• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.49-54
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• 2023

For unknown reasons, a few trees in a private chestnut orchard in Icheon si, Gyunggi-do suffered leaf chlorosis and growth decline. Based on symptoms, phytoplasma was a probable cause. Leaf samples were collected from two symptomatic and non-symptomatic trees in the orchard for phytoplasma detection. An amplicon of about 1.2 bp size was obtained from both symptomatic trees by PCR with the universal 16S rDNA primers. Sequences of these amplicons were found to have 99% nucleotide sequence identity to the corresponding genomic region of 16SrIII (X-disease group). More than 100 phytoplasma isolates, such as Candidatus phytoplasma pruni, Milkweed yellows phytoplasma, Goldenrod yellows phytoplasma, Tsuwabuki witches'-broom phytoplasma, Candidatus Phytoplasma trifolii, etc. were involved in the list. Phylogenetic analysis revealed that the sequence obtained in this study closely clustered with Candidatus phytoplasma groups. While one of the amplicons shared 91% identity with the Candidatus phytoplasma castaneae, the other shared only 47%. It needs further analysis and investigation to determine the exact taxonomy. Meanwhile, based on the analysis of the sequences, chlorosis, and small leaves were associated with phytoplasma.

• 한국기후변화학회지
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• 제8권4호
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• pp.369-375
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• 2017

In this study, it was intended to compare the two methodologies for forest management project through extension of rotation age: Korean Forest Carbon Offset Standard (KFOS) and Verified Carbon Standard (VCS). The amount of carbon removals and offset credits based on the two methodologies and their trends were analyzed in this study. The major difference between two methodologies were found at the process of estimation of baseline carbon removals. For instance, average carbon stock during the project period was used for estimation of baseline carbon removals in KFOS, while average carbon stock change during the 100 years was used in VCS. Due to the different approach for estimation of baseline carbon removal, the estimated offset credits were also different according to the two methodologies. In this study, 15 project scenarios were considered for comparison of two methodologies : 5 major coniferous stands in Korea (Pinus densiflora in Gangwon region, Pinus densiflora in Central region, Pinus koraiensis, Larix leptolepis, Chamaecyparis obtusa) with 3 project periods (30, 35, 40 years). The results showed that estimated carbon offset credits based on the KFOS methodology were higher for all 15 scenarios compared to those based on the VCS methodology. The KFOS showed a steep decline in the annual offset credit as project period gets longer, thus it is not desirable for projects with longer period. VCS is more acceptable for longer projects with a small difference according to the project periods. The results also indicated that Pinus densiflora in Gangwon, Pinus koraiensis, and Larix leptolepis are more desirable species for forest management project through the extension of ration age.

• 한국산림과학회지
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• 제104권2호
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• pp.254-260
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• 2015

이 연구는 수입 목제품과 국산 목제품의 수요가 불완전 대체관계에 있다고 가정하고 아밍턴 대체 탄성치를 추정하였으며 이에 근거하여 수입 목제품의 관세 인하가 국내 목제품 생산에 미치는 영향을 분석한 것이다. 분석 대상 목제품은 합판, 섬유판, 파티클보드로 하였다. 분석결과, 국산 목제품과 수입 목제품은 완전 대체관계에 있지는 않은 것으로 나타났다. 합판과 섬유판에서 국산품과 수입품의 대체 탄성치가 높게 나타나 관세를 인하하였을 때 그 영향이 적지 않을 것으로 생각된다. 이에 비해 파티클보드 시장에서 국산품과 수입품은 차별화되어 있으며 대체 관계가 낮은 것으로 보인다. 섬유판은 국내 숲가꾸기 산물을 원료로 사용하고 있기 때문에 섬유판 생산의 위축은 국내 임업에도 부정적 영향을 미치게 될 것이다. 따라서, 시장개방에 대응하여 국내 목제품 산업의 경쟁력 강화를 위한 대책이 필요하다.

• 한국산림과학회지
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• 제112권3호
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• pp.322-330
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• 2023

최근 기후변화의 심화가 지속되는 가운데 아고산 침엽수종의 쇠퇴 현상이 뚜렷하게 나타나고 있다. 이에 산림청에서는 고산지역 침엽수 7종에 대해 보전 대책을 수립하고 쇠퇴원인을 파악하고 보전전략 수립방안에 대한 연구가 진행되고 있다. 본 연구는 멸종위기 고산지역 침엽수종 보전전략 수립방안 중 멸종위기 고산지역 침엽수종에 대한 인식과 보전가치 평가를 통해 멸종위기 침엽수종에 대한 보전의 필요성과 가치를 알리기 위한 객관적인 자료를 제시하고자 경제적 가치평가방법인 조건부가치법(CVM, contingent valuation method)을 적용하였다. 멸종위기 침엽수종에 대한 인식과 보전가치 평가를 하기 위해 성별, 연령, 거주지에 대한 인구비례 할당을 통해 2,151명에 대한 설문조사의 결과를 분석하였다. 그 결과, 멸종위기 고산지역 침엽수종 1가구당 보전가치는 49,181원으로 추정되었다.

