• Title/Summary/Keyword: Composition of species

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Frog Habitats in the Rural landscape Known as Yato "dell with paddy fields"in suburban Area in South Kanto Plain

  • Osawa, Satoshi;Katsuno, Takehiko
    • Journal of the Korean Institute of Landscape Architecture International Edition
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    • no.1
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    • pp.75-83
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    • 2001
  • Residents of urban area like to be near rural animals during their daily life, so it is important conserve the suburban Yato landscape in Japan. This study targets the species of frogs that are commonly found in Yato paddies. It is necessary to various frogs inhabiting in Yato, because frogs are popular among Japanese, who as children enjoy capturing tadpoles and frogs. Its purpose is to clarify how that composition of frog species changes when the functionality of a frog habitat is diminished by urbanization. The survey, conducted in the Eastern Kanagawa area in central Japan, determined the distribution of each species of frog in grid cells measuring 0.5-$\textrm{km}^2$. It hsows wide distributing species (Hyla japonica; they always inhabit in all paddies), the middle range distributing species (Rhacophorus schlegelii and Rana porosa p.), the limited range distributing species (R. rugosa; they are most critical species, sine they are recognized only two cells), and so on. Correspondence analysis based on the frog species composition in each cell was performed to ascertain the adaptability of each species to various paddy field conditions. The results allowed us to classify cells into four groups according to the composition of the inhabiting species. And we recognized that the process by which frogs disappear occurs in reaction to either of two patterns of change. As paddy fields are improved by farmland consolidation, R. rugosa, R. ornativentris, R. japonica, and Bufo. japonica f. decline rapidly. In plateau areas, a smore andmore paddies are converted into strong, well-drained fields, only H. japonica and R. porosa p. remain. But in hilly areasd, the species composition becomes only H. japonica and R. schlegelii. Finally, we discuss the concept of ecological urban design in the context of the conservation of frog species in Yato paddies.

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Taxonomical Study by the Major Fatty Acid of Genus Rhus(anacardiaceae) in Korean (주요 지방산에 의한 한국산 옻나무屬의 분류학적 연구)

  • 정재민
    • Korean Journal of Plant Resources
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    • v.11 no.2
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    • pp.202-209
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    • 1998
  • Through total fatty acid analysis by the Gas chromatography, 17 different fatty acids were identified from the sap extracted from bark of Korean Rhus(Anacardiaceae), six species. Linoleic acid(C18 :2) and oleic acid(C18 : 1) were identified as major fatty acids for the species investigated, but except in R. chinensis.In the fatty acid composition for the species, one or two specific-fatty acid was detected, and its could be utilized as a useful taxonomic character.The result of cluster analysis by the 22 reliable characters in the fatty acid composition suggested first group was R.trichocarpa and R. succedanea, the second group, R.verniciflua, R.ambgua and R. sylvestris, but R.chinensis was a greatly independent species. The possible chemotaxonomic application of the fatty acid composition of bark in the genus Rhus was discussed.

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Species composition and abundance of larval fishes in the coastal waters off Gori, Korea in 2006 (2006년 고리 주변해역에 출현하는 자치어의 종조성과 출현양상)

  • Baeck, Gun Wook;Park, Joo Myun;Nam, Ki Moon;Huh, Sung-Hoi
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.3
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    • pp.284-292
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    • 2012
  • Species composition and abundance of larval fishes in the coastal waters off Gori in the southeastern Korea were investigated from January to December in 2006. During the study period, 32 larvae species belonging to 20 families were collected. The dominant species were Engraulis japonicius, Hexagrammos agrammus, Sillago japonicus, Acropoma japonicum, Apogon lineatus, and Konosirus punctatus. These six species accounted for 87.0% of the total number of individuals collected. The number of species, number of individuals, and species diversity indices fluctuated by season. The peak numbers of species and individuals occurred in July and May, respectively. Correlation analysis showed that monthly variations in water temperature and salinity could act as an indicators of seasonal variations in the larval fish community structure and abundance of the dominant species; in particular, the abundance of S. japonicus, A. japonicum, and A. lineatus were significantly corrected with the water temperature.

