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The Impact of Market Environments on Optimal Channel Strategy Involving an Internet Channel: A Game Theoretic Approach (시장 환경이 인터넷 경로를 포함한 다중 경로 관리에 미치는 영향에 관한 연구: 게임 이론적 접근방법)

  • Yoo, Weon-Sang
    • Journal of Distribution Research
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    • v.16 no.2
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    • pp.119-138
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    • 2011
  • Internet commerce has been growing at a rapid pace for the last decade. Many firms try to reach wider consumer markets by adding the Internet channel to the existing traditional channels. Despite the various benefits of the Internet channel, a significant number of firms failed in managing the new type of channel. Previous studies could not cleary explain these conflicting results associated with the Internet channel. One of the major reasons is most of the previous studies conducted analyses under a specific market condition and claimed that as the impact of Internet channel introduction. Therefore, their results are strongly influenced by the specific market settings. However, firms face various market conditions in the real worlddensity and disutility of using the Internet. The purpose of this study is to investigate the impact of various market environments on a firm's optimal channel strategy by employing a flexible game theory model. We capture various market conditions with consumer density and disutility of using the Internet.

    shows the channel structures analyzed in this study. Before the Internet channel is introduced, a monopoly manufacturer sells its products through an independent physical store. From this structure, the manufacturer could introduce its own Internet channel (MI). The independent physical store could also introduce its own Internet channel and coordinate it with the existing physical store (RI). An independent Internet retailer such as Amazon could enter this market (II). In this case, two types of independent retailers compete with each other. In this model, consumers are uniformly distributed on the two dimensional space. Consumer heterogeneity is captured by a consumer's geographical location (ci) and his disutility of using the Internet channel (${\delta}_{N_i}$).
    shows various market conditions captured by the two consumer heterogeneities.
    (a) illustrates a market with symmetric consumer distributions. The model captures explicitly the asymmetric distributions of consumer disutility in a market as well. In a market like that is represented in
    (c), the average consumer disutility of using an Internet store is relatively smaller than that of using a physical store. For example, this case represents the market in which 1) the product is suitable for Internet transactions (e.g., books) or 2) the level of E-Commerce readiness is high such as in Denmark or Finland. On the other hand, the average consumer disutility when using an Internet store is relatively greater than that of using a physical store in a market like (b). Countries like Ukraine and Bulgaria, or the market for "experience goods" such as shoes, could be examples of this market condition. summarizes the various scenarios of consumer distributions analyzed in this study. The range for disutility of using the Internet (${\delta}_{N_i}$) is held constant, while the range of consumer distribution (${\chi}_i$) varies from -25 to 25, from -50 to 50, from -100 to 100, from -150 to 150, and from -200 to 200.
    summarizes the analysis results. As the average travel cost in a market decreases while the average disutility of Internet use remains the same, average retail price, total quantity sold, physical store profit, monopoly manufacturer profit, and thus, total channel profit increase. On the other hand, the quantity sold through the Internet and the profit of the Internet store decrease with a decreasing average travel cost relative to the average disutility of Internet use. We find that a channel that has an advantage over the other kind of channel serves a larger portion of the market. In a market with a high average travel cost, in which the Internet store has a relative advantage over the physical store, for example, the Internet store becomes a mass-retailer serving a larger portion of the market. This result implies that the Internet becomes a more significant distribution channel in those markets characterized by greater geographical dispersion of buyers, or as consumers become more proficient in Internet usage. The results indicate that the degree of price discrimination also varies depending on the distribution of consumer disutility in a market. The manufacturer in a market in which the average travel cost is higher than the average disutility of using the Internet has a stronger incentive for price discrimination than the manufacturer in a market where the average travel cost is relatively lower. We also find that the manufacturer has a stronger incentive to maintain a high price level when the average travel cost in a market is relatively low. Additionally, the retail competition effect due to Internet channel introduction strengthens as average travel cost in a market decreases. This result indicates that a manufacturer's channel power relative to that of the independent physical retailer becomes stronger with a decreasing average travel cost. This implication is counter-intuitive, because it is widely believed that the negative impact of Internet channel introduction on a competing physical retailer is more significant in a market like Russia, where consumers are more geographically dispersed, than in a market like Hong Kong, that has a condensed geographic distribution of consumers.
    illustrates how this happens. When mangers consider the overall impact of the Internet channel, however, they should consider not only channel power, but also sales volume. When both are considered, the introduction of the Internet channel is revealed as more harmful to a physical retailer in Russia than one in Hong Kong, because the sales volume decrease for a physical store due to Internet channel competition is much greater in Russia than in Hong Kong. The results show that manufacturer is always better off with any type of Internet store introduction. The independent physical store benefits from opening its own Internet store when the average travel cost is higher relative to the disutility of using the Internet. Under an opposite market condition, however, the independent physical retailer could be worse off when it opens its own Internet outlet and coordinates both outlets (RI). This is because the low average travel cost significantly reduces the channel power of the independent physical retailer, further aggravating the already weak channel power caused by myopic inter-channel price coordination. The results implies that channel members and policy makers should explicitly consider the factors determining the relative distributions of both kinds of consumer disutility, when they make a channel decision involving an Internet channel. These factors include the suitability of a product for Internet shopping, the level of E-Commerce readiness of a market, and the degree of geographic dispersion of consumers in a market. Despite the academic contributions and managerial implications, this study is limited in the following ways. First, a series of numerical analyses were conducted to derive equilibrium solutions due to the complex forms of demand functions. In the process, we set up V=100, ${\lambda}$=1, and ${\beta}$=0.01. Future research may change this parameter value set to check the generalizability of this study. Second, the five different scenarios for market conditions were analyzed. Future research could try different sets of parameter ranges. Finally, the model setting allows only one monopoly manufacturer in the market. Accommodating competing multiple manufacturers (brands) would generate more realistic results.

