• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.150-164
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• 2022

This study was conducted to provide basic information for the development of silvicultural guidelines and manuals. This was achieved through analysis of tree and stand characteristics according to the first and second thinning in Korean white pine plantations. Data were collected from permanent plots installed at Korean white pine plantations according to thinning intensity, and residual tree and stand variables, including diameter at breast height (DBH), volume, and mortality at age 19-43, were analyzed using data repeatedly collected in 4-5 measurements by experiments. According to one-way variance of analysis, tree DBH and volume were significantly different according to thinning intensity (p<0.05). DBH distribution was skewed to the left side over time as thinning intensity was heavier. Thus, tree DBH values were larger in heavy thinning plots with increased age. The periodic annual increment (PAI) of DBH was higher with heavier thinning intensity and fewer years after thinning. The PAI range by thinning intensity was 0.48-0.95 cm/year at age 19-24. In addition, the PAI increased in heavy thinning plots after the second thinning; The PAI range by thinning intensity was 0.29-0.67 cm/year after the second thinning at age 37-42. The PAI of tree volume differed according to thinning intensity, and the PAI value did not decrease obviously, in contrast to the pattern of the DBH PAI. Stand volume was generally higher in high-density stands, and the PAI of stand volume was high in unthinned and light thinning plots. Mortality was highest in unthinned plots, and the differences in mortality according to thinning intensity increased over time. Consequently, the growth of DBH and tree volume was lower as stand density increased, but this growth was facilitated with appropriate first and second thinning operations.

• Journal of Korean Society of Forest Science
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• v.112 no.4
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• pp.502-514
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• 2023

This study was conducted to understand the long-term changes in soil physiochemical properties and seedling growth in Larix kaempferi (larch) stands planted in clear-cut larch and Pinus rigida (pine) forest soils over an 11-year period after reforestation. Two-year-old bare-root larch seedlings were planted in 2009-2010 at a density of 3,000 seedlings ha^-1 in clear-cut areas that harvested larch (Chuncheon and Gimcheon) and pine (Wonju and Gapyeong) stands. We analyzed the physiochemical properties of the mineral soils sampled at 0-20 cm soil depths in the planting year, and the 3^rd, 7^thand 11^th years after planting, and we measured seedling height and root collar diameter in those years. We found significant differences in soil silt and clay content, total carbon and nitrogen concentration, available phosphorus, and cation exchangeable capacity between the two stands; however, seedling growth did not differ. The mineral soil was more fertile in Gimcheon than in the other plantations, while early seedling growth was greatest in Gapyeong. The seedling height and diameter at 11 years after planting were largest in Wonju (1,028 tree ha^-1) and Chuncheon (1,359 tree ha^-1) due to decreases in stand density after tending the young trees. The soil properties in all plantations were similar 11 years after larch planting. In particular, the high sand content and high available phosphorus levels (caused by soil disturbance during clear-cutting and planting) showed marked decreases, potentially due to soil organic matter input and nutrient uptake, respectively. Thus, early reforestation after clear-cutting could limit nutrient leaching and contribute to soil stabilization. These results provide useful information for nutrient management of larch plantations.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.496-505
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• 1996

Soil respiration was measured every two weeks from May through November 1995 using the soda lime method in 40-Year-old Pinus rigida and Larix leptolepis plantations on a similar soil in Yangpyeong, Kyonggi Province. Treatments included control and no-roots(plots trenched and root regrowth into plots prevented). Root respiration was evaluated by comparing no-roots sub-plots to control plots. Mean soil respiration showed highly significant species effects(p<0.01) and was highest at the Pinus rigida control plot($0.38g/m^2/hr$) and lowest at the Larix leptolepis no-roots plot($0.31g/m^2/hr$). High soil respiration in Pinus rigida may be related to aboveground litter production. The annual $CO_2$ fluxes ranged from 23 to 27t/ha/yr. We found significant correlations between temperatures(air : $R^2$=0.53, soil : $R^2$=0.55) and soil respiration(p<0.01), but no significant correlations between soil moisture and soil respiration(p>0.1). Root respiration was 3% of total soil respiration. We might underestimate rapt respiration because of shallow trenches and $CO_2$measurements right after trenching. Factors controlling soil respiration including belowground litterfall(especially fine roots) inputs, litter quality should be well understood to predict soil carbon fluxes and relative contributions to total soil respiration in forest ecosystems.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.416-425
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• 1996

