• Title/Summary/Keyword: Number of individuals

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Impact of Topsoil Stockpiling Methods on the Viability of Seed Banks

  • Yi, Myung-Hoon
    • Journal of Environmental Science International
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    • v.27 no.10
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    • pp.907-923
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    • 2018
  • The aim of this study was to determine the appropriate stockpiling methods for revegetation by comparing the germination status of seed banks before and after preservation for 2 years. Soil temperature in stockpiled topsoil was higher in open treatment and at 1.5 m, whereas soil water content was maintained at lower levels (14.06-19.08%), than those in the control group. The seed banks in stockpiled topsoil had 48 species and 1,559 individuals, among which perennials showed the highest number in terms of life forms, whereas Compositae and Gramineae were dominant in terms of families. Based on seed bank type, persistent seed banks had the highest number of species, while transient seed banks had the highest number of individuals. By stockpiling period, the number of species in the seed bank started to increase after 24 months, while the number of individuals began increasing after 12 months and exceeded that of the control group after 24 months. Regarding the treatment of stockpiling methods, the number of species and individuals in open treatment were closer to those of the control group. When analyzed by height, the number of species and individuals were higher at 0 m, but still lower than those of the control group. A multivariate analysis of variance (MANOVA ) showed that the optimal combination was obtained in open treatment and the number of individuals increased with the lengthening of the stockpiling period.

A Study on the Status of Waterbirds by Taxon and Seasonal Arrival in the South-West Coast Islands

  • Hyun-Young Park;Sun-Jib Kim
    • International Journal of Advanced Culture Technology
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    • v.11 no.1
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    • pp.349-355
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    • 2023
  • This study surveyed the island located in Sinan-gun and Wando-gun four times, once per season from September 2020 to November 2021 in order to understand the distribution of waterbirds on the island of the southwest coast. As a result of the investigation, a total of waterbirds of 7 orders, 12 families of 50 species, and 3,680 individuals were identified. By taxon, the largest number of species were identified as 11 species of waders, and the number of ducks was the largest with 2,035 individuals. In Bigeum-do Island, where forests are distributed less, the proportion of farmland is large, and tidal flats are widely distributed, the largest number of species and individuals of herons and waders were identified. Ducks and gulls have also been identified in large numbers of individuals in Bigeum-do Island. Most of them are forests and farmland, and the largest number of species and individuals of ducks have been identified in Pyeongil-do Island, where the coast is deep. In addition, Nodae-do Island, Sobyeongpung-do, and Daebyeongpung-do Island with monotonous habitats have been identified with fewer species and individuals. As a result, We learned that various types of waterbirds lived in islands with various habitats, and that the preferred habitat was different depending on the characteristics of the taxon group. By season, the largest number of species was identified as 35 in autumn, and the largest number of individuals was identified as 1,681 in winter. Although most of the seasonally identified waterbirds were winter birds, the largest number of species were identified in autumn, and most of the confirmed waterbird migration were identified in the autumn, indicating that waterbirds used the west-south coast islands as an intermediate stopover while traveling.

Seasonal Fluctuation in Abundance and Species Composition of Fish Collected by a Small Otter Trawl in Coastal Waters off Yeosu (여수연안에서 소형기선저인망에 어획된 어류의 종조성 및 계절변동)

  • LEE, Sung-Hoon;YU, Tae-Sik;LEE, Dae-Gyu;HWANG, Tae-Yong;HAN, Kyeong-Ho
    • Korean Journal of Ichthyology
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    • v.31 no.3
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    • pp.172-177
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    • 2019
  • Seasonal fluctuation in abundance and species composition of fish in coastal waters off Dolsan island were investigated using seasonal samples collected by an otter trawl in 2012. A total of 4,848 fishes were sampled and classified into 52 species, 29 families, and 7 orders. The dominant species was Leiognathus nuchalis (2,786 individuals, 57.5%), Amblychaeturichthys hexanema (164 individuals, 3.4%), and Ilisha elongata (141 individuals, 2.9%). The highest number of individuals was found in summer (2,174 individuals), while the lowest number of individuals was found in winter (321 individuals). The diversity index was the highest in spring (H'=3.06) and the lowest in summer and fall (H'=1.77). Temperature was the principal factor to determine the collected number of individuals (r=0.94) and the number of species (r=0.83).

