• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.6
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• pp.1-17
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• 2009

This study was carried out to classify vegetation structure of the Anseong district in the Deogyusan National Park from May 2007 to September 2008 using the gradient analyses and phytosociological method. The vegetation communities were classified into Quercus mongolica, Carpinus laxiflara, Q. serrata, Fraxinus mandshurica, Betula davurica, B. costata, Pinus densiflora and Abies koreana. Characteristics of the vegetation such as species composition, layer structure, vegetation ratio, and the distribution of individual trees by DBH were significantly different among communities. The order of important value of the forest community with DBH 2cm above plants was Q. mongolica (40.02), C. laxiflora (25.65), Q. serrata (24.68), F. mandshurica (21.66), P. densiflora (19.12), Acer pseudosieboldianum (16.96), C. cordata (11.87), B. davurica (11.66), B. costata (10.90), Styrax obassia (10.90) and A. koreana (10.41). Distribution of DBH P. densiflora had a formality distribution, suggesting a continuous domination of these species over the other species for the time being. In contrast, F. mandshurica appeared limited to the valley of the sheet and a higher frequency of young individuals, suggesting a continuous domination of these species the development of a climax forest terrain. This study showed the correlation between each community and the environment according to DCCA ordination. The A. koreana community predominated on the northern slope of the park in the high elevation habitats which had many O-M. F. mandshurica community predominated in the highest elevation habitats which had many Moisture, EX-Cation and T-N. The P. densiflora community mainly occurred on the southern slope of the park in the low elevation habitats which had few Moisture, O-M and T-N. The Q. serrata community and C. laxifiora community appeared on the park in the middle habitats.

• Journal of Forest and Environmental Science
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• v.32 no.3
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• pp.280-290
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• 2016

Stem diameter variability is an essential inventory result that provides useful information in forest management decisions. Little has been done to explore the modelling potentials of standard deviation (SDD) and coefficient of variation (CVD) of diameter at breast height (dbh). This study, therefore, was aimed at developing and testing models for predicting SDD and CVD in stands of Pinus caribaea Morelet (pine) in south west Nigeria. Sixty temporary sample plots of size $20m{\times}20m$, ranging between 15 and 37 years were sampled, covering the entire range of pine in south west Nigeria. The dbh (cm), total and merchantable heights (m), number of stems and age of trees were measured within each plot. Basal area ($m^2$), site index (m), relative spacing and percentile positions of dbh at $24^{th}$, $63^{rd}$, $76^{th}$ and $93^{rd}$ (i.e. $P_{24}$, $P_{63}$, $P_{76}$ and $P_{93}$) were computed from measured variables for each plot. Linear mixed model (LMM) was used to test the effects of locations (fixed) and plots (random). Six candidate models (3 for SDD and 3 for CVD), using three categories of explanatory variables (i.e. (i) only stand size measures, (ii) distribution measures, and (iii) combination of i and ii). The best model was chosen based on smaller relative standard error (RSE), prediction residual sum of squares (PRESS), corrected Akaike Information Criterion ($AIC_c$) and larger coefficient of determination ($R^2$). The results of the LMM indicated that location and plot effects were not significant. The CVD and SDD models having only measures of percentiles (i.e. $P_{24}$ and $P_{93}$) as predictors produced better predictions than others. However, CVD model produced the overall best predictions, because of the lower RSE and stability in measuring variability across different stand developments. The results demonstrate the potentials of CVD in modelling stem diameter variability in relationship with percentiles variables.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.47-58
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• 2011

The forest of Korea had been severely degraded since early 1900s until 1950s. Korean Government has successfully accomplished the reforestation works since 1960s. However, some plantations showed poor survival and growth caused by ignoring site characteristics in selecting plantation species and lack of tending works such as thinning. The natural regeneration of indigenous species, such as Quercus species and Pinus densiflora Siebold & Zucc., were examined in the plantations of Pinus koraiensis Siebold & Zucc. and Larix kaempferi Fortune ex Gordon. Quercus species regenerated mainly by sprouting while P. densiflora regenerated naturally from a few mother trees that remained in the plantations. P. koraiensis showed poor survival ($IVI{\leq}25%$) and suppressed growth (height ${\leq}3m$ and $DBH{\leq}3cm$ at 20 year-old) by Quercus species or P. densiflora in the plantation areas, however had high survival ($IVI{\geq}70%$) and growth (8 m height and 14.1 cm DBH at 20 year-old) in areas where silvicultural practices were conducted. L. kaempferi showed good survival ($IVI{\geq}40%$) and growth (17.2 m height and 16.3 cm DBH at 30 year-old) mostly in valley areas, while it was nearly dead ($IVI{\leq}10%$) in ridge or ridge-slope areas and was replaced by indigenous species such as Quercus species ($IVI{\geq}25{\sim}55%$) or P. densiflora ($IVI{\geq}18{\sim}50%$).

