• 펄프종이기술
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• 제40권2호
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• pp.65-72
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• 2008

This work evaluated the extractability of tobacco stem biomass for the papermaking type Reconstituted Tobacco Sheet(RTS). The effects of the soaking conditions on the hydration of stem biomass and the effects of the hydrated state on the mechanical extraction were investigated. In order to simulate the mechanical expression process of a papermaking type RTS mill, for example, the screw press process, the novel mechanical pressing analyzer was developed for this study. The hydration of stem biomass by soaking process was greatly affected by the soaking time and the soaking temperature. The longer soaking time and the higher soaking temperature resulted in the higher hydrated stem biomass. Since the higher hydrated stem had more combined water in the inner structure and resulted in the more flexible structure, the higher hydrated stem leaded to the more compressed filter cake and the higher water contents in the filter cake after the mechanical pressing. The pilot pulping experiments showed the difference in hydration and extractability between burley and bright tobacco stem. The bulkier structure of the burley stem resulted in the faster hydration by pilot pulping and leaded to the larger reduction in water soluble components. And the hydration process showed the major influence on the separation efficiency of water soluble components.

• 한국산림과학회지
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• 제98권5호
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• pp.576-583
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• 2009

Based on the stem analysis and biomass measurement of 36 trees and 1,576 branches in Pinus sylvestris var. mongolica (Mongolian pine) plantations of Northeast China, this study was conducted to develop estimation model equation for leaf biomass of a single tree and branch, to examine the vertical distribution of leaf biomass in the crown, and to evaluate the proportional ratios of biomass by tree parts, stem, branch, and leaf. The results indicated that DBH and crown length were quite appropriate to estimate leaf biomass. The biomass of single branch was highly correlated with branch collar diameter and relative height of branch in the crown, but not much with stand density, site quality, and tree height. Weibull distribution function would have been appropriate to express vertical distribution of leaf biomass. The shape parameters from 29 sample trees out of 36 were less than 3.6, indicating that vertical distribution of leaf biomass in the crown was displayed by bell-shaped curve, a little inclined toward positive side. Apparent correlationship was obtained between leaf biomass and branch biomass having resulted in linear function equation. The stem biomass occupied around 80% and branch and leaf made up about 20% of total biomass in a single tree. As the level of tree class was increased from class I to class V, the proportion of the stem biomass to total biomass was gradually increased, but that of branch and leaf became decreased.

• Journal of Ecology and Environment
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• 제37권4호
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• pp.177-184
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• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• 한국산림과학회지
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• 제95권1호
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• pp.50-54
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• 2006

Biomass 확장계수와 줄기밀도의 값은 임목축적 자료를 이용하여 국가단위의 총 탄소 저정량으로 전환하는데 일반적으로 사용되어왔다. 본 연구의 목적은 우리나라 남부지방에 식재된 편백 임분을 대상으로 임령이 Biomass 확장계수와 줄기밀도에 미치는 영향을 조사하였다. 연구 대상지는 동일한 임지에서 다양한 임령(8~54년생)이 분포하는 전라남도 장성군 편백 조림지를 기본 모델로 조사하였으며, 조사대상지 임분은 20년 단위를 1 영급단위로 분류하여 총 3개의 영급단위로 구분하였다. 각 영급단위별로 최소 5주 이상의 표준목을 선발하여 총 25주의 표준목을 벌채하였고 줄기, 잎, 가지, 뿌리의 생중량과 건중량, 줄기밀도, Biomass 확장계수, 줄기의 Biomass에 의한 부위별 Biomass 전환계수 등을 분석하였다. 본 연구 결과, 전체 Biomass 확장계수는 임령이 증가함에 따라 3.64에서 1.44로 급격히 감소하는 반면에, 줄기밀도는 $0.35(g/cm^3)$에서 $0.44(g/cm^3)$로 약간 증가하는 경향을 나티내었다. Biomass 확장계수와 줄기밀도의 경우 영급에 따라 유의적인 차이가 있었으나 영급단위2와 영급단위3은 차이를 나타내지 않았다. 그러나 평균적으로 임령이 30년 이상인 경우에는 전체 Biomass 확장계수와 줄기밀도가 약 1.44와 $0.44(g/cm^3)$라는 일정한 값들을 나타내었다. 본 연구 결과로 얻어진 Biomass 확장계수와 줄기밀도를 편백 임분의 영급별 축적에 적용함으로써 정확도 높은 총 Biomass 및 탄소 고정량을 추정하는데 기초 자료로 활용할 수 있을 것이다.

