• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.305-313
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• 2011

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate growth performance, photosynthesis, chlorophyll fluorescence, and chlorophyll contents of Liriodendron tulipifera growing under three different fertilization treatments (Constant rate, Three-stage rate, and Exponential rate fertilization). Root collar diameter, height, and biomass of L. tulipifera were the highest at Constant treatment. Like growth performance, seedling quality index (SQI) were higher at Constant than at other treatments, but not significantly different among treatments. L. tulipifera showed good photosynthetic capacity at all treatments. Photochemical efficiency and chlorophyll contents were significantly lower at Exponential than at other treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.482-489
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• 2022

This study aimed to determine the optimal planting density of Fraxinus rhynchophylla assessed from the early growth performance at various planting densities over the 7-year period after planting. The study site was in Pyeongchang County, South Korea, and seedlings of 2-year-old (bare-root seedlings) F. rhynchophylla were planted at four densities (3,000, 5,000, 7,000, and 10,000 trees ha^-1) in March 2015. The survival rate, root-collar diameter (RCD), and height (H) were measured from 2015 to 2021, and the H/D (H/RCD) ratio and stem volume were calculated. The survival rate (84-97%) and H/D ratio (54.5-59.2%) were not affected by the planting density during the study period, but the RCD, H, and stem volume were significantly higher for 7,000 trees ha^-1 than for other planting densities. Especially, the stem volume (cm³ tree^-1) at 7 years after planting was highest for 7,000 trees ha^-1 (1,356.1), followed by 10,000 trees ha^-1 (958.6), 5,000 trees ha^-1 (773.0), and 3,000 trees ha^-1 (579.5). As the planting density increased, F. rhynchophylla seedlings showed initial rapid growth due to light competition, but relatively low growth at excessive planting densities. In the future, use of a suitable planting density considering planting costs should provide outstanding growth performance of F. rhynchophylla on plantations.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.17-25
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• 1993

Tree-ring data of subalpine conifers growing in Korea were analyzed to evaluate the possibility of enhanced tree growths due to increased atmospheric carbon dioxide. A total of 64 trees of three species(Taxus cuspidata, Pinus koraiensis, Abies koreana) were sampled from three mountain ranges (Seolak, Sobaek, Chiri) at 1200~1750m(above sea level) and four chronologies were developed in spans of 209~412 years. No apparent growth increases were found in the graphs of chronologies. As comparing the growths of 1900-1949 and 1950-1989 period, only one chronology possessed higher mean growth in the post-1950 period. Growth increase found in the Pinus koraiensis chronology from Mt. Seolak was 8% but it could not be solely attributed to increased carbon dioxide concentration.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.220-227
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• 2009

This study was conducted to select superior families based on the open-pollinated (OP) progeny tests of P. densiflora. A total of 232 OP families were analyzed for relative height growth. The OP progeny test trials were established at 1 to 4 sites from 1975 to 1987. To minimize temporal and spatial variation, we applied the standardization method for family selection. In each progeny test, superior and inferior families were selected at ages of 10, 20 and 30. Relative height growth rate (RHGR), growth speed at a given time unit, was comparatively high at age of 10 with range from 0.1 to 0.6 and showed a large variation among families. However, after age 15, the RHGR was low (average 0.04) and also the variation was not significantly different among families. To reduce selection errors due to age differences (from age 23 to 35) of tests, we made the family selection after age 15 when the values of RHGR were stable. Height growth at each age was transformed to be height growth at age 35 based on the RHGR. As the results, family CB2, CB3, KW99 and KW2 were selected as superior families and KW158, KW22, KB40 and GG1 were considered as inferior ones, respectively. Rank correlations (r) between test ages and selection age 35 were high and statistically significant; r = 0.881 between age 30 and 35, 0.653 between age 20 and 35, and -0.222 between age 10 and 35.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.462-469
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• 2021

