• Title/Summary/Keyword: Species difference

Search Result 2,137, Processing Time 0.027 seconds

Species Composition and Distribution of Trammel Net Catches in the Coastal Waters of Gangwon Province, Korea (강원 연안에서 삼중자망에 의한 어획물의 종조성 및 분포특성)

  • Sohn, Myoung Ho;Yoon, Byoung Sun;Park, Jeong-Ho;Choi, Young Min;Yang, Jae Hyeong
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.47 no.6
    • /
    • pp.945-959
    • /
    • 2014
  • This study was conducted to provide basic data for optimal fisheries management through the accurate understanding the catches, fishing level, species composition, distribution characteristics and fisheries status of trammel net in Gangwon Province. As the results of trammel net survey, Pisces were collected 77 species, 1,983.0 kg, Crustacea 9 species, 569.0 kg, Cephalopoda 5 species, 75.3 kg, Gastropoda 12 species, 16.5 kg in the coastal waters of Sokcho and Pisces 55 species, 3,681.5 kg, Crustacea 6 species, 2,229.8 kg, Gastropoda 10 species, 72.8 kg, Cephalopoda 4 species, 10.1 kg in the coastal waters of Donghae, respectively. The catches of important species with season and depths showed that the main target species is Pleuronectidae spp. at all depth and Aptocyclus ventricosus at <100 m in Sokcho, Liparis spp. and Dasycottus setiger at 200-500 m in Donghae, respectively. The mean total length (cm) of Gadus macrocephalus and Aptocyclus ventricosus didn't appear significant difference, but the mean total length of Pleuronectidae spp., Liparis spp. and D. setiger in Donghae is bigger than in Sokcho. From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed, catches data of dominant species in the coastal waters of Sokcho and Donghae was divided into three different groups of the demersal organisms community in 12 survey of Donghae (Group A) and Jul., Oct.-Dec. survey of Sokcho (Group B) and Jan.-Jun. and Aug.-Sep. survey of Sokcho (Group C).

Occurrence and distribution characteristics of weed species in organic paddy fields

  • Hwang, Ki Seon;Jung, Sunghoon;Kim, Sung-Chul;Chung, Doug-Young;Park, Kee Woong
    • Korean Journal of Agricultural Science
    • /
    • v.44 no.3
    • /
    • pp.325-331
    • /
    • 2017
  • This study was conducted to investigate the dominance and distribution of weed species in organic and conventional paddy fields. The organic paddy fields were maintained for organic farming for more than five years in Anseong, Gyeonggi province of Korea. According to the Braun-Blanquet method, 42 and 36 weed species were found in the organic paddy fields in 2015 and 2016, respectively, while 38 and 36 weed species were found in the conventional paddy fields in 2015 and 2016, respectively. As a result of two years' survey, 53 species from 24 families in the organic paddy fields were identified and classified as 32 annuals, 3 biennials and 18 perennials. In conventional paddy fields, 51 species from 24 families (30 annuals, 6 biennials, and 15 perennials) were identified. According to the classification by family, the most abundant weed species were Compositae (9 species), followed by Poaceae (8 species) and Polygonaceae (6 species) in organic paddy fields. In conventional paddy fields, Compositae (9 species) were the most abundant weed species, followed by Cruciferae (6 species), Poaceae, Polygonaceae, and Cyperaceae. This result indicates that the difference in diversity of weeds in paddy fields was influenced more by the agricultural environment than the type of cultivation. Our results could be used as a base data to control the occurrence of weed species in the paddy fields.

Variation of Medicinal Plants Species Richness along Vertical Gradient in Makawanpur District, Nepal

  • Gaire, Damodar;Jiang, Lichun;Yadav, Vijay Kumar;Shah, Jit Narayan;Dhungana, Sunita;Upadhyaya, Anju;Manjan, Shiv Kumar;Heyojoo, Binod Kumar
    • Journal of Forest and Environmental Science
    • /
    • v.37 no.2
    • /
    • pp.104-115
    • /
    • 2021
  • The research attempted to analyze the medicinal plant species richness in the vertical gradient from lower to the highest elevation of Makawanpur, focusing on the relationship between species richness and elevation which is very important for conservation and management of species diversity. Inventory was carried out in the study area by taking sampling intensity of 0.5% in the effective area. Altogether, 42 sample plots were laid in the field with the help of GIS software maintaining 50 m altitude difference. High species diversity was found in the herbs species whereas shrubs have comparatively low species diversity. The maximum species richness is found in herbs and poles whereas shrubs and trees have relatively low species richness. Research showed that species richness of medicinal plants increased with altitudinal gradient. While analyzing the species richness from 350 to 2,550 m (msl), the highest species richness was received with the elevation ranges from 1,800 m to 2,300 m. There was a positive relationship between species richness and altitudinal gradient in the study area. In addition, we have recorded the high value medicinal plants after 1,800 m altitude and rarely within 1,000 m. Medicinal plants correlated both positive and negative relationships with the increased altitude. The altitudinal response has positively seen except density (n/ha) of Shrubs. Domestication and cultivation of high value medicinal plants should be promoted in community forest including private lands. Training, workshops and awareness programs should be conducted to make people aware about medicinal plants resource utilization, conservation and commercialization of available medicinal plants.