• Journal of agriculture & life science
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• v.45 no.5
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• pp.25-31
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• 2011

This study was conducted to develop the growth model for diameter at breast height (DBH) and basal area (BA) of Larix leptolepis stands grown in eastern mountain areas, Jeollabuk-do and to enhance the precision of the models by adding regional and climatal factors, such as altitude, mean annual rainfall, and mean annual temperature. In results, it was analyzed that Schumacher polymorphic equation might be the best model to estimate DBH and BA growth. In case of the DBH growth model, precision was improved by adding altitude and mean annual rainfall. Moreover, in case of the BA growth model, precision was improved by adding mean annual rainfall. Meanwhile, it would be necessary for more precise model to add various factors, such as stand density, mortality, thinning ratio, and edaphic status along with regional and climatal factors.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.465-476
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• 2016

This study was conducted to elucidate the ecological characteristics of sub-alpine coniferous forest on Banyabong, Mt. Jiri. Soil pH was 4.20. The contents of organic matter, total N, available P and CEC were 14.15%, 0.43%, 10.1 ppm and $17.17cmol^+/kg$, respectively. Sub-alpine coniferous forest had a relatively soil moisture content with 22.9%. According to the results of importance value analysis, Picea jezoensis (42.7) and Abies koreana (34.0) for tree layer, Rhododendron schlippenbachii (25.5) for subtree layer and Tripterygium regelii (18.4) and Rhododendron mucronulatum (16.6) for shrub layer were high, respectively. Shannon's diversity ranged from 0.3560 to 1.050. Evenness and dominance ranged from 0.398 to 0.733 and 0.267 to 0.601, respectively. A. koreana population had a reverse J-shaped DBH distribution, while P. jezoensis population had a normal DBH distribution. Height growth according to DBH of A. koreana was higher than that of P. jezoensis, which indicate than A. koreana have more effective water use efficiency than P. jezoensis. Annual mean tree ring growth of P. jezoensis and A. koreana showed up 1.792, 1.652, 1.389 mm/yr and 2.081, 1.921, 1.576 mm/yr for small, middle and large diameter tree, respectively.

• Journal of Environmental Science International
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• v.32 no.4
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• pp.233-242
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• 2023

The objective of this study was to develop a management strategy for the recovery of carbon storage capacity of abandoned coal mine forest rehabilitation area. For the purpose, the biomass and stand carbon storage over time after the forest rehabilitation by tree type for Betula platyphylla, Pinus densiflora, and Alnus hirsuta trees which are major tree species widely planted for the forest rehabilitation in the abandoned coal mine were calculated, and compared them with general forest. The carbon storage in abandoned coal mine forest rehabilitation areas was lower than that in general forests, and based on tree species, Pinus densiflora stored 48.9%, Alnus hirsuta 41.1%, and Betula platyphylla 27.0%. This low carbon storage is thought to be caused by poor growth because soil chemical properties, such as low TOC and total nitrogen content, in the soil of abandoned coal mine forest rehabilitation areas, were adverse to vegetation growth compared to those in general forests. DBH, stand biomass, and stand carbon storage tended to increase after forest rehabilitation over time, whereas stand density decreased. Stand' biomass and carbon storage increased as DBH and stand density increased, but there was a negative correlation between stand density and DBH. Therefore, after forest rehabilitation, growth status should be monitored, an appropriate growth space for trees should be maintained by thinning and pruning, and the soil chemical properties such as fertilization must be managed. It is expected that the carbon storage capacity the forest rehabilitation area could be restored to a level similar to that of general forests.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.422-430
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• 2014

This study was conducted to investigate growth changes of DBH, height, crown width, volume, stem biomass, and dead trees after thinning treatments with different thinning intensity for Korean white pine (Pinus koraiensis) plantation. First thinning was applied with 29~69% intensity based on number of trees in 19-yearold plantation, and trees were measured three times: right after thinning (19-year-old), 5 years later (24-yearold), 12 years later (29-year-old). In the case of DBH growth, average DBH growth of heavily thinned plots was 19.6~19.9% higher 5 years later, and 13.3~24.7% higher 12 years later, compared to that of unthinned plots. Initial diameter growth rate was higher than late growth rate. The proportion of large pole candidates ($DBH{\geq}25cm$) was 31% in heavily thinned plot while only 2% was shown in unthinned plot. No difference was shown in height growth depending on plots, and average crown width growth in heavily thinned plots was 30.6~33.3% higher, 5 years later, and 35.0~40.0% higher, 12 years later, compared to that of unthinned plots. Average volume growth of individual trees in heavily thinned plots was 39.8~46.8% higher, 5 years later, and 23.0~52.0% higher, 12 years later, compared to unthinned plots. The maximum volume and biomass per unit area were shown in unthinned plot; the volume and biomass 5 and 12 years later after thinning were $133m^3/ha$ (51 kg/ha) and $344m^3/ha$ (132 kg/ha), respectivily. The significant difference appeared in crown width, volume, and biomass depending on thinning intensity. No dead trees occurred in heavily thinned plots for 12 years after thinning, while mortality rate in unthinned plots was 27.9~37.8%. As a result of analyzing annual increment using cores to determine the timing of second thinning, it suggested that second thinning be suitable around 10 years after first thinning.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.380-387
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• 2017

