• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.74-88
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• 2021

In the present study, the characteristics and changes in the vegetation of Mt. Cheongryang, Inchon, were examined to identify and determine appropriate ways to restore the health of the urban forest and to preserve its vegetation. The vegetation of the community of Quercus mongolica (Mongolian oak) on Mt. Cheongryang appeared to decrease in response to the control of the wilt disease of oak trees. The communities of Sorbus alnifolia (Korean mountain ash) and Styrax japonicus (Snowbell tree) have increased. Pinus rigida (Pitch Pine) had its overall territory decrease, but the current state of the Pinus rigida (Pitch Pine) was estimated to be stable due to its dominance as a tree layer species. In regards to Robinia pseudoacacia (Black Locust), the urbanized species of Sorbus alnifolia (Korean mountain ash), and Styrax japonicus (Snowbell tree), their areas have increased with the appearance of Magnolia obovate (Whiteleaf Japanese Magnolia). The biodiversity of Mt. Cheongryang has decreased by simplifying species in the tree layer and understory species thereof, and the initial success of species in marginal areas has increased. The absence of potential succession was attributed to the termination of ecological succession; thereby, the current vegetation structure was concluded to be remaining as it is for the time being. Soil texture in the mountain primarily consisted of sandy loam or loamy sand; the pH of the soil was in the range 4.26-4.86, rendering a mean pH of 4.59. The content of organic matter (O.M.) appeared having a distributing range of 2.18-9.60%, rendering a mean value of 4.33%. To promote species diversity, several methods are suggested, such as prevention of soil acidification, selecting nationally-grown trees from moist soil or valleys for afforestation, preventing species appearing due to urbanization or excessive growth, protecting the understory vegetation and species with hygropreference, and managing the forest to maintain a multi-layered vegetation structure.

• Korean Journal of Ecology and Environment
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• v.52 no.2
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• pp.143-150
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• 2019

Although inconspicuous marsh birds are an indicator of marsh health, there is little understanding of their status and population trends due to their behavioral characteristics and lack of reliable survey methods in Korea. We applied the Standardized North American Marsh Bird Monitoring Protocols(SNAMBMP) already validated in North America for effective survey of the marsh birds. We selected 29 sites with emergent marshes, rice fields and riparian forests in Seocheon-gun, Buyeo-gun and Gunsan-si. We conducted the survey with a combination of passive 5 minute point-count and vocal survey method (30 seconds call-broadcasting+30 seconds silence) that was targeted eight species 2~7 times/site from March to July 2017. Four species, Brown-cheeked Rail(Rallus indicus), Ruddy-breasted Crake (Porzana fusca), Watercock (Gallicrex cinerea) and Greater Painted-snipe (Rostatula benghalensis), were detected at one site respectively (naïve occupancy rate=0.035). Vocal survey method with conspecific call-broadcasting provided better on Brown-cheeked Rail and Watercock than the others. We suggest a combination of passive point-count and vocal survey method like SNAMBMP to monitor inconspicuous marsh birds at nationwide scale and collection of sound files through recording of the entire process during the survey.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.278-286
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• 2021

The habitat characteristics and feeding ecology of the Siberian stone loach Barbatula toni were investigated in Bukcheon (Stream), Eocheonri, Ganseong-eup, Goseong-gun, and Gangwon-do, Korea from January to December 2013. B. toni lived in rapids or slow rapids from the upper stream to downstream, with the largest number of inhabitants in the middle-downstream regions. As a result of analyzing habitat preferences by age, 0+ and 1+ to ≥3+ showed differences. Ages of 0+(juveniles) lived mainly in rapidly flowing water (37.6±26.79 cm/sec) and low water depths (13.3±9.47 cm) in the pebble bottoms (substratum particle size 9.5±6.66 cm), but ages 1+ to ≥3+ lived mainly in relatively slowly flowing water (13.3±17.33 cm/sec) and relatively deep depths (25.9±10.31 cm) in stone and large stone bottoms (substratum particle size 18.0±7.63 cm). B. toni was mainly eaten from March to December when the temperature was above 5℃, and the amount of food eaten peaked in June and October. Their main food sources analyzed by the index of relative importance (IRI) included Diptera (57.0%), Ephemeroptera (29.3%), and Trichoptera (13.5%). The juveniles (age 0+) fed on small-sized prey such as Diptera and Trichoptera whales, but as they grew, they mainly ate large-sized Ephemeroptera. These feeding habits and changes in food according to the growth of B. toni were very similar to those of sibling species, B. nuda.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.166-174
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• 2013