Two new Phyllopodopsyllus (Copepoda, Harpacticoida) from Korean marine interstitial

  • Karanovic, Tomislav
    • Journal of Species Research
    • /
    • v.6 no.spc
    • /
    • pp.185-214
    • /
    • 2017
  • The genus Phyllopodopsyllus T. Scott, 1906 is nearly cosmopolitan and contains around 60 valid species, but has not been previously recorded in Korea. One of the reasons is probably the paucity of research in marginal habitats, such as marine interstitial. I describe two new species here. Numerous specimens of both sexes of P. kitazimai sp. nov. were collected from a beach near Yeongdeok, while only two females of P. busanensis sp. nov. were collected from a beach near Busan. The new species differ in numerous macro-morphological characters, such as the segmentation and armature of the antennula, armature of the mandibula, maxillula, maxilliped, and the first three swimming legs, as well as the shape of the caudal rami and the female genital field. However, they show very little difference in the number and position of cuticular organs (pores and sensilla) on all somites, which might prove these rarely used micro-characters to be useful in the reconstruction of phylogenetic relationships in this group of harpacticoids. Both species have their closest relatives in Japan. Phyllopodopsyllus kitazimai is morphologically most similar to P. punctatus Kitazima, 1981, but can be distinguished by much longer third exopodal segments of the third and fourth swimming legs. Phyllopodopsyllus busanensis shares the largest number of morphological similarities with P. setouchiensis Kitazima, 1981, but can be distinguished by shorter caudal rami. A key to species is also provided.

Plant community development in the first growing season of a created mitigation wetland bank as influenced by design elements

  • Ahn, Chang-Woo
    • Journal of Ecology and Environment
    • /
    • v.33 no.4
    • /
    • pp.363-376
    • /
    • 2010
  • Vegetative communities of created wetlands often display lower species richness, less cover, higher occurrence of non-native or invasive species, and fewer obligate wetlands species than those in natural wetlands, thus failing to meet basic success criteria for wetland mitigation. This study examined the effects of two design elements, disking-induced microtopography and hydrologic regime, on the first year vegetation development pattern of a mitigation wetland newly created in the Virginia piedmont. Elevation and species cover were measured along replicate multiscale circular transects in two adjacent wetland sites that are different in their hydrologic regime. Two microtopographic indices, tortuosity (T) and limiting elevation difference (LD), were calculated from the elevation measurements. Both indices were higher in disked plots than non-disked plots, showing the effect of disking on microtopography. Out of forty-one vegetation taxa observed in the wetland, 29 taxa were naturally colonized and 12 taxa were seeded. All plots except one non-disked plot were dominated by wetland vegetation. Species richness and diversity were higher in disked than in non-disked plots. Vegetation community development seemed also influenced significantly by hydrologic regime of the site. The effect of microtopography on species richness and diversity was more pronounced in a relatively dry site compared to a wet site. In addition, percent cover, species richness and diversity of vegetation were positively correlated with microtopographic indices such as T and LD. Two design elements, microtopography and hydrologic regime, should be considered and incorporated in wetland creation to enhance plant community development.

Species Composition and Catch of Korean Tuna Longline Fisheries in the Indian Ocean from 2010 to 2015 (인도양 해역 우리나라 원양 연승어업의 어획물 종조성과 어획동향(2010-2015년))

  • Ku, Jeong Eun;Lee, Sung Il;Kim, Doo Nam
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.51 no.3
    • /
    • pp.286-297
    • /
    • 2018
  • We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

Influences of Exposures on Dry Matter Yields and Nutrient Contents of Grasses II. Comparative studies of south and north exposure on nutrient contents of temperate grasses (경사방향이 목초의 수량 및 양분함량에 미치는 영향 II. 주요 목초에 대한남북향사면의 양분함량비교)

  • 박근제;이필상;신재순;정연규
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.7 no.2
    • /
    • pp.97-102
    • /
    • 1987
  • To find out the nutrient contents of temperate grasses on the south and north slope, a field experiment was conducted with five forage species of Dactylis glomerata, Festuca arundinacea, Phleum pratense, Agrostis gigantea and Trifolium repens. It was treated by randomized block design with 4 replications and lasted from September, 1983 to October, 1986 in Suweon. The results obtained are summarized as follows: 1. Mean chemical compositions except NFE and crude fiber of the forage species on the south slope were a little more contented than that of north. But all crude components were significant difference among the species on the south and north exposure. 2. Production of TDN (total digestible nutrient), StE (starch equivalent) ME (metabolizable energy) and NEL (net energy lactation) of different grass species on the north slope were much more increased by 5-30% per ha (Dactylis glomerata by 5-876, Festuca arundinacea by 5%, Phleum pratense by 24-26% and Agrostis gigantea by 25-30%) than that of same grasses on the south, however, those of Trifolium repens were much more increased by 4 1-42% per ha in the south. 3. Mineral contents, Ca/P ratio and K/ (Ca + Mg) equivalent ratio of the species were slightly different between the exposures. But considering the factors of occuring grass tetany, those of the forage species on the north slope were better than that of same species on the south.

