• Korean journal of applied entomology
• /
• v.34 no.2
• /
• pp.120-126
• /
• 1995

This study investigated the soil oribatid mite community at planatations of the Korean white pine, planted in different years. The soil samples $(10\times10\times5cm)$ were taken monthly from Jun 1988 to July 1989, and soil microarthropods in th sample were extracted using the Tullgren funnel for 72 hors. The diversity indices decreased at the older plantation sites with the maximum point in January and the minimum in September. The richness indices showed the maximum point in June and the minimum in may. The dominance indices increased at the older plantation and showed the maximum point in April, May, the minimum in January. The indices of aggregation of Oribatid mites species showed concentrated distribution in the average 1.9. The older plantation, the more indices increase. The seasonal variation of th indices tended to be greatest in April, August and at lowest in January. The richness indices was positively correlated with shannon-wiener, evenness indices. The dominance, aggregation indices was negatively correlated with shannon, evenness, richness indices.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.36 no.5
• /
• pp.515-521
• /
• 2003

To understand interrelations between water quality and community structure of phytoplankton around the season of red tide outbreak, field surveys were conducted 10 times off the coast of Tongyeong from July to September in 2002. Because of heavy rain for 10 days, environmental conditions were changed and differed from the previous year, sustaining high nutrients and low salinity. During the surveyed period 48 species of 29 genera of phytoplankton were identified, and diatom and dinoflagellate was $51.8\%\;and\;38.0\%,$ respectively, At the time of bloom, cell counts of C. polykrikoides were outstanding but the number of species remarkably decreased. There were striking differences in dominant species among research stations before the bloom. Diatoms were the most dominant group in the whole study area in that period. Diversity and evenness index were highest just before outbreak of the red tides (2 Aug, 2002). During the bloom (4 Aug.), it decreased to the lowest value and then began to increase slowly. The result of PCA on water quality vs phytoplankton biomass showed that the land loads of nutrient may be the main cause of summer rally of phytoplankton biomass.

• Korean Journal of Ecology and Environment
• /
• v.42 no.3
• /
• pp.303-316
• /
• 2009

Benthic macroinvertebrate communities collected from eight different streams in South Korea were analyzed to compare community and biological indices across different levels of water pollution. The Self-Organizing Map (SOM) was utilized to provide overview on association of the proposed indices. The sample sites were accordingly clustered according to the gradient of pollution on the SOM. While the general trends of the indices were commonly observable according to different levels of pollution, the detailed differences among the indices were also illustrated on the SOM. The conventional diversity and evenness indices tended to be high even though the water quality state was poor representing relatively weak gradient at polluted sites, while the index presenting the saprobic degree such as family biotic index showed the stronger gradient at the polluted area and was robust to present the gradient. Our results also confirmed the general characterization of two indices: The Shannon index is more strengthened by the number of species occurring at the sample sites, while the Simpson index is more influenced by the degree of evenness among the species. The patterning based on the SOM was efficient in comparatively characterizing the proposed indices to present ecological states and water quality.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.43 no.4
• /
• pp.251-260
• /
• 2007

A species composition and population structure of fish, collected 16 times by bottom otter trawl in the coast of Geumo Island, from February 2002 to November 2005, was investigated. The fish species caught by bottom otter trawl from year 2002 to 2005 was entirely 72 species, 41 classes, and 12 orders, and the number of appearance and biomass was 5,999 individuals and 287,902.1g, respectively, being of the Perciformes(31 species and 19 classes; 43.1% in total number of species appeared) as a dominant species. 638 individuals of Leiognathus nuchalis which was 10.6% in total fish were appeared and 465 individuals of Konosirus punctatus(7.8%), 449 individuals of Engraulis japonicus(7.8%). biomass of Sebastes schlegeli was 33,258.7g as a dominant species(11.6% in total fish appeared) and 18,821.1g of Liparis agassizii(6.5%), 16,708.0g of Konosirus punctatus(5.8%). The diversity index of species per months of the collected by a small otter trawl in coastal water of Geumodo from year 2002 to 2005 was 2.860-3.639 and the evenness index was 0.825-0.887 in case of dominance index was 0.224-0.268 against the evenness index. The similarity of community structure per yearly was very high because of the relative difference(0.006), which was the least in 2004 and 2005.

• Fibers and Polymers
• /
• v.7 no.3
• /
• pp.317-322
• /
• 2006

Reduction of yam hairiness by nozzles in ring spinning and winding is a new approach. Simulation of the airflow pattern inside the nozzles provides useful information about actual mechanism of hairiness reduction. The swirling air current inside the nozzles is capable of wrapping the protruding hairs around the yam body, thereby reducing yam hairiness. Since production rate of winding is very high and the process itself increases yarn hairiness any method to reduce the hairiness of yarns at this stage is a novel approach. A CFD (computational fluid dynamics) model has been developed to simulate the airflow pattern inside the nozzles using Fluent 6.1 software. In this study, both S- and Z-type nozzles having an axial angle of 500 and diameter of 2.2 mm were used for simulation studies. To create a swirling effect, four air holes of 0.4 mm diameter are made tangential to the inner walls of the nozzles. S- and Z-twisted yams of 30 tex were spun with and without nozzles and were tested for hairiness, tensile and evenness properties. The total number of hairs equal to or exceeding 3 mm (i.e. the S3 values) for yam spun with nozzle is nearly 49-51 % less than that of ring yams in case of nozzle-ring spinning, and 15 % less in case of nozzle-winding, while both the yarn types show little difference in evenness and tensile properties. Upward airflow gives best results in terms of hairiness reduction for nozzle-ring and nozzle wound yams compared to ring yarns. Yarn passing through the centre of the nozzle shows maximum reduction in S3 values.

