• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.85-92
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• 2000

Four Chamaecyparis obtusa plantations of 6, 9, 14, and 20 years were studied to investigate biomass, net production and nutrient distribution. There was wide difference in DBH and height growth of the stands according to site and soil conditions. Total biomasses of the stands of 14 years and 20 years located in gentle slopes and good soil conditions were 96.2t/ha and 145.0t/ha, and total net productions of those were 22.4t/ha/yr and 23.5t/ha/yr, respectively. Total biomasses of the stands of 6 years and 9 years located in steep slopes and poor soil conditions were 0.7t/ha and 14.0t/ha, and total net productions of those were 0.3t/ha/yr and 4.7t/ha/yr, respectively. As stand age increased, the ratios of stem wood and branches to total biomass and total net production increased, while the ratios of leaves to total biomass and total net production and the ratios of roots to total biomass decreased. Concentrations of N, P, K and Mg were greatest in the leaf and concentration of Ca was greatest in the stem bark. As stand age increased, N concentrations of the stem bark, branch, dead branch and root and K concentration of the branch decreased, while Ca concentration of the stem bark increased. Nutrient contents of the whole tree were great in order of N, K, Ca, Mg and P.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.139-144
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• 2006

Chestnut trees have been severely damaged by the various cankers in Korea. Field surveys for elucidating the relationships between disease occurrence and environmental factors, i.e., tree age, temperature, rainfall precipitation, direction, degree of slope, chemical properties of soils, and so on, were carried out in the chestnut tree plantations located at Gyeongnam, Jeonnam, Chungnam, and Gyeonggi-Do Province. Totally, one thousand and one hundred thirty seven trees from 36 experiment plots were investigated. Trees infected by at least one of the canker fungi were estimated up to 66%. The most severely infested area was Sunchon in Jeonnam Province with the rate of 80%, while the most lightly infested area was Kongju in Chungnam Province with 39%. Disease occurrence was found to be highly correlated with tree age. The disease occurred most frequently on trees ranged from 7 to 12 years old, while it was relatively low on trees below 5 years old or above 25 years old. Canker positions on the tree formed by the pathogenic fungi were most often at 1.6-2.0m above the ground. Over five hundreds bark samples from the canker area on the tree were collected and the pathogenic fungi were isolated. The most commonly isolated fungus was identified as Cryphonectria parasitica, the chestnut blight fungus.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.285-291
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• 1999

Loblolly(Pinus taeda L.) and slash(Pinus elliottii Engelm.) pines are the most important timber producing species in the Southern United States. Site index equations to estimate site index curves(base age 25 years) for loblolly pine and slash pine plantations have been developed based on long-term repeated measurement data sets. To check magnitude of errors in estimating site index, each cumulative measurement cycle data sets and all combined data sets were used to recalculate site index values. The Chapman-Richards' growth function was selected for stand height prediction. Anamorphic base age invariant site index curves were presented based on this height prediction equation. Statistics used in the evaluation were mean of the differences and mean of the absolute differences. For plantation ages less than 5 years, site index values showed very sensitive fur both species based on the evaluation test.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.342-351
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• 1999

The forest vegetation developing on Mt. Inwang, an isolated forestland in Seoul, Korea was analyzed phytosociologically and its spatial distribution mapped out. Using the vegetation map, The characteristics of landscape structures in terms of the number and size of patches are discussed. Forest vegetation of the study area was classified into ten communities, ten groups, and eighty subgroups. Landscape element types were classified into secondary forests, relict communities, introduced plantations, and other elements including urbanized area. Pinus densiflora community, natural forest and Robinia pseudo-acacia community, plantation, formed matrix and some secondary forest elements, relict communities and the ether plantations of small size tended to distribute as small patches in such matrix. The number of patches per unit area in secondary forest elements was more than that in plantation elements. The result in patch size was vice versa. The vascular plant species richness of the landscape element types in Mt. Inwang was found to he positively related to their size. As the results of landscape ecological analyses, it was estimated that differentiation of patches recognized in community level would be related to human interference a and those in subordinate levels to natural process such as progression of succession.

• Journal of Korean Society of Forest Science
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• v.109 no.3
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• pp.281-290
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• 2020

The purpose of this study was to determine the optimal planting density for Zelokva serrata plantations. The study sites were located in Gyeongsan (GS) and Sunchang (SC), Korea. One-year-old, bare-root seedlings were planted at densities of 3,000; 5,000; 7,000; and 10,000 trees ha^-1 at the end of March 2015. We measured the root collar diameter and height each September from 2015 to 2019, and then calculated the H/D ratio and stem volume. The root collar diameter and height increased with increased planting density, and the stem volume was significantly higher at 10,000 trees ha^-1 than those at the other planting densities. Planting density did not affect the survival rate or H/D ratio. The root collar diameter, height, and stem volume were higher in GS than those in SC five years after planting. This study highlights that early growth performance was improved at increased planting densities at both sites. This study suggests that the initial planting density of 10,000 trees ha^-1 is suitable to improve the early growth performance of Z. serrata plantations, and that the improved growth performance at higher planting densities may be a silvicultural characteristic of Z. serrata.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.11-22
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• 2023

