• Journal of the Korean Wood Science and Technology
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• 제50권6호
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• pp.436-447
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• 2022

Lignocellulose nanofibrils (LCNFs) were prepared using a two-step deep eutectic solvent (DES) and enzymatic pretreatment followed by mechanical defibrillation, and we examined the effects of enzymatic pretreatment conditions on different characteristics of the LCNFs thus obtained. The LCNFs yielded using the two-step DES pretreatment (Enz-LCNF) exhibited a well-defibrillated entangled web-like structure with an average fiber diameter ranging from 15.7 to 20.4 nm. Furthermore, we found that the average diameter and filtration time of the Enz-LCNFs decreased with an increase in enzyme concentration and enzymatic treatment time, whereas we detected a concomitant reduction in the tensile strength of the Enz-LCNF sheets. The Enz-LCNFs were characterized by a typical cellulose I structure, thereby indicating that the enzymatic treatment causes very little damage to the crystalline form.

• 한국농림기상학회지
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• 제5권2호
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• pp.101-109
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• 2003

The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest Bone. At the old-growth deciduous forest near Soribong-peak (533.1 m) in KEF, we have established a 1 ha permanent plot ($100m{\times}100m$) and a flux tower, and the site was registered as a KLTER(Korean long-term ecological research network) and DK site of KoFlux. In this site, we made a stemmap of trees and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2 cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area $28.0m^2$/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66 cm. Soil texture is loam or sandy loam, and its pH was f개m 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the 1.2 m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30 cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. These ground survey and monitoring data will give some important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function.

• 한국환경생태학회지
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• 제9권1호
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• pp.30-41
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• 1995

불갑산지역의 상록활엽수림에 대한 식생구조를 분석하기 위하여 40개 조사구에 대한 TWINSPAN과 DCA Ordination 기법을 적용한 결과 5개 식물군집유형 즉 푸조나무군집, 참식나무-푸조나무-비자나무군집, 낙엽활엽수혼효림군, 갈참나무군집. 굴참나무-갈참나무군집으로 분리되었다. 그러나 불갑산 식생은 천이도중상의 불안정한 식생구조라고 판단된다. 상록활엽수림대에서 극상수종으로 판단되는 참식나무는 푸조나무와 정의 상관관계를, 개서어나무, 굴참나무, 갈참나무와 부의 상관관계를 나타냈다.

• 농촌계획
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• 제14권1호
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• pp.23-32
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• 2008

Landscape structure is important to understand a complex patterns and interaction with adjacent habitat in rural area. The aim of this study is to analyze relationship between landscape structure and insect spatial distribution in rural area to suggest applicable possibility of landscape structure as biological indicator. For this purpose, first, four landscape structure criteria such as distance from the forest; density of farmland-forest ecotone; landscape continuity; and field size are selected. Secondly, these criteria are applied to Gangsang-myeon, Yangpyeong-gun where mosaic feature are conserved at various spatial scale. Thirdly, application of landscape structure criteria is verified using correlation with species number, species diversity, and species richness of insect. As a result, it could be suggested that the landscape structure criteria are useful for explaining insect spatial distribution.

• 한국산림과학회지
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• 제98권5호
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• pp.593-601
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• 2009

Forest disturbances including forest fire, insect pests and diseases, landslides, and forest conversion from 1976 to 2005 were investigated to trace the changes of major forest disturbance agents and their characteristics over time in accordance with changes in natural and social environment in South Korea. While the damaged area by insect pests and diseases continuously decreased for the past 30 years, damaged areas by forest fire and landslide were fluctuating through years. The interval of large forest fires has become shorter with increased tree volume. The precipitation between January and April were significantly correlated with large fire occurrences as Pearson's correlation coefficient -0.400 (P=0.029). The composition of major insect pests and diseases damaging Korean forests has been changed continuously, and become more diversified. While damages by pine caterpillar (Dendrolimus spectabilis) and pine needle gall midge (Thecodiplosis japonensis) decreased, damage by introduced pests has been more serious recently. The change of precipitation pattern that brought more localized heavy rain or powerful typhoon resulted in the recent increase in landslide areas. The major land uses to induce forest conversion have been changed, reflecting the changes in industrial structure in South Korea as agriculture and mining in 1970s, mining and golf ranges classified in pasture in 1980s, and road and housing construction in 1990s and 2000s. Changes in forest disturbance patterns in South Korea show that a country's industrial development is jointly working with global warming on forest stand dynamics. Altering energy structure and land use pattern induced by industrial development accumulates forest volume and reforms microenvironments on forest floor, interacting with climate change, inducing shorter interval of large forest fire and changes in major species composition of forest insect pests and diseases.

• Journal of Forest and Environmental Science
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• 제33권1호
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• pp.66-73
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• 2017

This study was conducted to evaluate the ecological attributes of forest types which were classified by cluster analysis in the natural forest of Mt. Odae on the basis of the vegetation data (232 sampling points) from the point-quarter sampling methods. For the classified types, the species composition was expressed by importance value to describe the stand structure and the species diversity was quantified using the Shannon's diversity index. Recognized forest types were 1) Quercus mongolica-Pinus densiflora-Betula ermanii forest type, 2) Mixed mesophytic forest type, 3) Q. mongolica forest type, 4) B. ermanii forest type. Species diversity indices of total and overstory were highest in the Mixed mesophytic forest type (3.465 and 2.942), and lowest in the B. ermanii forest type (0.118 and 0.832). In addition to that, Q. mongolica-P. densiflora-B. ermanii forest type was calculated as 3.226 and 2.565, and Q. mongolica forest type was calculated as 2.776 and 1.218 in total and overstory, respectively. It was considered that after the P. densiflora and B. ermanii first invaded and site condition became good, Q. mongolica-P. densiflora-B. ermanii forest type was dominated by Q. mongolica. Mixed mesophytic forest type showed the most stable stand structure with various species distributed uniformly. Q. mongolica forest type would preserve the present stand status for a while, and the B. ermanii in B. ermanii forest type would be pressed by other species over time.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.405-413
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• 2015

