• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.646-657
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• 2018

The purpose of this study was to understand the ecological characteristics and vegetation structure of Mt. Daedun Provincial Park by setting up and surveying 42 plots ($100m^2$). The analysis using the TWINSPAN and DCA techniques found seven community groups: Quercus aliena community, Larix kaempferi community, Pinus densiflora community, Quercus variabilis-Quercus serrata community, Pinus rigida community, Carpinus tschonoskii community, and Quercus mongolica community. The results of a vegetation structure analysis showed that the dominant species of each community were likely to maintain the present structure, but, in the case of Pinus densiflora community, it is necessary to monitor the forest succession because of the competition with oak trees. The results of the DBH (diameter of breast height) analysis showed that the species in DBH 20-24cm and over 26cm were many observed, indicating that the communities were becoming stable. It is likely that the dominant species of tree canopies will maintain their state unless the unexpected physical environment changes, serious disturbance, pests or diseases occur. The results of the tree rings and annual growth analysis showed that the dominant trees had an average age of more than 40 years. The average annual growth was the highest for Quercus variabilis in community I at $3.51{\pm}2.39mm$ and the lowest for Quercus mongolica in community VII at $1.61{\pm}0.90mm$.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.132-138
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• 2016

The objectives of this study were to infer the parameters of forest stand growth functions of STEMS for Cryptomeria japonica stands of Jeju Hannam Experimental Forest, Korea Forest Research Institute, and to investigate the effects of thinning regimes on the patterns of stand growth and carbon absorption. The forest stand growth functions for the potential diameter growth, modifier, crown ratio and mortality are the major ones composing the independent-tree/distance-free forest stand growth simulator, STEMS. The parameters were inferred using the sets of growth data obtained from stem analyses of 39 trees, chosen from 13 sample plots of the forest stands. The effects of thinning regimes on the patterns of stand growth and carbon absorption were investigated by simulating the stand growth patterns of the case study stand with 3 different thinning regimes: no-thinning, early thinning with low intensity and late thinning with high intensity using the simulator. According to the results of the analyses, the different thinning regimes cause significant effects on the growth patterns of average DBH, average height, diameter distribution and stand volume as well as the amount of carbon absorptions.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.135-145
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• 1997

This study aimed at evaluating one curvilinear equation and nine non-linear equations for estimating stand growth characteristics(mean dbh, mean height and volume per ha) for the plantations of Pinus koraiensis and the natural stands of Quercus mongolica. The data were collected from 92 plots in Pines koraiensis stands and 83 plots in Quercus mongolica stands, and the site index of all the stands is 14. The curvilinear equation, $Y=at^be^{-c/t}$, used in preparing the yield tables was well fitted within the range of data, but was likely to give overestimates when extrapolating in old stage due to the tendency of linear increase. Among the non-linear equations, logistic equation and Sloboda equation gave overestimates in young stands and reached the asymptotic status early which means underestimates in old stage. Extrapolating in old stage, Hossfeld equation generally gave larger values than others due to its large estimates of parameter a, the maximum value. On the other hand, Bertalanffy equation gave underestimates in young and old stands and overestimates in middle-aged stands. The estimates with Korf equation was relatively low for Pinus koraiensis stands, and this tendency was more obvious in dbh growth of Quercus mongolica stands. Ueno-Ohzaki equation was liable to give over or underestimates depending on the value of parameter b when extrapolating in old stands. Considering the accuracy of estimates and the biological base of the growth equations, Gompertz equation, Chapman-Richards equation and Weibull equation were generally applicable for estimating the stand growth characteristics of both species in the whole range of stand ages including extrapolated range. To get more accurate and precise parameter estimates, more data, especially in old stands, should be required in further study.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.26-33
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• 2005

