• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.462-468
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• 1999

A natural mixed forest of Pinus densiflora and Quercus variabilis in Mt. Mohu area was studied to investigate patterns of species competition and productivity. Ten $10m{\times}10m$ plots were set up and eight sample trees of each Pinus densiflora and Quercus variabilis were harvested for dimension analysis. Mean tree age of Pinus densiflora was 33 years and that of Quercus variabilis was 26 years. DBH and height of Quercus variabilis were larger than those of Pinus densiflora untill tree age 15. After tree age 15, height of Quercus variabilis was higher than height of Pines densiflora while DBH of Quercus variabilis was smaller than DBH of Pines densiflora. For a tree of a given DBH, there was little difference in leaf dry weight between Pines densiflora and Quercus variabilis. For a tree of a given DBH, dry weights of stem wood, stem bark and branches of Quercus variabilis weighed more than those of Pinus densiflora, and the differences between the dry weights of the two species became greater as DBH increased. Net assimilation ratio of Quercus variabilis was higher than that of Pinus densiflora, and biomass accumulation ratio of Quercus variabilis was lower than that of Pinus densiflora. It may be given as a conclusion that Quercus variabilis was superior to Pinus densiflora in species competition owing to faster height growth, higher net assimilation ratio, and lower biomass accumulation ratio. Aboveground stand biomass was 87.7t/ha and aboveground stand net production was 8.3t/ha/yr.

• Korean Journal of Environment and Ecology
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• v.12 no.4
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• pp.361-372
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• 1999

Thirty-two plots have been set up and surveyed to investigate the plant community structure and distribution density of Pinus thunbergii-P. densiflora forest in Kojedo District, Hallyo-Haesang National Park. By DCA ordination technique P. thunbergii-P. densiflora forest was classified into P. thunbergii community, P. thunbergii-P. densiflora community, and P. densiflora community. The trend of plant community succession was invalid. The results of simple regression analysis between mean DBH(cm), mean distribution distance(m), and number of individual of P. thunbergii and P. densiflora were as follows: Distribution distance(m) = 0.094$\times$DBH(cm)-0.1248, Number of individual=1,820.1$\times$(cm)$DBH^{-1.6734}$ , Distribution distance(m)=6.6805$\times$Number of $individual^{-0.5425}$ .

• Journal of Environmental Science International
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• v.17 no.6
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• pp.647-655
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• 2008

The purpose of the study is to find the problems related to the current state of the stand age classes and the method of calculating it defined in the existing forest type map and propose the more accurate method of calculating the stand age classes. The object for the study was selected as the forest scattered around the Geesan village Paju city in Kyunggi province. For the accurate method of calculating the stand age classes, such items as, the type of actual vegetation, establishment of grid-type standard area scaled down at the level of the 5% of the actual area, the types, number, DBH and age of tree found by the plots, were investigated. It was found out actual vegetation was divided into the total 24 types and the 20 types of them belonged to the growing tree areas. As the plots, the 125 places(unit area: $400m^2$) were established the types of the trees found were distributed in the range where the minimum was 1 type, the maximum was 9, the mean was $4.4{\pm}1.5$, and the mode was 4 types. The number of the trees found was distributed in the range where the minimum was 17, the maximum was 125, the mean was $4.4{\pm}1.5$, and the mode was 70. In the DBH, the minimum was 6 cm, the maximum was 30 cm, the mean was 13 cm and the mode was 10 cm. As the result of measuring the age of the 5 trees corresponding to the value of the mode in DBH, selected among the dominant species by the plots, less than 20 years was 17 places, the 115 places were included in the range from 21 to 30 years, and more than 31 years was the 6 places.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.51-59
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• 2011

This study was conducted to analysis the growth characteristics and the diameter at breast height (10 cm) reached ages in natural stand and platation for the optimal planting density and planting timing of Acer mono for. rubripes. There was high correlation between the DBH and crown diameter (E-W: r=0.82, S-N: r=0.76) in natural stand, and between the DBH and crown diameter (E-W: r=0.76, S-N: r=0.90) in plantation. In natural stand, average reached age on DBH 10 cm was $21.1{\pm}7.0$, and was $9.2{\pm}1.3$ in plantation. Therefore, the collectable timing of sap in artificial planting short approximately 2.3 times over the natural regeneration.

