• Journal of the Korean Wood Science and Technology
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• v.43 no.5
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• pp.548-557
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• 2015

This study investigated environmental assessments of leachate containing formaldehyde from medium density fiberboard (MDF) disposed in laboratory-scale simulated landfills. Environmental impact assessment of leachate was conducted by measuring formaldehyde, toxicity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), bacterial enumeration, and pH. Amount of formaldehyde in leachate from MDF in soil decreased to the level of soil only treatment by 28 days, and toxicity decreased as the amount of formaldehyde decreased. BOD and COD levels in leachate from the treatments containing MDF exceeded permissible discharge levels of BOD or COD throughout the experimental period. The pH levels of all treatment were within permissible discharge range except on day 0. Fewer bacteria were observed in leachate from MDF in soil treatment than other treatments (MDF only, cured UF resin in soil, and soil only). Consequently, the leachate from disposal of MDF in soil detrimentally affect on environment. However, soil buffered formaldehyde leaching and pH on leachate in this study. Waste MDF may be required the pre-water soaking treatment for leaching formaldehyde to reclaim on land.

• Environmental Engineering Research
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• v.15 no.3
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• pp.157-161
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• 2010

Forest soils are often nitrogen-limited, and nitrogen input to forest soils can cause substantial changes in the structure and functions of a soil ecosystem. To determine the effects of nitrogen input on methane oxidation and the microbial enzyme activities, manipulation experiments were conducted using nitrogen addition to soil samples from Mt. Jumbong. Our findings suggested that the addition of nitrogen to the soil system of Mt. Jumbong did not affect the microbial enzyme activities. Conversely, the addition of nitrogen affected the rate of methane oxidation. Inorganic nitrogen in soils can inhibit methane oxidation via several mechanisms, such as substrate competition, toxic effects, and competition with other microbes, but the inhibitory effects are not always the same. In this research, seasonal changes were found to produce different inhibitory factors, and these different responses may be caused from differences in the methantrophic bacteria community structure.

• The Korean Journal of Ecology
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• v.15 no.4
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• pp.365-375
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• 1992

The environmental gradient analyses were applied for the distribution patterns of species populations in mt. moak provincial park in korea. The species populations were sequentially ordered along the environmental gradients such as soil moisture, soil ph, soil organic matter content and elevation and were grouped into seven ecological groups by the two-dimensional analyses of temperature-moisture gradient : zelkova serrata group on mesic-lower parts near the streames and well drained stony slopes, carpinus tschonoskii group on mesic-middle parts, quercus acutissima group on lower parts destroyed by human activities, quercus variabilis group on xeric-middle parts, quercus serrata group on xeric-upper middle parts, quercus mongolica group on xeric-upper parts and pinus densiflora group on xeric-rock ridge lines, hillocks and lower parts interfered by human. Four forest vegetation types, zelkova forest dominated by the c. tschonoskii group on mesic-middle parts, oak forest dominated by the groups of q. acutissima, q. variabilis, q. serrata and q. mongolica on xeric sites and pine forest dominated by the p. densiflora group on dry and poor sites, were separated in mosaic chart by the two-dimensional analysis.

• Korean Journal of Microbiology
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• v.13 no.1
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• pp.1-23
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• 1975

This experiment was designed to elucidate the environmental factors in rhizosphers of bamboo forest that affect the distribution and the population size of Azotobacter, and also to estimate the annual productivities of nitrogen fixed by Azotobacter species. The results of this experiment can be summarized as follows ; The rhizosphere of bamboo forest contained high free sugars as of 3-8 times more than non-rhizosphere (Bacon, 1968), and the contents of organic matter and amino acids of that are reltively higher than this. Because of high content of potassium, average of soil pH is near at 7.0. As above-mentioned enviromental factors, the population sizes of Actinomycetes, general fungi, general bacteria and Azotobacters are larger than those of non-rhizosphere and the ofllowings are general fungi and general bacteria by turns. Azotobacter is dependent upon the antagonistic Actinomycetes. The main carbon source for Azotobacter in nitrogn flxation at the rhizosphere was glucose and minors were fructose, maltose and sucrose by turns. Annual gains of nitrogen by Azotobacters in soil of bamboo forest within 10cm from surface are estimated as of 88.94 kg/ha at site A, 60.4kg/ha at site B and 67.38kg/ha at site C, respectively.

• Journal of Forest and Environmental Science
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• v.26 no.3
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• pp.193-202
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• 2010

To analyze the effects of tree roots on the stability of damage slope, distributional and physical properties of five-year Pinus densiflora roots were investigated. In the composition of roots, the proportion of main root to lateral root was 1 to 9 in slope condition. Root tensile force was increased in accordance with increased proportion to diameter of Pinus densiflora roots. However, tensile strength was decreased in proportion to diameter of roots. Root shear strength showed that soil containing Pinus densiflora roots was higher than that of non-treated soils. This result shows that Pinus densiflora roots significantly stabilize the surface-soil rather than sub-soil in damage slopes.

