• Title/Summary/Keyword: DEGRADED FOREST

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Degradation of Crystalline Cellulose by the Brown-rot Basidiomycete Fomitopsis palustris

  • Yoon Jeong-Jun;Kim Young-Kyoon
    • Journal of Microbiology
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    • v.43 no.6
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    • pp.487-492
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    • 2005
  • This study demonstrated that the brown rot basidiomycete Fomitopsis palustris was able to degrade crystalline cellulose (Avicel). This fungus could also produce the three major cellulases (exoglucanases, endoglucanases, and $\beta-glucosidase$) when the cells were grown on $2.0\%$ Avicel. Avicel degraded by F. palustris showed a decrease in relative crystallinity from $83\%\;to\;78.5\%$ after 14 days of incubation. The characterization study indicated that optimum pH was 4.5 and optimum temperature was $70^{\circ}C$ for exoglucanase (cellobiohydrolase) activity. Hydrolysis of Avicel by the crude enzyme from F. palustris yielded 1.6 mg/ml of glucose after 43 h, which corresponded to a cellulose conversion degree of $3.2\%$. Therefore, this study revealed for the first time that the brown rot basidiomycete F. palustris produces cellulases capable of yielding soluble sugars from crystalline cellulose.

Development of Evaluation Indices for Ecological Restoration of Degraded Environments Near DMZ in the Republic of Korea (DMZ 주변 훼손지의 생태복원 평가지표 개발)

  • Lee, Peter Sang-Hoon;Lee, Sanghyuk;Lee, Sol Ae;Choi, Jaeyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.1
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    • pp.135-151
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    • 2015
  • DMZ is considered as an ecologically sensitive landscape and one of the highest biodiversity regions in the Republic of Korea. There have been, albeit the significant value, increased interests in developing this region for a variety of purposes including tourism and commemorative events. As this region has been already facing a range of problems derived from previous development, natural disaster and invasive species, the necessity for active management of ecological health within this region has been increased, which weighs the importance of executing ecological restoration. The objective of this study was to develop evaluation indices as an effective management means of properly evaluating ecological restoration and sustainably maintaining the restored conditions on a long-term scale. Through literature review existing evaluation indices related to restoration were collected, and then the most suitable indices were selected based upon two interviews and one questionnaire survey targeting experts in the relevant field to ecological restoration. They were categorized by two major division and their subclasses (Ecological base - vegetation structure & composition, habitat characteristics, soil environment; landscape ecology - connectivity, landscape patch, boundary & surrounding) and 40 indices. These indices were considered helpful to comprehensively evaluate ecological restoration on degraded environments within ecologically sensitive areas, and sustainably manage target areas by employing a long-term monitoring approach. As this result played a meaningful role in providing the fundamentals of evaluating ecological restoration, it should develop a suitable evaluation system through further research.

On Possible Application of Microorganism for Chemical Pulping (화학(化學)펄프 제조(製造)에 미생물(微生物)의 응용(應用) 가능성(可能性))

  • Lee, Seon-Ho;Yoon, Byong-Ho;Lee, Won-Yong
    • Journal of Forest and Environmental Science
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    • v.13 no.1
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    • pp.143-152
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    • 1997
  • The decayed wood by Fomes pini (Thore) Lloyd required a smaller H factor than the sound wood for pulping to permanganate number 20. The H factors for the decayed wood pulping by the kraft and soda processes were reduced by 15% and 17%, respectively, in the presence of 1% anthraquinone. The wood components degraded by fungi are normally more readily solubilized in alkali than the corresponding components in sound wood. The nonphenolic ${\beta}$-O-4 type lignin model compound, veratrylglycerol-${\beta}$-guaiacyl ether(I), and phenolic model compound, syringylglycerol-${\beta}$-syringyl ether(III), were degraded by the white-rot fungi to yield ${\alpha}$-guaiacoxy-${\beta}$-hydroxypropioveratrone(II) from the former and ${\alpha}$-syringyloxy-${\beta}$-hydroxypropiosyringone(IV) from the latter. Structures of the degradation products indicated that C ${\alpha}$-oxidation could occur with white-rot fungi. It has been shown that the alkaline cleavage of ${\beta}$-aryl ether bonds in the lignin units is accelerated by the presence of ${\alpha}$-carbonyl groups.

