• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.150-168
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• 2017

This study was carried out to compare stand structure in Bihwajin basin Samcheok-si, Gangwon-do, Korea for ten years between 2003 and 2014, in which occurred the east coastal forest fire in 2000. Data were collected from 32 quadrates that followed by the analysis of vegetation classification according to plant sociology, importance value by Mclntosh and Curtise, species diversity and similarity index. In the result of vegetation classification, the vegetation unit decreased from 7 units to 4 units, and the number of species groups changed from 11 to 7. As a result of importance value (IV) changes, IV of Quercus mongolica, Q. serrata and Q. variabilis was increased by 6.8%, 5.2% and 2.9% in the order, respectively. However, that of Pinus densiflora was decreased by 2.8%. That of major planted species such as Castanea crenata, Chionanthus retusa, Prunus armeniaca var. ansu, Acer triflorum and Koelreuteria paniculata was reduced. As a result of species diversity, it was increased from 0.252 to 0.287 in tree layer, from 0.252 to 0.434 in subtree layer, and from 1.293 to 1.333 in shrub layer. But that in herb layer was decreased from 1.745 to 1.646. As a result of similarity index, it was 0.78, 0.65, 0.72 and 0.55 by layers that showed most difference in herb stratum. Considering the results, this study would be applied to the ecosystem diagnose and management of forest fire damaged area similar to the investigated area.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.214-218
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• 2014

We introduce a technical equipment of GATe (Green (algae)-tide) water combine developed by K-water. The GATe water combine consists of five modules: main body and buoyant, transfer hopper, screen conveyer, sludge remover, and separator of algae and waste. Also a sprinkler, as the pre-treatment step if necessary, is equipped to the device to spread out environmental-friendly algaecide under the circumstance that the level of algal bloom does not reach to the scum-forming condition. The overall module system of this device is very simple. Based on the field test, the device covers surface area of ca. $500,000m^2day^{-1}$ during the period from May to July, and treats water volume as much as $500,000m^3day^{-1}$ in spite of some variation depending on the water quality condition. The removal efficiency of the device appeared to be over 90%. In addition, the operating duration of the device was able to expand to cover the period between March and November. We expect this new technology can be used to solve algal bloom problems in drinking water resource and public water area.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.636-644
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• 2015

In this paper, we examined factors that affect the success of a policy on trekking time restriction using questionnaire survey data collected from the visitors of seven national parks where the trekking time restriction policy is in force as of 2014. Results suggest that the trekking time restriction policy has been successfully publicized. In total, 60.7% of the survey respondents were aware of trekking time restrictions in the national parks they were visiting. Using exploratory factor analysis, we identified three latent factors (visitors' careless trekking, park rangers' insufficient management and visitors' unpreparedness) that the visitors perceived the causes of trekking accidents in the national parks. Multiple regression analysis on the three extracted factors and respondents' socioeconomic status shows that the respondents who read information signs in national parks and who judged visitors' careless trekking and visitors' unpreparedness as the causes of trekking accidents tended to agree more with restricting trekking time. These results indicate that visitors who do not agree with the trekking time restriction tend to attribute trekking accidents in national parks not to individual visitors, suggesting that educating visitors is more effective in preventing trekking accidents in national parks than installing and maintaining safety facilities by park rangers.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.247-254
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• 2009

In this study, linear programming was applied to a case study in Gwangreung Experimental Forest of Korea Forest Research Institute investigating the effect of the desired future conditions on forest management. Considering the social, economic and ecological demands of people from the forest, the forest functions were classified into four including natural conservation, timber production, water yield and scenic conservation. The forest land areas were divided into four-types of forest functional zones and forest management prescriptions including the desired future conditions by the forest function type were established. The Model II linear programming was used in optimizing the forest management planning. The model includes management policies, as the constraints, for non-declining yield, allowable cutting area, allowable % age class distribution and allowable % species allocation as well as the land and other accounting regimes. Maximization of timber production was used the objective function. Based on the Model II formulations, the effects of the desired future conditions by the forest function type on forest management planning were investigated in terms of timber production, net present value and stand structures over time.

• Korean Journal of Environment and Ecology
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• v.21 no.1
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• pp.82-92
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• 2007

The purposes of this study were to classify community and to analyzse vegetation-environment relationships in the forest community of Ulleung Island. The forest community of Ulleung Island was classified into Pinus thunbergii community, Pinus densiflora community, Neolitsea sericea community, Pinus parviflora community, and Fagus multinervis - Sorbus commixta community. Since the results of phytosociological community classification were consistent with that of TWINSPAN, it proved that these two methods could complement when one does a community classification. There was a difference in chemical characteristic of soil among study communities. The community had high soil organic matter, total nitrogen, available phosphorous, and cation exchange capacity compared to forest soil of Korea. The soil pH ranged from 4.66 to 5.80. The soil texture in the study communities was loam or sandy loam. According to the ordination analysis, elevation, exchangeable Na, K, Ca, Mg, soil pH, and content of sand and silt affect the distribution of community.