• 농업생명과학연구
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• 제45권1호
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• pp.15-20
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• 2011

본 연구는 전북 무주지역 36년생 리기다소나무 임분을 대상으로 지상부 바이오매스 추정식을 개발하고, 줄기밀도와 바이오매스 확장계수를 산출하고자 하였다. 리기다소나무의 흉고직경을 독립변수로 하고 바이오매스를 종속변수로 하는 상대생장식을 추정한 결과, 잎 (78%)과 가지 (83%)를 제외하면 모든 부위에서 결정계수가 95% 이상의 높은 설명력을 나타냈다. 리기다소나무의 바이오매스량은 줄기 목질부 $65.9 Mg\;ha^{-1}$, 줄기 수피 $9.5Mg\;ha^{-1}$, 가지 $19.6Mg\;ha^{-1}$, 잎 $7.0Mg\;ha^{-1}$, 전체 $102Mg\;ha^{-1}$로 나타났으며, 바이오매스 구성비는 줄기목질부 (64.6%) > 가지 (19.2%) > 줄기 수피 (9.3%) > 잎 (6.9%) 순으로 나타났다. 리기다소나무의 줄기밀도 $(g/cm^{3})$는 0.453으로 나타났고, 바이오매스 확장계수는 1.344로 나타났다.

• 임산에너지
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• 제18권1호
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• pp.11-16
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• 1999

Dry weights of leaves, stem and floral organs of 15-year-old Tilia amurensis RUPR., were measured twice on 1 June and 20 August 1995 to examine the difference in biomass production between the reproductive and vegetative twigs which are morphologically neighboring and alternative. The following results were obtained : (1) The biomass of the reproductive twigs was greater than that of the vegetative twigs in both June and August. (2) The ratio of stem to total biomass in the reproductive and the vegetative twigs was greater in August than that in June, while the ratio of leaf biomass was greater in June than that in August. The ratio of floral organ to the total biomass in the reproductive twigs was 14.6% and 27.1% in June and August, respectively. (3) The total twig biomass per leaf biomass was greater in the reproductive twigs than that in the vegetative twigs in both June and August. (4) Net assimilation rate in the floral organs showed 21% of that in the leaves in June and 37% in August.

• 농업생명과학연구
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• 제44권5호
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• pp.45-53
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• 2010

본 연구의 목적은 전라북도 고창군 일대의 소나무림을 대상으로 바이오매스 추정식을 개발하고 이를 바탕으로 바이오매스 및 순생산량, 줄기밀도와 바이오매스 확장계수를 분석하고자 하였다. 유령임분과 성숙임분의 경우 평균 임령이 각각 10년과 48년으로 나타났으며 임목 전체 건중량은 8.59 kg, 166.66 kg으로 나타났고 임분밀도를 고려한 단위면적당 지상부 건중량은 17.55 Mg/ha, 122.05 Mg/ha으로 나타났다. 지하부를 포함한 임목전체 건중량은 21.48 Mg/ha, 154.16 Mg/ha으로 나타났다. 부위별 바이오매스 구성비는 유령임분에서 성숙임분으로 갈수록 줄기목질부, 줄기 수피, 뿌리는 증가하는 경향을 보이는 반면, 잎, 가지 구성비는 감소하는 경향으로 나타났다. 지상부 순생산량은 유령임분에서 6.30 Mg/ha으로 나타났고 임목 전체에서는 6.95 Mg/ha으로 나타났으며, 성숙 임분에서 11.61 Mg/ha, 임목전체에서 13.19 Mg/ha으로 나타났다. 줄기밀도($g/cm^3$)는 유령임분과 성숙임분에서 각각 0.338, 0.448로 나타났으며, 임령이 증가함에 따라 증가하는 일반적인 경향으로 나타났다. 바이오매스 확장계수는 유령임분과 성숙임분에서 각각 2.304~2.508, 1.318~1.644의 범위로 나타났다.

