• Title/Summary/Keyword: Species abundance

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Studies on the Functioanl Significance of Pollen Surface Characters (화분표면형질의 기능적 의의에 관한 연구)

  • 이상태
    • Journal of Plant Biology
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    • v.22 no.1_2
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    • pp.45-51
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    • 1979
  • From 32 angiosperm species, pollen surface characters such as sculpture pattern, roughness, oil abundance and stickiness were subjectively scored, and compared with size and weight of the grains, and pollination mechanisms. There was a linear relationship between size and weight of the grains. Animal-pollinated grains showed significantly higher roughness, oil abundance and stickiness than wind-pollinated grains. In the former, the grain size was highly correlated with roughness and oil abundance. No such relationship was found in the latter. It was suggested, therefore, that the large the animal-pollinated grains, the greater is the stickiness required, where the stickiness depends on the surface soil abundance and roughness. No functional significance of the sculpture pattern could not be detected in this study.

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Seasonal Variation in Species Composition of Fish in the Estuary of Saemangeum Waters during the Construction of a Dike in 2001-2002 (방조제 건설 중인 2001-2002년 새만금 하구역 어류 종조성의 계절 변동)

  • LEE Tae Won;MOON Hyung Tae;KIM Gwang Cheon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.3
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    • pp.298-305
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    • 2003
  • Seasonal variation in species composition of fish in the estuary of Saemangeum water in the western coast of Korea was determined using seasonal samples collected by an otter trawl from April 2001 to February 2002. Species compositions did not differ significantly among the 4 stations (p>0.05, Wilcoxon signed-rank test). The cumulative number of species and species diversity (H') approached asymptote after four 30-min trawl hauls. Therefore 30-min trawl samples from each of the four stations were pooled to represent each season. A total of 45 species 2758 individuals and 30,346.8 g of fish were collected during the study period. Of the fish collected Leiognathus nuchalis, Synechogobius hasta, Neosalanx jordani, Konosirus punctatus and Chaeturichthys stigmatias predominated in abundance accounting for $68\%$ of the total number of individuals. Seasonal variation of fish abundance showed a similar trend to those of the other western coastal waters of Korea. The resident species were collected only in spring and autumn. Number of species and biomass were highest in summer due to the catch of many migrating species. In winter catch amount was low, and only 7 species were collected.. Brackish water fishes were more abundant in the study area, and Johnius grypotus and Cynoglossus joyneri were not premominated compared to the other coastal waters. This difference in species compositions may be related to the lower salinity in this estuarine habitat than in the other western coastal waters of Korea.

Seasonal Change of Phytoplankton Dominant Species Based on Water Mass in the Coastal Areas of the East Sea (동해 연안 수괴 특성에 따른 식물플랑크톤 우점종의 계절 변동)

  • Shim, Jeong-Min;Kwon, Ki-Young;Kim, Sang-Woo;Yoon, Byong-Seon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.5
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    • pp.474-483
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    • 2015
  • In order to understand the seasonal change of phytoplankton as well as the effect of water physico-chemical parameters, we investigated 18 stations in coastal areas of the East Sea in February, May, August and November in 2009. The taxa of phytoplankton observed in this study were classified as 37 Bacillariophyceae, 22 Dinophyceae, 1 Euglenophyceae, 3 Dictyophyceae and 1 Cryptophyceae. Phytoplankton abundance ranged from $1.2{\times}10^3cells/L$ to $246.6{\times}10^3cells/L$(with a mean value of $24.8{\times}10^3cells/L$), the highest biomass was observed in May. The dominant species were Leptocylindrus danicus, Chaetoceros affinis, Pseudo-nitzschia pungens, Thalassionema nitzschioides and etc. Pearson's correlation co-efficient between phytoplankton abundance and other water parameters showed the positive relationships with pH, DO, Secchi-disk depth, and SS, the negative relationships with $SiO_2-Si$. Seasonal patterns of phytoplankton dominant species were affected by the characteristics of water masses based on T-S diagram analysis. In particular, phytoplankton distributional patterns were related with water temperature in May and salinity in August, respectively. According to the result of MDS(Multi-dimensional scaling) using the phytoplankton abundance and species composition, the spatial distribution of phytoplankton were characterized with Ganwon(Group A) and Gyeongbuk(Group B) at the coastal areas of Jukbyeon or Uljin.

Fish Distribution and Water Quality of Mountain Streams in the Jirisan National Park, Korea

