• Journal of Ecology and Environment
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• v.29 no.6
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• pp.531-537
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• 2006

We assessed the species composition and structure of the three representative forest stands(Pinus densiflora stand, Quercus variabilis stand, and Ouercus mongolica stand), dominated in the National Long-Term Ecological Research Sites of Mt. Worak, Korea and established a benchmark series of permanent plots and transects with which future changes in forest composition and structure could be monitored. Species richness of Q. mongolica stand was greater than other two stands, due in large part to the greater habitat heterogeneity. Number of trees and species are decreased with increasing DBH classes. The successional trends of the three study stands would be mostly changed as Q. mongolica forest, regardless of forest types. Mean density ratio between alive trees and dead trees of three forest stands appeared with Q. mongolica stand 75:25, Q. variabilis stand 94:6, and P. densiflora stand 86:14, Q. mongolica stand appeared most highly from in three stands. This may be due to interspecific or intraspecific competition that it follows in various successesional stages. One side, when it saw the tree status which shows the tree health, the three forest stands all standing alive type (AS) appeared most highly with 75% to 85% and fallen dead type (DF) did not appear entirely. Remeasurement of permanent plots at periodic intervals will provide useful information on the dynamics of the forest vegetation that can be used in the development of adaptive conservation plans.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.83-92
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• 2022

The 2020 summer extreme flood severely disturbed the riparian ecosystem of the Seomjin River. Some trees were killed by the flood impact, whereas others have recovered through epicormic regeneration after the disturbance. At the same time, several tree individuals newly germinated. This research aimed to explain the recovery of the riparian ecosystem by spatial proximity between each tree individual of different characteristics, such as "dead", "recovered", and "newly germinated". A spatial point pattern analysis based on K and g-functions revealed that the newly germinated trees and the existing trees were distributed in the spatially clumping patterns. However, further detailed analysis revealed that the new trees were statistically less attracted to the recovered trees than the dead trees, implying competitive interactions hidden in the facilitative interactions. Habitat amelioration by the existing trees positively affected the growth of the new trees, while "living" existing trees were competing with the new trees for resources. This research is expected to provide new knowledge in this era of rapid climate change, which likely induces stronger and more frequent natural disturbance than before. Environmental factors have been widely used for ecosystem modeling, but species interactions, represented by the relative spatial distribution of plant individuals, are also valuable factors explaining ecosystem dynamics.

• Mycobiology
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• v.40 no.1
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• pp.79-81
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• 2012

Cankers are localized dead areas in the bark of stems, branches or twigs of many types of trees and shrubs, and are usually caused by fungi. We observed severe canker symptoms in oak trees located in Gyeongnam province in 2011. A total 31 trees were discovered with cankers of varied size, with an average of $48.5{\times}15.2cm$. Black, half-rounded globular mound shaped stromata were associated with the cankers, and the asci of the fungi associated with the cankers were cylindrical shaped with their spore-bearing parts being up to 84 ${\mu}m$ in length. The average fungal ascospores size was $7.59{\times}4.23{\mu}m$. The internal transcribed spacer sequence for the canker causing fungus showed 99% similarity to the sequence of $Annulohypoxylon$ $truncatum$. In this study, the isolated fungus was precisely described and then compared with fungi of similar taxa.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.31 no.1
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• pp.98-107
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• 2013

Big and old trees in the scenic spots with the attributes of remote villas are vulnerable to man-made damages and very sensitive to the external environment such as soil conditions, so the corresponding management plans are required. Thus this study has been conducted to survey the big and old trees in the scenic remote villas and suggest the ideal management plans. The results can be summarized as follows. First, regarding the tree heath above the ground, transformation of tree, death of branches, and death of barks are closely related to tree vigor. Particularly, the areas receiving many visitors require prompt countermeasures against the dried and dead tress above the ground and the areas in which dried and dead tress occurred and also the safety measures for the visitors and facilities. Second, regarding the soil environment, visitor traffic is closely related to the tree vigor. In 15 remote villa gardens, 64% of trees are exposed to heavy traffic and the tree vigor has declined due to an increase of visitor. Thus, there is a need to give positive consideration the installation of the complementary facilities and the plantation of herbal plants in the congested areas to form the ground surface that can tolerate the heavy visitor traffic. Third, remote gardens are in general located adjacent to ponds and mountain streams and thus the trees in the waterfront areas require the prompt countermeasures against the decline of growth due to the excess-moisture in the soil. Further the blockage of the sewage system due to the heavy rains dampens the surrounding soil, which results in lethal damages to the trees. Thus, there is a need of the maintenance of the waterfront areas and sewage system before and after the rainy season. In addition, there is a need to establish medium-long term management polices through the recognition of the importance of the main trees of remote villa gardens in scenic spots and prepare the tree management manual depending on the attributes of the corresponding areas. I strongly suggest making manuals for the systematic management as well as the extensive PR activities and education for the preservation of tress on a long-term basis; and furthermore securing the budget and manpower for the research and development of a systematic management system.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.730-736
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• 2007