Aboveground biomass, distribution of N and P in tree components, forest floor and the top 20cm of mineral soil, and litterfall were determined in adjacent 37-year-old plantations of Pinus rigida Mill. and Larix leptolepis Gord. on a sandy clay loam soil in Yangpyeong, Kyonggi Province. Total above-ground tree biomass for P. rigida and L. leptolepis were 138.2 and 127.2 t/ha, respectively, and did not differ between the two species. Nitrogen concentrations in stembark and foliage were all greater in L. leptolepis. Understory biomass contributed less than 2.0% of the total aboveground biomass but contributed up to 12.0% of the aboveground nutrient contents. Soil below L. leptolepis had higher concentrations of N and P. Total ecosystem N content (kg/ha) was greater for L. leptolepis (5,579) than P. rigida (4,147). Litterfall dry mass (kg/ha/yr) was greater for P. rigida (6,020) than L. leptolepis (4,191) whereas N contents in leaf litterfall (kg/ha/yr) was almost twice as large in L. leptolepis (28) than P. rigida (16). This common garden experiment suggests a strong influence of tree species on nutrient distribution and cycling in a forest ecosystem.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.176-183
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• 2001

Loblolly pine (Pinus taeda L.) is the most economically important timber producing species in the southern United States. Much attention has been given to predicting diameter distributions for the solution of multiple-product yield estimates. The three-parameter Weibull diameter distribution yield prediction systems were developed for loblolly pine plantations. A parameter recovery procedure for the Weibull distribution function based on four percentile equations was applied to develop diameter distribution yield prediction models. Four percentiles (0th, 25th, 50th, 95th) of the cumulative diameter distribution were predicted as a function of quadratic mean diameter. Individual tree height prediction equations were developed for the calculation of yields by diameter class. By using individual tree content prediction equations, expected yield by diameter class can be computed. To reduce rounding-off errors, the Weibull cumulative upper bound limit difference procedure applied in this study shows slightly better results compared with upper and lower bound procedure applied in the past studies. To evaluate this system, the predicted diameter distributions were tested against the observed diameter distributions using the Kolmogorov-Smirnov two sample test at the ${\alpha}$=0.05 level to check if any significant differences existed. Statistically, no significant differences were detected based on the data from 516 evaluation data sets. This diameter distribution yield prediction system will be useful in loblolly pine stand structure modeling, in updating forest inventories, and in evaluating investment opportunities.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.480-487
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• 2000

Repeated measurement of 472 permanent subplots in slash pine (Pinus elliottii Engelm.) plantations were used to develop survival prediction equations for predicting future number of planted slash pine trees. On the average, about 40 percent of the slash pines in the experimental sites had a stem cankers due to fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme) incidence. A stand level survival prediction model was developed that incorporated the incidence of fusiform rust and allowed the transition paths of trees from an uninfected stage to an infected stage. Predicted total surviving number of trees is obtained by adding together the predicted number of infected and uninfected trees. The influence of natural hardwood density and site quality on slash pine survivals tended to show a negative effects on future survivals.

