• Korean journal of applied entomology
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• v.48 no.4
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• pp.553-556
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• 2009

We surveyed natural enemies of Pachynematus itoi Okutani, newly recorded sawfly pest of Larix leptolepis, and investigated their occurrence and life cycle at Cheolwon and Taebaek, Gangwon Province in 2006~2007. Endasys liaoningensis was identified as main natural enemy of P. itoi Okutani. Parasitism of E. liaoningensiswas was 42%. Emergence period of E. liaoningensis was from May to September, and the peak of emergence was from 21th May to 20th June. It was suggested that the occurrence number and period of E. liaoningensis were quite closely relative to those of host, P. itoi.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.207-217
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• 1995

Various factors reducing seed yield in 4 Larix species throughout the whole reproductive cycle were investigated and partitionate losses attributed to them were determined. Pollen quality, lack of pollination, and degeneration of female gametophyte played minor roles in reducing seed yield. Failure of pollinated ovules to be fertilized was an important factor causing seed loss. Embryo degeneration was also a major factor causing seed loss in all 4 species. Strobili abortion, which causes loss of all potential seeds in a cone, was the most important factor in reducing seed loss in this study. Based on the results obtained from this studs, hybridizations in either direction between European larch and Japanese larch are likely to resulting viable seed. However, hybridization between tamarack as a mother tree and European larch are not likely to result in viable seeds being produced.

• Journal of Korean Society of Forest Science
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• v.102 no.3
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• pp.455-462
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• 2013

The objectives of this study were to compare soil physical and chemical properties and early growth of Pinus densiflora and Larix kaempferi seedlings in harvested Larix kaempferi and Pinus rigida stands. Study stands were located in harvested L. kaempferi (Yeongju) and Pinus rigida (Wonju) plantations. Seedlings of L. kaempferi (1-1) and P. densiflora (1-0) were planted in April, 2008, Yeongju. Also, seedlings of L. kaempferi (1- 1) and P. densiflora (1-1) were planted with the density of 3,000 seedlings/ha in April, 2010, Wonju. We analyzed soil physical and chemical properties and the relative growth rate of seedlings using diameter at root collar and seedling height. Soil organic matter, total nitrogen and available phosphorus concentrations in harvested P. rigida stand were significantly higher than those in harvested L. kaempferi stand. The relative growth rate of P. densiflora seedlings with former stands were not significantly different. The relative growth rate of diameter at root collar of L. kaempferi seedling in harvested P. rigida stands were significantly higher than that in harvested L. kaempferi stand. Higher concentrations of organic matter, total nitrogen and available phosphorus in harvested P. rigida stand was probably positively affect to the early growth of seedlings.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.10-18
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• 2017

This study was carried out to suitable plantation site from comparison and analysis of regional early growth characteristics of planted Larix kaempferi trees in harvested L. kaempferi plantations. Two-year-old bare-root seedlings of L. kaempferi were planted with the density of $3000\;seedlings\;ha^{-1}$ at four sites (Yeongju, Gimcheon, Chuncheon, and Inje). All sites were established with three plots ($400m^2$ per plot) in 2010. We analyzed soil physical and chemical properties in October 2010 and 2013. We measured root collar diameter (RCD) and height of trees in October from 2010 to 2014, and then calculated H/D ratio and stem volume. Soil pH was significantly increased and available P was significantly decreased 3 years after planting. Annual mean RCD, height, and stem volume of 5-to 7-year-old in the Chuncheon site were significantly higher than those in the other sites, however them in the Yeongju site were the lowest. It is related to the fact that total nitrogen, available phosphorus, and organic matter concentrations in the Yeongju site were relatively lower than those in the other sites. As a results of this study, we could confirm the correlation between soil properties of L. kaempferi plantations and growth of L. kaempferi trees. We could suggest values of soil properties for reforestation of L. kaempferi.

• 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.

• Journal of Korean Society of Forest Science
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• v.83 no.4
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• pp.512-520
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• 1994

To enhance the utilization of Larch(Larix leptolepis Gorden) wood, the sawdusts were tested as cultivating media for Lentinus edodes(Mori 290) by varying the composition of the media. The economic efficiency for producing mushrooms from larch sawdusts was evaluated. The results are as follows. 1. Larch sawdust was as much efficient as oak sawdust in the growth of the mycelia and production of good quality of oak mushrooms. 2. The mushrooms were able to be harvested starting six months after beginning the cultivation. No differences were found among the qualities of the mushrooms produced by various treatments. 3. The contents of lignin(28.6-28.7%) in the fresh sawdust of larchwood are higher than those in the residues of the used media(18.2%). But lignin content of 1% NaOH extracts(30.4-34.4%) in fresh sawdust of larch was lower than those in the residues(68.0%). 4. The production of mushroom was relatively high to be 29.7-31.5%(760-780g.)/2.5kg pack) of mushroom weight. The net profit estimated was 1,475Won per pack.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.122-134
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• 2015

