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

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.75-84
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• 2015

Tropical forests play a critical role in mitigating climate change, and therefore, an accurate and precise estimation of tropical forest carbon (C) is needed. However, there are many uncertainties associated with C stock estimation in a tropical forest, mainly due to its large variations in biomass. Hence, we quantified C stocks in an intact lowland mixed dipterocarp forest (MDF) in Brunei, and investigated variations in biomass and topography. Tree, deadwood, and soil C stocks were estimated by using the allometric equation method, the line intersect method, and the sampling method, respectively. Understory vegetation and litter were also sampled. We then analyzed spatial variations in tree and deadwood biomass in relation to topography. The total C stock was 321.4 Mg C $ha^{-1}$, and living biomass, dead organic matter, and soil C stocks accounted for 67%, 11%, and 23%, respectively, of the total. The results reveal that there was a relatively high C stock, even compared to other tropical forests, and that there was no significant relationship between biomass and topography. Our results provide useful reference data and a greater understanding of biomass variations in lowland MDFs, which could be used for greenhouse gas emission-reduction projects.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.4
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• pp.309-315
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• 2014

Summer cabbages in an alpine area are very sensitive to the fluctuations in supply and demand. Yield variability due to weather conditions dictates the market fluctuations of cabbage price. This study reports an empirical relationship based on weather conditions to estimate the growth and harvestable biomass of cabbages, factors that are critical for supply of summer cabbages. Based on experimental results testing sowing date effects over the two years from 1997 to 1998, a logistic equation was parameterized to predict leaf area expansion of summer cabbages. This logistic model for leaf area expansion was then combined with an empirical allometric relationship to predict total biomass. The final equation for estimating fresh weight accumulation of Chinese cabbage is given by: $$Fresh\;weight=3500/(1+{\exp}(5.175-1.153{\times}(6/(1+{\exp}(6.367-0.0064{\times}PHU)))))$$ Where PHU is potential heat units ($^{\circ}C$). The model performance was tested using weather data from 2003 to 2006 to predict fresh harvestable biomass. Overall the model performance was satisfactory with the correlation efficient ranging between 0.89 and 0.94 for each year.

• Journal of Korean Society of Forest Science
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• v.99 no.6
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• pp.914-921
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• 2010

This study analyzed the above-and belowground biomass, net primary production, stem density, and biomass expansion factors for Pinus densiflora stands of Cheongyang and Boryeong regions in Chungnam. The total dry weights in Cheongyang and Boryeong regions were 122.36 kg/tree and 137.68 kg/tree while the aboveground biomass for these two regions were 72.23 Mg/ha and 143.27 Mg/ha, respectively. Total(above-and belowground) biomass were 91.77 Mg/ha and 178.98 Mg/ha, respectively. Net primary production of above-and belowground biomass in Cheongyang and Boryeong regions were 8.69 Mg/ha, 10.03 Mg/ha, 16.00 Mg/ha and 18.66 Mg/ha, respectively. Stem density (g/$cm^3$) was 0.457 and 0.421 while the above and total biomass expansion factors were 1.394~1.662 and 1.324~1.639, respectively. These results suggested that stand density and site quality could be influenced on the biomass and net primary production of the two regions. In addition, the results of this study could be very useful to calculate carbon sequestrations by applying stem density values and biomass expansion factors for Pinus densiflora in these two regions.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.127-136
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• 2015

This study aims to quantify the stand-level above ground biomass in intact tropical rain forest of Brunei using airborne LiDAR data. Twenty four sub-plots with the size of 0.09ha ($30m{\times}30m$) were located in the 25ha study area along the altitudinal gradients. Field investigated data (Diameter at Breast Height (DBH) and individual tree position data) in sub-plots were used. Digital Surface Model (DSM), Digital Terrain Model (DTM) and Canopy Height Model (CHM) were constructed using airborne LiDAR data. CHM was divided into 24 sub-plots and 12 LiDAR height metrics were built. Multiple regression equation between the variables extracted from the LiDAR data and biomass calculated by using a allometric equation was derived. Stand-level biomass estimated from LiDAR data were distributed from 155.81 Mg/ha to 597.21 Mg/ha with the mean value of 366.48 Mg/ha. R-square value of the verification analysis was 0.84.

• The Korean Journal of Ecology
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• v.28 no.3
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• pp.163-168
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• 2005

This study was carried out to estimate above-ground biomass and inorganic nutrient distribution for a Camellia japonica stand located Mt. Cheon-gwan, Jeonnam province. Regression analysis of biomass for stem, current twig, branch and foliage versus diameter at breast height(DBH) was used to calculate regression equations of the form of logY = a + blogD(Y: component biomass, D: DBH). Total above-ground biomass for a Camellia japonica stand was 115.2 ton/ha(47.9 for main stem, 1.4 for current twig, 53.4 for live and dead branch, 5.6 for current foliage and 6.9 for ${\geq}1$-yr-old foliage). Component biomass was non-linearly correlated with DBH, and the difference in biomass between ${\geq}1$-yr-old and current foliage increased in proportion to DBH. Current foliage and live branch showed higher N, P and K concentrations compared to ${\geq}1$-yr-old foliage and dead branch, respectively. However, Ca concentration of current foliage and live branch was lower than that of ${\geq}1$-yr-old foliage and dead branch, respectively. Total above-ground inorganic nutrient contents(kg/ha) were distributed as follows; K: 366.4. N: 442.7, Ca: 433.3, Mg: 118.4, P: 50.5 and Na: 25.3. The proportions of inorganic nutrient content for live branch were generally the highest in all the inorganic nutrients.