• Journal of Forest and Environmental Science
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• 제36권2호
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• pp.122-132
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• 2020

The study examined revenue generation trend and perception of challenges facing it by forestry personnel in Akwa Ibom State, Nigeria. Data for the study was generated through primary and secondary sources. Primary sources involved the use of questionnaire which was administered to all Forest Officers and Uniformed Field Staff in all the 31 Forest Division and Headquarter in the state. Secondary sources involved collation of generated revenue from all the divisions for the study period. Data obtained were analyzed using descriptive and inferential statistics including Least square regression. The results indicated an increasing trend in forest revenue for the state statistically defined by the function y=45631x-900000000＋e (p>0.05) with a coefficient of determination of 0.7492 or 74.92%. There was also a positive correlation (r=0.866) between generated revenue and year for the 20 years under review. The mean revenue was ₦4776247.00 with the highest generated revenue (₦9823550.00) in 2014. However, majority (55.13%) of the respondents perceived revenue generation in the state to be decreasing and attributed the decline majorly to lack of mobility (16.84%) and insufficient man power (15.79%). Attitude and level of offence in the study area was perceived to be fairly cooperative (62.81%) and high (43.80%), while recruitment of more personnel (11.05%) and provision of mobility (10.03%) was considered an effective means of improving revenue generation in the state. Also, educating the people and regular patrol by forest personnel was considered as the best ways of curtailing forest offences in the area. The study recommended increased allocation of funds to the sector in addition to tackling the challenges faced by the personnel.

• 한국산림과학회지
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• 제99권2호
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• pp.179-185
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• 2010

Organophosphate pesticides inhibit cholinesterase. It is likely that application of organophosphate pesticides affect behavior of arthropods. This study aimed to find changes in foraging behavior of ants due to application of fenitrothion, one of the widely used organophosphate pesticides. Foraging activity (FA) of ants was observed using bait cards in a pesticide sprayed pine stand and in an unsprayed stand before and after aerial application of fenitrothion in 2003 and 2004. Ant abundance and species richness of ants were also monitored using pitfall traps during the activity season in 2003 and 2004. There was not a significant decrease in abundance and species richness after the application of fenitrothion. However, FA of an ant, Paratrechina flavipes (Smith), which was abundant enough to be statistically compared, was depressed from 2 hours to 10 days after application of the pesticide. FA was fully recovered at day 14 in 2003, and was partially recovered at day 18 and fully at day 31 in 2004. FA of other ant species also decreased significantly during the FA depression period of P. flavipes. On the bait cards, workers of the species responded dully to baits during the FA depression period. Despite the decline in activity, alertness of P. flavipes to other species did not decrease even during the FA depression period.

• Journal of Forest and Environmental Science
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• 제32권2호
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• pp.113-119
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• 2016

The long lived iteroparous conifers produce male and female gametophyte for hundreds of years once they reach the reproductive stage, however, the production of seed is not frequent. This phenomenon of infrequent seed production in conifers is yet to be understood. An attempt to study this change in cone production in Cedrus deodara of Western Himalayas -a species reported to be mainly monoecious and rarely dioecious has been made. The observations recorded on selected trees of flowering/fruiting stage for four years at four different locations have shown the species to be dioecious with higher percentage of female trees during good seed year but with no definite or predictable pattern of reproduction in the trees. A decline in production of female trees was witnessed at all but one location immediately year after reaching the maximum (good seed year). The phenomenon of seed production has been observed to be cyclic and site specific. A change in the sexual behavior of the trees from male to female or vice-versa, male or female turning monoecious or vegetative and vegetative coming to reproductive was unpredictable.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제2권2호
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• pp.76-81
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• 2021

With continuous decline of Philippine forest cover, sustainable forest management and restoration are essential to restore destroyed forest ecosystems. Unfortunately, of ten most planted trees in reforestation projects in the Philippines, eight are exotic species, with large leaf mahogany (Swietenia macrophylla) being the most dominant. In this study, effect of Swietenia macrophylla in reforestation projects on native tree species was evaluated. Effects of S. macrophylla leaf litter, frequency, and canopy closure on the growth of the Philippine native species Pterocarpus indicus were investigated. Results showed that S. macrophylla leaf litter significantly inhibited the growth of P. indicus seedlings based on root collar-to-shoot height. The standardized growth rate of seedlings in plots without S. macrophylla leaf litter was significantly higher than the growth rate of seedlings in plots with leaf litter. Furthermore, there was no significant difference in the standardized growth rate of seedlings between plots without leaf litter and a control plot. On the contrary, S. macrophylla tree frequency and canopy closure showed no significant effect. These results attest to the negative effect of widely planted S. macrophylla to a valuable Philippine native tree P. indicus. With accumulating scientific evidence about negative effects of S. macrophylla on native trees, discontinued use in tree planting and reforestation efforts with active management of restoration sites previously planted with large leaf mahogany are needed.

• Journal of the Korean Wood Science and Technology
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• 제37권6호
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• pp.556-565
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• 2009

제재목 육안등급판정 자동화시스템은 정확한 입력 화상이 요구된다. 이송 중인 재장 3.6 m의 국내산 소나무의 제재목 화상을 생성시키기 위해서 영역카메라를 이용하여 부분 화상을 획득하였고 2종류의 템플릿 위치지정법과 6가지의 템플릿 크기 조건을 적용하여 병합하였다. 특징영역 추출법이 템플릿 고정법에 비해 병합 성능이 우수하였다. 길이오차의 발생 요인은 명도차이, 특정 패턴, 템플릿 크기 등에 의한 유사도 하락에 있었다. 부정합은 길이가 길고 반복적인 목리에서 주로 발생하였다. 템플릿 크기는 6가지 템플릿 종류 중에 크기가 가장 작은 $100{\times}100$ 화소가 가장 병합 성능이 우수하였다. 병합 성능을 향상시키기 위해서는 정밀한 템플릿의 크기 선정과 명도 차이를 감소시킬 수 있는 화상병합 전처리에 대한 연구가 요구된다.

• 한국산림과학회지
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• 제98권5호
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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.