• Title/Summary/Keyword: Forest gap

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A Comparison of Litterfall Dynamics in Three Coniferous Plantations of Identical Age under Similar Site Conditions

  • Jeong, Jae-Yeob;Kim, Choon-Sig;An, Hyun-Chul;Cho, Hyun-Seo;Choo, Gap-Chul
    • Journal of Ecology and Environment
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    • v.32 no.2
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    • pp.97-102
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    • 2009
  • This study was carried out to evaluate litterfall dynamics in three adjacent coniferous tree plantations (larch: Larix leptolepis; red pine: Pinus densiflora; rigitaeda pine: P. rigitaeda) planted in the same year (1963), and growing under similar environmental conditions in the Sambong Exhibition Forests, Hamyang-gun, Gyeongsangnam-do. Litter was collected monthly between July 2006 and June 2008. Needle, broad leaf and total litter inputs followed a similar monthly pattern in the three coniferous plantations. The amounts of needles, flowers, and miscellaneous litter were significantly lower in the larch than in the two pine plantations, while branch litter was significantly higher in the larch than in the two pine plantations. Average total litterfall for two years was significantly higher for the pine (5,475 kg $ha^{-1}\;yr^{-1}$ for red pine and 5,290 kg $ha^{-1}\;yr^{-1}$ for rigitaeda pine) plantations than for the larch (3,953 kg $ha^{-1}\;yr^{-1}$ plantation. Needle litter comprised about 73.1% of total litterfall for the rigitaeda pine, 70.8% for the red pine and 62.9% for the larch plantations. Our results demonstrate that litterfall inputs can be affected by tree species.

A Study on Trends and Prospects of Forest Products Trade in Korea (한국임산물무역(韓國林産物貿易)의 동태(動態)와 전망(展望))

  • Choi, Min-Hyu
    • Journal of the Korean Wood Science and Technology
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    • v.14 no.2
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    • pp.43-49
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    • 1986
  • In the light of real situation of Korean timber resources, it is no wonder that Korean economy depends on a lot of imported timber, however, we only need to draw attention how have they kept the balance of payment in the field of forest products trade for the last few decades, until the second oil crisis in 1979. Afterwards, the gap between imports and exports of forest products in terms of value has been widened so far, on account of various reasons inside and outside. However, according to national economic policy to drive more active exportation, new policy and strategy to expend world market of forest products urgently expectable in order to shorten the gap between imports and exports of forest products in the future. On the other hand, the current timber importation policy should be reconsidered, not only to support optimum domestic timber price level so as to compensate timber producers' cost but also to make suitable economic environment to induce new investments in the field of private forestry sector.

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Mining Information in Automated Relational Databases for Improving Reliability in Forest Products Manufacturing

  • Young, Timothy M.;Guess, Frank M.
    • International Journal of Reliability and Applications
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    • v.3 no.4
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    • pp.155-164
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    • 2002
  • This paper focuses on how modem data mining can be integrated with real-time relational databases and commercial data warehouses to improve reliability in real-time. An important Issue for many manufacturers is the development of relational databases that link key product attributes with real-time process parameters. Helpful data for key product attributes in manufacturing may be derived from destructive reliability testing. Destructive samples are taken at periodic time intervals during manufacturing, which might create a long time-gap between key product attributes and real-time process data. A case study is briefly summarized for the medium density fiberboard (MDF) industry. MDF is a wood composite that is used extensively by the home building and furniture manufacturing industries around the world. The cost of unacceptable MDF was as large as 5% to 10% of total manufacturing costs. Prevention can result In millions of US dollars saved by using better Information systems.

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Leaf Temperature Characteristics being Affected by Light Regimes (광조건에 따른 식물의 엽온 특성)

  • Park, Yong-Mok
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1599-1605
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    • 2011
  • To evaluate heat environment surrounding plants diurnal change of leaf temperature in the broad-leaved deciduous and evergreen trees was measured with microclimatic environmental factors including global solar radiation, and upward and downward long wave radiation. Maximum daily solar radiation was 961.2 and 976.3 w/$m^2$ in August 9 and 23, respectively. Upward long wave radiation was slightly higher than downward long wave radiation, showing 404.2 w/$m^2$ in August 9 and 394.5 w/$m^2$ in August 23. In addition, daily maximum vapor pressure deficit was 5.42 and 6.84 kPa in August 9 and 23, respectively, indicating high evaporative demand. Quercus glauca and Acer mono was differently responded to changing light regimes. On August 9, leaf temperature at the top-positioned leaves of Acer plants was higher than air temperature as well as those of Quercus plants in the morning. This indicates that stomata in Acer plants were closed by heat stress or water stress in the morning, while Quercus plant maintained active transpiration by opening stomata. These results indicated that improved light regimes such as gap opening in the closed forest may not always affect positively in the physiology of understory plants.