This study was carried out to determine fertilization effects on allometric equations and biomass production in a Moso bamboo (Phllostachys pubescens) stand of the Gajwa National Experimental Forests, Jinju, Korea. The study site was fertilized for approximately 30 years to produce edible bamboo shoots. Total 20 bamboos (10 fertilized and 10 unfertilized) were cut to develop allometric equations and to estimate biomass accumulation of each bamboo component. Allometric equations of each bamboo component in the fertilized and unfertilized plots were significant (P < 0.05) with diameter at 20 cm from ground ($D_{20}$), diameter at breast height (DBH), culm height (H), and $DBH^2{\cdot}H$. Aboveground biomass estimated by the allometric equations (DBH) was significantly higher in the unfertilized plots ($106.38Mg\;ha^{-1}$) in culm density of $6,833culm\;ha^{-1}$ than in the fertilized ($57.68Mg\;ha^{-1}$) plots in culm density of $4,633culm\;ha^{-1}$. The proportion of each biomass component was culm (79%), followed by branches (14%) and leaf (7%) in the fertilized plots, whereas it was culm (81%), followed by branches (13%), and leaf (6%) in the unfertilized plots. The results indicate that aboveground biomass accumulation in a Phllostachys pubescens stand was little affected by fertilizer application because of the difference of culm density.

• Development and Reproduction
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• v.6 no.2
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• pp.117-122
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• 2002

Dopamine(DA), norepinephrine(NE), and epinephrine(E) belong to a class of neurotransmitters known as catecholamine (CA) which are synthesized and secreted by mammalian brain and adrenal medulla. CA regulate several behavior patterns connected with breeding, and regulate GnRH-gonadotropin hormone axis' vitality between hypothalamus-pituitary gland linking with reproduction freeze. The present study examined effects of sex steroid hormone on the transcriptional activities of CA biosynthesis enzymes, tyrosine hydroxylase(TH), dopamine $\beta$ -hydroxylase(DBH), and phenylethaolamine-N-methyl transferase(PNMT). Mature female rats were ovariectomized(OVX) and implanted with 17 $\beta$-estradiol(E$_2$: 500 $\mu\textrm{g}$/ml) or sesame oil. Forty-eight hours after implantation all the animals were sacrificed. Total RNAs were extracted immediately and were applied to semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR). The expression level of TH was appeared by hypothalamus > SNc> adrenal medulla orders in OVX＋Oil group, and by SNc > hypothalamus) adrenal medulla orders in OVX+E$_2$ group. Treatment with E$_2$ significantly increased TH expression in SNc and adrenal medulla but in hypothalamus, the reduced TH expression was observed. The expression level of DBH was appeared by adrenal medulla > SNc > hypothalamus orders in OVX＋Oil group and in OVX＋E$_2$ group. Administration of E$_2$ significantly reduced DBH expression in SNc, and increased in adrenal medulla. Two cDNA products, large(PNMT1) and small(PMNTs) species of 110bp difference, were amplified in SNc and hypothalamus, but only PNMTs was observed in adenal medulla. The PNMTs expression level was in the order of adrenal medulla > hypothalamus > SNc in both OVX＋Oil and OVX＋E$_2$ group. The PNMTs expression in SNc and adrenal medulla was significantly increased byE$_2$. The present report demonstrated that estrogen effects on transcriptional activities for CA biosynthethic enzymes were tissue specific in adrenal medulla as well as different region of brain. These results suggest that it might be crucial relationship between the type of estrogen receptor and CA enzyme gene expression.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.58-68
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• 2015

This study compares the wind stability of Larix kaempferi (Lamb.) Carr., Pinus koraiensis Sie. & Zucc. and Abies holophylla Maxim. to understand and inform wind risk management of these plantation trees at Daegwallyeong, Korea. Temporary square plots of $20m{\times}20m$ ($400m^2$) were laid out, and DBH (Diameter at Breast Height) and height for trees greater than 10 cm in DBH were measured by species. A total of 15 plots with 5 plots each in L. kaempferi, P. koraiensis and A. holophylla stands were sampled at random. Among the species, A. holophylla and P. koraiensis have comparatively lower h/d (Height/DBH) ratios than L. kaempferi. These results indicate that the former two species are more wind firm than the latter species. About 9% of the L. kaempferi trees have higher h/d ratios than the critical threshold limit 80. These trees are vulnerable to wind damage and should be removed in the next thinning regime. The analysis of variance detected a significant difference (p < 0.05) in the h/d ratios and Gini coefficient indicating species differences and DBH size variation, respectively. Gini coefficient was 16.4% in A. holophylla, 15.9% in P. koraiensis and 14% in L. kaempferi stands indicating limited DBH size variation. Lower h/d ratios are attributed to thinning in these stands and tree morphological differences. To increase wind firmness, low thinning should concentrate to remove trees with the h/d ratio above 80 coinciding at the time of stand distinction phase. Forest managers and practitioners should measure and maintain h/d ratios of trees below the critical threshold limit of 80 through stand density management. Variable density thinning approach should be tested to increase tree DBH sizes of the even-aged stands.