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  • The Effects of Seaweed Gongjindan on Estrogen like Activities, Platelet Aggregation and Serum Lipid Levels in Ovariectomized Rats (해조공진단의 에스트로겐 유사활성 및 난소를 절제한 흰쥐의 혈소판 응집과 혈청 내 지질 조성에 미치는 영향)

    • Jeon, Myeongjeong;Kim, Seoyeon;Kim, Bo-Kyung;Cheon, Jihyeon;Park, Seong-Hwan;Oh, Eunjin;Lee, Sang-Hyeon;Kim, Mihyang
      • Journal of Life Science
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      • v.23 no.9
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      • pp.1155-1162
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      • 2013
    • Estrogen like activities were evaluated using ethanol and hot water extracts of gongjindan (GJD) and 3 types of brown algae by an in vitro detection system. Laminaria japonica and Undaria pinnatifida represented statistically significant (p<0.001) estrogen like activities, while GJD and Ecklonia stolonifera did not. Furthermore, activities of hot water extracts ($500{\mu}g/ml$) of Laminaria japonica and three mixture (Ecklonia stolonifera : Undaria pinnatifida : Laminaria japonica, 1: 1: 1) were stronger than that of $10^{-7}M$ $17{\beta}$-estradiol. These results suggest that Laminaria japonica contain estrogen like compounds. Based on these results, the prepared seaweed GJD were used for animal experiments about the effects on inhibition of platelet aggregation and serum lipid levels in ovariectomized rats. 9-week Old female SD-rats were randomly assigned to 3 groups as sham-operated rats, ovariectomized rats and ovariectomized rats that were treated with GJD. The rats were placed on prescribed diets for 5 weeks following ovariectomy. Total cholesterol and triglyceride contents on serum decreased in the SHAM group compared to the OVX-CON group. 5 weeks feeding of GJD resulted in significant lowering of triglyceride and a decreasing tendency of total cholesterol level. The level of HDL-cholesterol on serum increased significantly by feeding diets containing the GJD. The ability of platelet aggregation of group treated with GJD was less than that of the OVX-CON group. These results suggest that the beneficial effects of seaweed gongjindan may be used to improve menopausal syndrome.

