• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.222-238
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• 2024

Coniferous species in subalpine ecosystems are known to be highly sensitive to climate change. Therefore, it is becoming increasingly important to monitor community and population dynamics. This study monitored 37 plots within the distribution area of Abies koreana on Mt. Jirisan for a period of eight years. We analyzed the importance value, density of living stems, mortality rate, recruitment rate, basal area, DBH (diameter of breast height) class distribution, and tree health status. Our results showed changes in the importance value based on the tree stratum, with A. koreana decreasing by 3.6% and Tripterygium regelii increasing by 2.5% in the tree layer. Between 2015 and 2023, there were 149 dead trees/ha (17.99% mortality rate) and 12 living trees/ha (1.02% recruitment rate) of A. koreana. The decrease in basal area was attributed to a decrease in the number of living trees. Tree mortality occurred in all DBH classes, with a particularly high decline in the <10 cm class (65 trees/ha reduced). In terms of changes in tree health status, the population of alive standing (AS) type trees, initially consisting of 539 trees/ha, has been transformed into alive standing (AS), alive lean (AL), and death standing (DS), accounting for 69.7%, 0.5%, and 13.8%, respectively. Meanwhile, DS-type trees have transitioned into dead broken (DB) and dead fallen (DF) types. This phenomenon is believed to be caused by strong winds in the subalpine region that pull up the rootlets from the soil. Further research on this finding is recommended.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1373-1381
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• 2013

Mt. Yeonae is at Gijang-gun in Busan and is surrounded by farming lands on three sides. The search for the species composition and dynamics of local communities were studied at Mt. Yeonae of how spatial similarity decays with geographic distance. The index values of Z$\ddot{u}$rich-Montpellier School's phytosociology at the 12 plots was compared to a distribution of similarly using 20 m quadrates at 12 sites. The specific communities were five including Pinus densiflora - Quercus variabilis community. Six species were significant similarity between neighboring sites by using the spatial autocorrelation coefficient, Moran's I. If Mt. Yeonae was destroyed by an artificial action, some spatial correlated species such as P. densiflora and Q. variabilis will be collapsed because of no maintaining the effective population sizes.

• The Korean Journal of Ecology
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• v.27 no.4
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• pp.211-216
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• 2004

The complex ecological researches were made in the broad-leaved forest zone of Central Europe in nature reserves and national parks located on the banks of the river (hydrology, vegetation, soils, unconfined ground waters). The natural conditions of terrestrial ecosystems and natural sites were compared along the course of the rivers. The significant negative influence of low-dammed (low-confined hydrotechnic) construction and small reservoirs on vegetation and soils of floodplain was revealed. On the basis of analysis of mean annual water level and flow trends on the multi-years series (60-100 years) of the hydrometric stations on the rivers under consideration the significant influence of natural long-term variability of watering on vegetation dynamics in the floodplains was revealed.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.15-25
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• 1997

The deciduous shrubs, Lindera sericea belonging to family Lauracea are distributed in Mt. Chogye and Mudeung locally. To estimate the community structure of this shrub, the relationship between the floristic composition and environmental factors of 20 sites in Mt. Chogye were investigated. L. sericea community distributed at the hum양 zone of altitude 305-480 m in ES and NE slope of $15~30^{\circ}$. The floristic composition of this communities consisted of 17-32 species varied with sites. Sasa borealis, Sapium japonicum, and Quercus serrata were the constant species over 90%. The forest vegetation was classified as Sasa borealis-Lindera sericea community, and the Sasa borealis-Meliosma oldhamii, and Sasa borealis-Callicarpa japonica were as subunit community. Acidity, organic matter content, inorganic phophate, potassium, calcium, magnesium, cation exchange capacity and conductivity were determined as environmental factors. Diameter of stem at ground surface and stem, distribution area and growth property of this plant were investigated, and this plant was presumed to be a relic endemic species.