Ecological Studies on the Halophyto Communities at Western and Southern Coasts in Korea(IV)-The Halophyte Communities at the Different Salt Marsh Habitats (해변염생식물군집에 대한 생태학적 연구 (IV) - 입지조건이 다른 염생식물군집)

  • Kim, Cheol Soo;Tae Gon Song
    • The Korean Journal of Ecology
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    • v.6 no.3
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    • pp.167-176
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    • 1983
  • Species composition, life form, biomass and soil properties of the halophyte communities were investigated from July to September, 1982. At the reclaimed land of Sanho-ri, sand dune of Jido, salt marsh of Suncheon Bay, and Somjin River estuary of Baealdo, species numbers were 26, 14, 13 and 7, dominant species were Salicornia herbaceae, Carex pumila and Suaeda japonica, respectively. Species composition of the 4 investigated areas was 13 families, 25 genera and 39 species, and of them, 10 families, 21 genera and 24 species were attributed to halophytes. Out of 22 life forms, the representative for Jido was $ G-D_4-R_1-3-e.t$and those for the other sites were Th-G4-R5-e. Above ground biomass of all species for Sanho-ri, Jido, Suncheon Bay and Baealdo were 441.3, 202.0, 150.7 and 353.3 g.dw/m2 and the ratios of above ground biomass halophytes to all species were 93.5, 92.7, 90.8 and 100%, respectively. The leading dominant species formed a continuum according to the salt gradiant. The similarity between Baealo and Suncheon Bay was relatively high, and Jido was quite different from the others in species composition. Aster tripolium was stenohaline and appeared at the low salt concentration, but Suaeda maritima and Suaeda asparagoides were duryhaline and occured at the relatively high salt concentration.

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Fluctuations in abundance and species composition of fishes collected by gape net in Dolsan District of Yeosu (여수 돌산연안 낭장망에 어획된 어류의 종조성 및 계절변동)

  • KIM, Kee-Taek;HAN, Kyung-Ho;LEE, Sung-Hoon;YOUN, Byeong-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.2
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    • pp.142-151
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    • 2017
  • The fluctuation in the abundance and species composition of fish was investigated using gape net in Dolsan District of Yeosu Korea from July 2015 to April 2016. A total of 1,331 fishes were sampled and classified into 30 orders, 42 families, and 53 species. The dominant orders are Perciformes including 21 famailies and 24 species, followed by Scorpaeniformes including 7 families and 13 species, and Clueiformes including 6 families and 6 species. Among the 53 fish species collected, Engraulis japonicus was the most frequent species occupying 43.5%, followed by Argyrosomus argentatus (23.8%), and Leiognathus nuchalis (22.4%). The monthly diversity, evenness, and richness index were 1.83-2.90, 0.76-0.95 and 3.06-6.40.

Impact of parthenium weed invasion on plants and their soil seedbank in a subtropical grassland, central Nepal

  • Khatri-Chettri, Jyoti;Rokaya, Maan Bahadur;Shrestha, Bharat Babu
    • Journal of Ecology and Environment
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    • v.46 no.1
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    • pp.8-17
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    • 2022
  • Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m2. Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

Seasonal Variation in Species Composition of Demersal Fish in Yongil Bay, East Coast of Korea (영일만 저어류 종조성의 계절 변동)

  • Lee Tae Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.32 no.4
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    • pp.512-519
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    • 1999
  • Seasonal variation in species composition and abundance of demersal fish in Yongil Bay were determined by analyzing samples collected using an otter trawl from January to October 1991. Of 59 species identified, Repomucenus lunatus, Tridentiger trigonocephalus, Repomucenus heguenini, Ammodytes personatus and Sillago japonica were dominated in abundance. Number of spiecies and biomass were low in winter and high in spring and summer. Species composition did not show spatial variation but showed seasonal variation. Number of spicies, abundance in number of individuals ($630 inds./10^3\;m^2$) and in biomass ($13,131g/10^3\;m^2$), and species diversity (2.00-2.54) of fish in Yongil Bay were higher than those of the coastal waters in the Yellow Sea or in the South Sea of Korea.