The heterogeneity of forest environment plays an important role in the structure and dynamics of tree population, the composition of forest community, and the maintenance of species diversity. Based upon the research data of the nine hectare permanent plot in the typical mixed broadleaved-Korean pine forest, this study was conducted to analyze the characteristics of spatial pattern of Acer tegmentosum population for seedlings, saplings, and living and dead trees so as to evaluate the effect of micro-topography on spatial pattern of the species. The results noted that A. tegmentosum preferred to gentle slopes. There was no difference in density of seedlings by the variation of aspect, but the density of saplings, and living and dead trees was high on the western and southeastern slopes. Living trees of A. tegmentosum showed the clumped pattern for all scales within 150 m and highest at the scale of 30 m. Dead stems of the species indicated the clumped pattern within 111 m, highest at the scale of 72 m, and random pattern beyond the scale of 111 m (P < 0.01 ). The similarity of occurrence by developmental stages of A. tegmentosum showed that seedlings vs. saplings, saplings vs. living trees, and living trees vs. dead stems had highly positive correlation to each other, respectively (P < 0.01 ), indicating that the occurrence of previous developmental stages was positively correlated to following stages.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.362-366
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• 2001

This survey was carried out to investigate the effect of flooding by heavy rain on growth characteristics and disease incidence of 'Fuji'/M.26 mature apple tree in 1998 at Kyongbuk province. The surveyed regions were Andong, Uisung, and Gunwi area. The six orchards were selected from one area, totally 18 orchards were surveyed. The flooded depth of surveyed orchards was from 70 to 350 cm, and the flooded duration was from 6 to 72 h. Defoliation ratio, number of abnormal budding, and flowering per tree were increased along with the increment of flooded depth and duration. Rooting ratio was decreased rapidly with the increment of flooded duration, and dead root ratio was 16.2% in flooded orchards. Marssonia blotch (Diplocarpon mali), white rot (Botryosphaeria dothidea) of fruit, and phytophthora fruit rot (Phytophthora cactorum) incidence were increased in flooded orchards. The analysis results of pearson correlation coefficient among surveyed items showed that higher relationship of abnormal growth characteristics and increment of disease incidence of 'Fuji'/M.26 apple trees with flooded duration than with flooded depth. With these results, the flooded depth was found to be the main factor for the abnormal growth characteristics and disease incidences of 'Fuji'/M.26 apple trees.

• Journal of Environmental Science International
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• v.23 no.1
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• pp.39-46
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• 2014

This study surveyed Abies koreana to identify the correlation between its vegetation structure according to its slope direction and seedling establishment in a bid to build basic research data on the changes and conservation of the A. koreana in Hallasan Mountain. The findings of its vegetation structure revealed that in both areas, Importance value was given to the A. koreana for its tree layer, the Taxus cuspidata for its shrub layer, and the Sasa quelpaertensis for its herb layer. However, in the Youngsil area with the tree layer, high importance was given to deciduous broad-leaved trees such as Prunus maximowiczii, Quercus mongolica, and the young species of the A. koreana in the shrub layer that can maintain the A. koreana forest's greater importance in the Jindallebat than in the Youngsil. Thus, the A. koreana forest in the Jindallebat is believed to lastlonger. The findings of correlation between the quantity of seedlings and their location by area revealed that in each tiny quadrat, the A. koreana seedling averaged 5.3 in the Youngsil and 2.9 in the Jindallebat. Both areas were all found to have a positive correlation in terms of rock exposure ratio and dead tree ratio as well as a negative correlation with regard to the cover degree of S. quelpaertensis, the canopy gap, the total vegetation, and the herb layer. It was found that the cover degree of the herb layer in the Youngsil and the S. quelpaertensis in the Jindallebat had the largest impact on the A. koreana seedlings.