• Journal of Microbiology and Biotechnology
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• v.17 no.10
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• pp.1655-1660
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• 2007

A metagenome is a unique resource to search for novel microbial enzymes from the unculturable microorganisms in soil. A forest soil metagenomic library using a fosmid and soil microbial DNA from Gwangneung forest, Korea, was constructed in Escherichia coli and screened to select lipolytic genes. A total of seven unique lipolytic clones were selected by screening of the 31,000-member forest soil metagenome library based on tributyrin hydrolysis. The ORFs for lipolytic activity were subcloned in a high copy number plasmid by screening the secondary shortgun libraries from the seven clones. Since the lipolytic enzymes were well secreted in E. coli into the culture broth, the lipolytic activity of the subclones was confirmed by the hydrolysis of p-nitrophenyl butyrate using culture supernatant. Deduced amino acid sequence analysis of the identified ORFs for lipolytic activity revealed that 4 genes encode hormone-sensitive lipase (HSL) in lipase family IV. Phylogenetic analysis indicated that 4 proteins were clustered with HSL in the database and other metagenomic HSLs. The other 2 genes and 1 gene encode non-heme peroxidase-like enzymes of lipase family V and a GDSL family esterase/lipase in family II, respectively. The gene for the GDSL enzyme is the first description of the enzyme from metagenomic screening.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.367-383
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• 1995

The relationship between floristic composition and soil environmental factors was investigated in the forest vegetation of Mt. Mohu.The forest vegetation unit of the Mt. Mohu could be divided into three communities, Quercus mongolica community, Pinus densiflora community and Quercus variabilis community. There were two subcommunities in Quercus mongolica community, which were Rhododendron schlippcubachii subcommunity and Stephanandra incisa subcommunity. The Quercus mongolica community was distributed at the altitude of 600~900 m, Pinus densiflora and Quercus variabilis communities were distributed on south-west slope at the altitudes of 430~520 m and 400~500 m, respectively.The DBH class of dominant species in each community showed that Quercus mongolica had 9 individuals/a at 11~15 cm class, Quercus variabilis 5.6 individuals/a at 11~15 cm class, and Pinus densiflora 8 individuals/a at 16~20 cm class. Quercus mongolica. Quercus variabilis and Pinus densiflora communities showed a bell-shape distribution.The contents of organic matter and soil water, and cation exchange capacity of the soil increased and the pH decreased in proportion to increased altitude. The soil environmental conditions of Quercus mongolica community were more favorable than those of Pinus densiflora and Quercus variabilis communities.The supposed successional sere of the forest vegetation of Mt. Mohu was as follows: Pinus densiflora community.Quercus variabilis community.Quercus mongolica community

• Korean journal of applied entomology
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• v.28 no.4
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• pp.210-220
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• 1989

Studies on the distribution pattern of soil arthropods were carried in H.J. Andrews Expt. Forest. Forty-one species of Coleoptera in 14 families were recognized as the dominant group. Also, 7 species of soil mites in 6 families, Typhlodromus, Gymnodaeus, Phauloppia and Scleroribates were recognized without seasonal fluctuation, which made the difference to the outbreak pattern of the Palearctic region. Another species as 16 species of Collembola in 4, families, 16 species of Thysanoptera in 3 families, 10 species of Hymenoptera in 1 family, and 7 species of Acarina in 6 families were recognized. The result showed the importance of the soil arthropod as the primary decomposer in forest ecosystem and the relationship between species diversity and soil condition.

• The Korean Journal of Ecology
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• v.21 no.5_1
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• pp.465-473
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• 1998

This study was carried out to investigate the developmental process of plant community during the secondary succession and changes of soil properties in the burned areas lapsed 28 years after the forest fire in Mt.Palgong. The forest fire occurred on March, 1969 and the red pine (pinus densiflora) forest and its floor vegetation were burned down. The results are summarized as follows: the floristic composition of burned and unburned areas were composed of 49 and 48 species of vascular plants, respectively. The dominant species based on SDR4 of the burned sites were Lespedeza maximowicxii(87.75), Carex humilis (62.94), Rhododendron schippenbachii(55.78) and Miscanthus sinensis var.purpurascens (51.94). In contrast, Pinus densiflora (81.17), Quercus serrata (53.58)m Carex humilis (53.11) and Miscanthus sinenis var. purpuracens (52.42) were dominant in the unburned area. The biological spectra showed the $H-D_1-R_5-e$ type in both areas. The indices of similarity (CCs) between the two areas were 0.80. Degree of succession (DS) was 734 in the burned area and 809 in the unburned area. The species diversity (H) and evenness indices (e) in the burned and unburned areas were 2.05, 2.13 and 0.53, 0.55, respectively. Dominance index (C) in the burned and unburned areas were 0.30 and 0.32, respectively. Soil properties such as soil pH, content of organic matter, total nitrogen, total carbon, exchangeable potassium, sodium, calcium, and magnesium in burned area were comparatively higher than those of unburned area. Monthly changes of soil properties were of little significance except for some cases. These results suggest that there was relationship between trend of vegetation recovery and the changes of soil properties after the forest fire. Mixed forestation of fire-resistant species and nitrogen fixation species will be effective for reforestation after the forest fire.

• Journal of Korean Society of Forest Science
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• v.87 no.4
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• pp.584-589
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• 1998

The study was carried out to investigate heavy metals of rainfall and soil at industrial, urban and rural area, and to estimate the relationship between rainfall and soil. Heavy metals of stemflow, throughfall and rainfall in Pinus thunbergii and Quercus spp were ordered Zn>Cu>Pb>Cd in industrial area, and Zn>Pb>Cu>Cd in urban area. All heavy metals were detected high in industrial areas, and especially those of industrial area were high in stemflow. Heavy metals in soil by distance from stem were highest in 20cm distance from stem. Soil heavy metals in survey sites were the same order as those of rainfall. The correlation of heavy metals between rainfall and soil were positive, the regression obtained was as follows ; Zn was Y=7.79+4.78X($r=0.8685^{**}$), Pb was Y=7.90+4.53X($r=0.7242^*$) and Cu was Y=3.89+3.91X($r=0.8658^{**}$).