• Journal of Korean Society of Forest Science
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• v.108 no.4
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• pp.663-674
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• 2019

Birds are effective ecological indicators but there is no national protocol in place to monitor population dynamics of forest birds in Korea. To support the establishment of future monitoring protocols, we compared the results of two generally used monitoring methods for forest bird surveys in two temperate mixed forests in central Korea. There was no statistical difference in the number of species and individuals detected per unit survey effort when comparing line transects and point counts. The number of species and individuals were higher in a five-minute count than in a three-minute point count, but the total accumulated number of expected observed species showed no difference between the two count durations. The number of observed species and individuals increased in both methods as plot radius or transect width increased, suggesting that multi-layer or multi-band surveys may be useful for quantitative and qualitative objectives. The decreasing number of observed species and individuals after sunrise suggested that bird monitoring should be conducted earlier in the morning, within four hours after sunrise. To detect 70% of the total number of species, 7.0 to 7.6 survey hours, equivalent to 42 three-minute counts (95% confidence interval [CI]: 26 to 61) or 33 five-minute counts (95% CI: 19 to 53) were needed for unlimited radius point counts. On the other hand, 4.8 survey hours, equivalent to 26 line transect counts (95% CI: 15 to 45) using 200-m transects with unlimited width, were required to achieve the same level of species detection. Therefore, the line transect method may be more effective than the point count method, at least in terms of local species richness assessment. For national forest bird monitoring, our data indicated that one or both survey methods can be selected as a basic protocol, based on the goals and scales of monitoring, forest types, and the conditions of the target areas.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.203-208
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• 2007

The woody tissue respiration rates in stems ($R_{stem}$) of red pine (Pinus densiflora Sieb. et Zucc.) forest in Higashi-Hiroshima, west Japan, were measured using an open flow measurement system with several chambers in two seasons (the winter and summer in 2002). $R_{stem}$ ranged from 0.25 to $0.55{\mu}mol\;m^{-2}s^{-1}$ in winter, and from 1.25 to $1.63{\mu}mol\;m^{-2}s^{-1}$ in summer. The variability of $R_{stem}$ among the sampled trees (n=15) was similar between the two seasons, with the coefficient variation of about 23%. The numbers of sampling points required to estimate the stem respiration rate within 10 to 20% of its actual value were 24 and 6, respectively in both seasons (probability level is 95%). Based on the relationship between stem temperature and average $R_{stem}$ the $Q_{10}$ values of the winter and summer seasons were 1.49 and 1.45, respectively. The $R_{20}$($R_{stem}$ at $20^{\circ}C$ of stem temperature) was higher in summer ($1.23{\mu}mol\;m^{-2}s^{-1}$) than winter ($0.61{\mu}mol\;m^{-2}s^{-1}$). The woody tissue respiration in stems of red pine trees during the summer season amounted about 50% of the total respiration rates.

• Fire Science and Engineering
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• v.27 no.3
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• pp.1-7
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• 2013

The wildland fire intensity and scale are getting bigger owing to climate change in the world. In the case of domestic, the forest is distributed over approximately 63.7 % of country and the main facilities like a industrial facility or gas facility abuts onto it. Therefore there is potential that the wildland fire is developed to a large-scale disaster. In this study, the effect distances of the radiant heat flux from the crown fire are analysed according to the change of wind velocity. The safety criteria concerning the radiant heat flux to influence on the surrounding were researched to analyse the effect distances. The criteria of radiant heat flux were chosen $5kW/m^2$, $12.5kW/m^2$, $37.5kW/m^2$. WFDS, which is an extension of NIST's Fire Dynamics Simulator, was used to consequence analysis of the forest fire. In order to apply the analysis conditions, it is researched the forest conditions that is generally distributed in domestic region. As the result, the maximum effect distances by radiant heat were showed at the horizontal and vertical direction. When the wind velocity varied from 0 to 10 m/s, the maximum effect distance increased as the wind velocity increases. Interesting point is that the maximum effect distance were shown at the wind velocity of 8 m/s. The maximum effect distance was decreased according as the fuel moisture of trees increase. This study can contribute to analyse quantitative risk about the damage effect of the surrounding facilities caused by wildland fire.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.2
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• pp.122-131
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• 2010

