• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.115-125
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• 2021

This study surveyed the population ecology of Acheilognathus chankaensis (Pisces: Acheilognathinae) in the vicinity of the Churyeongcheon (Stream) and Seomjingang (River) in Jeonbuk, Korea, from February 2006 to May 2007. The survey found the habits mainly in the slow-flowing waters having sand, mud, and gravel bottoms. Age groups estimated by the standard length-frequency distribution of the population indicated that the one-year-olds were 30-46 mm long, the two-year-olds were 47-58 mm long, the three-year-olds were 59-68 mm long, and the four-year-olds were longer than 69 mm. The gonadosomatic index (GSI) and the ratio of ovipositor length/standard length were the highest in March (♀: 12.9%, ♂: 5.0%) and in April (46.3%), respectively. The ratio of mature egg diameters that were 1.6 mm was highest in May (13.2%). The comprehensive analysis of spawning characteristics showed that the spawning season was from March to June with water temperatures in 11.5-22.5℃, and the sex ratio of female:male was 1:1.13. The fecundity in the ovaries and the number of mature eggs were 318±174.5 (50~583) and 220±139.2 (50~406), respectively. The size of the mature eggs was 2.04±0.110 mm on the long axis and 1.55±0.100 mm on the short axis for the study period. Gut contents of A. chankaensis were mainly phytoplankton such as the genera Fragilaria, Synedra, Navicular, Cymbella (Bacillariophyceae), and Cosmarium (Chlorophyceae).

• Korean Journal of Environment and Ecology
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• v.26 no.3
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• pp.367-373
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• 2012

Population ecology (Ecological characteristics) of Squalidus japonicus coreanus from the Namhan River(Yangpyeong-gun Yangpyeong-eup Changde-ri), Gyeonggi-do, Korea were investigated from January to December 2011. Short barbel gudgeon inhabits habitats run of the lower river. The stream bed was mostly covered sand. Their current velocities were 0.14~1.38m/sec and depths were 80~120cm. The sex ratio of female to male was 1 : 0.82. It is presumed that the spawning season is from June to July and water temperatures were $18.5{\sim}24.3^{\circ}C$. Sexually matured individuals appeared over the two year of age. Frequency analysis of total length indicated that the group with 34~50mm in total length was one year old, the 51~74mm was two years old, and the group over 75mm was three years old. The average number of eggs in the ovaries was estimated as 1,871 per matured female. Stomach content of S. japonicus coreanus were Cyanophyta, Chlorophyta, Bacillariophyta, Rotatoria, Crustaceae, Copepoda, Ephemeroptera, Diptera, and Nematoda. omnivorous, mainly feeds on benthic invertebrates such as chironomidae larvae.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.520-528
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• 2017

The exotic black soldier fly, Hermetia illucens, has been paid much attention as an excellent organic matter decomposer. We conducted the nationwide survey and the population genetic study using a mitochondrial cytochrome C oxidase 1 gene to understand its genetic diversity and distribution pattern in Korea. The results show that it has successfully settled down in South Korea and there are only 10 haplotypes and the populations of the insect are highly differentiated. The results may indicate that their dispersal was restrained probably due to their short distance flying tendency since their introduction and settlement of only few maternal lineages with certain genotypes in Korea.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.385-389
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• 2019

Knowledge of abundance, or population size, is fundamental in wildlife conservation and management. Camera-trapping, in combination with capture-recapture methods, has been extensively applied to estimate abundance and density of individually identifiable animals due to the advantages of being non-invasive, effective to survey wide-ranging, elusive, or nocturnal species, operating in inhospitable environment, and taking low labor. We assessed the possibility of using coat patterns from images to identify an individual leopard cat (Prionailurus bengalensis), a Class II endangered species in South Korea. We analyzed leopard cat images taken from Digital Single-Lense Relfex camera (high resolution, 18Mpxl) and camera traps (low resolution, 3.1Mpxl) using HotSpotter, an image matching algorithm. HotSpotter accurately top-ranked an image of the same individual leopard cat with the reference leopard cat image 100% by matching facial and ventral parts. This confirms that facial and ventral fur patterns of the Amur leopard cat are good matching points to be used reliably to identify an individual. We anticipate that the study results will be useful to researchers interested in studying behavior or population parameter estimates of Amur leopard cats based on capture-recapture models.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.4
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• pp.35-45
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• 2019