Households' Characteristics, Forest Resources Dependency and Forest Availability in Central Terai of Nepal

  • Panta, Menaka;Kim, Kyehyun;Lee, Cholyoung
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.548-557
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    • 2009
  • For centuries, forests have been a key component of rural livelihood. They are important both socially and economically in Nepal. Firewood and fodder are the basic forest products that are extracted daily or weekly basis in most of the rural areas in Nepal. In this study, a field survey of 100 households was conducted to examine the degree of forest dependency and forest resource availability, households' livelihood strategy and their relationship with forest dependency in Chitwan, Nepal. A household' response indexes were constructed, Gini coefficient, Head Count Poverty Index (HCI) and Poverty Gap Index (PGI) were calculated and one way ANOVA test was also performed for data analysis. Data revealed that 82/81% of all households were constantly used forest for firewood and fodder collection respectively while 42% of households were used forest or forest fringe for grazing. The Forest Product Availability Indexes (FPAI) showed a sharp decline of forest resources from 0.781 to 0.308 for a 20-yr time horizon while timber wood was noticeably lowered than the other products. Yet, about 33% of households were below the poverty threshold line with 0.0945 PGI. Income distribution among the household showed a lower Gini coefficient 0.25 than 0.37 of landholdings size. However, mean income was significantly varies with F-statistics=246.348 at P=0.05 between income groups (rich, medium and poor). The extraction of firewood, fodder and other forest products were significantly different between the income group with F-statistics=16.480, 19.930, 29.956 at P=0.05 respectively. Similarly, landholdings size and education were also significantly different between the income groups with F-statistics=4.333, 5.981 at P=0.05 respectively. These findings suggested that income status of households was the major indicator of forest dependency while poor and medium groups were highly dependent on the forests for firewood, fodder and other products. Forest dependency still remains high and the availability of forest products that can be extracted from the remaining forestlands is decreasing. The high dependency of households on forest coupled with other socioeconomic attributes like education, poverty, small landholders and so on were possibly caused the forest degradation in Chitwan.Therefore, policy must be directed towards the poor livelihood supporting agenda that may enhance the financial conditions of rural households while it could reduce the degree of forest dependency inspired with other income generating activities in due course.

Vegetation Change after A Forest Fire in a Rural Japanese Red Pine Forest and Applications of Effective Microorganism (농촌 소나무림에서 산불에 의한 식생변화와 유용미생물의 적용)

  • Yeo, Ji Sean;Kim, Kee Dae
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.11 no.4
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    • pp.46-56
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    • 2008
  • This study examined the natural restoration of vegetation through monitoring of the development of a vegetation community from 2006 through 2007 after a forest fire. Approximately 5,000 $m^2$ in a forest near Topyeon-ri, Kangnae-myeon, Chungcheongbuk-do with Japanese red pine (Pinus densiflora) forest and its floor vegetation had been completely burned by a fire in April 2005. This area and another nearby Japanese red pine forest were selected as the experiment site and the control site, respectively. Vegetation survey was conducted at the experiment site and the control site. A seed bank experiment was carried out in the greenhouse to examine underground vegetation. Effective microorganism(EM) was applied to the seed bank experiment to estimate its effects on the direction of ecological succession. According to the results, a total of 36 plant species including shrub and herbaceous species were discovered in the experiment site. Quercus serrata, Lespedeza cyrtobotrya, and Castanea crenata, Rubus crataegifolius, Oplismenus undulatifolius, and Carex lanceolata were among the most abundant species. Biomass in the experiment site reached 2.4 times biomass than those in the control site, indicating the productivities of shrub and herbaceous layers are better in the experiment site. According to the result of the soil seed bank experiment of the experiment site, a total of 182 plants of 14 species were recorded. In addition, a total of 13 plants of 2 species were found from soil seed bank of the experiment site applied by EM. If EM is applied to the burned site, it will control the budding of herbaceous plants, creating the gap between herbaceous plants. This loss of competition is expected to help the restoration of trees in the burned area.