  • PDF

Prediction of Species Richness of Breeding Birds by Analysis of Land Cover at Seongnam City, Korea

  • Park, Chan-Ryul;Lee, Jang-Ho;Lee, Do-Won;Lee, Woo-Shin
    • The Korean Journal of Ecology
    • /
    • v.28 no.1
    • /
    • pp.1-6
    • /
    • 2005
  • This study was conducted to develop the predictive model for species richness of breeding birds by multivariate analysis of land covers (percentage value of each cover in 300 $\times$ 300m grid) including water area (WA), urbanized area (UA), green area (GA), forest area (FA) and agricultural area (AA) at Seongnam City in Korea. Fifty-nine species of birds were mapped on 155 grids in size of 300 $\times$ 300 m from 2000 to 2001. Species richness of breeding birds was significantly regressed ($R^2=0.85$, n=155) by estimates of WA ($4.59{\pm}1.13$, P<0.0001), UA ($6.50{\pm}0.86$, P<0.0001), GA ($7.11{\pm}1.25$, P<0.0001), FA ($8.51{\pm}0.62$, P<0.0001), and AA ($4.59{\pm}1.13$, P<0.0001). In validation of model, the results show no significant difference between predicted value of species richness and observed one. Developed model can be used as a predictive model of species richness of birds for selecting the proper location of corridors and parks in urban area.

Genotyping of Six Pathogenic Vibrio Species Based on RFLP of 16S rDNAs for Rapid Identification

  • Yoon, Young-Jun;Im, Kyung-Hwan;Koh, Young-Hwan;Kim, Seong-Kon;Kim, Jung-Wan
    • Journal of Microbiology
    • /
    • v.41 no.4
    • /
    • pp.312-319
    • /
    • 2003
  • In an attempt to develop a method for rapid and accurate identification of six Vibrio species that are clinically important and most frequently detected in Korea, 16S rDNA restriction fragment length polymorphism (RFLP) of Vibrio type strains, as well as environmental isolates obtained from the Korean coastal area, was analyzed using ten restriction endonucleases. Digestion of the 16S rDNA fragments amplified by polymerase chain reaction (PCR) with the enzymes gave rise to 2~6 restriction patterns for each digestion for 47 Vibrio strains and isolates. An additional 2~3 restriction patterns were observed for five reference species, including Escherichia coli, Aeromonas hydrophila, A. salmonicida, Photobacterium phosphoreum, and Plesiomonas shigelloides. A genetic distance tree based on RFLP of the bacterial species correlated well with that based on 16S rDNA sequences. The very small 16S rDNA sequence difference (0.1%) between V. alginolyticus and V. parahaemolyticus was resolved clearly by RFLP with a genetic distance of more than 2%. RFLP variation within a species was also detected in the cases of V. parahaemolyticus, V. proteolyticus, and V. vulnificus. According to the RFLP analysis, six Vibrio and five reference species were assigned to 12 genotypes. Using three restriction endonucleases to analyze RFLP proved sufficient to identify the six pathogenic Vibrio species.

Diversity of Oribatid Mites (Acari : Oribatida) in Namsan and Kwangreung Deciduous Forests (남산과 광릉 활엽수림지역의 날개응애류(Acari : Oribatida) 종 구성)

  • 정철의;이준호;배윤환;최성식
    • The Korean Journal of Soil Zoology
    • /
    • v.3 no.2
    • /
    • pp.91-105
    • /
    • 1998
  • This study was conducted to analyze oribatid mites communities in deciduous forests in Namsan and Kwangreung on which different levels of environmental stresses might press, and to select potential condidate of biological indicator species. In overall, pH was lower in soil than in litter layer. Also soil pH, total nitrate content and soluble sulfate content were significantly higher in Namsan than in Kwangreung (p<0.05). The flora in Namsan and Kwangreung deciduous forests were dominated by Quercus mongolica, and Carpinus laxiflora respectively. It indicated that Namsan was in the lower stage of the floral succession. The number of species of oribatid mites was significantly higher in Kwangreung (39 families, 65 genera and 114 species) than in Namsan (32 families, 53 genera and 89 species) (p<0.05). Common species found in two regions were 77 species. Mean density of oribatid mites was 1.8 times higher in Kwangreung than in Namsan and this difference came mainly from litter layer. Among correlation analyses between environmental factors and oribatid mites density and species number, only density was negatively correlated with fresh litter depth in Namsan litter layer (r=-0.89, p<0.05). The pH which was considered to affect distribution of oribatid mites didn't show significant results.

  • PDF