• Journal of Forest and Environmental Science
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• v.26 no.3
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• pp.171-179
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• 2010

Effect of chromium (Cr) stress on antioxidant enzyme activities and malondialdehyde (MDA) content were investigated in leaves and roots of mangrove (italic (L.) Druce) seedlings. Cr toxicity effects were also assessed on young seedlings. The seedlings were grown in green house condition for three months in nutrient solution with 0, 0.5, 1, 1.5, 2, 2.5, and 3 mg $L^{-1}$ $CrCl_3$. This study showed that Cr led to the change of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and activities at different concentrations. The activity of antioxidant enzymes in leaves of K. candel seedlings indicates that enzymes engaged in antioxidant defense in certain level especially in low concentration of Cr treatments. The activities of SOD and POD were activated by Cr in the root level, while CAT activity was inhibited. CAT activity decreased in response to high concentrations of Cr. In the present study indicated that SOD in root was active in scavenging the superoxide produced by Cr. Both in roots and leaves, an increase in malondialdehyde (MDA) content was observed with increase in metal concentration and exposure periods. Our finding indicated that the high concentration of excessive Cr supply may interfere with several metabolic processes of seedlings, causing toxicity to plants as exhibited by chlorosis, necrosis, photosynthetic impairing and finally, plant death.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.361-367
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• 2022

This study was conducted to identify annual variation of observation and activity pattern of Korean chipmunk (Tamias sibiricus) using camera traps in the Seoraksan and Jirisan National Parks, South Korea from May 2019 to May 2021. The annual variation was identified based on the observed frequency through weekly observations. Daily activity patterns of the species were also analyzed by season. The daily activity pattern of chipmunk appeared to be constantly diurnal across the years regardless of habitat or season. The Korean chipmunks living in the two different regions were observed in different time periods throughout the year. While the chipmunks inhabiting the Seoraksan were observed from 18^th to 45^th week, the chipmunks inhabiting the Jirisan National Park were observed from 7^th to 48^th week. This may be influenced by the hibernation period of chipmunks in the two different regions. In both regions, chipmunks were most frequently observed in autumn. It is considered that seasonal variation on population dynamic and activity patterns of chipmunks were reflected in the observation frequency. Although the observation frequency of camera trap is an indirect indicator and thus having a limitation that it cannot distinguish the population density and amount of activity for the target species, camera trapping is still an effective survey technique for monitoring mammals due to its high accessibility and easy use.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.169-173
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• 2000

Seasonal distribution of ectomycorrhizal associations in various types of forest in a boreal forest in Manitoba. Canada was investigated. Alsohe relationship between ectomycorrhizal growth and pine pollen nutrients was examined. In four different forest stands, ectomycorrhizas tended to be lower in the spring than in the summer and fall samples. In addition. a mature jack pine (Pinus banksiana) stand showed higher mycorrhizal activities than a young jack pine stand. Growth of Suillus brevipes hyphae wa ts stimulated by additions of pollen representing mean pollen deposition in Mistik Creek study area after 30 and 70 days of growth with dextrose availability. This result suggests that the peak ectomycorrhizal activity is followed by pollen deposition in the study region and therefore, addition of pine and spruce pollen in early or middle of June in the boreal forest can be an important seasonal nutrient source for ectomycorrhizal growth.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.141-150
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• 2015

Thirty-two actinomycetes isolates from Korean forest soil were screened for their nematicidal and reproduction suppression activity against pine wood nematode (PWN) which is widely spread in Korea. Culture filterates of 21 isolates showed more than 90% mortality at 2-fold concentration. Among them, AM210, SG16, YD116 and YD315 were more effective than others on reproduction of PWN. The YD116 isolate was identified as Streptomyces atratus by morphological and 16S rDNA analyses. Hydrazine hydrate, similar to hydrazidomycin which has cytotoxicity among substances from S. atratus against PWN, was tested for its nematicidal activity. Ten ppm of the hydrate showed 60.8% mortality. Additional studies are needed for practical use of the S. atratus YD116 isolate.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.247-254
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• 2015

Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.333-340
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• 2019

As the number of students in the multicultural background grows, the interest in their education is also increasing. The purpose of this study is to investigate the effect of forest healing factors on the improvement of language ability and ego-resilience of students from multicultural families. We conducted an after-school forest healing program of ten male and ten female middle school students of a multicultural preparatory school located in ${\bigcirc}{\bigcirc}$-dong in Cheongju, Chungnam Province. The experiment consisted of a total of 12 weekly one-hour (60 minutes) programs from April 12, 2018 to June 26, 2018. The forest healing program is an activity that uses the various environmental factors that exist in the forest to increase the immunity of the human body and restore physical and mental health. To determine the difference in ego-resilience before and after the program, we conducted a paired t-test and analyzed with the SPSS 18.0 program. The results showed that the ego-resilience significantly improved in all sub-factors including the positive thinking ability, problem-solving ability, intimacy ability, emotional adjustment ability, and autonomic behavior ability (p<.001). The descriptive statistics of the language ability showed the improvement in writing errors, pronunciation errors, sentence errors, tense errors, and errors in research and connection. We expect the results of this study can be used as the basic data to improve ego-resilience and language acquisition ability of middle-entry children and students from multicultural families.