• Korean journal of applied entomology
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• v.31 no.1
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• pp.10-22
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• 1992

Oribatid mites communities at plantations of the Korean white pine (Pinus koraiensis) were investigated for the composition and distribution at the Sudong area, Namyangju-gun, Kyung-gido, Korea. Oribatid mites collected were classified into 38 families, 64 genera, and 109 species. Among them the eurysphere, stenosphere, and sporosphere species were 35, 49, and 25 species, respectively. The species diversity of oribatid mites increased at sites from 3 years after to 5 years after transplanting and then decreased by afforested years. The dominant species of oribated mites at the surveyed areas were 6 species including Ceratozetes japonicus. Number of dominent species and recessive species decreased by afforested years. However, influential species increased. According to the MGP analysis I, type G was found in all sites. The eurysphere and the sporosphere species were type G. The stenosphere species were type P at an earlier planting stage, type G at a middle planting stage, type M at a latter planting stage. The semieurysphere species were type M. According to the MGP analysis II, site 1, 2, and 4 were type G, but site 3, 5, and 6 were type P.

• Journal of Ecology and Environment
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• v.29 no.3
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• pp.205-212
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• 2006

Effects of nitrogen and phosphorus fertilization on nutrient dynamics and litterfall production were determined in adjacent 41-year-old plantations of Pinus rigida Miller and Larix kaempferi Gordon on a similar soil in Yangpyeong, Gyeongggi Province. Litterfall production were significantly different among sampling dates and between the tree species, whereas it was not significantly different among the treatments. Total annual litterfall production was 6,377 kg/ha for P. rigida and 4,778 kg/ha for L. kaempferi, respectively. Litterfall nutrient concentrations of L. kaempferi were higher than those of P. rigida. For both tree species, litterfall nutrient concentrations were highest in summer when the least litterfall production occurred, and lowest in late-autumn when the greatest litterfall production occurred, except for Ca in the L. kaempferi stand. The amount of total organic matter in the forest floor of P. rigida and L. kaempferi plantations were 24,296 kg/ha and 10,763 kg/ha, respectively. Forest floor N and P contents were 126, 10 kg/ha for P. rigida and 102, 8 kg/ha for L. kaempferi, respectively.

• Journal of Korean Society of Forest Science
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• v.103 no.4
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• pp.528-536
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• 2014

The aim of this study was to investigate the damage characteristics induced by winter freezing of evergreen broad-leaved trees distributed in urban area of warm temperate forest zone, which are gaining increased interest recently as climate change. The results of the study indicated that, as for 'stem injury', Camellia japonica Linne (59.6%) had the weakest damage, while Ternstroemia gymnanthera Sprague (83.3%) had the most severe damage. By the visual evaluation of freezing injury according to the characteristics of plantations environment, the observations of single planting (p<0.01) in planting method had weaker damage than those of group planting, the observations of under tree (p<0.001), plain (p<0.001), and organic matter plenty (p<0.05) in plantations characteristics had significant differences with relatively weaker damage than the observations of open space, slop, and scarcity, respectively. Tree height (-0.432) and crown width (-0.470) among growth factors were negatively correlated with the severity of damage, respectively. Therefore, the selection of tree species is vital for the successful creation of these urban forested area by making considerations of planting environment, and further research on evergreen broad-leaved trees is needed in this aspect.

• Journal of Korean Society of Forest Science
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• v.107 no.1
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• pp.35-42
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• 2018

This study was carried out to investigate site and soil factors affecting growth of root collar diameter (RCD) and height (HT) of Larix kaempferi trees planted in harvested Larix kaempferi plantations. We were found effect factors of growth of RCD and HT using 15 of site and soil factors. And then we made the growth estimated equations of RCD and HT of 6-years-old L. kaempferi tree by the derived affecting factors. The growth of RCD was affected in order of available phosphorus (+), effective soil depth (+), organic matter (-), sand separate in soil (-), pH (-), and elevation (-), and the coefficient of determination ($R^2$) of the growth estimated equation of RCD was 0.51. The growth of HT was affected in order of effective soil depth (+), elevation (-) slope (-), and available phosphorus (+) and the $R^2$ of the growth estimated equation of HT was 0.46. The growth of RCD and HT were commonly affected by effective soil depth, available phosphorus, and elevation. Therefore, planting site of L. kaempferi should be considered the mainly effect factors in order to keep better early growth based on the current study.