    Metabolizing analysis according to the sawdust media of Pleurotus ostreatus (산겨릅나무와 옻나무 톱밥배지에서 재배한 느타리버섯의 함유성분 분석)

    • Shin, Yu-Su;Yang, Bo-Hyun;Kang, Bo-Yeon;Kim, Hyun-Soo;Lee, Ji-Hyun;Hong, Yoon-Pyo;Lee, Sang-Won;Lee, Chan-Jung;Kim, Seung-Yoo
      • Journal of Mushroom
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      • v.9 no.4
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      • pp.194-197
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      • 2011
    • The transitivity of Chemical constituents by Pleurotus ostreatus cultivated in different raw sawdusts, which are Acer tegmentosum MAX, Rhus verniciflura, was investigated. The HPLC chromatography patterns on the chemical constituents of P. ostreatus showed the similar chromatography patterns in the different raw sawdusts and control sawdust. The unknown chemical constituents of P. ostreatus cultivated in the mixed medium added 10 %, 20% raw sawdusts, respectively, were increased. But the significance results in the mixed medium added 50% raw sawdusts were not showed. The chromatography patterns of mycelia grown in media added the 80% MeOH extracts of A. tegmentosum and R. verniciflura showed the similar patterns in comparison with control mycelia. In the results, the secondary metabolites of functional media were not degrade and changed to other derivatives compounds by P. ostreatus.

    Pollutant Loading and Changes of the Self - Purification Capacity with Season in Gokneung Stream Ecosystem (곡릉천 생태계의 오염부하량과 계절에 따른 자정능의 변화)

    • 이선경;심규철;김재영;김준민;장남기
      • The Korean Journal of Ecology
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      • v.17 no.3
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      • pp.355-366
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      • 1994
    • The purpose of this study was to investigate the changes of water quality and the patterns of self-purification with season in Gokneung stream. The vegetation in the ecosystem around Gokneung stream was dominated by Quercus species. In the physicochemical analysis based on the contents of DO, BOD, conductivity and total phosphorus, the upstream seemed to have been polluted, but the downstream was self-purified. In biological investigation by bentic macroinvertebrates, the result was similar to that in the physicochemical analysis. The self-purification constant based on BOD of the upstream, 1.013, was the highest. In the self-purification constants with month, that of September was 0.995 and that of January was 0.272. These results indicated that the self purification capacities of spring and autumn were larger than those of winter and summer in Gokneung stream.

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    Distributions of 137Cs and 90Sr in the Soil of Uljin, South Korea (울진토양에서의 137Cs 및 90Sr 분포)

    • Song, JiYeon;Kim, Wan;Maeng, Seongjin;Lee, Sang Hoon
      • Journal of Radiation Protection and Research
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      • v.41 no.1
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      • pp.49-55
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      • 2016
    • Background: For the purpose of baseline data collection and enhancement of environmental monitoring the distribution studies of $^{137}Cs$ and $^{90}Sr$ in the soil of Uljin province was performed and the relation between surface soil activities and soil properties (pH, TOC and median of the surface soil) was analyzed. Materials and Methods: For 14 spots within 10 km from the NPP surface soil samples were collected and soils for depth profile were sampled for 3 spots in April 2011. Using ${\gamma}$-ray spectrometry with HPGe detector, the concentrations of $^{137}Cs$ were determined and the concentrations of $^{90}Sr$ were measured by counting ${\beta}$-activity of $^{90}Y$ (in equilibrium with $^{90}Sr$) in a gas flow proportional counter. Results and Discussion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ were $<0.479-39.6Bq{\cdot}(kg-dry)^{-1}$ (avg. $7.51Bq{\cdot}(kg-dry)^{-1}$) and $0.209-1.85Bq{\cdot}(kg-dry)^{-1}$ (avg. $0.74Bq{\cdot}(kg-dry)^{-1}$) which were similar to the reported values from other regions in Korea. The activity ratio of $^{137}Cs$ to $^{90}Sr$ in surface soils was around 9.67, which is much bigger than the initial value of 1.75 for worldwide fallouts because of faster downward movement of $^{90}Sr$ after fallout than that of $^{137}Cs$. For depth profile studies soils were collected down to 40 cm depth for the locations of Deokgu, Hujeong and Maehwa. The $^{137}Cs$ concentration distribution of the first two showed maximum values at top soils and decreased rapidly in exponential manner, while $^{90}Sr$ showed two local maximum values for soils near top and about 30 cm depth. Through linear fittings between the $^{137}Cs$ and $^{90}Sr$ concentrations of surface soil and pH, TOC and median of the surface soil, the only probable relationship obtained was between $^{137}Cs$ and TOC (determination coefficient $R^2=0.6$). Conclusion: The concentration ranges of $^{137}Cs$ and $^{90}Sr$ in Uljin were similar to the reported values from other regions in Korea. The only probable relationship obtained between activities and soil properties was between $^{137}Cs$ and TOC.

