• Korean Journal of Environmental Biology
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• v.21 no.3
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• pp.262-270
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• 2003

This study was carried out to analyze forest vegetation of Jinaksan in Geumsan, Chungnam Province. Employing the releve method of Braun-Blanquet, 26 plots were sampled in forest of Jinaksan. The communities were classified into Quercus mongolica, Quercus variabilis, Quercus aliena, and Pinus densiflora communities. Coverage rate was 79.4% in tree layer,27.6% in subtree layer,37.0% in shrub layer, 31.1% in herb layer, respectively. The importance values were 45.51 in Q. mongolica,44.17 in P. densiflora,26.56 in Q. variabilis,26.78 in Q. serrata,20.81 in Q. aliena, and 15.58 in Prunus serrulata var. spontanea, respectively. Most of the DBH in the Q. mongolica, Q. variabilis, Q. aliena, and p. densiflora was between 5 cm and 15 cm. Therefore, Q. mongolica, Q. variabilis, and Q. aliena will be dominant species in the study area for several decades.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.67-77
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• 2010

Stand structure and spatial associations of the dominant tree species in Quercus mongolica stands were investigated to understand interspecific relationships and the persistent dominance of Q. mongolica. We examined the species composition, DBH (diameter at breast height) distribution, and spatial distribution of trees (${\geq}\;2.5\;cm$ DBH) in two permanent $100\;m\;{\times}\;100\;m$ plots in Q. mongolica-dominant stands on the western part of Mt. Jiri. Ripley's K-function was used to characterize the spatial patterns and associations of dominant tree species. Q. mongolica showed a continuous and reverse-J shaped DBH distribution with clumped spatial distribution in both study sites. Q. mongolica and Abies koreana exhibited a negative association implying potential interspecific competition. The positive spatial association between Q. mongolica and Alnus hirsuta var. sibirica and Fraxinus sieboldiana were affected by site characteristics: limited habitat conditions with a large proportion of rock surface. Our results suggest that interactions among species were complex and ranged from positive to negative. Differences in stand and site characteristics and regeneration mechanisms among the species play an important role in regulating their spatial distribution patterns, while competition between individuals also contributes to spatial patterning of these communities. The high density and the early developmental stage of spatial distribution and structural characteristics of Q. mongolica and the relatively low importance values of other species in the stands imply that Q. mongolica will remain dominant in the study sites in the near future.

• The Journal of Korean Medicine
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• v.22 no.1
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• pp.78-89
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• 2001

Objectives : The purpose of this investigation is to evaluate the effects of Woohwangcheongsim-won on reperfusion following MCA occlusion in rats. Methods : To evaluate the effect of Woohwangcheongsim-won on reperfusion following MCA occlusion, the volume of cerebral ischemia and edema were measured and the change of the CAI pyramidal neuron in the hippocampus was investigated by light microscopy. And the changes of several neurotransmitters and enzymes were investigated with the immunohistochemical methods. Results : 1. The volume of the control group, which was ischemic-damaged was 23.6%, and that of the sample group was 13.5%. 2. The voluminalratio of the right/left hemisphere was 116 in the control group, and that of the sample group was 107. 3. The pyramidal cells of CAI area in the control group were greatly damaged. The cells were changed into discontinuous and unsystematic forms, and nuclei, and cytoplasms were shrunk. On the other hand, the cells of the sample group were less damaged. 4. On the immunohistochemical methods, the sensitivities of GABA, NOS, DBH in the control group were increased, and those of synapsin and $eEF-l{\alpha}$ were decreased as compared with the normal group. NOS and DBH which were negative in the normal group showed positive reaction. On the other hand, the sensitivities of GABA, NOS and DBH in the sample group were decreased, but those of NPY, synapsin, CaMKII and $eEF-l{\alpha}$ were increased as compared with the control group. Conclusions : Woohwangcheongsim-won reduced the volume of cerebral ischemia and edema, and minimized the damage of pyramidal cells. The mechanism was related to protein synthesis, such as synapsin, ${\alpha}CaMKII$ and $eEF-l{\alpha}$, which resist neurotoxicity of glutamate receptors.

• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.351-361
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• 2014

Leaf area ($A_0$) and leaf biomass ($M_0$) estimation are significant prerequisites to studying tree physiological processes and modeling in the forest ecosystem. The objective of this study was to develop allometric models for estimating $A_0$ and $M_0$ of Swietenia mahagoni L. from different tree parameters such as DBH and tree height of mahogany plantations in the northeastern region of Bangladesh. A total of 850 healthy and well formed trees were selected randomly for sampling in the five study sites. Then, twenty two models were developed based on different statistical criteria that propose reliable and accurate models for estimating the $A_0$ and $M_0$ using non-destructive measurements. The results exposed that model iv and xv were selected on a single predictor of DBH and showed more statistically accuracy than other models. The selected models were also validated with an additional test data set on the basis of linear regression and t-test for mean difference between observed and predicted values. After that, a comparison between the best logarithmic and non-linear allometric model shows that the non-linear model produces systematic biases and underestimates $A_0$ and $M_0$ for larger trees. As a result, it showed that the bias-corrected logarithmic model iv and xv can be used to help quantify forest structure and functions, particularly valuable in future research for estimating $A_0$ and $M_0$ of S. mahagoni in this region.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.853-860
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• 2003

Plants sequester atmospheric CO$_2$, a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pinus densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO$_2$ uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of CO$_2$ exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO$_2$ uptake per unit leaf area ranged from 1.6-6.7 mg/d㎡/h for P. densiflora and from 3.7-8.9 mg/d㎡/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO$_2$ uptake by total leaf area per tree, which subtracted the CO$_2$ release (i.e. respiration) by leaves and woody organs from the gross CO$_2$ uptake (diurnal uptake and release by leaves). Annual CO$_2$ release by leaves and woody organs accounted for 58-73％ of the gross CO$_2$ uptake across tree specimens. Annual CO$_2$ uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. densiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO$_2$ uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO$_2$ reduction of woody plants by forest type and age class.

• Journal of Korean Society of Forest Science
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• v.101 no.2
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• pp.279-285
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• 2012

This study was conducted to offer preliminary data for forest management from March and December 2011. Based on the number of standing trees by DBH classes, it is recommended to practice thinning and pruning to change the current young stand to mature stand. In Livelihood Environment Forest Protected Areas, young (0-10 years or 0-10 cm DBH) and detected trees need to be removed and selected healthy trees need to be heavily tended. Also, selected trees in age 20-30 (20-30 cm DBH class) need to receive concentrated tending. Since Livelihood Environment Forest Protected Areas had been vulnerable for erosion, the diversity of understory layer is low. In order to diversify deciduous trees, it is recommended to introduce new species and thin and prune existing trees. It is not proper to adapt clear cutting in a short time and should be partially regenerated using shelter-wood method or proper tending practices to the Pinus rigida dominanted forest. Tending existing under-story species including Quercus alina, Quercus variabilis, and Quercus serrata would be important.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.355-364
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• 2013

This study was conducted to investigate the population structure and dynamics of the Picea jezoensis stands which are located in Mt. Gyebangsan and surveyed from March to October 2012. Results showed that the diameter class distribution of P. jezoensis presented a reverse J-shaped distribution pattern with 32 trees less than 10 cm DBH, 20 trees in 10~30 cm DBH, and 11 trees more than 30 cm DBH. It showed seedlings and saplings of P. jezoensis seem to prefer areas with more sun light or with open upper layer. It was also observed that P. jezoensis preferes areas with organic soils and abundant water such as areas around stumps. Also, occurrences of P. jezoensis stands were analyzed through annual mean radial growth of the trees. And the results showed that the growth naturally or artificially occurred approximately on the years 1854, 1915, 1918, 1993 and 2002 years. Most of the gap-makers were classified as standing dead type with 23 individuals (45.1%).

• Journal of Forest and Environmental Science
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• v.31 no.3
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• pp.177-191
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• 2015

The effect of environmental variables on the presence and abundance of tree species in a tropical lowland undisturbed limestone and non-limestone forest in Ben En National Park, Vietnam was investigated. The relationships between 13 environmental variables and 29 tree species with a DBH ${\geq}10cm$, as well as between six 6 physical variables with 26 species of seedling and sapling communities were assessed by canonical correspondence analysis (CCA). Data concerning all tree species ${\geq}10cm$ DBH were collected from eighteen $400m^2$ sample plots, while the abundance of regeneration (all individuals ${\leq}5cm$ DBH) was counted in fifty $2{\times}20m$ strip-plots. The significance of species-environments correlations were tested by distribution-free Monte Carlo tests. The CCA of the 29 examined tree species and 13 environmental variables indicated that the presence and abundance of the tree species were closely related to topographic factors. We may confirm that soil properties including pH, soil moisture content, and soil textures, were the most crucial factor in tree species composition and their distribution. Several species including Pometia pinnata, Amesiodendron chinense, Gironniera cuspidate, Cinnamomum mairei, and Caryodaphnopsis tonkinensis were not controlled by soil properties and topographic variables. The CCA also indicated that the abundance of regeneration tree species at all sites had positive and significant correlations with soil depth, while the occurrence of several other tree species (such as Koilodepas longifolium and Aglaia dasyclada) was positively correlated with a higher slope and rocky outcrop.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.114-114
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• 2002