• Journal of Forest and Environmental Science
• /
• v.37 no.3
• /
• pp.243-250
• /
• 2021

Information on butterflies in the Niger Delta Region is relatively scanty because monitoring of their activities and distribution has not been fully documented and these are paramount to establish their conservation protocols. The study therefore aimed at evaluating the species richness distribution pattern, and relative abundance of butterflies in the University of Port Harcourt. The University Park was purposively selected for this study. The park was stratified into three different habitat types (secondary forest, farmland, and residential/garden). A sampling of each stratum was done three times; twice in the morning between 8:00 am and 12:00 pm as well as once in the evening between 4:00 pm and 6:00 pm along a 100 m line transects for 16 months (May 2017-August 2018). Data collected were analyzed for species diversity indices, evenness, and similarity index. A total of 1,932 individual butterflies belonging to 28 species, 18 genera, and five 5 families were identified in the study area. Species diversity and evenness were higher on farmland (1-D=0.909; H'=2.615; E=0.833), and least in the residential area/gardens (1-D=0.744; H'=1.975; E=0.659). The family Nymphalidae (39.0%) had the highest number of species occurrence while Hesperidae (0.4%) had the lowest composition. Anthene larydas (24.12%) had the highest relative abundance in the entire study area, followed by Acraea serena (17.49%). The study, therefore, recommends continuous monitoring of butterfly species diversity and composition also in other regions.

• Journal of Korean Society of Forest Science
• /
• v.100 no.1
• /
• pp.118-123
• /
• 2011

Pine (Pinus densiflora) forests of 315 sites were classified by applying the phytosociological method, TWINSPAN and DCA (detrended correspondence analysis). The floristic composition and diversity patterns of the vegetation types analyzed and documented. The vegetation types were classified 8 groups including 4 groups of Quercus mongolica type and 4 groups of Quercus serrata-Smilax china type. Taxonomically, Compositae was the most diverse family (21 genus, 45 species) and followed in order of Liliaceae (18 genus, 34 species), Rosaceae (17 genus, 34 species), and Leguminosae (15 genus, 25 species). The patterns of species richness, diveristy and evenness were significantly different among the vegetation types. In altitudinal pattern of species diversity, species richness monotonically decreased but species evenness increased with increasing altitude.

• Journal of Forest and Environmental Science
• /
• v.38 no.2
• /
• pp.90-101
• /
• 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 (F_3,86=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.

• Journal of Forest and Environmental Science
• /
• v.38 no.3
• /
• pp.207-217
• /
• 2022

We investigated the habitat distribution and diversity of ground beetles (Coleoptera: Carabidae), a bioindicator for assessing environmental changes on Geumo Mountain, in survey plots at different altitudes on the southern and northern slopes of Geumo Mountain in South Korea. From April to September 2021, we collected 1,384 individuals, 41 species, and 15 families of Carabidae from the survey sites. The dominant species collected was Synuchus cycloderus (347 individuals), followed by Carabus jankowskii (193 individuals). The monthly distributions of species richness and abundance were as follows: 24 beetles of 9 species in April, 115 beetles of 28 species in May, 288 beetles of 32 species in June, peaking at 379 beetles of 32 species in July, 354 beetles of 23 species in August, and 224 beetles of 14 species in September. Additionally, we collected 305 beetles of 32 species at 400 m, 326 beetles of 31 species at 500 m, 359 beetles of 27 species at 600 m, 582 beetles of 16 species at 700 m, and 112 beetles of 7 species at 800 m near the summit. The habitat distribution by slope was 307 beetles (20 species of 8 families) on the southern slope and 1,077 beetles (34 species of 15 families) on the northern slope. For the 307 beetles of 20 species collected from the southern slope, the diversity, evenness, and dominance indices were 0.981, 0.754, and 0.156, respectively. For the 1,077 beetles of 34 species collected from the northern slope, the diversity evenness, and dominance indices were 1.187, 0.775, and 0.101, respectively.

• Korean Journal of Environment and Ecology
• /
• v.36 no.1
• /
• pp.56-71
• /
• 2022

This study was conducted to build basic terrestrial insect data for the management of the persimmon plantations in the Sangju dried persimmon agricultural area. The survey identified terrestrial insect species were 7 orders, 77 families, and 1,925 individuals of 177 species. And the number of species that appeared in each village was in the order of Seoman II Village in Naeseo Township > Seoman I Village in Naeseo Township > Soeun Village in Oenam Township. Hemiptera and Coleoptera predominated throughout the site due to the characteristics of the cultivated land. The special species were 13 Korean endemic species, 2 vulnerable (VU) species, 22 least concern (LC) species, 42 not-evaluated (NE) species on the national red list, and 2 species of ecosystem disturbance wildlife. A result of the cluster analysis identified the Ectmetopterus micantulusas the dominant species and Ceutorhynchus albosuturalisas the subdominant species. The species diversity (H') was 1.1636-1.6022, evenness (J') was 0.6748-0.7611, and dominance (D) was in the range of 0.2389-0.3252.