    Changes in Plasma and Urine Endothelin Levels During Acute Exacerbation of Asthma (급성 천식발작시 혈장 및 요중 Endothelin 농도 변동)

    • Chang, Jung-Hyun;Shin, Tae-Rim;Woo, Ga-Eun;Kim, Jong-Seon;Hong, Eun-Soon;Seo, Gi-Yeoul;Cha, Joo-Hyun;Kim, Mi-Seon;Kim, Yeung-Seon;Cho, Young-Joo
      • Tuberculosis and Respiratory Diseases
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      • v.44 no.4
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      • pp.844-852
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      • 1997
    • Background : Recent studies have documented increased release of endothelin(ET) during acute attack of asthma. The purpose of this study is to observe the link between plasma level and urinary excretion of each and changes during acute exacerbation. Method : Plasma and 24 hour urine were collected from sixteen asthmatics during acute exacerbation, twice ; first day of symptomatic exacerbation and two weeks after treatment. Controls were ten healthy normal subjects. All patients were treated with corticosteroid and beta-2 adrenergic agonist on admission. ET was determined by radioimmmunoassay and had 100% cross reactivity with ET-1, 67% with ET-2, 84% with ET-3, and 8% with Big-ET. Results : Plasma ETs were significantly elevated during acute attack of asthma compared with those in remission and controls.,However, there was no significant changes in urine ET concentrations or total ET amounts in 24 hour urine during exacerbation upto two weeks. Those levels of urine ET in asthmatics were still higher than controls. ET concentrations in plasma or urine were not correlated with pulmonary functional parameters and hypoxemia. Conclusion : The findings suggests that increased plasma ETs are related with exaggerated release during acute asthma. Urinary ET excretion is increased in asthma. However, urine ET changes during exacerbation should be observed in a larger and longer scale.

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    Dietary Behaviors, Body Satisfaction and Factors Affecting the Weight Control Interest According to Gender of Middle School Students in Wonju Area (원주지역 중학생들의 성별에 따른 식행동과 신체만족도 및 체중조절 관심도에 영향을 미치는 변인)

    • Kim, Bok-Ran;Kim, Yoon-Sun
      • Journal of the Korean Society of Food Science and Nutrition
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      • v.39 no.9
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      • pp.1295-1304
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      • 2010
    • The purpose of this study was to investigate the BMI, dietary behaviors, body satisfaction and factors affecting the weight control interest according to gender of middle school students (195 boys and 251 girls) in Wonju area. The average height and weight of the boys were $164.8{\pm}8.3\;cm$ and $55.5{\pm}12.3\;kg$ respectively. Those of the girls were $158.8{\pm}5.0\;cm$ and $48.7{\pm}7.4\;kg$ respectively. The average body mass index (BMI) of the boys and girls was 20.3 and 19.3 respectively. In both boys and girls, 69.7% of them had regular meals and the main reason for skipping meals was insufficient time to eat due to oversleeping (33.6%). Most of the subjects consumed snacks more than once a day (95.5%). The dietary intake attitude score of the girls ($35.08{\pm}5.91$) was higher than that of the boys ($33.81{\pm}5.45$) (p<0.01). The eating disorders score of the girls ($12.92{\pm}6.22$) was higher than that of the boys ($10.70{\pm}9.82$) (p<0.01). Also, 87.2% of the subjects showed normal behavior and 12.8% of the subjects had eating disorders, but there was no significant difference according to gender. The body satisfaction score of the boys ($30.16{\pm}5.08$) was higher than that of the girls ($28.00{\pm}5.52$) (p<0.001). In general, body satisfaction score correlated positively with dietary intake attitude score, but correlated negatively with eating disorders score (p<0.05). Multiple regression analysis revealed that body satisfaction score was the most significant variable which affected the weight control interest. Therefore, development of the nutrition education program for adolescents will be effective not only for the improvement of dietary behaviors but also for the positive change in the misleading perception about the ideal body shape.

