• Journal of Forest and Environmental Science
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• 제39권4호
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• pp.203-212
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• 2023

Directional felling is a felling method practised by the Forestry Department in Peninsular Malaysia as prescribed in Field Work Manual (1997) for Selective Management Systems (SMS) in forest harvesting. Determining the direction of tree felling in Peninsular Malaysia is conducted during the pre-felling inventory 1 to 2 years before the felling operation. This study aimed to predict and analyze the direction of tree felling using the vector-based path distance back link method in Geographic Information Systems (GIS) and compare it with the felling direction observed on the ground. The study area is at Balah Forest Reserve, Kelantan, Peninsular Malaysia. A Path Distance Back Link (spatial analyst) function in ArcGIS Pro 3.0 was used in predicting tree felling direction. Meanwhile, a binary classification was used to compare the felling direction estimated using GIS and the tree felling direction observed on the ground. Results revealed that 61.3% of 31 trees predicted using the vector-based projection method were similar to the felling direction observed on the ground. It is important to note that dynamic changes of natural constraints might occur in the middle of tree felling operation, such as weather problems, wind speed, and unpredicted tree falling direction.

• 한국산림과학회지
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• 제99권1호
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• pp.153-162
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• 2010

본 연구는 경기도 용인 지역 전나무(Abies holophylla Maxim.) 임분의 구조를 분석하고, 이 지역 전나무 임분의 지속가능성을 알아보기 위하여 수행되었다. 용인시의 정수리, 대대리, 호동 지역 전나무 임분에서 매목조사를 실시하고, 관목층의 구조와 치수의 발생을 조사하였다. 산림 관리나 작업이 이루어지지 않았던 정수리와 대대리 임분에서 전나무는 중요도 40%로 임분을 우점하고 있었으며, 연속적인 연령과 직경분포를 보이고 있었다. 반면 호동 지역 임분은 간벌과 택벌 등의 산림 작업이 이루어졌던 지역으로 전나무가 흉고직경 10-45 cm 범위에 분포하나 대부분 25-30 cm 직경급에 몰려 있고, 단일수관층을 가지고 있었다. 전나무의 연령과 흉고직경의 상관 관계는 유의한 것으로 나타나긴 하였으나 높지 않았고($R^2$=0.2, P=0.03), 비슷한 연령대라도 다양한 흉고직경 값을 가졌다. 정수리 임분의 연속적인 직경 분포와 다층수관구조는 전나무가 조림 후 지속적으로 갱신이 이루어져 왔음을 보여주었다. 전나무의 치수는 ha당 2000-33000본까지 발생하였으나, 2-5 cm 직경급의 전나무는 ha당 70-150본 정도로 치수 단계에서 유령목으로 자라나는 동안의 생존율은 낮았다. 지속적인 천연갱신과 연간 약 0.6 cm의 직경생장율은 조사 지역의 환경이 전나무 서식에 비교적 적합한 지역임을 나타낸다. 또한 전나무 임분은 향후에도 지속적으로 유지될 것으로 보여 내음성 수종인 전나무를 대상으로 한 택벌림 경영의 가능성을 제시해주고 있다.

• Journal of Ecology and Environment
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• 제41권10호
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• pp.290-301
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• 2017

Background: Forest edges create distinctive ecological space as adjacent constituents, which distinguish between different ecosystems or land use types. These edges are made by anthropogenic or natural disturbance and affects both abiotic and biotic factors gradually. This study was carried out to assess edge effects on disturbed landscape at the pine-dominated clear-cut area in a genetic resources reserve in Uljin-gun, eastern Korea. This study aims to estimate the distance of edge influence by analyzing changes of abiotic and biotic factors along the distance from forest edge. Further, we recommend forest management strategy for sustaining healthy forest landscapes by reducing effects of deforestation. Results: Distance of edge effect based on the abiotic factors varied from 8.2 to 33.0 m. The distances were the longest in $Mg^{2+}$ content and total nitrogen, $K^+$, $Ca^{2+}$ contents, canopy openness, light intensity, air humidity, $Na^+$ content, and soil temperature followed. The result based on biotic factors varied from 6.8 to 29.5 m, coverage of tree species in the herb layer showed the longest distance and coverage of shrub plant in the herb layer, evenness, species diversity, total coverage of herb layer, and species richness followed. As the result of calculation of edge effect by synthesizing 26 factors measured in this study, the effect was shown from 11.0 m of the forest interior to 22.4 m of the open space. In the result of stand ordination, Rhododendron mucronulatum, R. schlippenbachii, and Fraxinus sieboldiana dominated arrangement of forest interior sites and Quercus mongolica, Vitis amurensis, and Rubus crataegifolius dominated spatial distribution of the open area plots. Conclusions: Forest interior habitat lies within the influence of both abiotic and biotic edge effects. Therefore, we need a forest management strategy to sustain the stability of the plant and further animal communities that depend on its stable conditions. For protecting forest interior, we recommend selective logging as a harvesting method for minimizing edge effects by anthropogenic disturbance. In fact, it was known that selective logging contributes to control light availability and wind regime, which are key factors affecting microclimate. In addition, ecological restoration applying protective planting for the remaining forest in the clear-cut area could contribute to prevent continuous disturbance in forest interior.

