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Forest structure and carbon dynamics of an intact lowland mixed dipterocarp forest in Brunei Darussalam

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Journal of Forestry Research 2018年第1期29卷 199-203页

作者： Sohye lee Jongyeol lee Seongjun Kim Yujin Roh Kamariah Abu Salim woo-kyun lee Yowhan Son Department of Environmental Science and Ecological Engineering Graduate School Korea University Environmental and Life Sciences Faculty of ScienceUniversiti Brunei Darussalam Department of Biological of Environmental Sciences Qatar University

Tropical forests play a critical role in mitigating climate change because they account for large amount o terrestrial carbon storage and ***,there are many uncertainties associated with the estimation o carbon *** estimated forest structure and carbon dynamics along a slope（17.3°–42.8°）and to assess the relations between forest structures,carbon dynamics,and slopes in an intact lowland mixed dipterocarp forest,in Kuala Belalong,Brunei *** biomass,basa area,stand density,crown properties,and tree family composition were measured for forest *** rate,litter production,and litter decomposition rates were also measured for carbon *** crown form index and the crown position index were used to assess crown properties,which we categorized into five stages,from very poor to *** living biomass,basal area and stand density were 261.5–940.7 Mg ha-1,43.6–63.6 m2ha-1and 6,675–8400 tree ha-1,*** average crown form and position index were 4,which means that the crown are mostly symmetrical and sufficiently exposed for *** mean biomass growth rate,litter production,litter decomposition rate were estimated as11.9,11.6 Mg ha-1a-1,and 7.2 g a-1,*** growth rate was significantly correlated with living biomass,basal area,and crown *** form appeared to strongly influence living biomass,basal area and biomass growth rate in terms of light ***,basal area,stand density,crown properties,and biomass growth rate did not vary by slope or tree family *** results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown *** of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.

关键词： Carbon dynamics Growth rate Litter flux Lowland mixed dipterocarp forest Slope

Selecting and applying quantification models for ecosystem services to forest ecosystems in South Korea

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Journal of Forestry Research 2016年第6期27卷 1373-1384页

作者： Hyun-Ah Choi woo-kyun lee Cholho Song Nicklas Forsell Seongwoo Jeon Joon Soon Kim So Ra Kim Department of Environmental Science and Ecological Engineering Korea University Seoul 02841 Republic of Korea Ecosystems Services and Management Program International Institute for Applied Systems AnalysisSchlossplatz 1 2361 Laxenburg Austria Department of Forest Management Kangwon National University Chuncheon 24341 Republic of Korea Korea Forest Conservation Association 186 Dongjak-daeroSeocho-gu Seoul 06559 Republic of Korea

There is growing interest in using ecosystem services to aid development of management strategies that target sustainability and enhance ecosystem support to humans. Challenges remain in the search for methods and indicators that can quantify ecosystem services using metrics that are meaningful in light of their high priorities. We developed a framework to link ecosystems to human wellbeing based on a stepwise approach. We evaluated prospective models in terms of their capacity to quantify national ecosystem services of forests. The most applicable models were subsequently used to quantify ecosystem services. The Korea Forest Research Institute model sat- isfied all criteria in its first practical use. A total of 12 key ecosystem services were identified. For our case study, we quantified four ecosystem functions, viz. water storage capacity in forest soil for water storage service, reduced suspended sediment for water purification service, reduced soil erosion for landslide prevention service, and reduced sediment yield for sediment regulation service. Water storage capacity in forest soil was estimated at 2142 t/ha, and reduced suspended sediment was estimated at 608 kg/ ha. Reduced soil erosion was estimated at 77 m^3/ha, and reduced sediment yield was estimated at 285 m^3/ha. These results were similar to those reported by previous studies. Mapped results revealed hotspots of ecosystem services around protected areas that were particularly rich in bio- diversity. In addition, the proposed framework illustrated that quantification of ecosystem services could be sup- ported by the spatial flow of ecosystem services. However, our approach did not address challenges faced when quantifying connections between ecosystem indicators and actual benefits of services described.