    Effects of Black Soybean and Fermented Black Soybean Extracts on Proliferation of Human Follicle Dermal Papilla Cells (검은콩과 발효검은콩 추출물이 인간 모유두 세포 성장에 미치는 효과)

    • Choi, Ji-Hye;Lee, Myoungsook;Kim, Hyun Jung;Kwon, Jung Il;Lee, Yunkyoung
      • Journal of the Korean Society of Food Science and Nutrition
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      • v.46 no.6
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      • pp.671-680
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      • 2017
    • This study was conducted to examine the effects and potential mechanisms of action of black soybean extracts and fermented black soybean extracts by Lactobacillus rhamnosus GG (LGG) and Bifidobacterium animals subsp. lactis BB-12 (BB-12) on proliferation of human follicle dermal papilla cells (HFDPC). We examined changes in pH, total polyphenol, sugar, and reducing sugar contents according to fermentation period of black soybean extracts. Assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was performed to determine cell toxicity levels of the four black soybean extracts [black soybean water extract (BWE), black soybean ethanol extract (BEE), fermented BWE (F-BEW), and fermented BEE (F-BEE)]. Changes in mRNA expression levels of hair growth promoting factors and hair growth inhibiting factors by the four black soybean extracts were measured by real-time PCR. In addition, phosphorylation levels of mitogen-activated protein kinase family proteins were measured by western blot analysis. As a result, fermentation of black soybeans significantly reduced pH, total polyphenols, and sugar/reducing sugar contents. All four black soybean extracts showed no cellular toxicity in HFDPC. In fact, BEE significantly enhanced cell viability of HFDPC at $100{\mu}g/mL$ compared to control. BWE, BEE, and BWE-F significantly increased mRNA expression of vascular endothelial growth factor, and all four extracts increased mRNA expression of fibroblast growth factor. However, mRNA expression levels of apoptosis-related genes were not affected by black soybean extracts in HFDPC. Furthermore, BWE, BEE, and BWE-F significantly increased phosphorylation levels of extracellular signal-regulated kinase compared to control. Taken together, we demonstrated that black soybean extracts enhanced proliferation of human follicle dermal papilla cells partially via activation of hair growth promoting factors, although no particular significant effects on proliferation were observed by fermentation of black soybeans.

    Chemoprevention of Helicobacter pylori-associated Gastric Carcinogenesis in a Mouse Model; Is It Possible?