Analysis of the fish community in the Lagoon Cheongcho, Korea, was investigated in 2008 and in 2012. A total 48 species, belonging to 26 falmilies, were sampled during the period. The dominant species was Tribolodon hakonensis (75.2%), and subdominant species were Acanthogobius flavimanus (5.4%), Pungitius kaibarae (3.1%). The results of the fish ecotypes according to origin of water body was compared by surveyed year, freshwater fish was reduced, whereas those of brackish water and seawater fishes were increased. Moreover, the result of similarity analysis based on species and individuals in five lagoons were divided into 2 major groups based on their similarity, and Lagoon Cheongcho was included group 'A' with Lagoon Gyeongpo, as having a montinous inflow of seawater. Hence, according to the characterization according to the analysis of fish community, Lagoon Cheongcho has lost the characteristics of a lagoon, and oceanization is considerably progressed. Therefore, we are considering the provision of a management strategy for hydrarch succession, as well as continuous research, in order to manage the recovery of essential characteristics of the lagoon ecosystem. Hence, according to the characterization according to the analysis of fish community, Lagoon Cheongcho has lost the characteristics of a lagoon, and oceanization is considerably progressed. Therefore, we are considering the provision of a management strategy for hydrarch succession, as well as continuous research, in order to manage the recovery of essential characteristics of the lagoon ecosystem.

• The Korean Journal of Ecology
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• v.25 no.2
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• pp.93-100
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• 2002

In order to analyze the life cycle of A. artemisiifolia var. elation dormancy and some environmental factors inducing germination of the seeds were examined. The results were as follows : Dormancy of fertile seeds was broken in part within a month after seed collection in case of adequate moisture and alternating temperature was also effective in breaking dormancy. The temperature range, which allow germination was 12℃ ∼ 32℃. Optimum temperature for germination was 24℃. The seed of A. artemisiifolia var. elatior was light-independent. The difference of storage period appeared to have no particular effect on the viability of seeds at any time during the 9-month storage period. In the increasing temperature(IT) regime, A artemisiifolia var. elatior seeds started to germinate at 16℃, showing the higher temperature the greater germination rate, the final germination percentage was 99.34%. On the other hand, in the decresing temperature(DT) regime, seeds began to germinate at 20℃ with the 1.34% germination. An induced dormancy occurred at 12℃ making the 5.34% fecal germination in the DT regime. Low temperature was more effective to break dormancy than higher temperature Seeds of A. artemisiifolia var. elatior seems to be germinated in mid to late autumn or germination delayed until following spring. The above results suggest these variation of germination response in diverse environmental factors seems to be a physiological strategy to maintain their existence and to reproduce in the extreme thermal variation.

• Korean Journal of Environment and Ecology
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• v.24 no.3
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• pp.318-324
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• 2010

The aim of this study is to examine feeding habits of the Korean water deer(Hydropotes inermis argyropus) from its rumen contents using a PCR-DGGE method. For this study, rumen contents were collected from water deer causalities by natural death or road-kill in two different sites(Cheorwon, Gangwon province and the Eastern part of Jeonnam province). DNA was extracted from rumen contents of a total of 44 individuals. Two primers, rbcLZ1aF(GC) and rbcL19bR, were used for PCR amplifications of ribulose-1,5-bisphosphate carboxylase large subunit (rbcL) gene. Among 44 samples, twenty-nine samples were successfully amplified by PCRs. The 29 PCR products of partial rbcL gene were applied for PCR-DGGE. Totally, six families of plants were detected from the diet analyses. Five families of plants were found in Cheorwon, Gangwon province, but only three families of plants were found in the Eastern part of Jeonnam province. The PCR-DGGE method will provide us with a potential tool to study feeding habits of ungulates including water deer, even though our results failed to identify the prey plants at the level of species.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.305-321
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• 2006