Maesa japonica (Thunb.) Moritzi & Zoll. is a rare evergreen shrub that occurs in west Gotjawal, Jeju island, Korea. This study was conducted to investigate effects of an artificial shading on flowering and growth characteristics of M. japonica seedlings. The level of shading had been set to be 35%, 55% and 75% using shading net. The stage of flowering and flowering ratio, seedling height, the number of leaves and stems, leaf area were measured. Flowering timings were delayed by shading. The number of flowering seedlings per plot and inflorescences per seedling were the most in 55% shading level. Tendency of decreased seedling height with increased shading level was shown. The number of leaves and stems were the fewest values in 75% shading level. The increased biomass with decreased shading level was statistically significant. Aboveground and underground biomass were 2.1 and 1.7 times higher in shading 35% than in shading 75%, respectively. Meanwhile, all seedlings in non-shading plots were dead in winter. Such might be speculated as results of the light stress. As a result, we conclude that M. japonica vitally demands the shading for growth and the optimal shading levels for growth and flowering are 35% and 55%, respectively.

• Journal of Forest and Environmental Science
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• v.13 no.1
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• pp.66-80
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• 1997

Pinus koraiensis is one of the major speciese which have been recently planted for ten years and consists of 31% of total plantation. Presently young stand less than 30 years consists of 87% of total forest, but tending thinning of it is hardly carried out and the desirable direction for the thinning is not established yet. The objective of the study is to introduce the optimum thinning plan and thinning method through the long-run experiment of tending thinning for the Pinus koraiensis stand. The experiments carry out to interprete its growth model on the subject of two thinning experimental plots and yield table of Pinus koraiensis. As the basic step for understanding the thinning process, a theoretical growth model which is suitable to express the growth process is required. For that purpose, three growth functions (Mitscherlich, 4 parameter Richards, 3 parameter Richards) are applied to the diameter growth of the sample trees which are taken in the two plots. The results show that 3 parameter Richards is the most suitable. It is also verified that the diameter growth, the height growth, and the decrease in the number of stocks can be estimated by this function. To estimate the growth change of single tree, growth model including parameter h which is related to the occupation area of single tree are introduced. The parameter h can be estimated by using the data of the diameter growth obtained from the established experimental plots. Therefore, if both verification and modification of the usefulness of the model suggested is made, equations which tell about the thinning effects could be drived by estimating the growth process of single tree in advance.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.101-101
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• 2021

본 연구에서는 금강 유역(9,645.5 km²)을 대상으로 SWAT(Soil and Water Assessment Tool)을 이용하여 장기간 지하수 양수와 산림 성장이 수문에 미치는 영향을 평가하였다. 1976년부터 2015년까지 40년의 지하수 이용량(GU)과 산림 성장(FG) 자료를 10년 단위(1980s; 1976~1985, 1990s; 1986~1995, 2000s; 1996~2005, 2010s; 2006~2015)로 구축하고, SWAT 입력자료와 증발산량 매개변수로 사용하여 연대별 지하수 양수와 산림 생장을 반영하였다. 금강 유역 내 위치한 2개의 다목적댐과 3개의 다기능 보에서 관측된 일별 유량으로 2006년부터 2015까지 10년을 검·보정하여 모델의 적용성을 검증하였다. 5지점에 대한 검보정 결과, NSE는 0.76에서 0.79, R²는 0.78에서 0.81, RMSE는 0.55 mm/day에서 1.96 mm/day, PBIAS는 -5.48%에서 8.56%로 통계적으로 유의한 수준으로 분석되었다. 적용성을 검증한 SWAT에 각 연대에 맞는 GU와 FG 정보를 입력하여 수문을 모의하였으며, 두 요인이 물순환에 미치는 영향을 평가하기 위하여 기상조건은 2010s로 고정하였다. 모의결과, GU와 FG 변화가 주는 영향으로 유역 출구의 총유출량은 7.8%(60.7 mm/year) 감소하였으며, 1980s과 2010s에서 각각 775.0 mm/year, 714.3 mm/year의 값을 보였다. 물순환 분석 결과, 지표유출, 중간유출, 기저유출, 침투량, 토양수분은 감소하는 경향을 보였고, 증발산량과 지하수 충전량(GWR)은 증가하는 경향을 보였다. GU의 증가로 인한 지하수위의 지속적인 감소가 GWR이 증가하는 원인으로 판단하였으며, 강우 기간에 포장용수량 이상의 토양수가 빠르게 흘러 지하수 충전량을 증가시켰다고 추론하였다. 또한, 유황 곡선을 분석한 결과, 유량이 지하수 양수와 산림 생장에 영향을 받은 지역에서 시간 흐름에 따라 감소하였고, 저유량 구간에서 상대적으로 많이 감소하였다.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.1-6
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• 2009