• Journal of Ecology and Environment
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• 제44권4호
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• pp.241-255
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• 2020

Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

• 한국산림과학회지
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• 제99권5호
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• pp.726-735
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• 2010

Publications with the data on allometric equation, biomass and productivity of major oak forests in Korea were reviewed. Different allometric equations of major oak species showed site- or speciesspecific dependences. The biomass of major oak forests varied with age, dominant species, and location. Aboveground tree biomass over the different oak species was expressed as a power equation of the stand age. The proportion of tree component (stem, branch and leaf) to total aboveground biomass differed among oak species, however, biomass ranked stem > branch > leaf in general. The leaf biomass allocation over the different oak species was expressed as a power equation of total aboveground biomass while there were no significant patterns of biomass allocation from stem and branch to the aboveground biomass. Tree root biomass continuously increased with the aboveground biomass for the major oak forests. The relationship between the root to shoot ratio and the aboveground tree biomass was expressed by a logarithmic equation for major oak forests in Korea. Thirteen sets of data were used for estimating the net primary production (NPP) and net ecosystem production (NEP) of oak forests. The mean NPP and NEP across different oak forests was 10.2 and 1.9 Mg C $ha^{-1}year^{-1}$. The results in biomass allocation, NPP and NEP generally make Korean oak forests an important carbon sinks.

• 한국산림과학회지
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• 제94권6호
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• pp.441-445
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• 2005

기후변화 협약과 관련된 교토 의정서를 계기로 산림의 탄소 축적량을 조사하기 위하여 전국 규모의 산림 현존량 추정에 대한 연구가 진행되고 있다. 전국 규모의 산림 현존량 추정은 일반적으로 임업통계상의 임목축적 자료를 이용하고 있으며, 산림 현존량은 줄기의 건중량 대 재적 비인 줄기밀도와 임목 전체 건중량 대 줄기 건중량 비인 현존량확장계수에 의하여 산출할 수 있다. 본 연구는 한국 소나무의 대표적 생태형인 금강형 소나무와 중부지방 소나무를 대상으로 임령에 따른 줄기밀도와 현존량확장계수를 조사분석함으로써 임목축적에 의한 현존량 추정에 대한 정보를 제공하는데 목적이 있다. 금강형 소나무와 중부지방 소나무는 모두 영급이 증가함에 따라 줄기밀도가 증가하였으며, 현존량확장계수는 감소하였다. 금강형 소나무 줄기밀도의 경우 20년생 이하 영급과 40-60년생 영급 간에는 유의적인 차이가 있었으며, 중부지방 소나무의 뿌리를 제외한 지상부 현존량확장계수의 경우 20년생 이하, 20-40년생, 40-60년생 영급간에 모두 유의적인 차이가 있었다. 동일 영급에서 금강형 소나무는 중부지방 소나무에 비하여 줄기밀도와 현존량확장계수가 모두 낮은 값을 보였다. 20년생 이하와 20-40년생 영급의 경우 줄기밀도와 현존량확장계수 모두 금강형 소나무와 중부지방 소나무간에 유의적인 차이가 있었다. 이상을 종합하면, 임업통계상의 임목축적을 이용하여 소나무림의 현존량을 추정할 경우 전환계수인 줄기밀도와 현존량확장계수는 금강형 소나무와 중부지방 소나무를 구분하고 적정 범위의 영급에 따라 달리 적용함으로써 정확도를 높일 수 있는 것으로 나타났다.