This study was conducted to investigate the potential of torrefied larch wood as a raw material of pellets. First of all, larch chip was torrefied at the temperatures of 230, 250 and $270^{\circ}C$ for 30, 50 and 70 min. Secondly, moisture content, moisture absorption, higher heating value and ash content of the torrefied chip were measured to examine the effects of torrefaction conditions on the fuel characteristics of larch. Thirdly, surfaces of the torrefied chip were observed by light microscope (LM), field emission scanning microscope (FE-SEM) and SEM-energy dispersive spectroscopy (EDXS). With the increases of torrefied temperature and time, contents of lignin increased and those of hemicellulose reduced. Moisture content of torrefied larch chip was greatly lower than that of non-torrefied chip. Moisture absorption of the torrefied chip decreased as torrefaction temperature increased. As torrefaction temperature increased, higher heating value and ash content of larch chip increased. However, durability of torrefied-larch pellets was remarkably lower comparing to non-torrefied-larch pellets. When surface of larch chip was observed by LM and FE-SEM, surface color and cell wall of the chip was getting darker and more collapsed with the increases of torrefaction conditions. Through the analysis of SEM-EDXS, distribution and quantity of lignin existing on the surface of larch chip increased with the increases of torrefied conditions. In conclusion, $270^{\circ}C$/50 min might be an optimal condition for the torrefaction of larch with the aspect of fuel characteristics, but torrefaction condition of $230^{\circ}C$/30 min should be considered according to the durability of torrefied-larch pellets.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.136-144
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• 2007

The objectives of this study were to compare nutrient input by throughfall, stemflow and litterfall and concentration of nutrient in soil water between deciduous forest stand and Larix kaempferi plantation at Mt. Joongwang, Pyongchang-gun, Gangwon-do. The amount of rainfall interception during study period in deciduous forest stand and L. kaempferi plantation was 12% and 36%, respectively. Concentrations of cation ($Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$) in throughfall were not different, while concentration of $Cl^-$ in stemflow was higher in L. kaempferi plantation. The results indicated that annual nutrient inputs by rainfall with the exception of $Cl^-$ were significantly greater in deciduous forest stand. In soil water, concentrations of anion ($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) in A-layer, and $Ca^{2+}$ and $Cl^-$ in B-layer were higher in L. kaempferi plantation. Litterfall input during study period was $2,589kg\;ha^{-1}$ in deciduous forest stand and $1,046kg\;ha^{-1}$ in L. kaempferi plantation. Concentration of N was higher in L. kaempferi plantation, while N input from litterfall was greater in the deciduous forest stand ($36.81kg\;ha^{-1}yr^{-1}$) than L. kaempferi plantation ($16.16kg\;ha^{-1}yr^{-1}$). $Na^+$, $Mg^{2+}$, $K^+$ and $Ca^{2+}$ in litterfall collected from deciduous forest stand were found to be higher than those from the L. kaempferi plantation. Also, input of those were greater in deciduous forest stand. Thus, total nutrient input by throughfall, stemflow and litterfall was greater in deciduous forest stand than L. kaempferi plantation, significantly.

• 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.88 no.2
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• pp.266-272
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• 1999

Aboveground biomass and nutrient contents of a 31-year-old pitch pine(Pinus rigida) and a 31-year-old Japanese larch(Larix leptolepis) plantations were measured in the Chungbu Forest Experiment Station, Kyunggi Province. Aboveground biomass was 170.2ton/ha in the pitch pine and 87.2ton/ha in the Japanese larch plantations. Aboveground biomass difference between both plantations was due to the difference of stand density. Aboveground biomass in both plantations was allocated as follows : stemwood>branch>stembark>needle. The concentrations of all nutrients(N, P, K, Ca, Mg) were generally higher in the Japanese larch needle than in the pitch pine because of high nutrient uptake characteristics of larch compared with pine tree species. The nutrient concentration in different tree tissues in both tree species decreased in the order of needle>branch>stembark>stemwood. Nutrient contents of aboveground biomass were : N, 335.9 ; P, 40.4 ; K, 121.4 ; Ca, 188.6 ; Mg, 93.8kg/ha in the pitch pine plantation, while nutrient contents in the Japanese larch plantation were : N, 226 ; P, 11.5 ; K, 72.9 ; Ca, 75.7 ; Mg, 37.1kg/ha. The nitrogen use efficiency calculated as the biomass produced by one unit of nitrogen was higher in the pitch pine than in the Japanese larch plantations. This result suggests that pine with high nitrogen use efficiency could be adapted in lower site productivity area compared with larch tree species.