• Title, Summary, Keyword: Forest degradation

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Kinetics of Thermal Degradation of Polypropylene/Nanoclay/Wood Flour Nanocomposites

  • Mohan, D. Jagan;Lee, Sun-Young;Kang, In-Aeh;Doh, Geum-Hyun;Park, Byung-Dae;Wu, Qinglin
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.3
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    • pp.278-286
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    • 2007
  • As a part of enhancing the performance of wood-plastic composites (WPC), polypropylene (PP)/ nanoclay (NC)/ wood flour (WF) nanocomposites were prepared using melt blending and injection molding process to evaluate their thermal stability. Thermogravimetric analysis (TGA) was employed to investigate thermal degradation kinetics of the nanocomposites both dynamic and isothermal conditions. Dynamic scans of the TGA showed an increased thermal stability of the nanocomposites at moderate wood flour concentrations (up to 20 phr, percentage based on hundred percent resin) while it decreased with the addition of 30 phr wood flour. The activation energy $(E_a)$ of thermal degradation of nanocomposites increased when nanoclay was added and the concentration of wood flour increased. Different equations were used to evaluate isothermal degradation kinetics using the rate of thermal degradation of the composites, expressed as weight loss (%) from their isothermal TGA curves. Degradation occurred at faster rate in the initial stages of about 60 min., and then proceeded in a gradual manner. However, nanocomposites with wood flour of 30 phr heated at $300^{\circ}C$ showed a drastic difference in their degradation behavior, and reached almost a complete decomposition after 40 min. of the isothermal heating. The degree of decomposition was greater at higher temperatures, and the residual weight of isothermal degradation of nanocomposites greatly varied from about 10 to 90%, depending on isothermal temperatures. The isothermal degradation of nanocomposites also increased their thermal stability with the addition of 1 phr nanoclay and of wood flour up to 20 phr. But, the degradation of PP100/NC1/MAPP3/WF30 nanocomposites with 30 phr wood flour occurs at a faster rate compared to those of the others, indicating a decrease in their thermal stability.

Application of Vegetation Indices for Forest Degradation Using Landsat TM Data

  • Kim, Choen;Joung, Khang-Ho
    • Proceedings of the KSRS Conference
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    • pp.192-197
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    • 1998
  • This paper demonstrates that it is feasible to evaluate forest degradation and to detect deforestation in the 8156$km^2$ study area affected by expand farming using vegetation indices derived from Landsat TM data. The NDVI-growing stock relation was applied on th Landsat TM data and a 3 second grid DEM, whose coverages could improve the assessment of forest degradation and also estimate the rate of change of forest cover area depending on elevation intervals. The strength of the relationship between the ratio of the greenness and brightness indices and forest degradation conditions would have been more interesting in the deforested areas which were converted to crop farming land.

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POPULATION GROWTH, POVERTY INCIDENCE AND FOREST DEPENDENCY IN NEPALESE TERAI

  • Panta, Menaka;Kim, Kye-Hyun;Neupane, Hari Sharma;Joshi, Chudamani;Park, Eun-Ji
    • 한국공간정보시스템학회:학술대회논문집
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    • pp.280-285
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    • 2007
  • Since the human civilization, people's livelihood is dependent on natural resources primarily on forest. Human dimensions such as population, poverty, agricultural expansion and infrastructure development are some of the underlying factors and their interrelated associations which could play a vital role in deforestation and forest degradation. This process is not only related to the human population but also connected to the various socioeconomic factors. This paper focuses to link the spatio-temporal extent of population, poverty incidence and forest dependency and their severity on Terai forest of Nepal. Secondary data on censuses were used. ArcGIS and descriptive statistics were also used for data analysis. Based on analysis & literature review we concluded that population, poverty and forest dependency have largely expanded over time in Terai and their interrelated associations substantively influence on deforestation. However, the direct relationship of such factors with deforestation and forest degradation found to be incompatible, complex and hard to perceive with fragmented and inconsistency censuses data. So, deforestation and forest degradation issues intertwined with socioeconomic factors need detailed analysis to comprehend where these linkages are still unravel.

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Anticancer Activity of the Branch Extracts from Vaccinium oldhamii through Cyclin D1 Proteasomal Degradation in Human Cancer Cells

