• Title/Summary/Keyword: Occurrence ecology

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Stomach Contents of the Southern Rough Shrimp Trachysalambria curvirostris (Stimpson) in the Coastal Area of Yeosu, Korea

  • Yoon, Ho-Seop;Soh, Ho-Young;Park, Sang-Duk
    • Korean Journal of Environmental Biology
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    • v.21 no.4
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    • pp.342-351
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    • 2003
  • The southern rough shrimp Trachysalambria curvirostris (Stimpson) was monthly sampled from the coastal area of Yeosu, Korea from June 2000 to May 2001 and its stomach contents were investigated. Mysids and amphipods were the most dominant prey, comprising >40% of the diet in both % occurrence and % abundance. In particular, mysids were most important food without regard to seasons, size classes, or sexes. The abundance and occurrence composition of food items showed a seasonal fluctuation: mysids and amphipods were the predominant prey items in spring (33.8%), summer (41.1%), autumn (43.9%), and winter (49.2%). For small-sized shrimps (>25 mm CL), mysids and amphipods consist of more than 45% of its food in both % abundance and % occurrence. For large-sized shrimps (>25 mm CL), these were clearly dominant. The quantities and items of food did not differ in both genders, which mainly fed on mysids and amphipods. The trophic diversity and equality of diet varied with seasons and size classes. The diet diversity for smaller shrimps was highest in spring, while that for the larger shrimp lowest in winter. Also, the mandibular structure of Trachysalambria curvirostris indicates that the species is carnivorous.

Occurrence of Virus Disease of Chinese Cabbage and Its Influence on Cabbage Production in Alpine Area (고랭지배추 바이러스병의 발생 및 피해요인 분석)

  • 최준근;이재홍;이세원;함영일;안재훈;최장경
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.433-439
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    • 1998
  • The studies on the ecology of virus disease on Chinese cabbage (Brassica campestris subsp. pekinensis) cultivated in alpine area of Kangwon province during summer season to analyse its influence on damage and develope a prediction model were performed from 1993 to 1997. Virus disease on Chinese cabbage occurring in the alpine area showed various symptom types and among there, necrotic spots and dwarf were mainly detected. The disease was increased from early August and continued mid September in every year. The occurrence of virus disease was the highest in 1994 with 20.5%, and the number of aphid vectors were also the highest during the same period. The number of aphids in the alpine areas showed twice peaks every year. For the analysis of damage by virus infection, the infection and injured ratio of all treatments were more than 90% and 80%, respectively. The most important factor for the occurrence of virus disease on Chinese cabbage was temperature. Factors influencing the development of the viral disease in the alpine area were maximum temperature and number of aphid vectors.

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New records of genus Scenedesmus (Chlorophyceae) found in Korea

  • Kim, Yong Jae
    • Journal of Ecology and Environment
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    • v.38 no.2
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    • pp.213-227
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    • 2015
  • This study summarizes the taxonomic notes and distribution of 13 taxa of the genus Scenedesmus (Chlorophyceae) collected from several swamps, reservoirs, and rivers throughout South Korea from 2012 to 2014. In this study, light microscopy images of all 13 taxa are presented and briefly discussed with regard to their taxonomy, distribution, and ecology and environmental factors of occurrence sites. All 3 subgenera (subgenus Scenedesmus 1 taxon; subgenus Acutodesmus 2 taxa; subgenus Desmodesmus 10 taxa) are newly described in Korean freshwater algal flora: S. linearis, S. acuminatus var. elongatus, S. acuminatus var. tetradesmoides, S. carinatus, S. denticulatus var. disciformis, S. gutwinskii var. heterospina, S. helveticus f. bicaudatus, S. lefevrei, S. oahuensis var. clathratus f. longiclathratus, S. oahuensis var. clathratus, S. pannonicus, S. polydenticulatus, and S. tenuispina.