The purpose of this study was to analyze annual tree ring growth characteristics for major tree species distributed in Chungbuk province. A total of 800 sample trees from 56 permanent sampling plots measured by the 5th Korean National Forest Inventory Program in 2007 was used for the calculation of annual growth rates. According to the results of this study, the species of Robinia pseudoacacia(2.30mm/yr) showed the best annual tree ring growth rates and the others are Quercus serrata(2.27mm/yr)>Prunus sargentii(1.98mm/yr)> and Larix leptolepis(1.98mm/yr) in order. Most of the major tree species in Chungbuk province, as tree age and stand density increased, annual tree ring growth rates tended to decreased. This information could be very useful for forest managers to understand annual tree ring growth characteristics in Chungbuk province.

• Journal of Korean Society of Forest Science
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• v.106 no.2
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• pp.249-257
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• 2017

This study was conducted to analyze the relationship between tree-ring growth of Pinus densiflora and climate factors based on national forest inventory(NFI) data. Annual tree-ring growth data of P. densiflora collected by the $5^{th}$ NFI were first organized to analyze yearly growth patterns of the species. Yearly growing degree days and standard precipitation index based on daily mean temperature and precipitation data from 1951 to 2010 were calculated. Using the information, yearly temperature effect index(TEI) and precipitation effect index(PEI) were estimated to analyze the effect of climate conditions on the tree-ring growth of the species. A tree-ring growth estimation equation appropriate for P. densiflora was then developed by using the TEI and PEI as independent variables. The tree-ring growth estimation equation was finally applied to the climate change scenarios of RCP 4.5 and RCP 8.5 for predicting the changes in tree-ring growth of P. densiflora from 2011 to 2100. The results indicate that tree-ring growth of P. densiflora is predicted to be decreased over time when the tree-ring growth estimation equation is applied to the climate change scenarios of RCP 4.5 and RCP 8.5. It is predicted that the decrease of tree-ring growth over time is relatively small when RCP 4.5 is applied. On the other hand, the steep decrease of tree-ring growth was found in the application of RCP 8.5, especially after the year of 2050. The results of this study are expected to provide valuable information necessary for estimating local growth characteristics of P. densiflora and for predicting changes in tree-ring growth patterns caused by climates change.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.336-343
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• 2018

This study was carried out to provide the technology of silvicultural practices and management for regeneration by sprouts in the oak forests distributed on the slope. A total of 1,451 stumps were examined for the following factors relative to the occurrence and growth of the sprouts: stump height & diameter; location & quantity and root collar diameter & height of arisen sprouts. The amount of sprouts deceased or increased as the stump diameter increased. However, it tended to increase with stump height. The difference in the stump height between direction of the upwards (DUS) and downward slopes (DDS) was occurred, because oak trees were felled lower based on direction of the upward for convenience of regeneration works on the slope. The number of sprouts was higher relatively in the stumps of DDS. The rate of arisen side and root sprouts was higher in the stumps of DDS and DUS, respectively. The stump height difference was found to affect the arisen part of sprouts. As a result of comparing the sprouts growth according to the arisen part, there was no difference in the stump of DUS, but the growth of side sprouts in the stump of DDS was higher than that of the root. In order to improve the quality of oak sprouts considering the distribution characteristics of the oak forests in South Korea, it is necessary to apply the silvicultural technique, making the cutting surface parallel with the slope to reduce the stump height difference, to suppress arising side sprouts.