• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.272-279
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• 2015

The aim of this study was to assess the interaction between Daphnia similis and various organisms related to the rice paddy ecosystem. We selected several organisms that are likely to prey on D. similis and evaluate predation rate as well as responses of D. similis to the chemical compounds exuded by these organisms. As a result of predation experiment, larval dragonfly (Anax parthenope) and Triops longicaudatus were clearly shown decreasing abundances of D. similis. Especially, Triops longicaudatus was observed higher feeding rates on D. similis than larval dragonfly. Chemical compounds from the vertebrates such as fish (Misgurnus anguillicaudatus, Pseudorasbora parva, Micropterus salmoides) and tadpole of frog (Rana nigromaculata) did not affect the life history of Daphnia. However, a potential predatory fish P. parva induced significantly longer tail spine in Daphnia. In addition, among the invertebrates (T. longicaudatus, A. Parthenope, Micronecta spp., Palaemon paucidens), chemical compounds exuded by T. longicaudatus induced shorter body and significantly longer tail spine in D. similis.

• Journal of Environmental Impact Assessment
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• v.22 no.3
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• pp.277-290
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• 2013

This study was carried out to propose the new procedure to apply Habitat Evaluation Procedure(HEP) of target species using delphi technique, which is suitable to develop endangered species with few researches and ecological knowledges. To identify habitat quality of specific species in development project site, we can develop habitat model and create habitat suitability maps. In this study, we select the Common Kestrel(Falco tinnunculus) as target species in four areas(Paju, Siheung, Ansan, Hwaseong) which is located near the Seoul metropolitan area. The Delphi technique was selected to get the reliable information on the species and habitats requirements. Through the delphi approach, seven habitat components were determined as suitable variables for the Common Kestrel: density($n/km^2$) of small mammals, area($km^2$) of bare-grounds, pasturelands and riparian, and open area(%), spatial distribution and area of croplands, landscape diversity, breeding sites(tall trees, cliffs, high-rise buildings), and the length of shelf. Habitat variables used in this model were classified into two categories: % of suitable land-cover type(open areas, croplands, pasturelands, wetlands, and baregrounds) and the quality of feeding sites(within 250m from edges of woodlands). Habitat quality of the Common Kestrel was assessed against occurred sites derived from the nationwide survey. Predicted habitat suitability map were closely related to the observed sites of the endangered avian species in the study areas. With the habitat suitability map of the Common Kestrel, we assess the environmental impacts with habitat loss after development project in environmental impact assessment.

• Korean Journal of Ecology and Environment
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• v.42 no.4
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• pp.441-451
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• 2009

The major objectives of this study were to evaluate trophic state of reservoirs using major water quality variables and its relations in terms of trophic guilds and tolerance guilds with dominant lentic fishes. For this study, we selected 6 artificial reservoirs such as Namyang Reservoir ($N_yR$), Youngsan Reservoir ($Y_sR$), Daechung Reservoir ($D_cR$), Chungju Reservoir ($Cj_R$), Chungpyung Reservoir ($C_pR$), and Paldang Reservoir ($P_dR$), and collected fish during 2000~2007 along with data analysis of water quality monitored by the ministry of environment, Korea. Biological oxygen demand (BOD) and chemical oxygen demand (COD), indicators of organic matter pollution, varied depending on types of the reservoirs and the spatial patterns in terms of trophic gradients were similar to patterns of nutrients, Secchi depth and chlorophyll-a. Analysis of trophic state index (TSI) showed that reservoirs of $D_cR$ and $C_jR$ were mesotrophy and other 4 reservoirs were eutrophic state. The relations of trophic relations showedthat TSI (Chl-a) had a positive linear function [TSI (CHL)=0.407 TSI (TP)+28.2, n=138, p<0.05] with TSI (TP) but had a weak relation with TSI (TN). Also, TSI (TP) were negatively correlated ($R^2=0.703$, p<0.05) with TSI (SD), whereas TSI (TN) was not significant (p>0.05) relations with TSI (SD). Tolerance guilds of lentic fishes, based on three types of the reservoirs, reflected the exactly water quality in the TN, TP, BOD, and COD, and similar trends were shown in the fish feeding/trophic guilds.

