• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.149-152
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• 2008

This study is the result between the variation of fuel moisture and the risk of forest fire through measuring the change of moisture containing ratio on-site and its average analysis for fallen leaves layer, humus layer, and soil layer in the forest. The measurement was performed on six days from the day after a rainfall. The fuel moisture on-site was measured on the day when the accumulated rainfall was above 5.0mm, and the measurements was 2 times in spring and 1 time in fall. From the pine forest which were distributed around Samcheok and Donghae in Kangwondo, three regions were selected by loose, medium, and dense forest density, and the fuel moisture was measured on fallen leaves layer, humus layer, and soil layer in the forest. for six days from the day after a rainfall. The study showed that the moisture containing ratio converged on 3 - 4 days in spring and fall for fallen leaves layer, and the convergence was made more than six days in spring and fall for the humus layer. In the other case of soil layer, the variation of moisture containing ratio after rainfall was not distinguishable regardless of season.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.289-296
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• 2020

BACKGROUND: There is a need for a revolutionary method to overcome the problem of biochar, which has relatively low adsorption capacity for existing anion pollutants, along with collectively recycling fallen leaves, a kind of forest by-product. Therefore, the objective of this study was to prepare iron-decorated biochar derived from fallen leaves (Fe-FLB), and to evaluate their adsorption properties to Congo red (CR) as anionic dye. METHODS AND RESULTS: The adsorption properties of CR by fallen leaves biochar (FLB) and Fe-FLB were performed under various conditions such as initial CR concentration, reaction time, pH and dosage with isotherm and kinetic models. In this study, Fe-FLB prepared through iron impregnation and pyrolysis of fallen leaves contained 56.9% carbon and 6.3% iron. Congo red adsorption by FLB and Fe-FLB was well described by Langmuir model and pseudo second order model and the maximum adsorption capacities of FLB and Fe-FLB were 1.1 mg/g and 25.6 mg/g, respectively. In particular, it was found that the adsorption of CR was occurred by chemical adsorption process by the outer boundary layer of Fe-FLB. CONCLUSION: Overall, the production of Fe-FLB using fallen leaves and using it as an anion adsorbent is considered to be a way to overcome the problem of biochar with relatively low anion adsorption in addition to the reduction effect of waste.

• Fire Science and Engineering
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• v.23 no.5
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• pp.24-31
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• 2009

Based on fallen leaves of major Korean conifer species 'Pinus densiflora' and major Korean broadleaved species 'Quercus variabilis', this study sought to identify combustion emission gas types and measure their concentration by means of FTIR (Fourier Transform Infrared) spectrometer. As a result, it was found that there were total 13 types of combustion gas detected from fallen leaves of Pinus densiflora and Quercus variabilis, such as carbon monoxide, carbon dioxide, acetic acid, butyl acetate, ethylene, methane, methanol, nitrogen dioxide, ammonia, hydrogen fluoride, sulfur dioxide and hydrogen bromide. Notably, nitrogen monoxide was additionally detected from fallen leaves of Quercus variabilis. It was found that the overall concentration of combustion gas emitted from the fallen leaves of Pinus densiflora was 4.5 times higher than that from fallen leaves of Quercus variabilis. Particularly, it was found that emission concentration of some combustion emission gas types like carbon monoxide, carbon dioxide and butyl acetate exceeded the upper limit of their time-weighted average (TWA, ppm), while the emission concentration of carbon monoxide and carbon dioxide exceeded their short-term exposure limit (STEL, ppm) for both species. Thus, it was found that carbon monoxide and carbon dioxide have higher hazard to health than other gas types, because these two gas types account for higher than 99% of overall gas emission due to combustion of surface fire starting from litter layer in forest.

• Fire Science and Engineering
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• v.26 no.1
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• pp.49-60
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• 2012

The change in fuel moisture in accordance with the number of days after rainfall is an important factor in predicting forest fire dangers and supporting forest fire rangers. Therefore, in order to clear up these forest fire occurrence conditions, forest fire danger levels for surface fuel 0.6 cm or lower, 0.6~3.0 cm, 3.0~6.0 cm, and 6.0 cm or above by fallen leaves layer, humus layer, soil layer, and diameter after rainfall of 5.0 mm and higher in accordance with tree density in 2008, 2009 Spring/Autumn Young Dong region have been analyzed. Research showed an approximate 17 % fuel moisture which is a dangerous forest fire occurrence level after 5 days from rainfall in medium-density areas and 3 days after rainfall in loose-density areas of Spring time in the fallen leaves layer. On the other hand, the humus layer showed a 40 % or higher fuel humidity even after 6 days from rainfall regardless of the season, while the upper and lower parts of the soil layer had a little change. In loose-density areas with 0.6 cm or less surface fuel per diameter in Spring time, the fuel humidity displayed a dangerous level in fire forest occurrence after 3 days, and 4days in medium-density areas, and for loose-density areas with 0.6~3.0 cm surface fuel per diameter in Autumn time it showed a dangerous level in forest fire occurrence after 3 days, and for medium-density areas, 5 days. In the case of 3.0~6.0 cm of fuel moisture per diameter in both Spring and Autumn times, even after 6 days, low and medium-density areas showed that they maintain fuel moisture and therefore the dangers of forest fires were very low, and in the case of 6.0 cm or higher, it showed 25 % or higher fuel moisture even after 6 days from rainfall regardless of the season.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.17-22
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• 1988