포유동물에서 뇌와 부신에서 합성.분비되는 카테콜아민(Catecholamine, CA)계 신경전달물질인 dopamine(DA), norepinephrine(NE), epinephrine(E)은 체내 각종 생리현상의 조절에 필수적이며, 생식과 관련지어서는 시상하부-뇌하수체 간 GnRH-gonadotropin 호르몬 축의 활성을 조절하는 기능 외에도 번식과 관련된 여러 행동양식을 조절함이 잘 알려져 있다. 본 연구는 CA 생합성 효소들인 tyrosine hydroxylase(TH), dopamine beta-hydroxylase(DBH), phenylethanolamine-N-methyltransferase(PNMT)의 유전자 발현에 미치는 sex steroid의 영향을 조사하였다. 성숙한 암컷 횐쥐(SD strain)의 난소를 제거하고 1주 경과 후 vehicle(sesame oil; OVX+Oil 실험군) 또는 estradiol 17$\beta$(235ug/m1; OVX+E$_2$실험군)이 든 silastic capsule(길이 14mm; 내경 1.55mm; 외경 3.125mm)을 48 시간 동안 처리한 뒤 희생시켰다. 적출된 조직으로부터 RNA를 추출한 후 semi-quantitative RT-PCR을 시행하였다. (i) TH의 발현 정도는 OVX+Oil 군에서는 시상하부) substantia nigra(SNc)) 부신 순으로, OVX+E$_2$군에서는 SN글 부신) 시상하부 순으로 나타났다. TH 발현에 미치는 estradiol의 효과로 SNc과 부신에서는 유의한 증가를 보인데 비해 시상하부에서는 유의한 감소를 관찰하였다. (ii) DBH 발현 정도는 OVX+Oil군에서는 SNc> 부신> 시상 하부 순으로, OVX+E$_2$군에서는 부신＞ SNc＞ 시상하부 순이었다. DBH 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 감소하는 경향을 보였다. (iii) PNMT의 발현의 경우 SNc와 시상하부에서는 기보고된 바와 같이 alternative splicing에 의해 110bp 차이의 크고 작은 두 형태의 cDNA(PNMTI & PNMTs)가 증폭되었으나 부신에서는 작은 cDNA 만이 관찰되었다. PNMTs의 발현 정도는 OVX+Oil군과 OVX+E$_2$군에서 공히 부신＞ 시상하부＞ SNc 순이었고, PNMTI의 발현은 SNc가 시상하부 보다 다소 높은 경향이었으나 유의성은 없었다. PNMTs 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 증가하는 경향을 보였다. 본 연구에서는 CA 생합성 효소들의 유전자 발현의 조절에 미치는 estrogen 의 영향이 세포 기원이 neural crest cell인 부신 수질은 물론 뇌의 상이한 지역간에서도 조직특이적임을 관찰하였다. 이러한 결과는 각 조직에서의 estrogen 수용체 유형의 차이 혹은 작용 모드와 각 효소 유전자 발현 사이에 중요한 상관관계가 있음을 시사한다.

• Journal of Korean Society of Forest Science
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• v.94 no.4 s.161
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• pp.258-263
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• 2005

Amounts of sap collected by DBH class and contents of mineral and free sugar in the sap of Acer mono for. rubripes indigenous in Geojedo were investigated. The collectable periods of sap of A. mono for. rubripes were 17 days and the total amount of sap was 193 l from 60 trees. Sap of A. mono for. rubripes were increased with increasing DBH, being 40 l (21 %), 49 l (25%) and 104 l (54%) from small, middle and large diameter tree, respectively. This may be due to increase in crown width and extention of root system. Amounts of sap was affected by temperature fluctuation between day and night. The pH and the contents of solid and sugar in the sap of A. mono for. rubripes were 6.5 and 2.40% and 1.99%, respectively. Free sugar determined in the sap was sucrose with 19.9 g/l, but glucose, fructose and maltose were not detected. The sap of A. mono for. rubripes contained seven kinds of minerals and the prominent minerals were Ca and K with their concentration being 441 mg/l and 383 mg/l, respectively.