• Journal of the Korean Dietetic Association
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• v.17 no.1
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• pp.58-71
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• 2011

The purpose of this study was to investigate the perceptions of an unbalanced diet by elementary school students using a qualitative approach to nutrition counseling. To achieve the purpose of this study, client-centered counseling was performed over one semester with four volunteer children in the fifth grade who admitted eating an unbalanced diet. Their perceptions of an unbalanced diet were examined while focusing on cause. The contents of the counseling sessions were recorded and their eating habits observed. The proposed perceptions of the clients of an unbalanced diet were as follows: regarding the causes of an unbalanced diet, there may have been a certain negative event or memory related to food as well as an individual disease or history of disease; regarding the meaning of an unbalanced diet, the clients had two kinds of time concepts (formal one and informal one) and defined the meaning of an unbalanced diet as a matter of being able to eat proper amounts of food within an inter-meal time; and regarding the results of an unbalanced diet, they based their results on the approval of their parents and teachers. Feeding at school was used as the background of this study, which examined the meanings and results of an unbalanced diet, and there existed a correlation between the meanings and the results.

• Journal of Ecology and Environment
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• v.30 no.2
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• pp.109-119
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• 2007

The effect of water flow on the growth of Gafrarium tumidum was studied in the field using open cages constructed with stainless steel net and perspex in which holes were drilled. Cages with different flows (25, 50 and 75% of the control) were made by varying the area of perspex being drilled. Reduction in flow rate was directly proportional to the undrilled area, and the mean flow rate of the different treatment groups varied from 3.12 cm/s for the 25% exposure to 12.48 cm/s for the control cages. At the end of the 3-month experiment, no significant differences in sediment characteristics were found among the treatments. Growth in shell length, shell weight and tissue dry weight was, however, positively correlated with flow rate. Percentage increases ranged from $3.0{\sim}8.3%$ for shell length, $9.9{\sim}23.1%$ for shell weight and $17.2{\sim}53.3%$ for tissue dry weight. Condition index of the clam was not significantly different among the treatments. Seston depletion effect could reduce growth in G. tumidum only when water flow was reduced to 25% of the control. G. tumidum also exhibited different responses in shell and tissue growth at low flow rates, in which shell growth continued to decrease as flow rate decreased whereas tissue growth was relatively independent of low flows at 25 and 50% of the control. It was suggested that when seston flux was reduced at slow flows, it would be a better strategy for G. tumidum to channel energy for gonad development instead of shell growth during the reproductive stage.

• Journal of Korean Society of Forest Science
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• v.7 no.1
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• pp.40-44
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• 1968

1. The larvae of the pine gall-midge begin to grow slowly from early July but grow rapidly from September. 2. The number of larvae in the galls does not decrease during the feeding period. 3. Pine needles infested by pine gall-midge cease to grow as soon as the gall starts to form. 4. In Seoul district the effective felling season of the pine trees for the Control of the pine gall-midge seems to be around 20th September when the size of larvae reaches 1.4-1.5mm in length. 5. The stratification and direction of the Crown, and the length of new shoot had no effect on the degree of infestation by pine gall-midge. However the degree of infestation differed among the trees of different ages as well as at the different levels of the mountain.

• Mycobiology
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• v.49 no.3
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• pp.223-234
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• 2021

Itajahya rosea was found growing in association with Leucaena leucocephala plants at Savitribai Phule Pune University campus in India. The species identity was confirmed by phylogenetic analysis based on ITS and LSU regions of rDNA, wherein, our fugus was placed along with I. rosea in phylogenetic tree. It represents first record of I. rosea from India. Frequent visitation by Drosophila species on I. rosea fruiting body particularly on gleba was observed. The Drosophila got attracted to the detached gleba under the laboratory conditions and even sometimes, they prefer to sit over the gleba as compare to their food banana. It suggested that I. rosea gleba or pseudostipe produces some compounds for attraction and feeding behavior of Drosophila species. Therefore, we characterized the volatile attractants produced by gleba and pseudostipe of I. rosea by GC-MS analysis. Nineteen compounds were identified from gleba while nine compounds were recovered from the pseudostipe. Out of them, blends of three abundant odor producing volatile compounds were reported namely, Hexadecane, Pentadecane and Nonadecane, which are responsible for attraction of Drosophila toward the gleba. Three fatty acids namely 9,12-octadecadienoic acid (Z,Z), hexadecanoic acid and benzoic acid ethyl ester produced are served as an appetitive signal through olfactory response of Drosophila, so the flies were feed on the gleba. Two pheromones' compounds, heneicosane and (+)-(5S,9S)-5,9-dimethylpentadecane, were also reported in pseudostipe and gleba, respectively, which play a role in Drosophila for breeding. Our study highlights an intriguing chemical ecology of fungus-Drosophila interaction.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.163-169
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• 2021