Recognition of Forest Certification by Consumption Propensity and Socio-Economic Characteristics of Wood Cabinet Consumers (목재수납장 구매자의 소비성향 및 사회·경제적 특성에 따른 산림인증 인식도 조사)

  • Shin, Hye-Jin;Kim, Eui-Gyeong;Kim, Dong-Hyeon;Kim, Hyeon-Guen
    • Journal of agriculture & life science
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    • v.45 no.6
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    • pp.57-63
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    • 2011
  • This study was performed to figure out the recognition on forest certification by consumption propensity and socio-economic characteristics of wood cabinet consumers. The mean score of recognition on SFM and FSC showed comparatively low, 2.25 and 2.20(5-point likert scale), from the analysis result on 88 valid questionnaires of 90. The respondents rate of eco and non eco-friendly group formed 80.7% and 18.2%, there is a significant gap between two groups on total questionnaires. The percentage of respondents recognizing on SFM and FSC was about 31% (eco-friendly), 5.6%(non eco-friendly, SFM) and 2.8%(non eco-friendly, FSC) within each group. It showed that the socio-economic characteristics on eco-friendly respondents were higher than the others about more 1.3 times in the married rate, average age and monthly householding income.

Gap characteristics and natural regeneration in Mt. Makiling rainforest, the Philippines

  • Kim, Hyun-Ji;Kim, Tae-Geun;Kim, Eun-Hee;Castillo, Manuel L.;Cho, Do-Soon
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.157-165
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    • 2011
  • This study was conducted to determine the characteristics of gaps and natural regeneration of trees on Mt. Makiling, the Philippines. Canopy gaps in or around two 1-ha permanent plots and on 3-km line transects were investigated. Most of the gaps studied were formed or affected by Typhoon Milenyo, which hit the study site in September 2006. The most frequent mode of gap maker death was snap-off, whereas uprooting was relatively less important. The most frequent gap maker was balobo (Diplodiscus paniculatus) followed by magabuyo (Celtis luzonica) and katmon (Dillenia philippinensis). In contrast, the most frequent gap filler was magabuyo (C. luzonica). At the sapling layer, the most important species was magabuyo (C. luzonica), but there was a high proportion of lianas and palms. Most of the gaps had leaf area index (LAI) values between 3 and 5. A clear trend of a decrease in gap size and an increase in LAI was observed for 2 years from 2007 to 2009. New seedlings emerged very abundantly during the same time period. The rapid changes in the gaps were partially due to the excellent capability of tropical trees to resprout after the crown or stem was damaged by the typhoon. This study on gap dynamics may contribute to a better understanding of the natural regeneration process of trees in tropical rainforests.

Study on Moisture Variation in Light Frame Wall with Different Wall Assemblies (I) - Evaluation of Improvement with Laboratory Test - (벽체구성에 따른 목조벽체 내 수분변화에 대한 연구(I) - 실내 실험을 통한 개선 가능성 평가 -)

  • Kim, Se-Jong;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.4
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    • pp.320-329
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    • 2009
  • The purpose of this study was reducing the moisture accumulation in a wall, which can threaten the structural safety of light-frame wall and make residential environment poor. For the purpose, the laboratory test was carried out with different wall assemblies. Vapor retarder and air gap for ventilation were added to the typical wall. The improved performance of the proposed walls was examined through the test with distinct difference of temperature and relative humidity between outdoor and indoor air conditions. Increased dampproofing performance of additional vapor retarder was effective on reduction of moisture transmission from inside the house into the wall. However, unexpected high relative humidity was shown in the wall with two additional vapor retarder because of excessive dampproofing performance or inadequate location of vapor retarder. And, the open air gap induced the moisture transfer from inside the wall into outdoor air by ventilation. If the alternative to the induction of moisture transmission from inside the house into the wall with open air gap can be found, moisture reduction effect of that will be increased obviously.