• Journal of Korean Society of Forest Science
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• v.94 no.3 s.160
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• pp.161-167
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• 2005

Above and belowground biomass for Phyllostachys pubescens was determined in Jinju, Gyeongsangnam-do. Regression analyses of dry weights of culms, foliages, and twigs versus diameter at breast height were used to calculate regression equations of the form of log Y = a + blogX. Total aboveground biomass for Phyllostachys pubescens was 69.7 ton/ha and rhizomes and roots biomass were 13.7 ton/ha and 7.5 ton/ha, respectively. Culms account for about 60% of total aboveground biomass. The aboveground biomass of each component was decreased in the order of culms>foliages>twigs. As diameter at breast height grew thicker, the proportion of culms to total aboveground biomass increased. The proportion of dry weight of culms to green weight gradually increased with height in a bamboo tree and ages. Nutrients (kg/ha) of litter layer were distributed as follows: N(45.1), Ca(17.3), K(6.1), Mg(3.6), P(3.5) and Na(0.7). Nitrogen and K were given much weight in total nutrients of rhizomes and roots. These results will be useful in measuring carbon stock and drawing up management plan to increase it for Phyllostachys pubescens stand.

• Journal of Ecology and Environment
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• v.43 no.1
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• pp.43-60
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• 2019

Background: Tropical montane forests played an important role in the provision of ecosystem services. The intense degradation and deforestation for the need of agricultural land expansion result in a significant decline of forest cover. However, the expansion of agricultural land did not completely destruct natural forests. There remain forests inaccessible for agricultural and grazing purpose. Studies on these forests remained scant, motivating to investigate biomass and soil carbon stocks. Data of biomass and soils were collected in 80 quadrats ($400m^2$) systematically in 5 forests. Biomass and disturbance gradients were determined using allometric equation and disturbance index, respectively. The regression modeling is employed to explore the spatial distribution of carbon stock along disturbance and environmental gradients. Correlation analysis is also employed to identify the relation between site factors and carbon stocks. Results: The result revealed that a total of 1655 individuals with a diameter of ${\geq}5cm$, representing 38 species, were measured in 5 forests. The mean aboveground biomass carbon stocks (AGB CS) and soil organic carbon (SOC) stocks at 5 forests were $191.6{\pm}19.7$ and $149.32{\pm}6.8Mg\;C\;ha^{-1}$, respectively. The AGB CS exhibited significant (P < 0.05) positive correlation with SOC and total nitrogen (TN) stocks, reflecting that biomass seems to be a general predictor of SOCs. AGB CS between highly and least-disturbed forests was significantly different (P < 0.05). This disturbance level equates to a decrease in AGB CS of 36.8% in the highly disturbed compared with the least-disturbed forest. In all forests, dominant species sequestrated more than 58% of carbon. The AGB CS in response to elevation and disturbance index and SOC stocks in response to soil pH attained unimodal pattern. The stand structures, such as canopy cover and basal area, had significant positive relation with AGB CS. Conclusions: Study results confirmed that carbon stocks of studied forests were comparable to carbon stocks of protected forests. The biotic, edaphic, topographic, and disturbance factors played a significant variation in carbon stocks of forests. Further study should be conducted to quantify carbon stocks of herbaceous, litter, and soil microbes to account the role of the whole forest ecosystem.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.425-436
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• 2015

The carbon cycle came into the spotlight due to the climate change and forests are well-known for their capacity to store carbon amongst other terrestrial ecosystems. The annual organic carbon of litter production, forest floor litter layer, soil, aboveground and belowground part of plant, standing biomass, net primary production, uptake of organic carbon, soil respiration, etc. were measured in Mt. Worak in order to understand the production and carbon budget of Quercus serrata forest that are widely spread in the central and southern part of the Korean Peninsula. The total amount of organic carbon of Q. serrata forest during the study period (2010-2013) was 130.745 ton C ha^-1. The aboveground part of plant, belowground part of plant, forest floor litter layer, and organic carbon in soil was 50.041, 12.510, 4.075, and 64.119 ton C ha^-1, respectively. The total average of carbon fixation in plants from photosynthesis was 4.935 ton C ha^-1 yr^-1 and organic carbon released from soil respiration to microbial respiration was 3.972 ton C ha^-1 yr^-1. As a result, the net ecosystem production of Q. serrata forest estimated from carbon fixation and soil respiration was 0.963 ton C ha^-1 yr^-1. Therefore, it seems that Q. serrata forest can act as a sink that absorbs carbon from the atmosphere. The carbon uptake of Q. serrata forest was highest in stem of the plant and the research site had young forest which had many trees with small diameter at breast height (DBH). Consequentially, it seems that active matter production and vigorous carbon dioxide assimilation occurred in Q. serrata forest and these results have proven to be effective for Q. serrata forest to play a role as carbon storage and NEP.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.244-250
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• 2019

We investigated the relationship between morphological characteristics and individual dry weight to develop a method for estimating the individual dry weight of sheet form macroalgae: Ulva australis, Ulva linza, Pachymeniopsis lanceolata, and Pyropia yezoensis. In Total, 319 thalli of various sizes were collected at six sites from February 2017 to December 2018. An interspecific allometric exponent of 0.28 was found for length-biomass allometry in four sheet form macroalgae, corresponding to a 1/4-power law for primary producers. The relationships between surface area and individual dry weight, as well as between individual fresh weight and individual dry weight, were found to fit significantly using linear regression equations. This explained 94-99 % of individual dry weight, indicating that surface area and individual fresh weight can be used to accurately estimate individual dry weight. We propose the use of this method when experimental processes do not allow individual dry weight to be measured directly, so researchers can save both time and expense.