• Title/Summary/Keyword: Postfire

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Effects of Postfire Logging on Bird Populations and Communities in Burned Forests (산불 발생 지역의 피해목 벌채에 따른 조류 개체군과 군집의 변화)

  • Choi, Chang-Yong;Lee, Eun-Jae;Nam, Hyun-Young;Lee, Woo-Shin
    • Journal of Korean Society of Forest Science
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    • v.96 no.1
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    • pp.115-123
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    • 2007
  • We investigated the effects of postfire logging on bird populations and communities through 57 point counts in unburned, burned and logged burned plots of coniferous forests in Samcheok, Korea. We found that lower species richness, abundance, and diversity in logged plots where were controlled by a typical postfire management. As results of guild analysis for nest sites and food resources, postfire logging reduced densities of ground-shrub nesters, primary and secondary cavity nesters, but was also related to reduction in densities of some foraging groups such as timber drillers and foliage searchers. These results suggest that snag-retention is essential for birds in burned forests and that postfire logging is incompatible with the maintenance of bird populations and communities. Consequently we need to develope guidelines of postfire management for snag-retention in burned forests through intensive researches focused on some target species such as Great spotted woodpeckers Dendrocopos major.

Postfire reliability analysis of axial load bearing capacity of CFRP retrofitted concrete columns

  • Cai, Bin;Hao, Liyan;Fu, Feng
    • Advances in concrete construction
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    • v.10 no.4
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    • pp.289-299
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    • 2020
  • A reliability analysis of the axial compressive load bearing capacity of postfire reinforced concrete (RC) columns strengthened with carbon fiber reinforced polymer (CFRP) sheets was presented. A 3D finite element (FE) model was built for heat transfer analysis using software ABAQUS. Based on the temperature distribution obtained from the FE analysis, the residual axial compressive load bearing capacity of RC columns was worked out using the section method. Formulas for calculating the residual axial compressive load bearing capacity of the columns after fire exposure and the axial compressive load bearing capacity of postfire columns retrofitted with CFRP sheets were developed. Then the Monte Carlo method was used to analyze the reliability of the axial compressive load bearing capacity of the RC columns retrofitted with CFRP sheets using a code developed in MATLAB. The effects of fire exposure time, load ratio, number of CFRP layers, concrete cover thickness, and longitudinal reinforcement ratio on the reliability of the axial compressive load bearing capacity of the columns after fire were investigated. The results show that within 60 minutes of fire exposure time, the reliability index of the RC columns after retrofitting with two layers of CFRPs can meet the requirements of Chinese code GB 50068 (GB 2001) for safety level II. This method is effective and accurate for the reliability analysis of the axial load bearing capacity of postfire reinforced concrete columns retrofitted with CFRP.

Species Composition and Nutrient Absorption by Plants in the Immediate Postfire Year (산화 당년에 재생되는 식물군집의 종 구성과 식물의 영양염류 흡수량)

  • 문형태;정연숙
    • The Korean Journal of Ecology
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    • v.20 no.1
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    • pp.27-33
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    • 1997
  • Species composition and the amount of nutrients absorbed by regenerating plants on a pine forest in the immediate postfire year were compared with those in an unburned pine forest in Kosung, Kangwon Province. Pteridium aquilinum var. latiusculum, Cyperus amuricus, Lespedeza biolor, Quercus serrata, Lysimachia clethroides were the most abundant species in burned area. In unburned area. Quercus mongolica, Rhododendron mucronulatum, Carex humilis, Rhododendron schlippenbachii, Spodiopogon sibiricus were the most abundant species. Standing biomass of understory vegetation in burned and unburned area was 170.2 g $D.W/m^2$ and 171.3g $D.W/m^2$, respectively. Nutrient concentrations of plants in burned area, especially for phosphorus and potassium, were higher than those in unburned area. The amounts of nutrients absorbed by understory plants in burned and unburned area were 37.4 and 33.6 kg/ha for N, 0.36 and 0.19 kg/ha for P, 30.6 and 18.8 kg/ha for K, 8.5 and 7.8 kg/ha Ca, 5.2 and 5.7 kg/ha for Mg, respectively. This suggests that regenerating vegetation can hold the significant amount of nutrients, although there may be considerable losses of nutrients from ecosystem after fire.