Atmospheric Acid Deposition: Nitrogen Saturation of Forests: Volume weighted annual average wet deposition of nitroge at 33 sites in Korea during 1999-2004 ranged 7.28 to $21.05kgN{\cdot}ha^{-1}{\cdot}yr^{-1}$ with average $12.78kgN{\cdot}ha^{-1}{\cdot}yr^{-1}$, which values are similar level with nitrogen deposition of Europe and North America. The temperate forests that suffered long-term high atmospheric nitrogen deposition are gradually saturated with nitrogen. Such nitrogen saturated forest watersheds usually leach nitrate ion ($NO_3^-$) in stream water and soil solution. It may be likely that Korean forest ecosystems are saturated by much nitrogen deposition. In leaves with nitrogen saturation ratios of N/P, N/K and N/Mg are so enhanced that mineral nutrient system is disturbed, suffered easily frost damage and blight disease, reduced fine-root vitality and mycorrhizal activity. Consequently nitrogen saturated forests decrease primary productivity and finally become forest decline. Futhermore understory species are replaced the nitrophobous species by the nitrophilous one. In soil with nitrogen saturation uptake of methane ($CH_4$) is reduced and emission of nitrogen monoxide (NO) and nitrous oxide ($N_{2}O$) are increased, which gases are greenhouse gas accelerating global warming.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.319-327
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• 2000

The feeding behavior of 1-year-old silver carp, Hypophthalmichthys molitrix (Val.) on phytoplankton species in a shallow hypertrophic lake was studied from 22 May to 18 September, 1997. Over the experimental period, the filter-pore sizes of the fish, the total biomass of the phytoplankton and the water temperature in each enclosure changed little with time. The fish biomass in each enclosure increased with time, while their percentage of weight gain correlated negatively to the stocking density, due perhaps to competition for prey. An analysis of gut contents of silver carp showed a strong similarity between the algal communities in the foregut and the water, and was significant for the fish enclosure with a low density (p<0.05). The presence of silver carp rarely suppressed the abundance of phytoplankton such as Oscillatoria, Anabaena and Melosira even at high ingestion levels. There were weak relationships between the IU values of each phytoplankton and the selectivity of fish on them (r = 0.001, p>0.5). There was no doubt that the silver carp fed unselectively when cyanobacteria populations were high, even though the selectivity index for diatoms was slightly higher than those for cyanobacteria, green algae and cryptomonads. Improvements in methodologies are needed to clearly understand and generalize the feeding behavior of silver carp.

• Journal of Korean Society of Forest Science
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• v.103 no.2
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• pp.307-312
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• 2014

Wild boar have increased in recent years in Korea where damage to agricultural crops is considered as a social issue. The ecological studies on wild boar are essential for the effective management in the future. During May and December 2012, We collected 79 wild boar stomach samples from culling program implementation to reduce agricultural damage in Geochang County and analyzed stomach contents to figure out wild boar diet habit and which crop was preferred. There was seasonal variation in the diet. Plant foods represented up to 93.5% of the diet and were consumed more frequently than animal foods. Invertebrates occurred with high frequency but were underestimated in dry weight because they are rapidly digested. Agricultural crops consumed comprised mainly chestnuts(33%), rice(33%), and apples(24%). Agricultural crops are also a potentially important food resources for wild boar. The frequency of occurrence of earthworms was 50% of diet. Earthworm consumption generally increased in summer, and then decreased in winter. Our results show that wild boar can be considered an omnivore whose diet consists of plant and animal foods. To reduce wild boar agricultural damages, We have to focus on the prevention effort to rice paddy adjacent to chestnut forest and to apple orchard.