• Korean Journal of Environment and Ecology
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• v.19 no.2
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• pp.162-176
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• 2005

This study was carried out as a field survey and a review of articles to investigate a characteristic of the distribution pattern in Korean endemic Corylopsis coreana. Distribution of Corylopsis coreana was found in Boseung-gun, Gwangyang-si, Suncheon-si, Jeumam-myeon Goheung-gun, Ganjeon-myeon Gurye-gun, Mt, Cheongwan Jangheung-gun, Nogodan Mt. Jiri in Jeollanam-do, Mt. Cheonhwang Namwon-si and Beamsagol and Banyabong Mt. Jiri in Jeollabuk-do, Sancheong-gun, hadong-gun and Namhea-gun in Gyeongsangnam-do and Mt. Backun, Pocheon-si in Gyeonggi-do. Total flora in the distribution region of Coryloplsis coreana was recorded as 242 taxa; 70 families, 159 genus, 216 species, 22 varieties, 4 forma. Ratio of taxonomic categories was consisted of Pteridophyte $5.8\%$, Gymnosperm $3.7\%$, Dicotyledon $18.6\%$ and Monocotyledon $71.9\%$. Ratio of Life cycle styles was Annual $1.7\%$ and Perennial $93.3\%$. Ratio of growth habit was appeared to Herb $44.2\%$, Vine $12.4\%$, Shrub $17.8\%$ and Tree $25.6\%$. The distribution region of Corylopsis coreana found to typical type which distribute in N, NE or NW slope. The native Corylopsis coreana of Sinjeonri Sungju-eup in Jellanam-do appeared to have a declining tendency which was caused by influence of tree lager.

• Korean Journal of Environment and Ecology
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• v.10 no.1
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• pp.14-23
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• 1996

Visitors to Naejangsan National Park were surveyed from October 31 to November 3 in 1995, 151 visitors were participated. Of those individuals, 55% were males. 48% of respondests reported that they had gone beyond high school, and over one-half(52%) had gone as far as college. 61.3% were 20 years of age. The largest percentage of respondents were reported that they visited Naejangsan Nat'l Park to see the scarlet maple leaces there. Most respondents who witness other visitors' littering were not likely to intervene to stop their visitors' depreciative behavior(Bystander intervention Begavior). Most of visitors got information for use Naejangsan Nat'l Park from a guide sign(31.8%) or guide themselves(29.1%). They didn't know the Clean-up Time Movement Program. But they understood it after notice hanging placards(81.6%). Most of visitors responded that didn't hear the mass communication program in National. But they recognized necessity of the mass communication program in National Park. The results showed that most visitors believed that Clean-up Time Movement was in succession consequently it turned out to be effective in managing visitors' littering behavior. And it seemed to effective in managing depreciative behavior through the mass communication program in National Park.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.725-735
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• 2011

This study was carried out to analyze the vegetation properties, soil characteristics, and ordination of Stewartia koreana community of Mt. Jirisan in Korea. The S. koreana community was classified into S. koreana-Quercus mongolica serrata community, S. koreana-Quercus mongolica community, and Typical community. In specific, S. koreana-Q. serrata community was classified into two subgroups such as Carpinus laxiflora subcommunity and typical subcommunity. The S. koreana community was found out to be located at an elevation of 409m to 1,604m. The Results of importance value on the S. koreana community consisted of the following in order: 75.47% of S. koreana, the highest, 21.83% of Q. serrata, 18.65% of Q. mongolica, 18.19% of Acer pseudosieboldianum, 10.56% of Rhododendron schlippenbachii, 10.36% of Styrax japonicus. In the targeted study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, soil moisture and soil pH were 3.15~39.1%, 0.37~11.7%, 0.9~45.4mg/kg, $0.09{\sim}1.48cmol^+/kg$, 19.28~55.47% and 4.08~5.65, respectively. The results of the correlation between communities and soil conditions of S. koreana community by DCCA ordination method are as follows: S. koreana-Q. serrata community was found in the highest elevation and followed in order S. koreana typical community, S. koreana-Q. serrata typical subcommunity, and C. laxiflora subcommunity.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.521-529
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• 2006

This study was carried out to classify all forest vegetation types in Ulleung Island, Korea using the methodology of the Z.-M. school's phytosociology, and map out the spatial distribution patterns of those vegetation types. The forest vegetation was classified into the mountain forest type (Acer okamotoanum community group) and maritime forest type (Artemisia scoparia community group). Vegetation units at the community level were divided into three categories; six communities, sixteen groups, and seven subgroups, giving a total of 22 communities. Total area for mapping was 5,544.9 ha, of which Fagus engleriana community accounted for 1,952 ha (35.2%), Hedera rhambea community ror 1,196 ha (21.6%), Camellia japonica community for 1,104 ha (19.9%), Sambucus sieboldiana var. pendula community for 612 ha (11.0%), Aster spathulifolius community for 506 ha (9.1%), and Tsuga sieboldii - Pinus parviflora community for 174 ha (3.1%). According to canonical correspondence analysis (CCA), variables such as $Mg^{2+}$, pH, $Ca^{2+}$ were positively correlated in maritime vegetation types, and variables such as total nitrogen, carbon content, C/N ratio and ration exchange capacity (CEC) were highly correlated in mountain vegetation types, respectively. The sea level and the slope direction were not showing regular trend as a factor to decide on species diversity, evenness and richness in this research area. But it seems to be affected by topography, slope degree and dominance vegetation.

• Environmental and Resource Economics Review
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• v.28 no.2
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• pp.277-306
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• 2019

Mackerel is one of the most widely consumed aquatic products in Korea. Concerns about the depletion of stocks have also arisen as the catch has decreased. The primary purpose of this study is to estimate the mackerel stock and derive the optimal level of catch in Korea. We apply a generalized maximum entropy econometric method to estimate the mackerel growth function, which does not require the steady state assumption. We incorporate a bootstrapping approach to derive the significance levels of parameter estimates. We found that the average ratio of catch to the estimated total stock was less than 30% before the 1990s but exceeded 40% in the 1990s. After 2000, it dropped back to about 36%. This finding indicates that mackerel may have been over-fished in the 1990s, but the government regulations introduced in the 2000s alleviated over-fishing problems. Nevertheless, our dynamic optimization analysis suggests that the total allowable catch may need to be carefully controlled to achieve socially optimal management of resources.