  • Jang, Min-Ho;Cho, Ga-Ik;Song, Ho-Bok;Byeon, Hwa-Kun;Kim, Hyun-Woo;Joo, Gea-Jae
    • The Korean Journal of Ecology
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    • v.26 no.6
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    • pp.297-305
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    • 2003
  • Fish fauna of mountain streams in the Jirisan National Park area of S. Korea (total area: 440.45 $\textrm{km}^2$, height: 1,915 m) was investigated at 33 sites from May 1997 to September 1999. A total of 4,670 individuals of fishes were collected and classified into 30 species and 12 families. Zacco temmincki (relative abundance (RA), 63.9%) was found to be the most abundant inhabitant. Subdominant species were Pungtungia hem (RA 6.2%), Zacco platypus (RA 6.1 %) and Coreoleusiscus splendidus (RA 4.8%). Among the total species, 13 species were identified as the Korean endemic species (7 families, 17.2% of 802 individuals). Dominant Korean endemic species was C. splendidus (relative abundance endemics (RAE), 27.8%). Superiors were Coreoperca heizi (RAE 21.8%) and Liobagrus mediadiposalis (RAE 19.8%). One exotic species (Oncorhynchus mykiss, a site and 5 ind.) and translated species (Hypmesus niponensis, two sites and 174 ind.) were collected in this survey. The proportion of Korean endemic species in the park (43.3%) was higher than the average of Korean Peninsular (25.9%). From this study, we conclude that the Jirisan National Park area in Korea would be very important for fish diversity and conservation, especially for the Korean endemic and endangered species.

Ichthyofauna and Structure of the Fish Community in Wangpi Stream, Korea (왕피천 유역의 어류상과 군집구조)

  • Kim, Kgu-Hwan;Cha, Jae-Seok;Park, Hee-Cheon
    • Korean Journal of Ichthyology
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    • v.21 no.1
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    • pp.47-54
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    • 2009
  • The ichthyofauna and fish community were surveyed at eight stations in the Wangpi stream from July 2007 to Jun 2008. During the survey period 23 species belonging to 9 families were collected. Of them cyprinid fishes comprised 47.8% (11 species), and Gobiidae 13.0% (3 species), Cobitidae 8.7% (2 species), Siluridae 8.7% (2 species) and other 4.2% (1 species). Eight species (34.8%) of observed species were endemic species. The dominant and subdominant species were Zacco koreanus (relative abundance : 31.0%) and Pungtungia herzi (relative abundance : 27.4 %). As the result of analyzing fish community in the surveyed area, the species diversity, evenness and dominant indicated that the community structure was similar between the upper and lower area of Wangpi stream.

Analysis of Composition and Diversity of Natural Regeneration of Woody Species in Jebel El Gerrie Dry Land Forest East of Blue Nile State, Sudan

  • Abuelbashar, Ahmed Ibrahim;Ahmed, Dafa-Alla Mohamed Dafa-Alla;Siddig, Ahmed Ali Hassabelkreem;Yagoub, Yousif Elnour;Gibreel, Haithum Hashim
    • Journal of Forest and Environmental Science
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    • v.38 no.2
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    • pp.90-101
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    • 2022
  • The study aims to assess composition, diversity and population indices of natural regeneration of woody species in Jebel El Gerrie forest reserve, Blue Nile State, Sudan. We conducted field work between December 2018 and January 2019. We used random sampling to collect vegetation data in the forest where we made a total of 90 circular sample plots (radius 17.84 m) and distributed them proportionally to the area of each of the four density-based vegetation classes of the forest i.e. high density (C1), medium density (C2), low density (C3) and crop land (C4). In each sample plot we identified all regenerating tree species and counted their regeneration frequencies. We calculated ecological metrics of regeneration frequency, density, abundance, richness, evenness, diversity and importance value index (IVI) and drew abundance rank curve. Results revealed that out of fifteen mature tree species present, natural regeneration of 8 species, which belong to 6 families, was observed. The relatively most frequently naturally regenerating and abundant species were Anogeissus leiocarpa and Combretum hartmannianum. Richness, evenness and diversity of regenerating species were 1.33, 0.82 and 1.7, respectively. One-way ANOVA (α=0.05) of mean regeneration densities disclosed that there were significant differences (F3,86=16.77, p=0.000) between C2 & C3 (p=0.000) and C2 & C4 (p=0.000). While regeneration of seven tree species were absent, two, two and four species were of good, poor and fair regeneration status, respectively. A comparison of mean density of natural regeneration with that of parent trees reflects a poor regeneration status of the forest. The study provides empirical results on the regeneration status of species and signifies the need for management interventions for species conservation and restoration, maintenance of biodiversity and sustainable production.

Arthropod Community in Small Rice Field associated with Different Planting Methods in Suwon and Incheon (파종방법을 달리한 수원 및 이천 지역 소규모 수도포장에서의 절지동물 군집)

  • 이준호;김광호;임언택
    • Korean journal of applied entomology
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    • v.36 no.1
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    • pp.55-66
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    • 1997
  • This study was conducted to analyze arthropod community patterns in small rice fields associated with different planting methods (water seeding, drill seeding, and hansplanting) in Suwon and Icheon in 1994. Total 15 orders and 45 families of arthropods were collected. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'natural enemy>pest(phytophage)>non-pest' in their densities in all sites. The pest (phytophage) species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stsl, Sogatella fircifera Horvath and Laodelphax striatellus Fallen) and Cicadelidae (Nephotettir cincticeps Uhler). They constituted >80% of pest abundance. Differences in pest abundance were not found among rice fields associated with different planting methods. Spiders were the most dominant group in the natural enemy and constituted >90% of natural enemy abundance. Hunting spiders constituted >SO% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str. (Lycosidae). Pacliygnatha clerki Sundevall (Tetragnathidae) was a dominant species in webbing spiders. No differences were found in species richness and diversity in spider community among rice fields associated with different planting methods. The nonpest species were mainly Diptera and occurred abundantly in early growing season and decreased drastically as rice development proceeded. The non-pest abundance was higher in direct seeding sites than in transplanting site, and especially abundant in a drill seeding site.

