• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2019.08a
• /
• pp.292-292
• /
• 2019

• Journal of Korean Society of Forest Science
• /
• v.100 no.2
• /
• pp.266-272
• /
• 2011

This study was conducted to analyze the characteristics of crown fuel biomass and to develop allometric equations for the estimation of crown fuel biomass by subjectively categorized the crown component in Pinus densiflora stands. A total of ten representative trees were destructively sampled in Youngju region. Crown fuel were weighed separately for each fuel category by size class. The results of this study showed that foliar moisture content was 119% while the average crown moisture content was 105.3%. The crown fuel/total fuel loading ratio was 30%, needles and twigs with less than 1 cm diameter accounted 50.3% for its fuel/crown fuel loading ratio. Adjusted multiple coefficient of determination of suggested allometric equations ranged from 0.6846 to 0.9246 for crown fuel biomass, 0.8308 for crown volume.

• Journal of Korean Society of Forest Science
• /
• v.99 no.3
• /
• pp.391-396
• /
• 2010

To analyze the characteristics of canopy fuel in Pinus densiflora stand, which is essential to assess the crown fire hazard, allometric equations for estimation of crown fuel biomass were developed by subjectively categorized crown fuel component and crown bulk density was analyzed by available fuel component categories. Ten trees were destructively sampled at Pinus densiflora stand in Mt. Palgong in Daegu and their crown fuels were weighed separately for each fuel category by size classes and by living and dead. Regression equations that estimate crown fuel load by diameter at breast height(D) or additional total height(H) were derived. The adjusted coefficient of determination values were the highest (${R^2}_{adj}$=0.835-0.996) and standard error of estimate were the lowest (SEE=0.074-0.638) in the allometric equation lnWt=${\alpha}+{\beta}lnD+{\gamma}lnH$ in average. However, in needles and small branches categories, the differences in ${R^2}_{adj}$ and SEE between equations were not significant. Crown bulk density (CBD), which was calculated by crown fuel load divided by crown volume, was 0.067 kg/$m^3$ in average when only needles were considered as available crown fuel and 0.097 kg/$m^3$ when needles and branches (0-0.5 cm diameter) were considered. The increments of CBD of needles and small branches were little even when diameter at breast height increased.

• Journal of Korean Society of Forest Science
• /
• v.104 no.1
• /
• pp.104-110
• /
• 2015

The objective of this study was to develop allometric equations for the estimation of crown fuel biomass of Pinus koraiensis in Korea. A total of twenty four representative sample trees were destructively sampled in Gapyeong, Hongcheon, and Jeongseon. Crown fuels were weighed separately for each fuel category by size class and by living and dead. The results of this study showed that the needles contributed the largest biomass (16.6 kg, 34.7%), followed by live branches with size ranging from 2~4 cm (9.0 kg, 18.9%), 1~2 cm (6.6 kg, 13.8%), <0.5 cm (5.1 kg, 10.6%), 0.5~1 cm (4.9 kg, 10.3%), and dead branches (3.2 kg, 6.8%), while the live branches with 4 cm (2.4 kg, 4.9%) as the lowest. The adjusted coefficient of determination values were the highest ($R^2_{adj}=0.6021{\sim}9742$) and standard error of estimate were the lowest (S.E.E.=0.2018~0.7271) in allometric equation $lnWt={\beta}_0+{\beta}_1lnD$. The available fuels that are consumed during crown fires (i.e., needles and twigs with diameter less than 1 cm) comprised 55.6% of the total crown fuel biomass.

• Journal of Korean Society of Forest Science
• /
• v.112 no.1
• /
• pp.32-39
• /
• 2023

Using the logarithmic methods and the generalized method of moments (GMM), this study developed carbon storage equations for maple trees (Acer palmatum Thunb.) planted in an urban settlement area. A total of 20 maple trees of various ages and diameters were destructively harvested to determine their dry weight and carbon concentration by component. The allometric equations with DBH and DBH²×H as independent variables were developed to estimate the carbon storage for each tree component. The carbon concentration of tree components was the highest in stem wood (49.8%) and lowest in stem bark (46.5%). Allometric equations to estimate the carbon storage of tree components (stem, root, aboveground, and total) showed a similar coefficient of determinations (R²) between the allometric equations of the logarithmic method (0.7494-0.9036) and the GMM (0.7085-0.8847). However, the R² values of the leaves and branches were in the range of 0.3027 to 0.6380, lower than those of the R² of the other tree components. These results indicate that the carbon storage of maple trees growing in urban settlement areas can be efficiently predicted from the equations of GMM methods in the case of a small sample size or the heteroscedasticity of logarithmic equations.