Occurrence of Brown Blight Caused by Waitea circinata var. zeae on Cool Season Turfgrass in Korea

  • Chang, Taehyun;Lee, Yong Se
    • Mycobiology
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    • v.44 no.4
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    • pp.330-334
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    • 2016
  • In 2010, disease symptoms, including necrotic lesions on stems and leaves with circular yellow-brown or irregular brown color patches, were observed on cool-season turfgrass at golf courses (OHCC) and the Daegu University research farm in Gyeongbuk, Korea. We isolated the causal agent and identified it as Waitea circinata var. zeae by morphological characterization and molecular analysis. To the best of our knowledge, this is the first report of brown patch caused by W. circinata var. zeae on cool-season turfgrass in Korea.

The Influence of Skinning a Carcass on Insect Succession and Decomposition

  • Yoon, Joo-Hyuk
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.4
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    • pp.204-211
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    • 2022
  • Forensic entomology is a field of study that includes the succession of insects attracted to and found on cadavers. One of its main focusses is estimating post-mortem interval (PMI) based on the growth stage of insects found in and around human cadavers. In many countries, the diversity of insect occurrence is studied in relation to the environmental conditions a cadaver may be exposed to or the effects of different clothes. In this study, changes in the decomposition process and differences in insect succession were investigated by comparing skinned and intact water deer carcasses. Five orders, 15 families, and 21 species of insects were identified, most of which were Dipteran and Coleopteran. The skinned carcass decomposed more rapidly than the intact carcass, which was linked to differences in insect succession. The difference in the decomposition rate and insect succession according to the external conditions of the carcass can be used as basic data for estimating the PMI of the carcass and setting the forensic entomological indicator species.

Plant co-occurrence patterns and soil environments associated with three dominant plants in the Arctic

  • Deokjoo Son
    • Journal of Ecology and Environment
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    • v.47 no.1
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    • pp.1-13
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    • 2023
  • Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.

The Analysis on Causes of Areas with Public Appeals to the Ecosystem and Nature Map (생태·자연도 이의신청지역의 원인 분석)

  • Jung, Tae-Jun;Song, Il-Bae;Lee, Ji-Seon;Lee, Sung-Je;Cho, Kwang-Jin;Song, Kyo-Hong;Kim, Ki-Dong;Cha, Jin-Yeol;Cho, Jang-Sam;Leem, Hyosun;Joung, Hae-Joung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.1
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    • pp.25-34
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    • 2017
  • The objective of this study is to seek for improvement measures to make the Ecosystem and Nature Map by analyzing causes for grade changes and distributional characteristics of areas with public objections to the Ecosystem and Nature Map notified by e-official gazette from 2014 to June 2016. The receipt of public appeals has been recently increased from average 23 cases a year(2007-2013) to average 33 cases a year(2014-June 2016) while there were 42 areas with public appeals for less than the minimum area($62,500m^2$) for the evaluation of grade of the Ecosystem and Nature Map. Most of the public appeals focused on the 1st grade zone of the Ecosystem and Nature Map. Before grade changes by public appeals, the 1st grade zone of the Ecosystem and Nature Map were 76.0% of the whole areas with public appeals. However, after grade changes by public appeals, it was rapidly decreased to 25.2%, which means that a lot of the 1st grade zone with public appeals were lowered. In the results of analyzing the distributional characteristics of areas with public appeals, they were mostly distributed in lowland(less than 250m altitude), section with $10{\sim}20^{\circ}$ slope, and areas close to or within 100m from built-up area. Regarding areas with public appeals, the biggest time difference between the period of the existing research by National Ecosystem Survey and the period of notice after completing the treatment of public appeals was 18 years while areas showing 6-15 years of time difference were about 70%. Thus, there were huge differences in time of research and notice. Also, the biggest causes for grade changes were boundary errors caused by small-scale survey, and then followed by changes in evaluation of endangered species and occurrence of built-up area and damaged land. Analyzing areas with public appeals in each evaluation item of the Ecosystem and Nature Map, vegetation part was 73.0%, and endangered species area was 23.1% while topography and wetland was less.