关键词： Classification Ecosystem services Quantification Stepwise approach

Assessing vulnerability of forests to climate change in South Korea

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Journal of Forestry Research 2016年第3期27卷 489-503页

作者： Guishan Cui Hanbin Kwak Sungho Choi Moonil Kim Chul-Hee Lim woo-kyun lee Joon-Soon Kim Yeora Chae Department of Geography Yanbian University Department of Environmental Science and Ecological Engineering Korea University Department of Earth and Environment Boston University College of Forest and Environmental Science Kangwon National University Division of Adaptation Research Korea Environment Institute

This study demonstrated a framework to assess vulnerability of forests to climate change. We focused on how alterations of temperature and precipitation might affect forest type distributions and carbon-related functions. In particular, our framework considered three sectors of forest type distribution, net primary production, and soil carbon storage. Future projections were derived from mechanistic models for South Korean forests under the A1 B scenarios of the intergovernmental panel on climate change. Forest type distributions were simulated by the Hydrological and thermal analogy group model, while the MAPSS and CENTURY1 models estimated forest carbon flux/storage. We quantified normalized vulnerability indices for each sector. Our results indicate that the overall vulnerability of forest type distribution is greater in the west central regions and southeastern inlands. The vulnerabilities of carbon flux/storage show that net primary production of South Korean forests is relatively less susceptible to climate change, but a highly vulnerable area of soil carbon storage mainly spreads from the west central to the south east region. The spatio-temporal vulnerability map with a synoptic overview from this study might be useful for policy makers in preparing adaptive measures and identifying management priorities.

关键词： Vulnerability Forest Climate change Forest assessment

Carbon and nitrogen dynamics in a Pinus densiflora forest with low and high stand densities

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Journal of Plant Ecology 2013年第5期6卷 368-379页

作者： Nam Jin Noh Choonsig Kim Sang Won Bae woo kyun lee Tae kyung Yoon Hiroyuki Muraoka Yowhan Son Division of Environmental Science and Ecological Engineering Korea UniversitySeoul 136-713Republic of Korea River Basin Research Center Gifu UniversityGifu 501-1193Japan Department of Forest Resources Gyeongnam National University of Science and TechnologyJinju 660-758Republic of Korea Department of Forest Conservation Korea Forest Research InstituteSeoul 130-712Republic of Korea

Aims Understanding carbon(C)and nitrogen(N)dynamics and their dependence on the stand density of an even-aged,mature forest provides knowledge that is important for forest *** study investigated the differences in ecosystem total C and N storage and flux between a low-density stand(LD)and a high-density stand(HD)and examined the effects of stand density on aboveground net primary productivity(ANPP),total belowground C allocation(TBCA)and net ecosystem production(NEP)in a naturally regenerated,65-to 75-year-old Pinus densiflora *** *** LD(450 trees ha^(−1))and HD(842 trees ha^(−1))were established in an even-aged,mature *** forest in September *** forest had been naturally regenerated following harvesting,and the stand density was naturally maintained without any artificial management such as *** diameter at breast height(DBH≥5.0cm)of all live stems within the stands was measured yearly from 2007 to *** compare C and N storage and fluxes in LD and HD,C and N pools in aboveground and belowground biomass,the forest floor,coarse woody debris(CWD)and soil;soil CO_(2) efflux(R_(S));autotrophic respiration(R_(A));litter production;and soil N availability were ***,ANPP,TBCA and NEP were estimated from plot-based measurement *** Findings Ecosystem C(Mg C ha^(−1))and N(Mg N ha^(−1))storage was,respectively,173.0±7.3(mean±SE)and 4.69±0.30 for LD and 162±11.8 and 4.08±0.18 for *** were no significant differences in C and N storage in the ecosystem components,except for soils,between the two *** contrast,there were significant differences in aboveground ANPP and TBCA between the two stands(P<0.05).Litterfall,biomass increment and R_(S) were major C flux components with values of,respectively,3.89,3.74 and 9.07 Mg C ha^(−1) year^(−1) in LD and 3.15,2.94 and 7.06 Mg C ha^(−1) year^(−1) in ***-based NEP(Mg C ha^(−1) year^(−1))was 4.18 in LD and 5.50 in *** the even-aged,mature P

关键词： aboveground net primary productivity net ecosystem production Japanese red pine stand density total belowground carbon allocation

Radial growth response of Pinus densiflora and Quercus *** topographic and climatic factors in South Korea

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Journal of Plant Ecology 2013年第5期6卷 380-392页

作者： Jae Gyun Byun woo kyun lee Moonil Kim Doo Ahn Kwak Hanbin Kwak Taejin Park woo Hyuk Byun Yowhan Son Jung Kee Choi Young Jin lee Joachim Saborowski Dong Jun Chung Jin Hyun Jung Institute for Environmental Research(Biology V) RWTH Aachen UniversityWorringerweg 152074 AachenGermany Division of Environmental Science and Ecological Engineering Korea UniversitySeoul136-701Korea GIS/RS Center for Environmental Resources Korea UniversitySeoul 136-173Korea Department of Forest Management Kangwon National UniversityChunchon 200-701Korea Department of Forest Resources Kongju National UniversityKongju 341-701Korea Institute of Forest Biometry and Informatics Georg-August-University Gottingen37077 GottingenGermany National Forestry Cooperative Federation Daejeon 306-808Korea