• Korean Journal of Child Studies
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• v.35 no.4
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• pp.223-247
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• 2014

This study aimed to verify the positive effects of forest activities for children from economically underprivileged households in local children's centers and the effect of such activities on the protective factors of their development. One hundred and eighty five children participated in the Forest Activities Program, which conducted over a total 8 sessions. Pre-post tests of the subjective well-being scale, DAS, multiple life satisfaction scale, ego-resilience scale were conducted and the children then made picture stories during the program itself. The results of the analysis of differences between pre-post tests were as follows: first, the negative emotions of participating children decreased significantly. Second, the school-satisfaction and self-satisfaction levels of the participating children increased. Third the participating children's positive perceptions of self and interpersonal relationships also increased through the forest activities. Finally, there were differences of the change types of picture stories that children created while they were participating in the program; and these divergences were related to the effectiveness of the program. These forest activities had positive effects upon the economically disadvantaged children who participated in this study. However, in order to increase the effects of such forest activities qualitatively, greater support for the active involvement of children is required.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.479-490
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• 2009

This research was carried out to understand the actual condition of Forest Management Agency System, Cooperative Forest Program and People's Forest Program with Public Participation and to boost the program. To carry out a quantitative survey among selected 5 Regional Forest Service and 27 National Forest Office, we investigated the activity-awareness concepts of officers on Importance, Performance, and problems of program. As a results, the difference of understanding on National Forest Management System involved with the results of agreement achieved. Also most serious problem of Forest Management Agency System were the shortage of participation will and the limitation of security benefit. The prime reason for the program problem is lack of investment in People's Forest Program. The final results on survey of National Forest Management System with the Importance and Performance as followed. It indicated that I(Keep Up Good Work) have 5 Factors, II(Concentrate Here) have 2 Factors, III(Low Priority) have 6 Factors, and IV(Possible Overkill) have 2 Factors. Base on above investigation, we finally suggest that new organization exclusive responsible for the improvement of management and encouragement of Build Transfer Operate.

• The Journal of the Korean Institute of Forest Recreation
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• v.22 no.4
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• pp.49-58
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• 2018

The purpose of this study was to investigate the effect of weekend forest healing programs using urban forest on family cohesion and family relationship improvement and parental satisfaction with programs. 21 families (65 people)participated in the weekend forest healing program in Incheon Grand Park from April to August 2018. The program using family forest experience activity and forest healing therapy was newly constructed and implemented with 4 times 8 hours for 2 hours each week. The results of this study is that weekend forest healing programs for family gave a positive effect on family cohesion and family relationship, and parents' satisfaction showed high satisfaction in most items. Therefore, we concluded that forest healing activities are suitable for effective healing activities in modern society where functions such as family cohesion and emotional bond are recognized as important by improving family cohesion and family relationship. Further research should be extended to different types of families, and the development of diverse and interesting family-experience forest healing programs that reflect family needs should continue.

• Parasites, Hosts and Diseases
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• v.60 no.5
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• pp.339-344
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• 2022

The development of drug resistance is one of the most severe concerns of malaria control because it increases the risk of malaria morbidity and death. A new candidate drug with antiplasmodial activity is urgently needed. This study evaluated the efficacy of different dosages of aqueous extract of Strychnos ligustrina combined with dihydroartemisinin and piperaquine phosphate (DHP) against murine Plasmodium berghei infection. The BALB/c mice aged 6-8 weeks were divided into 6 groups, each consisting of 10 mice. The growth inhibition of compounds against P. berghei was monitored by calculating the percentage of parasitemia. The results showed that the mice receiving aqueous extract and combination treatment showed growth inhibition of P. berghei in 74% and 94%, respectively. S. ligustrina extract, which consisted of brucine and strychnine, effectively inhibited the multiplication of P. berghei. The treated mice showed improved hematology profiles, body weight, and temperature, as compared to control mice. Co-treatment with S. ligustrina extract and DHP revealed significant antimalarial and antipyretic effects. Our results provide prospects for further discovery of antimalarial drugs that may show more successful chemotherapeutic treatment.