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Object-oriented Classification and QuickBird Multi-spectral Imagery in Forest Density Mapping

  • Jayakumar, S.;Ramachandran, A.;Lee, Jung-Bin;Heo, Joon
    • Korean Journal of Remote Sensing
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    • v.23 no.3
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    • pp.153-160
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    • 2007
  • Forest cover density studies using high resolution satellite data and object oriented classification are limited in India. This article focuses on the potential use of QuickBird satellite data and object oriented classification in forest density mapping. In this study, the high-resolution satellite data was classified based on NDVI/pixel based and object oriented classification methods and results were compared. The QuickBird satellite data was found to be suitable in forest density mapping. Object oriented classification was superior than the NDVI/pixel based classification. The Object oriented classification method classified all the density classes of forest (dense, open, degraded and bare soil) with higher producer and user accuracies and with more kappa statistics value compared to pixel based method. The overall classification accuracy and Kappa statistics values of the object oriented classification were 83.33% and 0.77 respectively, which were higher than the pixel based classification (68%, 0.56 respectively). According to the Z statistics, the results of these two classifications were significantly different at 95% confidence level.

Assessment of Carbon Stock in Chronosequence Rehabilitated Tropical Forest Stands in Malaysia

  • Kueh, Roland Jui Heng;Majid, Nik Muhamad;Ahmed, Osumanu Haruna;Gandaseca, Seca
    • Journal of Forest and Environmental Science
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    • v.32 no.3
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    • pp.302-310
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    • 2016
  • The loss and degradation in tropical forest region are some of the current global concern. Hence, these issues elevated the role of rehabilitated forests in providing ecological products and services. The information on the carbon stock is important in relation to global carbon and biomass use, but lacking from the tropical region. This paper reports the assessment of tree and soil carbon stock in a chronosequence rehabilitated tropical forest stands in Malaysia. The study site was at the UPM-Mitsubishi Forest Rehabilitation Project, UPMKB. $20{\times}20m$ plot was established each and assessed in 2009 at 1-, 10- and 19-year-old sites while an adjacent ${\pm}23-year-old$ natural regenerating secondary forest plot was established for comparison. The overall total carbon stock was in the order of 19-year-old>${\pm}23-year-old$>10-year-old>1-year-old. When forest carbon stock is low, the soil component plays an important role in the carbon storage. The forest carbon recovery is crucial to increase soil carbon stock. The variations in the carbon stock showed the different stages of the forest recovery. Species survived after 19-years of planting are potential species for carbon sequestration activities in rehabilitated forest. Human intervention in rehabilitating degraded forest areas through tree planting initiatives is crucial towards recovering the forest ecological role especially in forest carbon stock capacity.

The Influence of Forest Fire on the Characteristics of Polymer Insulator for Transmission Lines (산불영향에 따른 송전용 폴리머애자의 특성)

  • Lee Donu-Il;Chung Yong-Woon;Yu Kun-Yang;Choi In-Hyuk
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.3
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    • pp.127-131
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    • 2005
  • Big fire such as mountain fire may cause the prevention of the functions of the overhead cables and insulators, which may affect the operation of the transmission lines. In the worst case, this kind of disaster may have a huge effect on the whole industry of a country. However, the study on the effect of the mountain fire on the transmission line is very rare. Therefore, in order to understand the effect of the mountain fire on the polymeric insulator for transmission lines, the author observed the deformation of the sheds of the polymeric insulators and the change of the discs of the porcelain insulators under fire, varying the ignition time using the artificial ignition testing equipment which simulates the mountain fire, and investigated the electrical and mechanical characteristics of the insulators after the ignition test. For the test, the miniature insulators made of polymeric material and porcelain have been utilized. As the result, the following conclusions were obtained. First, the porcelain insulator was degraded in electrical characteristics when the insulator was subjected to the fire for approximately 5 minutes; whereas, the polymeric insulator was not degraded though there were some damage on its sheds. Second, after 20 minute exposure to the fire, the polymeric insulator lost a lot of parts of sheds, but the electrical characteristics was lowered by around $20\%$, but the porcelain insulators were electrically degraded by more than $80\%$.

Effect of Mycorrhizal Treatment on Growth of Acacia spp. On Sandy BRIS Soils in Peninsular Malaysia