Study of ecological investigation and disease occuring possibility natural monument wintering-birds in Gangwon-do (강원도에 집단 도래하는 천연기념물 겨울철새의 생태조사 및 질병발생 가능성에 관한 연구)

  • Kim, Jong-Taek;Kim, Hyeon-Cheol;Pak, In-Chul;Cheong, Ki-Soo;Jang, Hwan
    • Korean Journal of Veterinary Service
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    • v.30 no.3
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    • pp.445-457
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    • 2007
  • This report studied the individual number, their favorite habitat, and change pattern of family and group number in Cheolwon Basin, starting in the early Oct. 2004 until late March. 2005 to investigate the ecological features of the Red-crowned Crane and the White-naped Crane. The Cranes arrived Cheolwon Basin in mid-October until next mid-March, and passed the winter in mid-November until next late-February The most visiting number amounted to 550 individuals and, that period was the most frosting mid-January to mid-February. The White-naped Crane visited Cheolwon Basin in autumn, the early winter and spring. Approximately, the wintering-number is 550 individuals, also, the mid-March was the peak-period of arrival and, the number amounted to 2,162 individuals. The cranes chose the farming area around mountains as their wintering habitat and were less likely to choose the farming area around lake as habitat. The Red-crowned Crane and the White-naped Crane showed the different periodical pattern in familial and group numbers. In case of the crane, the familial pattern was stable, but varied in grouping number, and this pattern was similar to the variation of overall individual number. And, also, the most grouping number was shown in the most freezing period of wintering period. The White-naped Crane showed the similar pattern of the Red-crowned Crane that is, stable family number and varying group number, this pattern affected the total number of entire individuals. Grouping number increased in migration period. Parasite infection rate is G japonensis 35.0%, G vipio 38.7%.

Seasonal Variation in Species Composition of Fishes Collected by a Three Sided Fyke Net from Sannam Reservoir in Changwon-si, Gyeongsangnam-do (경상남도 창원시 산남저수지에서 삼각망으로 채집된 어류의 계절별 종조성)

  • Kim, Kyung Ryul;Park, Jong Hyeok;Park, Jong Sick;Choi, Mun Seong;Lee, Dae Hyun;Baeck, Gun Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.6
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    • pp.745-751
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    • 2019
  • Seasonal variation in species composition of fishes in the Sannam reservoir in Changwon, Korea was determined using samples collected by a three-sided fyke net in 2018. During the study period, we collected 2,181 individuals of 9 species, with a total weight of 111,552.2 g. The dominant species were Lepomis macrochirus, Carassius carassius, Erythroculter erythropterus, and Cyprinus carpio. These species accounted for 96.1% of the total number of individuals. The number of fish species, number of individuals, biomass and species diversity indices fluctuated with the seasons. The peak number of fish species occurred in May and August, the biomass of fishes was highest in May. Whereas the number of individuals was highest in February.

Seasonal and Interannual Variation in Species Composition and Abundance of Decapod Assemblages Collected using Pots in the Coastal Waters off Gori, Korea (고리 주변해역 통발에서 채집된 십각류 종조성의 계절변동과 연간변동)

  • Huh, Sung-Hoi;Park, Joo-Myun;Jeong, Dal-Sang;Baeck, Gun-Wook
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.5
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    • pp.503-509
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    • 2010
  • The seasonal and interannual variation in the species composition and abundance of the decapod assemblage (shrimps, crabs, and hermit crabs) collected using pots in the coastal waters off Gori were studied between 2005 and 2008. During the study period, 49 decapod species belonging to 19 families were collected. The dominant species were Crangon hakodatei, Pandalus gracilis, Carcinoplax longimana, Charybdis bimaculata, Carcinoplax vestita, Diogenes edwardsii, and Dardanus arrosor. These seven species accounted for 95.46% of the total number of individuals collected. The number of species, number of individuals, biomass, and species diversity indices fluctuated with the seasons. The peak number and biomass of individuals occurred in July 2006. The number and biomass of individuals were higher in summer and lower in winter, and the diversity indices were lower in summer than in the other seasons. The abundance of dominant species showed some seasonal and interannual change; in particular, those of C. hakodatei and P. gracilis corresponded with the bottom water temperature.

Fish Assemblages Collected by Bottom Trammel Gill Net around Gampo in the East Sea of Korea (동해 감포 주변해역에서 저층삼중자망에 어획된 어류 군집)

  • Kang, Pil Jun;Kim, Chong Kwan;Hwang, Sun Wan
    • Korean Journal of Environmental Biology
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    • v.33 no.1
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    • pp.27-33
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    • 2015
  • Fish assemblages in the coastal waters off Gampo in the East Sea of Korea were analyzed using the samples of fishes collected with bottom trammel gill nets June, September, and December 2005 and, March 2006. During the study period, a total of 32 fish species, 695 individuals, and 180,012.0 g representing 21 families were collected. The fish assemblages predominantly consisted of Ditrema temminckii, which accounted for 52.4% of the number of individuals and 40.4% in the biomass. The next major specimens were Hexagrammos otakii, Sebastes schlegelii, Stephanolepis cirrhifer, Sebastes taczanowskii, Halichoeres poecilopterus. These six fishes accounted 77.6% of total number of individuals and 77.5% of total biomass. The number of fish species, the number of individuals and biomass were fluctuated with month. The number of species was highest in June 2005 and lowest in March 2006. The number of individuals and biomass was highest in September 2005 and lowest in June 2005.