• Journal of Wetlands Research
• /
• v.16 no.2
• /
• pp.245-250
• /
• 2014

This study developed allometry equation and estimated the aboveground-biomass of Quercus glauca, a warm-temperature, evergreen broad-leaved tree, growing in Kotzawal wetland located on Jeju Island. The allometric equations between DBH(diameter at breast height) and dry weights of stems (Ws), branches (Wb), leaves (Wl) and aboveground biomass (Wab) of Q. glauca were as follows: logWs=2.4042logDBH-1.3045, logWb=2.6436logDBH-1.6232, logWl =1.5428logDBH-1.3692 and logWab=2.3324logDBH-0.9181. The allometric equations between $D^2H$ and Ws, Wb, Wl, and Wab of Q.glauca were as follows : logWs=$0.853logD^2H-1.4252$, logWb=$0.8453logD^2H-1.5834$, logWl=$0.5328logD^2H-1.4073$ and logWab=$0.8453logD^2H-1.0327$. The $R^2$ between DBH and Ws, Wb, Wl and Wab were 0.9873, 0.9711, 0.7979 and 0.993, respectively. The $R^2$ between $D^2H$ and Ws,Wb,Wl and Wab were 0.9841, 0.9174, 0.7537 and 0.9876, respectively. There was no significant difference between observed and calculated values of the allomatric equations from DBH and $D^2H$(p>0.05, Kolmogorov-Smirnov test). Thus, to estimate the aboveground biomass of Q. glauca, use of DBH and $D^2H$ as an independent variables in the allometric equation is recommended.

• Journal of the Korean Society of Radiology
• /
• v.14 no.3
• /
• pp.289-294
• /
• 2020

In order to control the quality of X-ray images and patient exposure, it is necessary to document the output dose(air absorption dose(mGy)) output from the X-ray unit from the measurement. The purpose of this study is to find an equation that can calculate the output dose from the measurement of the output dose and output factor(Of) of the X-ray Unit. The output dose and output factors of the X-beam irradiated from the X-ray unit were measured using an XR multi-detector. The output dose calculation formula was obtained by fitting the measured output dose divided by the tube current-exposure time product(mAs) and the set tube voltage with Allometric1. The final output dose calculation formula was obtained by multiplying this formula with the output factor. It is considered that the obtained final output dose calculation formula will be useful for all tube voltages, tube currents, exposure times, field sizes, and distances.

• Journal of Ecology and Environment
• /
• v.41 no.1
• /
• pp.19-28
• /
• 2017

Background: In order to investigate organic carbon distribution, carbon budget, and cycling of the subalpine forest, we studied biomass, organic carbon distribution, litter production, forest floor litter, accumulated soil organic carbon, and soil respiration in Taxus cuspidata forest in Halla National Park from February 2012 to November 2013. Biomass was calculated by using allometric equation and the value was converted to $CO_2$ stocks. Results: The amount of plant organic carbon was $13.60ton\;C\;ha^{-1}year^{-1}$ in 2012 and $14.29ton\;C\;ha^{-1}year^{-1}$ in 2013. And average organic carbon introduced to forest floor through litter production was $0.71ton\;C\;ha^{-1}year^{-1}$. Organic carbon distributed in forest floor litter layer was $0.73ton\;C\;ha^{-1}year^{-1}$ on average and accumulated organic carbon in soil was $51.13ton\;C\;ha^{-1}year^{-1}$ on average. In 2012, Amount of released $CO_2$ from soil to atmosphere was 10.93 ton $CO_2ha^{-1}year^{-1}$. Conclusions: The net ecosystem production based on the difference between net primary production of organic carbon and soil respiration was $-1.74ton\;C\;ha^{-1}year^{-1}$ releasing more carbon than it absorbed.

• Ecology and Resilient Infrastructure
• /
• v.4 no.3
• /
• pp.149-155
• /
• 2017

Willow plants are representative biomaterials used in river restoration and main target trees in stream managements. In order to understand the changes in the growth of Salix subfragilis and S. chaenomeloides with their stand ages, we investigated the density, height and basal area of stems and biomass at their different aged stands of the riparian zone of the sand-bed stream, the Nakdong River, Korea. We also developed allometric equations for estimating the biomass of these two species by establishing the relationship between diameter at breadth height and tree height with above-ground biomass. The stem density showed a sharp decrease for 3 years after germination for S. subfragilis and 6 years for S. chaenomeloides, resulting in strong self-thinning. The stem height of the two species increased to 7.5 m in 15 years for S. subfragilis, and to 14 m in 13 years for S. chaenomeloides. Aboveground biomass also increased rapidly at the early stage of growth. The biomass increased to 17 ton DM/ha in 13 years for S. subfragilis and to 1,110 ton DM / ha in 13 years for S. chaenomeloides. It is expected that the allometric equations of two Salix species derived from this study will be applied to the objectively estimating the biomass of willow plants for the management of floodplain trees in streams.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.16 no.1
• /
• pp.29-38
• /
• 2014

Allometric equations for leaf, branch, stem and total above ground biomass of Pinus koraeinsis trees were developed with diameter at breast height(DBH) of trees, which were growing in a pine plantation with the stand density of 410 tree $ha^{-1}$ and the average DBH of $29.1{\pm}5.2$ cm in Mt. Taewha, Gyeonggi. Damage by Acantholyda parki reduced leaf biomass compared to other studies, however, its contribution to total biomass was minimal among parts. Comprehensive analysis revealed that constant in allometric equation for total above ground biomass (logY=a + blogX) was affected by average DBH and stand density, however, constant b was not. At the stand level, biomass for leaf, brach, stem, total above ground biomass were 6.68 Mg $ha^{-1}$, 18.82 Mg $ha^{-1}$, 101.02 Mg $ha^{-1}$, 126.53 Mg $ha^{-1}$, respectively. We developed a Korean pine stand biomass regression, which explained about 98% of variation with DBH and stand density based on comprehensive analysis.