Trends in Leopard Cat (Prionailurus bengalensis) Research through Co-word Analysis

  • Park, Heebok;Lim, Anya;Choi, Taeyoung;Han, Changwook;Park, Yungchul
    • Journal of Forest and Environmental Science
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    • v.34 no.1
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    • pp.46-49
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    • 2018
  • This study aims to explore the knowledge structure of the leopard cat (Prionailurus bengalensis) research during the period of 1952-2017. Data was collected from Google Scholar and Research Information Service System (RISS), and a total of 482 author keywords from 125 papers from peer-reviewed scholarly journals were retrieved. Co-word analysis was applied to examine patterns and trends in the leopard cat research by measuring the association strengths of the author keywords along with the descriptive analysis of the keywords. The result shows that the most commonly used keywords in leopard cat research were Felidae, Iriomte cat, and camera trap except for its English and scientific name, and camera traps became a frequent keyword since 2005. Co-word analysis also reveals that leopard cat research has been actively conducted in Southeast Asia in conjugation with studying other carnivores using the camera traps. Through the understanding of the patterns and trends, the finding of this study could provide an opportunity for the exploration of neglected areas in the leopard cat research and conservation.

Composition of the insect diet in feces of yellow-throated marten, Martes flavigula, in Jirisan National Park, South Korea

  • Choi, Moon Bo;Woo, Donggul;Choi, Tae Young
    • Journal of Ecology and Environment
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    • v.38 no.3
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    • pp.389-395
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    • 2015
  • The composition of the Martes flavigula diet has been extensively studied, but little is known about its insect component. This study characterized the insect diet and insect nest materials in the feces of M. flavigula. A total of 952 fecal samples were collected in Jirisan National Park from January 2009 to November 2011, and 1379 species or taxonomic groups were identified. M. flavigula fed on insects (8.7%) and bee wax (5.0%), which comprised 2.9% and 4.4% of the dry weight of M. flavigula feces, respectively. A total of 12 insect species belonging to 8 families in 3 orders were identified. The most frequently found insects were Hymenoptera (frequency of occurrence, FO, 89.1), including Vespa simillima simillima (FO, 37.3) and Vespula koreensis koreensis (FO, 20.0). The Vespidae constituted the majority of the insect diet in autumn when the diversity of marten's prey was strongly reduced, probably because the numbers of social insects were sufficient for M. flavigula. In addition, the data suggest that M. flavigula attacks the nests of social wasps in late autumn when males do not have a venomous sting and new queens are less aggressive than workers. Bee wax appeared in all seasons and the highest rate was from spring to early summer. However, the remains of honeybees were not found in feces; thus, M. flavigula presumably eats honey but not honeybees.

Recolonization of benthic macroinvertebrates after anthropogenic disturbance in natural streams, South Korea

  • Chun, Seung-Phil;Chon, Seung-Hoon;Lee, Seung-Oh;Im, Jang-Hyuk;Lee, Woo-Kyun;Kim, Myoung-Chul
    • Korean Journal of Environment and Ecology
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    • v.29 no.2
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    • pp.228-235
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    • 2015
  • Stream ecosystems are closely related to many human activities. Therefore, streams are affected by anthropogenic disturbances such as riverine development and gravel-mining as well as deterioration of water quality. The goal of this study was to elucidate the recolonization process of the macroinvertebrate community after a small-scale anthropogenic disturbance. Field studies were conducted at three sites in a natural stream. The number of recolonizing species tended to increase slightly over time, exceeding the total species number of the control. Ephemeroptera contributed the most to shaping the recolonizing pattern of the entire community. From the result of changes in dominant species, the early recolonizers of each site were the species that showed more frequent occurrence particulary at each sites. But the late recolonizers are Chironomidae at all the sites commonly. This result implies that the actual differences exist among the recolonizing trends of each benthic macroinvertebrate taxon. Collector-gatherers and scrapers comprised about 70% of the recolonizing species. These results indicate that the recolonizing process of an aquatic community after an artificial disturbance depends on the environmental conditions(particularly substratum composition or organic pollution) of the habitat.