Aims This study aimed to develop radial growth models and to predict the potential spatial distribution of Pinus densiflora(Japanese red pine)and Quercus spp.(Oaks)in South Korea,considering topographic and climatic *** We used a dataset of diameter at breast height and radial growth estimates of individual trees,topographic and climatic factors in systematic sample plots distributed over the whole of South *** the basis that radial growth is attributed primarily to tree age,we developed a radial growth model employing tree age as an explanatory *** estimated standard growth(SG),defined as radial growth of the tree at age 30,to eliminate the influence of tree age on radial *** addition,SG estimates including the Topographic Wetness Index,temperature and precipitation were calculated by the Generalized Additive *** Findings As a result of variogram analysis of SG,we found spatial autocorrelation between SG,topographic and climatic *** temperature had negative impacts on radial growth of *** and positive impacts on that of Quercus *** was associated with positive effects on both tree *** on the model,we found that radial growth of *** would be more vulnerable than that of Quercus *** climatic *** simulation with the radial growth model,it was predicted that *** stands would be gradually replaced with Quercus *** in eastern coastal and southern regions of South Korea in the *** models developed in this study will be helpful for understanding the impact of climatic factors on tree growth and for predicting changes in distribution of *** and Quercus *** to climate change in South Korea.

关键词： standard radial growth general additive model climatic factors climate change forest-cover change

Estimation of Non-CO_2 GHGs Emissions by Analyzing Burn Severity in the Samcheok Fire,South Korea

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Journal of Mountain Science 2012年第6期9卷 731-741页

作者： WON Myoung Soo KOO Kyo Sang lee Myung Bo lee woo kyun KANG Kyu-Young Division of Forest Disaster Management Korea Forest Research Institute130712 SeoulRepublic of Korea Faculty of Environmental Science and Ecological Engineering Korea University-Seoul136701 SeoulRepublic of Korea Department of Biological and Environmental Science Dongguk University-Seoul100715 SeoulRepublic of Korea

This study was performed to estimate the emission of non-CO 2 greenhouse gases(GHGs) from biomass burning at a large fire *** extended methodology adopted the IPCC Guidelines(2003) equation for use on data from the Samcheok forest fire gathered using 30 m resolution Landsat TM satellite imagery,digital forest type maps,and growing stock information per hectare by forest type in *** burn ratio(NBR) technique was employed to analyze the area and severity of the Samcheok forest fire that occurred in *** differences between NBR from pre-and post-fire datasets are examined to determine the extent and degree of change detected from *** results of burn severity analysis by dNBR of the Samcheok forest fire area revealed that a total of 16,200 ha of forest were *** proportion of the area characterized by a 'Low' burn severity(dNBR below 152) was 35%,with 'Moderate'(dNBR 153-190) and 'High'(dNBR 191-255) areas were at 33% and 32%,*** combustion efficiency for burn severity was calculated as 0.43 for crown fire where burn severity was 'High',as 0.40 for 'Moderate' severity,and 0.15 for 'Low' severity surface *** emission factors for estimating non-CO 2 GHGs were separately applied to CO 130,CH 4 9,NO x 0.7 and N 2 O ***-CO 2 GHGs emissions from biomass burning in the Samcheok forest fire area were estimated to be CO 44.100,CH 4 3.053,NO x 0.238 and N 2 O 0.038 Gg.

关键词： Biomass burning Non-CO 2 GHGs Normalized burn ratio Combustion efficiency Emission factor Landsat TM

Stabilized sub-grain and nano carbides-driven 1.2 GPa grade ultra-strong CrMnFeCoNi high-entropy alloy additively manufactured by laser powder bed fusion

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Journal of Materials Science & Technology 2022年第22期117卷 8-22页

作者： Young-kyun Kim Kee-Ahn lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea Korea Institute of Materials Science(KIMS) Changwon 51508Republic of Korea