• 멤브레인
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• 제26권6호
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• pp.432-448
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• 2016

최근 이온 교환 고분자 전해질 막을 활용한 고효율 에너지 전환 및 저장 장치에 대한 연구가 활발히 이루어지고 있다. 고분자 전해질 연료전지, 레독스 흐름전지 및 역전기투석 등 다양한 에너지 시스템에서 에너지 효율 향상을 위해 이온교환 전해질 막의 양/음이온의 선택적 수송 거동이 중요시되고 있다. 본 총설은 각각의 고효율 전해질 전지 시스템에 따라 요구되는 다양한 이온 교환막의 선택적 양/음이온 투과 거동의 한계점을 고찰하고, 한계를 극복하기 위한 다양한 구조의 고분자 이온 교환 복합막의 장점 및 단점을 정리하였다. 고분자 가교법 및 다공성 지지체 복합막 이외에 다양한 구조의 신규다공성 무기 나노입자를 유-무기 이온교환 복합막에 도입하는 시도가 이루어지고 있는 동시에, 이온 선택도 향상을 위한 다양한 형태의 표면 개질 방법이 개발되고 있으며, 이를 통해 이온 교환 복합막의 선택적 양/음이온 거동의 한계를 극복하는 전략을 제시하고 있다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.28-30
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• 2005

Because of high population diversity in soil microbial communities, it is difficult to accurately assess the capability of biodegradation of toxicant by microbes in soil and sediment. Identifying biodegradative microorganisms is an important step in designing and analyzing soil bioremediation. To remove non-important noise information, it is necessary to selectively enrich genomes of biodegradative microorganisms fromnon-biodegradative populations. For this purpose, a stable isotope probing (SIP) technique was applied in selectively harvesting the genomes of biphenyl-utilizing bacteria from soil microbial communities. Since many biphenyl-using microorganisms are responsible for aerobic PCB degradation In soil and sediments, biphenyl-utilizing bacteria were chosen as the target organisms. In soil microcosms, 13C-biphenyl was added as a selective carbon source for biphenyl users, According to $13C-CO_2$ analysis by GC-MS, 13C-biphenyl mineralization was detected after a 7-day of incubation. The heavy portion of DNA(13C-DNA) was separated from the light portion of DNA (12C-DNA) using equilibrium density gradient ultracentrifuge. Bacterial community structure in the 13C-DNAsample was analyzed by t-RFLP (terminal restriction fragment length polymorphism) method. The t-RFLP result demonstates that the use of SIP efficiently and selectively enriched the genomes of biphenyl degrading bacteria from non-degradative microbes. Furthermore, the bacterial diversity of biphenyl degrading populations was small enough for environmental genomes tools (metagenomics and DNA microarrays) to be used to detect functional (biphenyl degradation) genes from soil microbial communities, which may provide a significant progress in assessing microbial capability of PCB bioremediation in soil and groundwater.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권2호
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• pp.140-147
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• 2012

Microvascular reconstruction, in the oral and maxillofacial regions, is a widely accepted as the best way to overcome the complex oral cavity defects. Many patients requiring composite reconstructions have been treated previously with radiation therapy, chemotherapy, selective and/or functional neck dissection or any of these combinations. In many cases of these patients, inadequate neck vessels for the microanastomosis of free flap are available, due to a lack of recipient vessels in the neck, poor vessel quality or vessel caliber mismatch. To achieve a tension-free anastomosis, vein grafting must be considered to span the vessel gap between the free flap pedicle and the recipient neck vessels. Although most microsurgeons believed that interpositional grafts are to be avoided due to vessel thrombosis and increased number of necessary microanastomosis, we, authors have some confidence of equivalency between reconstruction with and without interpositional saphenous vein graft. The great saphenous vein, also known as the long saphenous vein, is the large subcutaneous superficial vein of the leg and thigh. It joins with the femoral vein in the region of femoral triangle at the saphenofemoral junction, and coursed medially to lie on the anterior surface of the thigh before entering an opening in the fascia lata, called the saphenous opening. For a better understanding of the great saphenous vein graft for the interpositional vessel graft in the oral cavity reconstructions, and an avoidance of any uneventful complications during these procedures, the related surgical anatomies with their harvesting tips are summarized in this review article in the Korean language.