Inhibitory effect of L. leptolepis fallen leaf extracts on the germination of Pinus densiflora, ${\times}$ Pinus rigitaeda, Pinus rigida, Pinus thunbergii and Larix leptolepis was investigated. Germination of those seeds in culture room and in pot at field showed the highly significant inhibitory effects by the aqueous extracts from L. leptolepis fallen leaves. Among them L. leptolepis was the most severely inhibited by the aqueous extracts used. To identify allelopathic substances, thin-layer chromatography was employed. Gallic, ferulic, t-cinnamic and vanillic acids were identified from fallen leaves of L. leptolepis. From the results, it is assumed that autotoxicity of L. leptolepis may act as inhibitory factors on germination of the species in natural stands.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.3
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• pp.83-95
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• 2022

This study aims to present primary data for habitat restoration and artificial breeding conditions of L. unmunsana by identifying the habitat conditions and the larvae's food sources. In order to investigate the habitat characteristics of the adult L. unmunsana and land snails, which are the primary food sources for the larvae, field surveys were conducted on a total of 10 habitats in south-central parts of Korea including Sanseongcheon, Jeonju. The results revealed that the L. unmunsana habitat in the Sanseongcheon area had a broadleaf forest with a multi-layered vegetation structure, adjacent water features, and the north/northeast/northwest slopes with little effect of artificial lighting. The adult L. unmunsana in the Sanseongcheon area appeared from the end of May to the end of June, and was especially intensively observed around the middle of June. The most active time was from 23:30 to 00:30 with a temperature range of 19~22℃ and higher than 80% humidity. The peak count of the observed adults L. unmunsana was a total of 774 on June 11, 2021. In the case of land snails, 11 families and 23 species were observed in 10 habitats of L. unmunsana, and Euphaedusa fusaniana was the most extensive and the most observed in the five survey areas. The land snails of L. unmunsana habitats are mostly found under the organic layers of leaves and a fallen tree branch in broadleaf forests, where a thick organic material layer buffers temperature changes and provides high humidity for various snails. These habitat conditions are suitable for the larva of L. unmunsana and land snails to inhabit, feed, hide and hibernate.

• Mycobiology
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• v.31 no.2
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• pp.105-112
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• 2003

Sclerotia of Grifola umbellata were cultivated by two methods such as burying and root inoculation methods. The sclerotia of G. umbellata produced by the burying method were $6.0{\sim}6.8{\times}3.4{\sim}4.6{\times}1.8{\sim}1.9cm$(Width$\times$Length$\times$Thickness) in size and $17.3{\sim}19.6g$ in weight, respectively. Their increase rate was $1.10{\times}1.12$ times. On the other hand, the sclerotia cultivated by the root inoculation method were $18.3{\sim}31.5{\times}12.5{\sim}26.4{\times}3.1{\sim}3.7cm(W{\times}L{\times}T)$ in size and $219.1{\sim}576.6g$ in weight, respectively. Their growth increment was $11.18{\sim}39.77$ times. The rhizomorphs of Armillaria mellea were developed with a high density under fallen leaves layer covering cultivation site, and distributed mainly between soil surface and soil depth of about 10 cm as well as colonized prominently on the inoculated wood logs. Fungal interaction between G. umbellata and A. mellea were observed mainly in the stage of white sclerotium of G. umbellata. The sclerotia of G. umbellata which were developed newly and harvested in the root inoculation method were twined with root hairs of host tree and rhizomorphs of A. mellea. The sclerotia of G. umbellata decomposing root hairs of host tree were confirmed through SEM examination. Physiochemical characteristics of soil in all cultivation sites had no significant differences. Soil pH were in the range of pH $3.98{\sim}4.40$. Organic matters were the range of $17.97{\sim}23.86%$ and moisture contents of soil were $12.00{\sim}18.20%$. Soil temperatures showed $12.9{\sim}13.8^{\circ}C$ in November and $22.0{\sim}23.9^{\circ}C$ in August, respectively. In conclusion, the root inoculation method seems to be a practical method for cultivating sclerotia of G. umbellata due to its many advantages such as simplicity of inoculation process, shortening of cultivation periods and facility of harvest.