• Journal of Forest and Environmental Science
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• v.24 no.1
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• pp.41-46
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• 2008

Progeny tests of Abies holophylla were established with 32 open-pollinated families at Hwaseong and Gangneung in 1994. Growth characteristics (height, DBH and volume index) were measured at the age of 15, showing that Gangneung site showed in general better performance than Hwaseong site. Analysis of variance (ANOVA) of the growth characteristics showed that there was a significant difference among families in Gangneung but not in Hwaseong, and Hwaseong site showed that DBH and volume index were statistically different among replications. At Gangneung site, family ${\times}$ replication interaction was significant in DBH and volume index. Based on the combined analysis of both sites, all characteristics except height showed highly significant differences between sites and among families. On the other hand, family ${\times}$ replication interaction was not significant, implying that growth pattern of families could be similar at Gangneung and Hwaseong. Individual heritabilities ($hi^2$) at Gangneung were 0.485 in height, 0.611 in DBH and 0.538 in volume index, and the values of $hi^2$ at Hwaseong were 0.121 in height, 0.054 in DBH and 0.080 in volume index, respectively. Based on both sites, $hi^2$ was estimated as 0.204 in height, 0.326 in DBH and 0.238 in volume index. Individual heritabilities (0.054~0.611) were lower than family heritabilities (0.089~0.723) for all growth characteristics. Realized gain was estimated to be 2.5% in height, 9.2% in DBH and 23.6% in volume. When inferior families (about 50% of all families) are genetically thinned from a seed orchard, genetic gain would be 9.55% in height, 17.0% in DBH and 46.8% in volume.

• 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 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.

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.527-535
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• 2015

With results from previous Korean studies on forest thinning, we conducted a meta-analysis on the effect of thinning on diameter at breast height (DBH) growth and carbon (C) stocks (tree, litter layer, coarse woody debris (CWD), and soils) in Korean forests. Thinning increased the DBH growth and the C stocks in soils by 39.2% and 12.8%, respectively, while it decreased the C stocks in tree by 30.9%. In contrast, thinning had no significant effect on the C stocks in litter layer and CWD. The DBH growth and the C stocks in tree showed significant correlations with thinning intensity and recovery time. The C stocks in litter layer correlated with recovery time while those in CWD and soils did not show significant correlation neither with thinning intensity nor with recovery time. Regression models of the DBH growth and the C stocks in tree were developed to quantify the effect of thinning intensity and recovery time. An integration of the regression model of the tree C stock into forest carbon models is expected to be essential to quantify the effect of thinning on the C stocks in litter layer, CWD, and soils. We also suggested expansion of study species, long-term and frequent monitoring, and investigation on understory vegetation in order to elucidate changes in Korean forests following thinning practices.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.525-534
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• 2012

This study was conducted to classify community and verify vegetation structure of Picea jezoensis community in subalpine zone of Mt. Kyebang, Mt. Jiri, Mt. Deogyu, 39 releves set up and was carried out to analyze ordination. P. jezoensis Community was classified into Acer ukurunduense subcommunity, Quercus mongolica subcommunity, Syringa reticulata var. mandshurica subcommunity and P. jezoensis typical subcommunity. The order of important value of the forest community with DBH 2cm above plants was P. jezoensis (89.22), Acer komarovii (30.50), Abies koreana (18.81), Rhododendron schlippenbachii (18.10), Sorbus commixta (17.19), Betula ermanii (16.89), Pinus koraiensis (16.80), Taxus cuspidata (12.45), Acer ukurunduense (11.73). The DBH analysis suggests that P. jezoensis will maintain dominant position.

• The Korean Journal of Ecology
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• v.8 no.4
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• pp.197-200
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• 1985

The relations of crown width and DBH for Pinus densiflora, Pinus rigida, Pinus koraiensis, and Ginkgo biloba were accomplished to estimate the level of crown competition. Measurements of the relations revealed that crown width and DBH were highly correlated for the same species. Also it seems that these relations are independent of age and site quality. The results of regression analysis were as follow: P. densiflora, Y=0.3477X+0.3828 r=0.95 p. rigida, Y=0.3537X+0.1645 r=0.95 P. koraiensis, Y=0.2895X+0.6310 r=0.92 G. biloba, Y=0.4360X+0.0995 r=0.90 The significant differences between G. biloba and pine species seems due to their structural differences of crown formation according to tree species. As results of computing Maximum Crown Area and Crown Competition Factor as indices of crown competition, they indicated that P. densiflora would grow better under the natural conditions.