This study was established to provide basic information necessary for ecological management to restore the naturalness of black locust (Robinia pseudoacacia L.) plantations located in the mountains of Gyeongbuk, Korea. Using vegetation data collected from 200 black locust stands, vegetation types were classified using the TWINSPAN method, the spatial arrangement status according to the environmental gradient was identified through DCA analysis, and a synoptic table of communities was prepared based on the diagnostic species determined by determining community fidelity (Φ) for each vegetation type. The vegetation types were classified into seven types, namely, Quercus mongolica-Polygonatum odoratum var. pluriflorum type, Castanea crenata-Smilax china type, Clematis apiifolia-Lonicera japonica type, Rosa multiflora-Artemisia indica type, Quercus variabilis-Lindera glauca type, Ulmus parvifolia-Celtis sinensis type, and Prunus padus-Celastrus flagellaris type. These types usually reflected differences in complex factors such as altitude, moisture regime, successional stage, and disturbance regime. The mean relative importance value of the constituent species was highest for black locust(39.7), but oaks such as Quercus variabilis, Q. serrata, Q. mongolica, Q. acutissima, and Q. aliena were also identified as important constituent species with high relative importance values, indicating their potential for successional trends. In addition, the total percent cover of constituent species by vegetation type, life form composition, species diversity index, and indicator species were compared.

• Journal of Plant Biotechnology
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• v.6 no.1
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• pp.1-7
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• 2004

Forestry sector has witnessed some unprecedented events in the recent past both in terms of galloping biotechnological developments and heated environmental debates over risks associated with release of transgenic trees. Improvements in the in vitro propagation techniques has made it possible to develop tissue culture based plant regeneration protocols just for about any tree species. And with the inclusion of every new species within the realms of tissue culture technology, it becomes a candidate for genetic improvement through recombinant DNA technology, the so called genetic engineering. Poplars and their hybrids serve as the model tree species on which most of the genetic transformation work as been carried out. A lot of work has also gone in genetic transformation of fruit trees and trees of horticultural interests. Trees have been successfully transformed for traits ranging from reduction of length of juvenile phase to alteration of tree architecture to altering wood quality by lignin and cellulose modification. More-over trees have been genetically engineered successfully to combat various types of insect pests and pathogens causing diseases. But all these developments have ignited controversies over the possible benefits and risks associated with transgenic plantations by various environmental agencies and activists. Solutions to most of these concerns can be found out with more intensive prioritized research.

• The Plant Pathology Journal
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• v.33 no.1
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• pp.9-20
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• 2017

Incidence of leaf blast on nursery plants and pitting disease on maturing banana bunches has been recorded in banana plantations during rainy season in Eastern India during 2014 to 2015. Taxonomical identification as well as DNA sequence analysis of the internal transcribed spacer region of fungus isolated from affected tissue culture derived plantlets and fruits confirmed the pathogen to be Pyricularia angulata Hashioka "in both the cases". Koch's postulates were proved on young plantlets as well as on maturing fruits of cv. Grand Naine under simulated conditions. Evolutionary history was inferred and presented for our P. angulata strain PG9001 with GenBank accession no. KU984740. The analysis indicated that the P. angulata is phylogenitically distinct from other related species related to both Pyricularia and Magnaporthe. Detailed symptoms of blast lesions on young leaves, transition leaves, mid rib, petioles, peduncle, maturing bunches, bunch stalks and cushions were documented. Notably, the distinct small pitting spots on maturing bunches reduced the visual appeal of mature fruits. Appearance of pitting symptoms on fruits in relation with age of fruits and their distribution pattern on bunch and fingers was also documented in detail. Further, the roles of transitory leaves, weed hosts, seasonality on disease occurrence have also been documented.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.485-491
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• 2008

This study was performed in 14 unthinned Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantations in northeast China. Data were collected on 70 sample trees of different canopy position with diameter at breast height (DBH) ranging from 6.9 cm to 34.5 cm. Diameter and length of knots per whorl below the living crown were studied by different vertical levels divided by relative knot height (RHK) in this paper. Models taking DBH and height to the crown base (HCB) as independent variables were developed to predict knot diameter (KD) in a sample whorl. According to the vertical distribution tendency and range of sound knot length (KLsound), KLsound was modeled as multiple linear function of DBH, KD and relative knot height (RHK). The loose knot length (KLloose) was described as a function of DBH, KD and height above the ground for knots (HK) in a mixed log-linear model. Results from this study can provide abundant knot information so as to describe the knot size and vertical distribution tendency of Mongolian pine plantation.

• Journal of Environmental Science International
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• v.15 no.12
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• pp.1087-1091
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• 2006

This paper describes the current spatial patterns of the net primary productivity (NPP) of the terrestrial vegetation and carbon emission (C) in the world due to the burning of fossil fuels in order to clarify the amount of expansion of human activity. The C/NPP value varies spatially from almost zero to several tens of thousand times the local NPP. C/NPP is higher under the condition of extensive human activities due to a high human population density or when the local NPP is extremely low in severe climatic zones. In contrast, the low C/NPP areas are distributed mainly in sparsely populated districts, loading to a low impact of human activity. Although the area where C/NPP is less than 10% accounts for about 70% of the entire land area, one-third of these areas cannot contribute to carbon absorption because of low NPP with a shortage of climatic resources. Since more than half of the areas of the remaining areas are agricultural land and forest ecosystems with high NPP, the possible afforestation area was evaluated to be maximum of $30{\times}10^{6}\;km^{2}$; here only sequestrate carbons that correspond to 2% of the global total NPP are present. These analyses revealed that presently most of the areas where the NPP is high are those exclusively used by humans and that it is difficult for large-scale forest plantations to absorb a substantial amount of the carbon emitted annually by humans.