We classified the streamside plant community by phyto-sociological method and analyzed the relationship between environment factors and vegetation structure by using the classification and ordination method. We found that twenty one plant communities were classified according to dominant species at the natural streamside valley forest with surveying the 65 quadrats (10 m × 10 m). From the survey results, the hardwood plant communities were classified as streamside valley forest and the softwood plant communities as riparian forest according to the degree of flooding. The valley forest had a distribution of 17 plant communities which was 65% (42 quadrats) of 65 quadrats: Maackia amurensis community, Betula davurica community, Quercus variabilis community, Pinus densiflora community, Q. serrata community, Prunus sargentii community, and Meliosma oldhamii community etc. The riparian forest had a distribution of four plant communities which was 35% (23 quadrats) of 65 quadrats: Salix koreensis community, S. rorida community, S. purpurea var. japonica community, and S. glandulosa community, etc. From the two-way indicator species analysis (TWINSPAN) analysis, we found indicator species Oplismenus undulatifolius and Lindera obtusiloba for the streamside valley forest and Humulus japonicus, Phragmites japonica, and S. koreensis for the riparian forest. From the results of the canonical correspondence analysis (CCA), coordinates, altitude, and stream structure showed low correlation to the distribution of the plant community. Therefore, it seemed that valley forest and riparian forest were distinguished by the stream gradient and waterway width which determined by the stream water level.

• 한국농림기상학회지
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• 제16권4호
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• pp.259-266
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• 2014

산불 확산 패턴 분석은 산림 생태계 안정화를 이해하는데 중요한 요소이다. 하지만 규모의 문제로 인해 실제적인 실험이 불가능하여 많은 학자들이 시뮬레이션 모델을 이용하여 산불 확산의 행동기작을 이해하고 산림 피해를 예측하였다. 그러나 많은 모델들이 연료의 종류, 바람, 습도 같은 여러 환경 요소들의 복잡한 관계를 표현하는데 한계를 가지고 있다. 본 논문에서는 지형의 구조와 두 종의 나무들로 구성된 산림에서 미치는 영향을 분석하는 간단한 모델을 제안하였다. 두 종의 나무는 가연성이 높은 나무와 가연성이 낮은 나무가 있으며, 서로 다른 산불 전이 확률을 가지고 있다. 전체 나무는 시뮬레이션 공간에 0.5에서 1.0까지의 비율로 무작위로 배치된다. 가연성이 높은 나무는 가연성이 낮은 나무 보다 높은 산불 전이 확률을 가진다. 전소한 나무의 수를 기준으로 지형의 구조와 전체 나무의 밀도가 산불 확산에 얼마나 영향을 미치는지 민감도를 분석하였다. 우리는, 본 논문에서 제시한 모델이 앞으로 산불 확산 패턴을 연구하는데 유용할 것으로 기대한다.

• 한국환경복원기술학회지
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• 제12권6호
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• pp.123-130
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• 2009

Fragmentation due to land developments causes disturbances and changes of composition in forest vegetation. The purpose of the study was to develop the impact assessment model for quantitative distance or degree of disturbance by land developments. This study conducted a survey about structure and composition of forest vegetation to determine degree of impact from land developments. The results of field survey, there was a difference in structure and composition of forest vegetation such as tree canopy, herbaceous cover, and number of vine and alien species the distances from edge to interior area such as 0m, 10m, 20m, 40m, and over 60m. To assess the disturbance of forest vegetation, the factors selected were the rate of vine's cover and appearance of alien species. The impact assessment model about vine species explained by a distance, forest patch size, type of forest fragmentation, and type of vegetation ($R^2$=0.44, p<0.001). The other model about alien species explained by a distance, type of forest fragmentation, type of vegetation, and width of road (85.9%, p<0.005). The models applied to Samsong housing development in Goyang-si, Gyunggi-do. The vines and alien species in the study area have had a substantial impact on forest vegetation from edge to 20 or 40m. The impact assessment models were high reliability for estimating impacts to land developments. The impact of forest vegetation by development activities could be minimized thorough the adoption of the models introduced at the stage of EIA.

• The Korean Journal of Ecology
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• 제20권4호
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• pp.265-274
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• 1997

All landscapes are mosaics of habitat patches of different types. Therefore, there are always edged between habitat patches in a landscape. Forest animal has an important role in vegetation development and maintenance by seed dispersal around forest. Movement of animals depends on the spatially heterogeneous structure and pattern of vegetation landscapes because each animal has special habitats in a landscape. Especially, forast edge with high permeability and prey density is one of the important habitats to the animals. Therefore, understanding the ecological characteristics of the forest edges as a corridor connecting mosaic vegetation patches is necessa교 새 establish the strategies for the nature conservation and sustainable vegetation management. Under this idea, we examined the animal influenced on pine seeds as one of the method of monitoring the animal activity in mosaic vegetation. Man-made mosaic vegetations including open, edge and inner forests were carefully selected in the rural landscape. We carried out predation test on pine seeds during one year. A result was that damages on seed was more significant at forest edge than inner and open forest. Pine seed on seedbeds was mainly attacked by squirrels and mice than birds. Pine seed was damaged by squirrels in different types of vegetation by seasons. Rate of seed predation at forest edge was, in special, higher than that of other sites. According to this results, it is suggested that the relationship between animal behavior and spatial vegetation structure relating to human impact such as the distance from settlement to vegetation appeares to be in the rural vegetation landscape.