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Seasonal Variations in Species Composition of Larval Fish Assemblage in the Coastal Waters off Uljin, East Sea (동해 울진 연안의 어류 자치어 종조성과 계절변동)

  • Joo Myun Park;Jong Hun Kim;Se Hun Myoung;Yun-Hwan Jung;Dae-Won Lee;Dong Mun Choi;Hee Gab Lee
    • Korean Journal of Ichthyology
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    • v.36 no.2
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    • pp.156-163
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    • 2024
  • This study investigated the temporal patterns of species composition and abundance of larval fish assemblages through seasonal samplings in the coastal waters off Uljin, East Sea from April 2022 to February 2023. A total of 27 taxa of larval fishes were collected in the study area. The dominant fish larvae were Pseudopleuronectes herzensteini, Sebastes inermis, Ammodytes japonicus, Pseudopleuronectes yokohamae, Rudarius ercodes and Parablennius yatabei constituting 86.6% of total larval fish abundance. The number of species, abundance, and diversity index fluctuated according to season, showing the highest species number and abundance in April (spring) and diversity in July (summer). Larval fish assemblages were divided into three seasonal groups, including spring, summer and winter groups based on relative abundance of each fish larvae. Among abundant fish larvae, P. herzensteini predominated during spring, while P. yatabei and R. ercodes were abundant during summer. S. inermis, A. japonicus and P. yokohamae constituted the most abundant larval fish group during winter. These temporal changes in larval fish assemblages were attributed to seasonal changes in surface water temperature. The results from this study may elucidate our understanding of larval fish diversity and contribute to evaluating the nursery function of coastal habitats in the East Sea.

Study on Resources Annexation in Tongyeong Marine Ranching I. Effects of Zooplankton Attraction by Night-lights (통영 바다목장 자원조성을 위한 연구 I. 야간점등에 의한 동물플랑크톤 유도효과)

  • Yoon, Ho-Seop;Choi, Sang-Duk
    • Korean Journal of Environmental Biology
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    • v.24 no.2 s.62
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    • pp.126-137
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    • 2006
  • Effect of night-lights on zooplankton attraction has been studied in Tongyeong marine ranch area during the period from 12 July to 30 August, 2004. Each sampling has been carried out to collect zooplankton from both control area in natural waters experiment area of night-lights waters at night. A total of 43 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 15 species. Acartia erythraed and Copepodite occurred abundantly in night-lights waters. Zooplankton abundance appeared to increase in night-lights mainly due to the gathering of copepods and larvae through the study period. Average $3\sim166$ times of zooplankton abundance was recorded in night-lights when compared with that in control area of natural waters due to the gathering of copepods and larvae. Cluster analysis, based on monthly abundance data of the 13 most frequent species, showed that the species were seperated into two different groups: the photo-positive group and the photo-negative group.

Distribution Pattern and Feeding Preference of Asterias amurensis (Echinodermata: Asteriidae) in Tongyeong, Korea (통영해역에 서식하는 아므르불가사리의 분포 특성과 서식처에 따른 먹이 선호도 비교)

  • PARK Sang-Gyu;PARK Heung-Sik;YUN Sung Gyu;YI Soon Kil
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.37 no.6
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    • pp.469-477
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    • 2004
  • This study examined distributional patterns of Asterias amurensis in Tongyeong, the central South Sea of Korea. The density of the sea star was estimated at 10 chosen sites in the inner and the outer parts of the Tongyeong coast from December 2000. The mean density of the species in this area was $2.4ind./m^{2}$. The seasonal surveys conducted at 3 arbitrary chosen sites (i.e., sea cage, reef and soft sediment) also showed that the abundance of the species at the sea cage site $(density:\;3.6\;ind./m^{2};\;biomass:\;250.7\;gwwt/m^{2})$ was significantly higher than at the reef site $(density:\;1.7\;ind./m^{2};\;biomass:\;63.5\;gwwt/m^{2})$ and the soft sediment site $(density:\;0.4\;ind./m^{2};\;biomass:\;18.9\;gwwt/m^{2})$. Densities were higher at sea cages areas than at reefs and soft bottom sites. At sea cage site, A. amurensis population exhibited a strong aggregated distributional pattern. In contrast, at reef and soft bottom sites, A. amurensis population showed a random distributional pattern. The spatial difference in prey species and its abundance was the primary factor determining the spatial heterogeneity of the sea star in its behavior characteristics. Experiments on the feeding preference indicated that A. amurensis had a strong selectivity on its prey, but this selectivity varied between populations living in different sites. In particular, A. amurensis populations at the reef site showed a strong selectivity on various sessile and mobile animals living in reef areas, suggesting that these animal groups may play a role as "windows for the survival of A. amurensis". These results suggest that the distribution of A. amurensis in Tongyeong is closely associated with abundance of prey species and the bottom composition.