    • Hahm, Ki-Baik;Song, Young-Joon;Oh, Tae-Young;Lee, Jeong-Sang;Surh, Young-Joon;Kim, Young-Bae;Yoo, Byung-Moo;Kim, Jin-Hong;Ha, Sang-Uk;Nahm, Ki-Taik;Kim, Myung-Wook;Kim, Dae-Yong;Cho, Sung-Won
      • BMB Reports
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      • v.36 no.1
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      • pp.82-94
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      • 2003
    • Although debates still exist whether Helicobacter pylori infection is really class I carcinogen or not, H. pylori has been known to provoke precancerous lesions like gastric adenoma and chronic atrophic gastritis with intestinal metaplasia as well as gastric cancer. Chronic persistent, uncontrolled gastric inflammations are possible basis for ensuing gastric carcinogenesis and H. pylori infection increased COX-2 expressions, which might be the one of the mechanisms leading to gastric cancer. To know the implication of long-term treatment of antiinflammatory drugs, rebamipide or nimesulide, on H. pylori-associated gastric carcinogenesis, we infected C57BL/6 mice with H. pylori, especially after MNU administration to promote carcinogenesis and the effects of the long-term administration of rebamipide or nimesulide were evaluated. C57BL/6 mice were sacrificed 50 weeks after H. pylori infection. Colonization rates of H. pylori, degree of gastric inflammation and other pathological changes including atrophic gastritis and metaplasia, serum levels and mRNA transcripts of various mouse cytokines and chemokines, and NF-${\kappa}B$ binding activities, and finally the presence of gastric adenocarcinoma were compared between H. pylori infected group (HP), and H. pylori infected group administered with long-term rebamipide containing pellet diets (HPR) or nimesulide mixed pellets (HPN). Gastric mucosal expressions of ICAM-1, HCAM, MMP, and transcriptional regulations of NF-${\kappa}B$ binding were all significantly decreased in HPR group than in HP group. Multi-probe RNase protection assay showed the significantly decreased mRNA levels of apoptosis related genes and various cytokines genes like IFN-$\gamma$, RANTES, TNF-$\alpha$, TNFR p75, IL-$1{\beta}$ in HPR group. In the experiment designed to provoke gastric cancer through MNU treatment with H. pylori infection, the incidence of gastric carcinoma was not changed between HP and HPR group, but significantly decreased in HPN group, suggesting the chemoprevention of H. pylori-associated gastric carcinogenesis by COX-2 inhibition. Long-term administration of antiinflammatory drugs should be considered in the treatment of H. pylori since they showed the molecular and biologic advantages with possible chemopreventive effect against H. pylori-associated gastric carcinogenesis. If the final concrete proof showing the causal relationship between H. pylori infection and gastric carcinogenesis could be obtained, that will shed new light on chemoprevention of gastric cancer, that is, that gastric/cancer could be prevented through either the eradication of H. pylori or lessening the inflammation provoked by H. pylori infection in high risk group.

    Ecological Studies on Vegetation Recovery of Burned Field after Forest Fire (산화적지의 식생회복에 관한 생태학적 연구)

    • Kang, Sang Joon;Jong Tai Lee
      • Journal of environmental and Sanitary engineering
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      • v.5 no.1
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      • pp.54-62
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      • 1990
    • The recovery of vegetatiion and soil properties in the burned fields after forest fire were studied in Chung Cheong Buk Do area, Korea, from July 23 to 28, 1981. Miscanthus sinensis var. purpurascens, Carex humilis and Lespedeza bicolor were dominant species in the burned field of the second year after forest fire as well as unburned field. Especially, Lespedeza bicolor was gradually grown to the dominant species. Lespedeza bicolor, Carex humilis and Miscanthus sinensis var. purpurascens were the dominant species in the burned field of the fifth year after forest fire. Biological spectra of the burned fields were similar to the umburned fields with $H-e-D_1-R_5$ or $Ph-e-D_1-R_5$ from the second year after forest fire. Accordingly, biological spectra were recovered to the unburned fields from the second year. Degree of successiion was DS=423 in the burned field and DS=524 in the unburned field in 1981. The DS of the burned fields was gradually increased and recovered to be similar to the unburned from the second year. In the species diversities and evenness index, H,e and $\beta$ of the burned field in 1981 were higher and $\lambda$ was lower than the unburned field, but all of the indices were recovered to the unburned field from the second or third years. Accordingly, the vegetation of the first year was the complex community in view floristic composition, but it was recovered to the simple community as unburned field fromthe second or third years. In the soil preperties, pH, total nitrogen, available phosphorus, exchangeable potassium, exchangeable calcium and exchangeable magnesium were increased and organic matter was decreased due to forest fire, and then was recovered to the unburned field from the second or third years. The vegetation and soil properties of the burned field after forest fire were similary recovered to the unburned field from the second or third years. Accordingly, there was a close relationship between the trend of vegetation recovery and the changes of soil characteristics after forest fire.

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