The study was carried out to provide information about growth and ecological characteristics by site types of natural deciduous forest in Pyeongchang, Gangwon Province. The data were collected from four aspects(the East, the West, the South, and the North) with three elevation(higher than 1.000 m, 700~1,000 m, lower than 700 m) and three topographical conditions(ridge, hill, and valley). Growth parameters by site types were evaluated based on the growth performances of dbh for the last 5 to 10 years; which were also estimated based on both Pressler and Schneider formulae. In addition, ecological characteristics such as Shannon-Wiener's diversity index, evenness index and richness index were analyzed by site types. The management methods by site types were suggested by considering stand density, growth patterns, and ecological characteristics. It was found that the stands on the South and the East are necessary the tending practices to improve growth and ecological characteristics. On the other hand, the West and the North needed the tending practices focusing on stand density management to increase growth rate rather than ecological management. It was also found that the area lower than 700 m in elevation showed Higher growth rate than other areas. As a management standard considered in terms of growth rate, it was suggested that tending practices should be applied to the stands of which growth rate for the last 5 to 10 years were lower than 2%. Considering topographical conditions, valley area showed better ecological characteristics than both ridge and hilly areas. Consequently, it was revealed that the valley areas were suitable for the ecological management.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.131-138
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• 2006

This study was conducted to assess the diameter growth patterns of Quercus mongolica and Quercus variabilis dominant species in natural deciduous forests in Korea. The diameter growth data were collected from 83 destructively sample trees for stem analysis in Gangwon-Do region. The relationship between diameter growth and 14 tree measurements was also analyzed. The average diameter growth rate of dominant trees for both species increased until ages of 15-20 years, and exhibited generally constant trend for subsequent ages. The diameter growth rate of both species ranged from 0.09-0.83 cm/yr across the all ages. Average annual diameter growth for last 5 measurement years was 0.28 cm/yr for Quercus mongolica and 0.27cm/yr for Quercus variabilis. The observed growth rate decreased with decreasing crown class. The difference between diameter growth rates for different crown classes was only statistically significant (p<0.0001) for Quercus mongolica. Pearson correlation coefficient between the diameter growth rate decreased with relative diameter (r=0.64), relative height (r=0.61), exposed crown area (r=0.58) and total crown area (r=0.56) for Quercus mongolica. For Quercus variabilis, Pearson correlation coefficient decreased with dbh (r=0.57), crown width (r=0.55), age (r=0.39), competition index (r=-0.39), and height (r=0.35).

• Journal of Korean Society of Forest Science
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• v.104 no.4
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• pp.536-542
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• 2015

This study was examined for the growth response of tree diameter and volume to thinning treatments from different thinning intensities using three long-term thinning trials for Japanese Evergreen Oak (Quercus acuta Thunb.) stands in Wando island, Korea. After thinning in 1999, annual tree growth of diameter and volume was highest in heavy thinned stands for individual tree and this growth pattern of thinning response showed similar tendency to the individual tree growth response in light thinned stands. By increasing diameter growth, the value of H/D ratio (HDR) as an indicator of stem form was properly decreased and improved up to 80%. Although there is significant growth response of basal area in both heavily and lightly thinned stands, the growth potential both of heavily and lightly thinned stands in total stand volume is not likely to reach at the level of unthinned stands because of basal area growth loss associated with both light and heavy thinnings.

• Korean Journal of Agricultural and Forest Meteorology
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• v.4 no.1
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• pp.1-11
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• 2002

This study was conducted to reveal the effects of local climatic conditions on the early growth of Korean white pine progeny test stands. For this, stand variables such as mean DBH, mean height, basal area per hectare, and volume per hectare by stand age and locality were first measured and summarized for each stand. Based on these statistics, annual increments for 10 years from stand age 10 to 20 were calculated for each of stand variables. The effects of local climatic conditions as one of environmental factors on the growth were then analyzed by both a topoclimatological method and a spatial statistical technique. From yearly climatic estimates,30 climatic indices which affect the tree growth were computed for each of the progeny test stand. The annual increments were then correlated with and regressed on the climatic indices to examine effects of local climatic conditions on the growth. Gapyung area provided the best conditions for the early growth of Korean white pine and Kwangju area ranked second. On the other hand, the growth pattern in Youngdong ranked last overall as expected. It is also found that the local growth patterns of Korean white pine in juvenile stage were affected by typical weather conditions. The conditions such as low temperature and high relative humidity provide favor environment for the early growth of Korean white pine. Especially, it was concluded that the low temperature is a main factor influencing the early growth of Korean white pine based on the results of correlation analysis and regression equations developed far the prediction of annual increments of stand variables.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.124-132
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• 2001