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Effects of Hillslope Treatments for Vegetation Development and Soil Conservation in Burned Forests (산불 피해 산림의 식생 발달과 토양 보존을 위한 사면 처리 효과)

  • Kim, Chang-Gi;Choung, Yeon-Sook;Joo, Kwang-Yeong;Lee, Kyu-Song
    • Journal of Ecology and Environment
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    • v.29 no.3
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    • pp.295-303
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    • 2006
  • Clear-cut followed by tree planting has been a conventional management practice in burned forests in Korea. Because this can considerably increase soil loss, hillslope treatments may be needed in order to improve soil stability at poorly regenerating areas. This paper reviews the effects of hillslope treatments, such as seeding, mulching and log erosion barriers, which have been applied to restore vegetation and conserve soil in burned forests in North America and Europe. Seeding has been the most common method for postfire restoration. However, the effects of seeding on vegetation cover and soil erosion are not clear and seeding with non-native species has been reported to inhibit regeneration of native vegetation. Mulching has been found to be effective at reducing soil erosion. However, this also can introduce non-native plant species and inhibit native plant regeration. Although studies on the effect of log erosion barriers are very few, it appears that log erosion barriers are effective in the period of little rainfall. Hillslope treatments for postfire restoration is not necessary for naturally regenerating areas and therefore, they should be restricted to the areas where regeneration potential is low and runoff and soil loss is considerable. Long-term monitoring is needed to assess the effectiveness of hillslope treatments on soil erosion, the introduction of non-native plant species and the inhibition of natural plant regeneration.

Effects of Fire on Species Composition of Understory Vegetation and Seed Germination of Melica onoei in Black Pine Forest (산불이 곰솔림 산화지의 하층식생 구성과 쌀새(Melica onoei Fr.)의 종자발아에 미치는 영향)

  • Mun, Hyeong-Tae
    • The Korean Journal of Ecology
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    • v.24 no.3
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    • pp.131-136
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    • 2001
  • Comparisons of understory vegetation between the burned and the unburned area, and effects of fire on seed germination of Melica onoei, which increased importance value in burned area, were investigated in the black pine forest. The number of plant species in burned and unburned area was 38 and 20, respectively. Melica onoei, indigofera kirilowii, Lespedeza bicolor Miscanthus sinensis were the most abundant species in burned area. A number of seedlings and sprouts of these species were found in burned area. Standing biomass of understory vegetation in burned and unburned area was 88.7g/㎡ and 299.8g/㎡, respectively, in the immediate postfire year. However, standing biomass in burned area increased to 537.2g/㎡ and relative standing biomass of Melica onoei was the highest with a value of 25.7% in the second year Seed germination of Melica onoei in control(C), dark (D), leaf (L), leaf extract (E) treatment was 92.5%, 86.0%, 45.5% and 39.0%, respectively. However, seed germination in L+E and D+L+E treatment was 10.5% and 4.0%, respectively. It is assumed that higher importance value of M. onoei in the postfire vegetation in this study area might be due to the removal of allelopathic inhibitors and the improvement of light condition after fire.

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Fire-Induced Forest Disturbance Mapping by Using QuickBird Imagery (QuickBird 화상을 이용한 산불 삼림교란도 작성)

  • Kim, Choen
    • Korean Journal of Remote Sensing
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    • v.25 no.1
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    • pp.85-94
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    • 2009
  • This paper presents the capability to use QuickBird imagery for effects of forest disturbance in Okgye burned area. Particular attention of this paper deals with the NBR-derived mapping burn severity on QuickBird imagery to locate reliable rehabilitation(namely, secondary succession) over postfire surface. Comparisons of the mapping forest disturbance derived from QuickBird NBR data and the mapping burn severity derived from Landsat ${\Delta}NBR$ data show substantial agreement (KHAT value =0.7886). The method calculated from the correlation between QuickBird wetness and Landsat ETM+ band7 may have application to forest harvest disturbance.

Change of Soil Microbial Populations after Forest Fire (산불 발생 후 토양 미생물의 밀도 변화)

  • 박동진;육연수;김종진;이상화;김창진
    • Korean Journal of Microbiology
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    • v.35 no.1
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    • pp.78-81
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    • 1999
  • The change of soil microbial populations was studied at the burnt areas of Mt. Jirisan in Hddong-Gun, Kyungsangnam-Do, where the fire had occurred on Oct. 21 in 1997. On the first day of the fireextinguished, the microbial density (CFUIg dry soil) was investigated at the surface, 5 cm, 10 cm, 20cm, and 30 cm depth of soils. Bacteria at the surface and 5cm depth of burnt sites were estimatedwith the low density level of $10^2$ CFW/g soil comparing to the $10^6$ CFUIg soil of the neighboring unburntsites. Actinomycetes of burnt sites were completely disappeared at the surface, and were estimatedwith the low density level of $10^3$ CFUig soil at thc 5 cm depth comparing to the 10"CFUigsoil at the depth of unburnt sites. Fungi wcrc not isolated at the surface and 5 cm depth at all.However, the rarest lire was not found to decrease the microbial populalions at the lower depths than10 cm. In addilion, the recovery or soil microbial populations following the fire was bimonthly investigatedat the surrace and 5 cm depth. Most of microbial densities at the burnt sites were greatlyincreased two months after the fire, being enough to he compared with the neighboring unburnt sites.However, actinomycetes only at the surface of burnt sites still were estimated the low density level of$10^4$ CFUig soil 4 months after the fire comparing to the $10^6$CFIg soil of unburnt sites.TEX>CFIg soil of unburnt sites.

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