  • Park, Su Bin;Kim, Ha Na;Park, Gwang Hun;Son, Ho-Jun;Eo, Hyun Ji;Song, Jeong Ho;Song, Hun Min;Park, Ji Ae;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.31 no.3
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    • pp.218-227
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    • 2018
  • In this study, we investigated the effect of the extracts from Vaccinium oldhamii on cell proliferation and the regulatory mechanisms of cyclin D1 protein level in human cancer cells. The branch extracts from Vaccinium oldhamii (VOB) showed higher inhibitor effect against the cell growth than leave extracts (VOL) and fruit extracts (VOF) in human colorectal cancer, breast cancer, prostate cancer, non-small lung cancer, pancreatic cancer and liver cancer cells. In addition, VOB decreased cyclin D1 level at both protein and mRNA level. MG132 treatment attenuated VOB-mediated cyclin D1 downregulation. A point mutation of threonine-286 to alanine attenuated cyclin D1 degradation by VOB. In addition, the inhibition of nuclear export by leptomycin B (LMB) attenuated cyclin D1 degradation by VOB. But, the treatment of PD98059 (ERK1/2 inhibitor), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), LiCl ($GSK3{\beta}$ inhibitor), LY294002 (PI3K inhibitor) or BAY 11-7082 ($I{\kappa}K$ inhibitor) did not affect VOB-induced cyclin D1 degradation. In conclusion, VOB induced cyclin D1 degradation through redistribution of cyclin D1 from the nucleus to cytoplasm via T286 phosphorylation of cyclin D1, which resulted in the inhibition of cancer cell proliferation.

Evaluation of Suitable REDD+ Sites Based on Multiple-Criteria Decision Analysis (MCDA): A Case Study of Myanmar

  • Park, Jeongmook;Sim, Woodam;Lee, Jungsoo
    • Journal of Forest and Environmental Science
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    • v.34 no.6
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    • pp.461-471
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    • 2018
  • In this study, the deforestation and forest degradation areas have been obtained in Myanmar using a land cover lamp (LCM) and a tree cover map (TCM) to get the $CO_2$ potential reduction and the strength of occurrence was evaluated by using the geostatistical technique. By applying a multiple criteria decision-making method to the regions having high strength of occurrence for the $CO_2$ potential reduction for the deforestation and forest degradation areas, the priority was selected for candidate lands for REDD+ project. The areas of deforestation and forest degradation were 609,690ha and 43,515ha each from 2010 to 2015. By township, Mong Kung had the highest among the area of deforestation with 3,069ha while Thlangtlang had the highest in the area of forest degradation with 9,213 ha. The number of $CO_2$ potential reduction hotspot areas among the deforestation areas was 15, taking up the $CO_2$ potential reduction of 192,000 ton in average, which is 6 times higher than that of all target areas. Especially, the township of Hsipaw inside the Shan region had a $CO_2$ potential reduction of about 772,000 tons, the largest reduction potential among the hotpot areas. There were many $CO_2$ potential reduction hot spot areas among the forest degradation area in the eastern part of the target region and has the $CO_2$ potential reduction of 1,164,000 tons, which was 27 times higher than that of the total area. AHP importance analysis showed that the topographic characteristic was 0.41 (0.40 for height from surface, 0.29 for the slope and 0.31 for the distance from water area) while the geographical characteristic was 0.59 (0.56 for the distance from road, 0.56 for the distance from settlement area and 0.19 for the distance from Capital). Yawunghwe, Kalaw, and Hsi Hseng were selected as the preferred locations for the REDD+ candidate region for the deforestation area while Einme, Tiddim, and Falam were selected as the preferred locations for the forest degradation area.

Assessment of Land Cover Changes from Protected Forest Areas of Satchari National Park in Bangladesh and Implications for Conservation

  • Masum, Kazi Mohammad;Hasan, Md. Mehedi
    • Journal of Forest and Environmental Science
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    • v.36 no.3
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    • pp.199-206
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    • 2020
  • Satchari National Park is one of the most biodiverse forest in Bangladesh and home of many endangered flora and fauna. 206 tons of CO2 per hectare is sequestrated in this national park every year which helps to mitigate climate issues. As people living near the area are dependent on this forest, degradation has become a regular phenomenon destroying the forest biodiversity by altering its forest cover. So, it is important to map land cover quickly and accurately for the sustainable management of Satchari National Park. The main objective of this study was to obtain information on land cover change using remote sensing data. Combination of unsupervised NDVI classification and supervised classification using maximum likelihood is followed in this study to find out land cover map. The analysis showed that the land cover is gradually converting from one land use type to another. Dense forest becoming degraded forest or bare land. Although it was slowed down by the establishment of 'National Park' on the study site, forecasting shows that it is not enough to mitigate forest degradation. Legal steps and proper management strategies should be taken to mitigate causes of degradation such as illegal felling.

Catabolic Pathway of Lignin Derived-Aromatic Compounds by Whole Cell of Phanerochaete chrysosporium (ATCC 20696) With Reducing Agent

  • Hong, Chang-Young;Kim, Seon-Hong;Park, Se-Yeong;Choi, June-Ho;Cho, Seong-Min;Kim, Myungkil;Choi, In-Gyu
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.2
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    • pp.168-181
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    • 2017
  • Whole cell of Phanerochaete chrysosporium with reducing agent was applied to verify the degradation mechanism of aromatic compounds derived from lignin precisely. Unlike the free-reducing agent experiment, various degraded products of aromatic compounds were detected under the fungal treatment. Our results suggested that demethoxylation, $C_{\alpha}$ oxidation and ring cleavage of aromatic compounds occurred under the catabolic system of P. chrysosporium. After that, degraded products stimulated the primary metabolism of fungus, so succinic acid was ultimately main degradation product of lignin derived-aromatic compounds. Especially, hydroquinone was detected as final intermediate in the degradation of aromatics and production of succinic acid. In conclusions, P. chrysosporium has an unique catabolic metabolism related to the production of succinic acid from lignin derived-aromatic compounds, which was meaningful in terms of lignin valorization.