  • Lee, Su See;Mansor, Patahayah;Koter, Rosdi;Lee, Don Koo
    • Journal of Korean Society of Forest Science
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    • v.95 no.5
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    • pp.516-523
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    • 2006
  • Marginal soils such as BRlS (Beach Ridges Interspersed with Swales) soils and ex-tin mining land make up approximately 0.5 million ha or about 2% of Malaysia's land area. In the coastal areas of the east coast of Peninsular Malaysia impoverished sandy BRIS dominates the landscape with most lying idle as there is no national management plan for their utilization. A field study was carried out to see whether mycorrhizal application had any effect on the growth of three exotic Acacia spp., i.e. Acacia auriculiformis, A. mangium and Acacia hybrid (A. auriculiformis ${\times}$ A. mangium) on BRIS soils. Two types of mycorrhizal inoculum, namely, a commercially available arbuscular mycorrhizal inoculum marketed as $MycoGold^{TM}$ and an indigenous ectomycorrhizal Tomentella sp. inoculum were tested. In the initial six months, height growth of all three tree species inoculated with the arbuscular mycorrhizal inoculum was significantly improved compared to the ectomycorrhizal inoculated and uninoculated control plants. The mycorrhizal effect was not evident thereafter and repeated application of the arbuscular mycorrhizal inoculum may be necessary for continued growth enhancement. Of the three species, A. mangium had the highest relative height growth rate over the 24 months on BRlS soils.

Demands for Forest Development in Kyrgyzstan and Tajikistan and International Cooperation Strategies of Rep. of Korea (키르기스스탄과 타지키스탄의 산림분야 개발수요와 한국의 협력 전략)

  • Choi, Eunho;Lim, Soojeong;Park, Hyun
    • Journal of Korean Society of Forest Science
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    • v.107 no.3
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    • pp.294-304
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    • 2018
  • Since joining the OECD Development Assistance committee in 2010, the Republic of Korea has been continuously striving to promote its international standing. A new era of cooperation is about to open between Korea and Central Asia, with the $25^{th}$ anniversary of the establishment of diplomatic relationship between Korea and Central Asia, and the welcoming the $80^{th}$ anniversary of the Koryoin (Korean) immigration in 2017. Central Asia is also attracting attention with a rapidly growing economy based on the endowed resources. Therefore, Kyrgyzstan and Tajikistan, among others, were investigated in the following statuses: politics, diplomacy, economy, official development assistance and national strategies. In particular, this study suggests the South Korea's Country Partnership Strategy for Forest with the nations by analyzing the forest environment and forest policy regime, and both forest cooperation strategies: 'Ecotourism Projects using a Walnut Forest' in Kyrgyzstan and 'Projects Restoring Forest and Securing Fuel Woods of Degraded Land in Tugai' in Tajikistan.

Ultrastructural Observation of Bacterial Attacks on the Waterlogged Archaeological Woods (세균에 의한 수침고목재 피해양태의 초미시구조적 관찰)

  • Kim, Y.S.;Choi, J.H.;Bae, H.J.;Nilsson, T.;Daniel, G.
    • Journal of Conservation Science
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    • v.1 no.1 s.1
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    • pp.3-11
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    • 1992
  • Micromorphological changes in waterlogged archaeological woods excavated from Sweden and Germany were investigated. Especially bacterial attacks on those wood samples under near anaerobic conditions were examined by transmission electron microscopy(TEM). The major feature of micromorphological alterations in those wood samples was the preferential destruction of secondary wood cell wall. In contrast, the middle lamella was not extensively degraded. Three distinct degradation patterns by bacteria were observed : erosion, cavitation and tunnelling bacteria. Erosion and cavitation bacteria attacked primarily $S_2$ layer, whereas tunnelling bacteria made the tunnel-like degradation along the $S_1$ layer. Tunnelling bacteria, in some samples, were able to degrade tunnel in the lignin-rich areas, such as middle lamella, suggesting that these bacteria had the capacity to degrade the lignin. IR spectra indicate that hemicellulose and cellulose in the waterlogged woods were preferentially decomposed. Breakdown of the lignin, on the other hand, was much slower.

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Wood and Leaf Litter Decomposition and Nutrient Release from Tectona grandis Linn. f. in a Tropical Dry Deciduous Forest of Rajasthan, Western India

  • Kumar, J.I. Nirmal;Sajish, P.R.;Kumar, Rita.N.;Bhoi, Rohit Kumar
    • Journal of Forest and Environmental Science
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    • v.26 no.1
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    • pp.17-23
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    • 2010
  • The present study was conducted to quantify wood and leaf litter decomposition and nutrient release of a dominant tree species, Tectona grandis Linn. F. in a tropical dry deciduous forest of Rajasthan, Western India. The mean relative decomposition rate was maximum in the wet summer and minimum during dry summer. Rainfall and its associated variables exhibited greater control over litter decomposition than temperature. The concentrations of N and P increased in decomposing litter with increasing retrieval days. Mass loss was negatively correlated with N and P concentrations. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both wood and leaf litter. Tectona grandis was found to be most suitable tree species for plantation programmes in dry tropical regions as it has high litter deposition and decomposition rates and thus it has advantages in degraded soil restoration and sustainable land management.