This paper introduces the concept of a virtual ecosystem and reports the following three mathematical approaches that could be widely used to construct such an ecosystem, along with examples: (1) a molecular dynamics simulation approach for animal flocking behavior, (2) a stochastic lattice model approach for termite colony behavior, and (3) a rule-based cellular automata approach for biofilm growth. The ecosystem considered in this study consists of artificial organisms and their environment. Each organism in the ecosystem is an agent that interacts autonomously with the dynamic environment, including the other organisms within it. The three types of model were successful to account for each corresponding ecosystem. In order to accurately mimic a natural ecosystem, a virtual ecosystem needs to take many ecological variables into account. However, doing so is likely to introduce excess complexity and nonlinearity in the analysis of the virtual ecosystem's dynamics. Nonetheless, the development of a virtual ecosystem is important, because it can provide possible explanations for various phenomena such as environmental disturbances and disasters, and can also give insights into ecological functions from an individual to a community level from a synthetic viewpoint. As an example of how lower and higher levels in an ecosystem can be connected, this paper also briefly discusses the application of the second model to the simulation of a termite ecosystem and the influence of climate change on the termite ecosystem.

• Journal of Korean Society of Forest Science
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• v.98 no.6
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• pp.748-756
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• 2009

The key for cultivating Lentinula edodes in sawdust bags with an appropriate strain and medium is to encourage the mushroom growth, while discouraging contaminating fungi by controlling environment, especially temperature and relative humidity (RH). To investigate the daily and seasonal fluctuation of temperature and RH in two L. edodes cultivation sheds types, HOBO data loggers was set and the collected data were analyzed. In a Taiwan type L. edodes cultivation shed, temperature and humidity changes were divided into five characteristic periods: mycelium growing winter, mushroom fruiting spring, mushroom fruiting early summer, mushroom nonfruiting summer and mushroom fruiting autumn. First, the mycelium growing winter was December to early March with daily mean temperature of $-1{\sim}8^{\circ}C$. Second, mushroom fruiting spring was mid March to late May with daily mean temperature of $8{\sim}21^{\circ}C$ and day-night temperature difference of $15^{\circ}C$. Third, the Mushroom fruiting early summer was early June to early July with 17 to $25^{\circ}C$. Fourth, nonfruiting summer was mid July to mid August with daily mean temperature of $25{\sim}28^{\circ}C$. Lastly, mushroom fruiting autumn was late August to October with daily mean temperature of $10{\sim}23^{\circ}C$ and with cyclic temperature change by $7^{\circ}C$ decrease and 5 increase every 5 to 7 days. In a Chinese type shed, temperature ranged $-1.9{\sim}5.0^{\circ}C$ during winter and $15{\sim}32^{\circ}C$ during June to October. Temperature and relative humidity changed $12{\sim}30^{\circ}C$ and 40~100%, respectively, depending on 0~150 cm shelf heights of by positions in the shed. In conclusion, to grow L. edodes but to discourage contaminating fungi, that is, not to be too high in temperature and RH, the growers changed temperature and RH by adjusting shading, aeration and insulation in the shed.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.147-155
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• 1992

Litterfall, decomposition, and dynamics of n and p in decomposing litter were investigated for 2 years in red pine ( pinus densiflora) and chinese thuja( thuja orientalis)stands in the limestone area. Average litterfall in red pine and chinese thuja stands were 4, 535kgDM ha-1 yr-1 and 5, 010 kgDM ha-1 yr-1, respectively. Seasonal litterfall in red pine and chinese thuja stands showed peaks in November. concentrations of N and P in the needle litter were lowest in the winter when the greast litterfall occurred, and highest in the summer when the least litterfall occurred. However, those in chinese thuja scale leaf litter showed litter seasonal variation.amount of N and P returned to the forest floor through litterfall were 29.02kgN ha-1 yr-1 , 2.81 kg P ha-1 yr-1 for red pine stand, and 31.06 kg N ha-1 yr-1 , 2.86kgP ha-1 yr-1 for chinese thuja stand, respectively. After 21 mounts elapsed, needle and chinese thuja scale leaf litterbags lost 34.8% and 32.5% of the initial weight, respectively. N concentrations in the docomposing needle and chines thuja scale leaf litter decreased by 19% and 30%, respectively, after 1 month elapsed, and then gradually increased to exceed the initial concentration after 9 months elapsed and then gradually increased to exceed the initial concentration after 9 months elapsed in both of them, P in needle and chines thuja scale leaf litter decreased by 54% and 57% of the initial concentration, respectively, after 1 month elapsed. unlike N, P concentration in the decomposing litter did not exceed that of initial ones. Neyt immobilization period of N and P in decomposing litter did not occur over the study period.