• Korean Journal of Heritage: History & Science
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• v.44 no.1
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• pp.122-137
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• 2011

The purpose of this study was to present the characteristics of tree growth and the status of the ecosystem in Yeongdeok Docheon-ri Docheon forest, which was designated as Natural Monument No. 514. Results showed that most of the soil properties were generally within desirable levels except for some properties. The forest was composed of 503 trees. Major trees included Zelkova serrata, Celtis sinensis, Cornus walteri, Diospyros lotus, Hemiptelea davidii, and Evodia daniellii. In particular, trees such as Zelkova serrata, Celtis sinensis, and Cornus walteri showed D.B.H ranging from 10cm to 70cm. These trees appeared to be major tree species since the beginning of Docheon forest's existence. The wild birds observed from the site were from 18 families, 20 species, and 95 individuals. Also were found 1 mammal species, 1 reptile species, and 1 amphibian species. A dead Aix galericulata (designated Natural Monument No. 327) was found in the forest. The annual tree diameter growth of the sample trees was 2.3mm per year on average. The average age of the overstory trees was approximately 101 years, and the oldest tree was estimated to be 300~400 years old.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.91-93
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• 2004

이동 객체의 현재와 미래 위치 질의에 최적화된 색인 구조로써 TPR-트리가 있다 TPR-트리는 기존의 공간 색인 구조와 달리 이동 객체와 경계 사각형을 참조 위치와 속도 벡터를 매개 변수로 한 시간에 대한 선형 함수 형태로 모델링 함으로써 갱신 비용을 줄이고 현재 및 가까운 미래 위치 정보의 예측을 가능하도록 한다 . 하지만 TPR- 트리는 시간의 정파에 따라 경계 사각형이 선형적으로 환장됨으로 인해 경계 사각형 내의 객체를 제외한 나머지 공간인 사장 공간과 경계 사각 혈들 간의 겹침 현상을 증가시켜 정의 성능이 떨어진다는 단점을 가진다. 본 논문에서는 질의 성능을 향상시키기 위하여 경계 사각형 내의 이동 객체들이 이동함에 따라 변경되는 최소 경계 사각형 (MBR: Minimim Bounding Rectangle)을 베지어 곡선 함수를 이용하여 근사함으로써 사장 공간을 줄이는 적응 경계 사각형 (ABR: Adaptive Bounding Rectangle) 기법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.332-335
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• 2011

GPS 칩을 내장한 다양한 이동 통신 기기의 사용으로 위치 정보를 이용한 응용이 점차 확산될 전망이다. 위치 정보를 기반으로 한 응용 시스템에서는 다수 이동 객체의 위치 정보를 실시간으로 기록하고, 미래 시점의 객체 위치를 추정할 수 있어야 한다. 이런 요구에 따라 효과적인 이동 객체 색인에 고안된 기법이 TPR*-트리이다. 하지만 TPR*-트리는 고정 위치 색인에 최적화된 R-트리에 기본을 두었기 때문에 갱신 비용이 매우 커질 수 있다는 문제가 있다. R-트리에서는 갱신 연산이 빈번하지 않을 수 있지만 TPR*-트리의 경우는 이동 객체가 속도를 변화시킬 때마다 갱신 연산이 요구되기 때문에 상대적으로 매우 큰 갱신 비용이 발생할 수 있다. 이런 문제점을 부분적으로 해결하기 위해 본 논문에서는 쿨링다운 노드를 사용한 TPR*-트리를 제안한다. 제안된 트리는 트리의 상위 계층에 일부 이동 객체를 버퍼링함으로써 갱신 연산을 최소화 할 수 있다. 또한 지나친 사장 영역(dead space)의 확대를 방지함으로써 검색 성능 저하를 효과적으로 줄일 수 있다.