Are Poverty and Illiteracy to Blame for Forests Degradation? A Case Study of Mbeya Range Forest Reserve. Mbeya-Tanzania

  • Ngondya, Issakwisa Bernard;Ibrahim, Rashid Ismael Hag;Choo, Gab-Chul
    • Journal of Forest and Environmental Science
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    • v.27 no.2
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    • pp.93-99
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    • 2011
  • In this study, a total of 350 households contained 700 individuals in Iganzo village were surveyed to study their literate and poverty levels and their impacts to conservation of the Mbeya Range Forest Reserve. The study included 350 women and 350 men. The majority of respondents were between the ages of 31-40 years old (53%), while the rest were between 41-50 years old (25%) and 21-30 years old (22%). The total income per day per household was calculated and averaged to 4,570 Tanzanian shillings that is equal to about 3 U.S. dollars. The average number of members per household was seven. It was reported that, there is a tremendous decrease in biodiversity composition of the reserve mainly due to poverty (80%) and ignorance (76%) of the people on the importance of the reserve. Other causes for this decrease were reported to be grazing of livestock in the reserve (23%), poor farming systems (68%), which resulted in soil erosion, encroachment (64%) through expansion of farms towards the reserve boundary and charcoal burning (34%). Respondents from Mbeya Urban Water Supply Authority and District Forest Office mentioned lack of funds (49%) and lack of experts (56%) as challenges that face the conservation of the reserve. It was revealed that 25% of respondents had never gone to school, 53% had primary level of education as their highest level of education, 20% had secondary education and 2% had first degree. The null hypothesis that poverty and illiteracy have a positive correlation to forest degradation was accepted based on these findings at a probability of p>0.85. Thus, it was concluded that poverty and illiteracy among Iganzo village residents are the main causes for the degradation of biodiversity in Mbeya Range Forest Reserve.

A Preliminary Review of REDD Mechanism for Rehabilitating Forest Degradation of North Korea (북한 산림황폐지 복구를 위한 REDD 메커니즘 사전 검토)

  • Bae, Jae Soo
    • Journal of Korean Society of Forest Science
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    • v.102 no.4
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    • pp.491-498
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    • 2013
  • Preliminary feasibility of REDD mechanism to combat forest degradation in North Korea is reviewed as a means of cooperation between South Korea and North Korea. North Korea has not established a national REDD+ strategy and a forest monitoring system which are required to implement REDD+ under the United Nations Framework Convention on Climate Change. Credible statistical data of forest resources is a necessary condition for implementing REDD mechanism in the developing countries. However, other than forest area data using satellite images, statistical data of forest resources of North Korea are mostly estimated based on simple hypothesis rather than transparent and robust results from national forest inventory. The review of statistical data of forest resources of North Korea shows that North Korea is in a pre-stage of REDD readiness. The study suggests that following research and cooperation agendas should be considered to implement REDD mechanism in North Korea: 1) detecting land use change since 2000, measuring carbon stock change, and identifying causes of deforestation and forest degradation; and 2) establishing a national REDD+ strategy' and a national forest inventory system in North Korea.

Terrace Fields Classification in North Korea Using MODIS Multi-temporal Image Data (MODIS 다중시기 영상을 이용한 북한 다락밭 분류)

  • Jeong, Seung Gyu;Park, Jonghoon;Park, Chong Hwa;Lee, Dong Kun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.1
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    • pp.73-83
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    • 2016
  • Forest degradation reduces ecosystem services provided by forest and could lead to change in composition of species. In North Korea, there has been significant forest degradation due to conversion of forest into terrace fields for food production and cut-down of forest for fuel woods. This study analyzed the phenological changes in North Korea, in terms of vegetation and moisture in soil and vegetation, from March to Octorber 2013, using MODIS (MODerate resolution Imaging Spectroradiometer) images and indexes including NDVI (Normalized Difference Vegetation Index), NDSI (Normalized Difference Soil Index), and NDWI (Normalized Difference Water Index). In addition, marginal farmland was derived using elevation data. Lastly, degraded terrace fields of 16 degree was analyzed using NDVI, NDSI, and NDWI indexes, and marginal farmland characteristics with slope variable. The accuracy value of land cover classification, which shows the difference between the observation and analyzed value, was 84.9% and Kappa value was 0.82. The highest accuracy value was from agricultural (paddy, field) and forest area. Terrace fields were easily identified using slope data form agricultural field. Use of NDVI, NDSI, and NDWI is more effective in distinguishing deforested terrace field from agricultural area. NDVI only shows vegetation difference whereas NDSI classifies soil moisture values and NDWI classifies abandoned agricultural fields based on moisture values. The method used in this study allowed more effective identification of deforested terrace fields, which visually illustrates forest degradation problem in North Korea.