The objective of this study is to analyze habitat distribution on tiger, wolf, and leopard in Joseonwangjosilok. Nowaday, we only come to meet these kind of animals at the historical records because of haman-induced habitat encroachment. Historically, extinct animal became an object of game by people. So, we try to get distribution information for restoration on historical extinct animals. We made distribution map by constructing 402 counts on tiger(350), leopard(51) and wolf(1) recordsfrom 14th to Early 20th century for study. Analyzing historical materials, criteria for data analysis took into account objectivity, location information, accuracy for extinct animals. We carried out location identification of animals by using geocoding comparing with geographical name of the Joseon Dynasty period, topographic map of time under the rule of Japanese imperialism, present place name and historical materials. Database items are constructed 20 types for example appearance year of animal, population, location, damage, etc. As a result of analysis for appearance regions, tigers were recorded in capital area of higher density population intensively, and also were frequently seen at Daegu, Andong etc. Leopard and wolf were founded at regionally Gyeonggi-do and Jinju with limitation, relatively seen a few number. The reason of the appearance records like this, tiger prefer game of open and water-front area in near human residential area, there are lots of historical records such as 'Hosang'(mourning someone who killed by Tiger) and hunting. But leopard and wolf inhabit rocky area and dense forest, the reason why they made a few contact with human. Results of this are expect to be applicable restoration research for extinct animal by providing for populations, habitat environments and distribution information.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.353-357
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• 2001

Differential response of genotypes to temporal environmental heterogeneity may contribute to the long-term persistence of these genotypes within a population. In this experiment, we experimentally tested whether groups by season interactions for germination and seedling growth can explain genetic variability within the population. To determine whether seeds collected during the four seasons respond differentially to temperature treatments, two-way ANOVA was performed. This study indicates that seasonal environments have large effects on demography. Groups within populations respond differentially to seasonal environments by influencing population growth that may in turn influence community composition. Most importantly, the study showed that temporal heterogeneity in the environment might functions as a mechanism that maintains within-population genetic diversity.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.512-523
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• 1995

The central theme of Habital heterogeneity is to provide animals with habital complexity or structural diversity and to allow resource partitioning among individuals. In turn, the leads to population stability because prey can escape more easily with more hiding places causing less population fluctuation. Species diversity is characterized due to more potential niches both horizontally and verticall. Empirically, in homogeneous habitats population was less abundant, reproduction and survival were lower, spacing behavior, competition and dispersal were higher than in heterogeneous habitats. The results imply that diversity and conservation of species can be maintained through providing heterogeneous habitats.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.453-461
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• 1994

Size class structure and vegetative growth of a perennial herb of the temperate deciduous forests, Symplocarpus renifolius Schott, were studied from 1991 to 1994 in Namhansansung, Kyonggi Province, Korea. The size class structures of leaf number and leaf area per individual followed bell-shape curve, i.e. frequency of middle class was relatively high. The leaf area increased from the late-March to mid-May. At the end of the growing season, leaf area(length X breadth) was proportional to biomass, especially aboveground biomass. The leaf number and leaf area per individual increased at the rate of 0.08 leaf/year and 9.7 $cm^2/year$, respectively. The size of the individuals in large-sized classes, in leaf number and leaf area, decreased in next year, while the size of the individuals in small-sized classes increased. Therefore, it was concluded that the size class structure of S. renifolius population was largely determined by the growth form.

• Journal of Ecology and Environment
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• v.37 no.2
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• pp.99-104
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• 2014

We estimated the influence of environmental factors on zooplankton communities at 25 reservoirs during winter (December 2010 to January 2011). Among zooplankton groups, Cyclops vicinus is more dominant during winter, and this is positively related to withered vegetation area and dissolved oxygen level. Therefore, the presence of withered vegetation might be considered as an important factor to determine C. vicinus distribution during winter. We considered that withered vegetation might be utilized as a habitat for C. vicinus, as well as provide an attachment substrate for periphytic algae. Abundance of periphytic algae can lead to high concentration of dissolved oxygen. Although copepods prefer high water temperatures for increasing their population growth, if Cyclops can overcome low temperature stress that leads to disruption of population, their population growth initiation in the next growing season (i.e. next spring) is possibly propelled by the winter population.

• Journal of Species Research
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• v.10 no.1
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• pp.63-71
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• 2021

Anteholosticha bergeri and Bakuella granulifera were isolated from soil samples collected from Muuidong and Songdo-dong, Incheon and confirmed new to South Korea. Including these two newly recorded species, 11 species of Anteholosticha and four species of Bakuella have been recorded in South Korea to date. Anteholosticha bergeri was discriminated from congeners by following characters: cortical granules, 12-16 macronuclei, 5-8 midventral pairs, 2-3 pretransverse cirri, 4-6 transverse cirri, and three dorsal kineties. Bakuella granulifera was identified by cortical granules, 5-11 buccal cirri, 2-5 frontoterminal cirri, 2-5 midventral cirri rows, and 8-12 transverse cirri. The Korean A. bergeri population corresponds to the Austrian population, except for the number of marginal and transverse cirri, and the Korean B. granulifera population corresponds to the Namibian population, except for body size. In addition, small subunit ribosomal RNA(18S rRNA) gene sequences from both species were determined.