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Seasonal Variation in Species Composition of Fish Collected by a Bag Net in the Geum River Estuary, Korea (개량안강망에 채집된 금강하구 어류 종조성의 계절 변동)

  • HWANG Sun-Wan;HWANG Hak-Bin;NOH Hyung-Soo;LEE Tae-Won
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.38 no.1
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    • pp.39-54
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    • 2005
  • Seasonal variation in species composition of fish in the Geum River estuary was determined using monthly samples collected with a bag net from February to December 2003. Of a total of seventy-three species collected, four groups of fishes were distinguished. Estuarine fishes such as Chelon haematocheilus and Synechogobius hasta were collected almost all the seasons and predominated in abundance during cold months. Coastal fish species such as Sardinella zunasi, Konosirus punctatus, Engraulis japonicus, Johnius grypotus and Thryssa kammalensis were dominated from late spring to autumn. Their adults entered into the estuary in spring and a large number of their juveniles were collected in summer and autumn till moving out to deeper waters for over-wintering. A few freshwater fishes were collected when the freshwater was discharged during the rainy season. Anguilla japonica elvers (diadromous fish) and Coilia nasus (amphidromous fish) were collected in spring during their upstream migration. The principal component analysis revealed that the seasonal variation in species composition of fishes was principally determined by water temperature and/or water temperature related factors.

Selection of Desirable Species and Estimation of Composition Ratio in a Natural Deciduous Forest (천연활엽수림(天然闊葉樹林)의 경영대상(經營對象) 수종(樹種) 선정(選定) 및 구성비율(構成比率) 추정(推定))

  • Yang, Hee Moon;Kang, Sung Kee;Kim, Ji Hong
    • Journal of Korean Society of Forest Science
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    • v.90 no.4
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    • pp.465-475
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    • 2001
  • Based on the community structural attributes, such as species composition, diameter and height distribution, topographic position, and species diversity in the natural deciduous forest of Mt. Gari area, this study suggested desirable species and composition ratio to achieve ecological management of forests so as to maintain forest stability and enhance economical values. The results are as follows : 1. Twenty-five tree species were growing in the study forest. Of these Quercus mongolica, Pinus densiflora, Juglans mandshurica, Quercus serrata, Cornus controversa, Acer mono, Fraxinus rhynchophylla, and Tilia mandshurica were selected for desirable species through the evaluation of dominant and dominant potential. Kalopanax pictus, considered to be highly valuable species, was also included. 2. Taking account of different species composition pattern by topographic positions, we select as desirable species of J. mandshurica, C. controversa, Q. mongolica, A. mono, T. mandshurica, and F. rhynchophylla in the valley area, Q. mongolica, Q. serrata, A. mono, T. mandshurica, F. rhynchophylla, and K. pictus in the mid-slope area, and Q. mongolica, P. densiflora, Q. serrata, and Fraxinus rhynchophylla in the ridge area. 3. Based on the estimation of species diversity index for the overstory components, the reasonable forest stability levels of the indices were estimated at 1.96, 1.68, 1.94, and 1.27 for whole forest, valley, midslope, and ridge, respectively. 4. The recommended species composition ratios in the study forest were suggested Q. mongolica to be 30%, A. mono, F. rhynchophylla, Q. serrata, and T. mandshurica to be 10%~15%, J. mandshurica, P. densiflora, and C. controversa to be 5%~10%, and K. pictus to be 5%.

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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.