Monthly fluctuation in abundance and species composition of fish collected by a shrimp beam trawl in coastal waters off Oenaro Island, Goheung (고흥 나로도 연안에서 새우조망에 어획된 어류의 종조성 및 월변동)

  • YU, Tae-Sik;LEE, Seong-Hoon;JI, Hyun-Il;HAN, Kyeong-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.56 no.1
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    • pp.18-25
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    • 2020
  • Monthly fluctuation in abundance and species composition of fish in coastal waters off Oenaro island, Goheung were investigated using seasonal samples collected by a shrimp beam trawl in 2018. A total of 5,981 fishes were sampled and classified into 48 species, 32 families, and 9 orders. The dominant species was Engraulis japonicus (993 individuals, 16.60%), Amblychaeturichthys hexanema (844 individuals, 14.11%), and Thryssa kammalensis (674 individuals, 11.27%). The highest number of individuals was found in August (958 individuals), while the lowest number of individuals was found in January (136 individuals). The diversity index was the highest in November (H' = 2.37) and the lowest in January (H' = 1.77).

A Study on the Numerical Modeling of the Fish Behabior to the Model Net - Parameter Estimation in Numerical Model of Fish Behavior - (모형그물에 대한 어군행동의 수직 모델링에 관한 연구 - 어군행동을 나타내는 수치 모델의 파라메터 추정 -)

  • Lee, Byoung-Gee;Lee, Dae-Jae;Chang, Ho-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.307-325
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    • 1995
  • IN order to gain a fundamental data for forecast or control of fish behavior and evaluated the feasibility of an application of the modeling technique to a field, in this paper a numerical model for describing the behavior of fishes in a water tank was presented. The parameters of the model were estimated by using the time-series data on the three-dimensional position of fishes and by applying the least squares algorithm. The estimated parameters were standardized to examine the variation of parameters according to the number of individuals and flow speed that the mean values of parameters were to be zero and their variances were to be one. The results obtained can be summarized as follows: (1) The standardized parameter $a^*$of propulsive force decreased according to increased the number of individuals and the flow speed. (2) The standardized parameter ${k_b}^*$ of interactive force increased according to increased the number of individuals, but decreased according to the flow speed. (3) The standardized parameter ${k_c}^*$ of schooling force increased according to │increased the number of individuals and the flow speed. (4) The standardized parameter │${k_w}^{+*}$│ of repulsive force against wall or bottom increased according to increased the number of individuals, but decreased according to the flow speed. (5) The standardized parameter │${k_w}^{-*}$│ of attractive force against wall or bottom was generally constant according to increased the number of individuals, but increased according to the flow speed. (6) The standardized parameter $\upsilon$ super(*) of damping force increased according to increased the number of individuals, but decreased according to the flow speed.

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Constructing the Functional Models of Wetland Biotopes - Focused on the Bangdong Wetland - (습지형 비오톱 기능모델 구성 - 방동소택지를 사례로 -)

  • Koo, Bon-Hak;Kim, Kwi-Gon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.2 no.2
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    • pp.1-8
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    • 1999
  • This study is one of the processes to build the artificial wetlands in the urban area. The purpose of this study was to survey biotic or physical environments, and to review modelling techniques to find out the ecological structure and function. Case study site was the Bangdong wetland in the north west side of Taejon metropolitan city. The number of species of insects decreased during monitoring. But the number of individuals of insects decreased abruptly after increasing. And then biodiversity index dropped and dominance index increased. So the structure of biotopes was affected by weather conditions. And in the restricted area such as urban area, the changes of insects were affected sensitively by not physical but environmental changes. As for birds, the number of species was reduced a little, but the number of individuals increased abruptly. And dominance index increased slowly. The changes of water depth and increase of temperature affected the habitat condition of vegetations and birds, so the dominance index of specific species increased. In urban areas it is necessary to continue management for water environmental changes, such as the depth and area of water. The number of species of fishes was reduced a little, but the number of individuals increased abruptly. And dominance index and biodiversity index decreased slowly. But the water environments was so changeable that it is difficult to explain current status as some specific trends. The number of species of reptiles and amphibians changed little, but the number of individuals increased abruptly. And dominance and biodiversity were not changed. The changes of water depth and temperature affected the habitat of every species the environmental changes affected.

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