This study was conducted to reveal the relationship between physiological characteristics and growth by family for open-pollinated progeny stand of Korean white pine in Gapyung site. Average growth performance of total 25 families for 18 years old progeny stand in this study site showed 5.9m in mean height, 8.9cm in mean DBH, $12.0m^2$ in basal area per hectare and $46.5m^3$ in volume per hectare, respectively. By the analysis result of growth performance for all 25 families, family No. 20 showed the most excellent growth and middle in family No. 10. On the other hand, family No. 3 represented the worst growth among the 25 families. The change of seasonal photosynthesis rate by increasing luminous intensity was the same tendency as the growth pattern of all 25 families and showed the same results in all four seasons. In the seasonal analysis, the photosynthesis rate was increased as the season has changed from winter to summer. Chlorophyll contents was also increased from winter to summer. Especially, family No. 20 which is the best in growth performance has more chlorophyll contents than the others. In addition, family No. 20 was also better than other families in the weight of assimilation tissue(g), length of needle(cm), width of needle(cm), and number of Stoma. However, in water utilization rate, family No. 3 which is the worst in the growth performance showed the best result that is reverse tendency compared with the photosynthesis rate. The changes of water utilization rate represented to be increased as the season has changed from winter to summer.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.4
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• pp.233-237
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• 2003

This study was conducted to provide a rational forest management method for a natural oak (Quercus variavilis) forest stand in the central part of South Korea based on characteristics of growth and water relation parameters. Average volume per hectare was 175.1 ㎥ in the study site of oak stands. Basal area and volume of each direction appeared to increase as the slope direction moves from north to south, but annual mean increment and periodic annual increment of DBH for 10 years showed the lowest value at the southern aspect. Maximum water potentials measured between 12 and 14 o'clock were analyzed by direction and elevation in the oak stands. Water potential of oak decreased as the slope changed from the north to the south aspect and water potential increased at lower elevations. Soil water content for the oak stands tended to decrease as the aspect shifted from north to south. Water potential and soil moisture content were highly correlated. It appears that oaks have a higher moisture requirement at the southern aspect, because of stand density related to intraspecific competition.

• Journal of Ecology and Environment
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• v.41 no.8
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• pp.223-234
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• 2017

Background: Spatial structure of plants in a population reflects complex interactions of ecological and evolutionary processes. For dioecious plants, differences in reproduction cost between sexes and sizes might affect their spatial distribution. Abiotic heterogeneity may also affect adaptation activities, and result in a unique spatial structure of the population. Thus, we examined sex- and size-related spatial distributions of old-growth forest of dioecious tree Torreya nucifera in extremely heterogeneous Gotjawal terrain of Jeju Island, South Korea. Methods: We generated a database of location, sex, and size (DBH) of T. nucifera trees for each quadrat ($160{\times}300m$) in each of the three sites previously defined (quadrat A, B, C in Site I, II, and III, respectively). T. nucifera trees were categorized into eight groups based on sex (males vs. females), size (small vs. large trees), and sex by size (small vs. large males, and small vs. large females) for spatial point pattern analysis. Univariate and bivariate spatial analyses were conducted. Results: Univariate spatial analysis showed that spatial patterns of T. nucifera trees differed among the three quadrats. In quadrat A, individual trees showed random distribution at all scales regardless of sex and size groups. When assessing univariate patterns for sex by size groups in quadrat B, small males and small females were distributed randomly at all scales whereas large males and large females were clumped. All groups in quadrat C were clustered at short distances but the pattern changed as distance was increased. Bivariate spatial analyses testing the association between sex and size groups showed that spatial segregation occurred only in quadrat C. Males and females were spatially independent at all scales. However, after controlling for size, males and females were spatially separated. Conclusions: Diverse spatial patterns of T. nucifera trees across the three sites within the Torreya Forest imply that adaptive explanations are not sufficient for understanding spatial structure in this old-growth forest. If so, the role of Gotjawal terrain in terms of creating extremely diverse microhabitats and subsequently stochastic processes of survival and mortality of trees, both of which ultimately determine spatial patterns, needs to be further examined.