High-entropy alloys(HEAs)with interstitial atoms that are produced by additive manufacturing have gained intensive interest in the materials science community because of their suitability for constructing high-strength net-shape ***,a strategy to additionally enhance the strength of selective laser melted carbon-containing HEAs was *** as-built carbon-containing HEAs(C_(x)(Cr_(20)Mn_(20)Fe_(20)Co_(20)Ni_(20))_(100-x)(x=0.5 at.%,1.0 at.%,and 1.5 at.%))contain supersaturated carbon,and the extent of supersaturation increases as the carbon content *** subjected to aging treatment at 650°C for 1 h,the microstructure of the three alloys did not change at the grain ***,the microstructure at the sub-grain scale changed markedly,and these changes influenced the tensile properties and deformation *** particular,the tensile strength of aged 1.5C-HEA at 650°C was∼1.2 GPa at room temperature,which is higher than those reported for CrMnFeCoNi ***,the main deformation mechanism changed from deformation twinning to dislocation-mediated slip,resulting in much higher strain hardening capacity after the aging *** work led to the development of an alternative promising method that involves tailoring the microstructure,to enhance the mechanical properties of additively manufactured metallic materials that contain interstitial atoms.

关键词： Selective laser melting High-entropy alloy Carbon contents Aging Microstructure evolution Tensile property Deformation mechanism

Effect of carrier gas species on the microstructure and compressive deformation behaviors of ultra-strong pure copper manufactured by cold spray additive manufacturing

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Journal of Materials Science & Technology 2022年第2期97卷 264-271页

作者： Young-kyun Kim Kee-Ahn lee Department of Materials Science and Engineering Inha UniversityIncheon 22212Republic of Korea

Cold spray(CS)which has recently become a promising additive manufacturing(AM)technology,was used to fabricate ultra-strong pure *** addition,the effects of carrier gas species on the microstructural characteristics,mechanical properties and deformation mechanisms were systemically *** CSAM copper manufactured with N_(2) carrier gas reveals a heterogeneous bimodal microstructure consisting of ultra-fine grains at the particle interface and relatively coarse grains in inner *** He carrier gas,a homogeneous grain structure consisting of ultra-fine grains in most areas was *** tests showed that N_(2) and He carrier gasses enabled ultra-high yield strengths of 340 and415 MPa,*** values are comparable to severely plastic deformed copper,which has extremely low ductility and shape *** the other hand,both samples showed a strain-softening phenomenon that does not commonly occur at room *** deformation microstructures revealed that dynamic recovery(DRV)and dynamic recrystallization(DRX)phenomena were generated despite being deformed at room *** on the above findings,the overall deformation mechanisms according to the carrier gas species in the CSAM copper manufacturing process were ***,the work hardening and softening behaviors of CSAM Cu are predicted by using a constitutive equation.

关键词： Cold spray additive manufacturing Carrier gas Pure Cu Mechanical properties Deformation behavior

Changes in the distribution of South Korean forest vegetation simulated using thermal gradient indices

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Science China(Life Sciences) 2010年第7期53卷 784-797页

作者： CHOI Sungho lee woo-kyun SON Yowhan YOO Seongjin LIM Jong-Hwan Department of Environmental Science and Ecological Engineering Korea University Korea Forest Research Institute

To predict changes in South Korean vegetation distribution,the Warmth Index(WI) and the Minimum Temperature of the Coldest Month Index(MTCI) were *** climate data of the past 30 years,from 1971 to 2000,was obtained from the Korea Meteorological *** Fifth-Generation National Center for Atmospheric Research(NCAR) /Penn State Mesoscale Model(MM5) was used as a source for future climatic data under the A1B scenario from the Special Report on Emission Scenario(SRES) of the Intergovernmental Panel on Climate Change(IPCC).To simulate future vegetation distribution due to climate change,the optimal habitat ranges of Korean tree species were delimited by the thermal gradient indices,such as WI and *** categorize the Thermal Analogy Groups(TAGs) for the tree species,the WI and MTCI were orthogonally plotted on a two-dimensional grid *** TAGs were then designated by the analogue composition of tree species belonging to the optimal WI and MTCI *** a result of the clustering process,22 TAGs were generated to explain the forest vegetation distribution in *** primary change in distribution for these TAGs will likely be in the shrinkage of areas for the TAGs related to Pinus densiflora and ***,and in the expansion of the other TAG areas,mainly occupied by evergreen broad-leaved trees,such as Camellia japonica,Cyclobalanopsis glauca,and Schima *** the TAGs to explain the effects of climate change on vegetation distribution on a more regional scale resulted in greater detail than previously used global or continental scale vegetation models.

关键词： climate change forest distribution warmth index minimum temperature thermal analogy group