Background: Understanding the habitat characteristics of the endangered Siberian flying squirrel Pteromys volans is the first step in conserving and managing the forests it requires for nesting, gliding, and feeding. Therefore, in the present study, we characterized the habitats of P. volans using GIS analysis of 411 forest sites in South Korea where fecal droppings were found. Results: Fecal signs of P. volans were found in various regions in South Korea, including the Baekdudaegan Mountains. GIS analysis with six environmental layers (vegetation type, wood-age class, diameter at breast height [DBH], crown density, elevation, and distance from stream) revealed that fecal signs of P. volans were more frequently found in broad-leaved deciduous forests (42%) located 200-399 m above sea level (43.1%) and 0-199 m from the nearest stream (53%), with 5th class wood-age (35.3%), middle size class DBH (51.1%), and high crown density (71%). Conclusions: The present study provides information on the biotic and abiotic characteristics of P. volans habitats. In South Korea, the fecal droppings of P. volans were found predominantly old deciduous broadleaf forests. Further studies are needed to reveal whether the more frequent occurrence of P. volans dropping in broadleaf forests may be due to a particular preference of this species for the forests or to a simple reflection of the area of the broadleaf forests occupying a much larger area than other forest types in Korea.

• Animal Bioscience
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• v.37 no.1
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• pp.74-83
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• 2024

Objective: Mitragyna speciosa Korth is traditionally used in Thailand. They have a high level of antioxidant capacities and bioactive compounds, the potential to modulate rumen fermentation and decrease methane production. The aim of the study was to investigate the different levels of microencapsulated-Mitragyna leaves extracts (MMLE) supplementation on nutrient degradability, rumen ecology, microbial dynamics, and methane production in an in vitro study. Methods: A completely randomized design was used to assign the experimental treatments, MMLE was supplemented at 0%, 4%, 6%, and 8% of the total dry matter (DM) substrate. Results: The addition of MMLE significantly increased in vitro dry matter degradability both at 12, 24, and 48 h, while ammonia-nitrogen (NH₃-N) concentration was improved with MMLE supplementation. The MMLE had the greatest propionate and total volatile fatty acid production when added with 6% of total DM substrate, while decreased the methane production (12, 24, and 48 h). Furthermore, the microbial population of cellulolytic bacteria and Butyrivibrio fibrisolvens were increased, whilst Methanobacteriales was decreased with MMLE feeding. Conclusion: The results indicated that MMLE could be a potential alternative plant-based bioactive compound supplement to be used as ruminant feed additives.

• Journal of Environmental Impact Assessment
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• v.25 no.6
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• pp.477-486
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• 2016

We investigated the growth pattern of Red-tongued viper snakes (Gloydius ussuriensis), which were captured from the islet of the Jeju Island, Gapado between April, 2006 and November, 2009. The results indicated that there were some snakes that grew relatively fast, but most snakes either almost did not grow or grew around 10mm in snout-vent length during one year period. High growth rates was April and June. Since the growth rate of snakes is highly correlated with their foods, these results implied that the feeding activity of Red-tongued viper snakes is high during this period compared to other months. In female, difference in body condition between good-conditioned and bad-conditioned snakes became large as time elapsed from April to June. The body condition of the male Red-tongued viper snakes improved with the progression of time from April till June. Many of the Red-tongued viper snakes were captured between April and June, while they were rarely captured between July and September. Some of the Red-tongued viper snakes were captured during the autumn season. This tendency was because snakes were rarely active during hibernation and peak summer seasons. Thus, Red-tongued viper snakes are active between April and June and between September and November. They then go into hibernation as the temperature dropped in November. Furthermore, the limitation of the movement period of the Red-tongued viper snakes restricted their feeding activities while foods became scarce, which ultimately restricted their overall growth rate. The growth rate of the snakes decreased with age. The snout-vent length of the Red-tongued viper snakes and growth rate showed a negative correlation (r = -0.591), however, it was not statistically significant due to small sample size. The findings from this study could provide meaningful information in the further study of the life cycle of Red-tongued viper snakes.