected earthworm species were not dominant trend in golf courses.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.287-296
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• 2021

This study was conducted to investigate the species composition collected by fyke net and characteristics of the Erythroculter erythropterus population in the Asan Lake and Chungju Lake from June to September, 2021. The collected fish in Asan lake were identified as 4,977 individuals of 13 species from a total of six families and in Chungju lake were identified as 2,436 individuals of 18 species from a total of eight families. The dominant species in Asan lake, both the individuals and biomass were E. erythropterus with 4,470 (89.8%) and 498,424g (84.5%). The dominant species in Chungju lake, both the individuals and biomass were E. erythropterus with 1,327 (54.5%) and 301,818 g (77.5%). The results of the community analysis showed that a dominant index value of Asan lake was 0.93, higher than 0.71 of Chungju lake, and a diversity, evenness, and richness index value of Chungju lake were higher than of Asan lake. The frequency distribution of the total length analysis of the E. erythropterus population showed the appearance rate of 1~2 year olds was high in Asan lake, and the appearance rate of more than 2 years old were high in Chungju lake. The length-weight analysis of E. erythropterus in Asan Lake and Chungju Lake showed a regression coefficient b of 3.06 and 3.04, a condition factor (K) of 0.000128 and 0.000051 with a positive slope. This study could be served as baseline data for assessing habitat characteristics based on the species composition of fishes, and identifying health conditions of E. erythropterus in Asan Lake and Chungju Lake, artificial lakes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.1
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• pp.39-48
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• 2022

Using environmental DNA (eDNA) in the fisheries and oceanography fields, research on the diversity of biological species, the presence or absence of specific species and quantitative evaluation of species has considerably been performed. Up to date, no study on eDNA has been tried in the area of fisheries acoustics in Korea. In this study, the biomass of a dominant species in the northwestern waters of Jeju Island was examined using 1) the catch ratio of the species from trawl survey results and 2) the ranking ratio of the species from the eDNA results. The dominant species was Zoarces gillii, and its trawl catch ratio was 68.2% and its eDNA ratio was 81.3%. The Zoarces gillii biomass from the two methods was 7199.4 tons (trawl) and 8584.6 tons (eDNA), respectively. The mean and standard deviation of the acoustic backscattering strength values (120 kHz) from the entire survey area were 135.5 and 157.7 m²/nm², respectively. The strongest echo signal occurred at latitude 34° and longitude 126°15' (northwest of Jeju Island). High echo signals were observed in a specific oceanographic feature (salinity range of 32-33 psu and the water temperature range of 19-20℃). This study was a pilot study on evaluating quantitatively aquatic resources by applying the eDNA technique into acoustic-trawl survey method. Points to be considered for high-quality quantitative estimation using the eDNA to fisheries acosutics were discussed.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.758-769
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• 2012

This study is aimed at analyzing the structural characteristics of vegetation in the Sangwonsa(Temple) valley, Yongmunsan(Mt.), and to collect basic data for research of large mountains which are located in the temperate, central region. The research on the entire vegetation struc trees are distributed over a wide area, accounting for 75.0% of theture of Sangwonsa(Temple) valley observed that oak total vegetation in the area. We examined 17 plots(unit area: $400m^2$) in the deciduous forest, dividing the trees into 5 community types based on the average important value. The 5 community types are as follows: A mixed dominant group of Carpinus laxiflora and Quercus serrata, a mixed dominant group of Quercus serrata and Quercus variabilis, a mixed dominant group of Quercus mongolica and Quercus serrata, a dominant group of Quercus serrata, a dominant group of Acer pictum supsp. mono. It is expected that the oak trees competing with Carpinus laxiflora and Acer pictum supsp. mono would flourish in a deciduous forest. The Shannon's species diversity index(H') was 0.3708~1.3083.