• 한국산림과학회지
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• 제104권1호
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• pp.14-25
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• 2015

본 연구는 백두대간 중부권역의 구룡산, 소백산, 백화산, 속리산, 백학산 등 5지역을 대상으로 복잡 다양한 천연림 군집을 분류하고 산림피복유형을 집약하기 위해 실시되었다. 점표본법을 이용하여 1,114개의 표본점에서 식생자료를 수집하였으며, 조사된 식생자료를 바탕으로 Cluster 분석을 실시하였다. 그 결과 총 27개 군집으로 분류되었으며, 분류된 군집의 상층 수종구성의 유사성을 바탕으로 신갈나무림형, 중생혼합림형, 굴참나무림형, 소나무림형, 기타활엽수림형, 졸참나무림형, 아고산대림형 등 총 7개의 산림피복유형으로 집약하였다. 연구 대상지에서 신갈나무림형이 가장 넓게 분포하였고, 산림피복유형마다 신갈나무의 구성 비율이 증가함에 따라 종다양성지수가 낮아지는 경향을 나타내었다. 중생혼합림형과 기타활엽수림형은 계곡에 많이 분포하였고, 신갈나무림형과 소나무림형은 능선 부위에 많이 분포하는 것으로 조사되었다.

• Journal of Ecology and Environment
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• 제42권3호
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• pp.128-138
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• 2018

Background: This study investigated the variation of soil organic carbon in four land cover types: natural and mixed forest, cultivated land, Eucalyptus plantation and open bush land. The study was conducted in the Birr watershed of the upper Blue Nile ('Abbay') river basin. Methods: The data was subjected to a two-way of ANOVA analysis using the general linear model (GLM) procedures of SAS. Pairwise comparison method was also used to assess the mean difference of the land uses and depth levels depending on soil properties. Total of 148 soil samples were collected from two depth layers: 0-10 and 10-20 cm. Results: The results showed that overall mean soil organic carbon stock was higher under natural and mixed forest land use compared with other land use types and at all depths ($29.62{\pm}1.95Mg\;C\;ha^{-1}$), which was 36.14, 28.36, and 27.63% more than in cultivated land, open bush land, and Eucalyptus plantation, respectively. This could be due to greater inputs of vegetation and reduced decomposition of organic matter. On the other hand, the lowest soil organic carbon stock under cultivated land could be due to reduced inputs of organic matter and frequent tillage which encouraged oxidation of organic matter. Conclusions: Hence, carbon concentrations and stocks under natural and mixed forest and Eucalyptus plantation were higher than other land use types suggesting that two management strategies for improving soil conditions in the watershed: to maintain and preserve the forest in order to maintain carbon storage in the future and to recover abandoned crop land and degraded lands by establishing tree plantations to avoid overharvesting in natural forests.

• 펄프종이기술
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• 제42권3호
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• pp.22-27
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• 2010

Pulping properties of the imported mixed eucalyptus chips and the domestic yellow poplar chips were investigated for comparing two chips as the raw materials for the hardwood chemical pulp. Soda-AQ (anthraquinone) pulping was applied for this study. The pulp from yellow poplar showed higher pulp yield than pulp from mixed eucalyptus, which comes from the lower hot-water soluble extractives and the higher polysaccharides in yellow poplar chips than those of the mixed eucalyptus chips. The yellow poplar pulp had higher average fiber length and fiber width than those of the mixed eucalyptus pulp, which led to the better respond to beating and the higher tear strength than those of the pulp from the mixed eucalyptus chips.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.14-16
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• 2004

Although there have been wide range of studies to characterize forest stands based upon spectral information of satellite image, it was not fully understood the texture information of forest stand using high resolution data. The objective of this study is to evaluate several texture measures for characterizing forest stand structure, such as species composition, diameter at breast height(DBH), stand density, and age. High resolution IKONOS satellite imagery data were acquired in August 200 lover the forested area near Ulsan, Korea. Primary forest types were plantation pine, mixed forest, and natural deciduous forest of stand age ranging from 10 to 50 years old. Several GLCM-based texture measures were compared with forest stand characteristics. In overall, a texture measure (contrast) calculated using red band were better to differentiate species and age group than other texture measures and near infrared bands.

• 한국산림과학회지
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• 제81권4호
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• pp.325-336
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• 1992

본 연구는 오대산(五臺山) 국립공원내(國立公園內)의 활엽수(闊葉樹)-젓나무속(屬) 혼효림(混淆林)에서 삼림천이(森林遷移) 경향과 잠재(潛在) 삼림식생(森林植生)을 검토 분석한 것이다. 88개의 $5m{\times}50m$ 대상표본구(帶狀標本區)를 설치하여 상층(上層) 우세목(優勢木)의 아래에서 생육하는 하층목(下層木)에 의해서 세대(世代) 교체(交替)되는 과정을 바탕으로 천이(遷移) 경향을 평가하였다. 조사 대상 삼림(森林)의 천이(遷移) 경향 분석은 Markov chain의 수학적(數學的) 이론에서 변형된 추이행렬(推移行列) 모델을 사용하였다. 본 연구 결과가 암시하는 바에 의하면 조사 삼림(森林)은 천이(遷移)의 중간단계(中間段階)에 있으며, 수종(樹種) 구성상(構成上) 극성상림(極盛相林)에 도달하려면 700년(年) 이상의 기간이 소요될 것으로 나타났다. 현재 28%와 13%의 높은 상대밀도(相對密度)를 유지하고 있는 신갈나무와 피나무는 극성상(極盛相)의 안정상태(安定狀態)가 되면 각각 3%와 5% 이하로 수종(樹種) 구성비율(構成比率)이 감소하리라 예상된다. 반면에, 젓나무, 당단풍, 까치박달, 그리고 잣나무의 구성비율(構成比率)은 증가할 것으로 사료되며, 현재 활엽수(闊葉樹)와 침엽수(針葉樹)의 혼효율(混淆率)이 6.5 : 3.5에서 5.0 : 5.0로 변화할 것이다. 신갈나무의 천이계열상(遷移系列上)의 문제점을 고찰한 바, 신갈나무는 천이(遷移) 중반단계의 우세종(優勢種)으로써 역할을 하며 극성상(極盛相) 수종(樹種)은 아닌 것으로 추정한다. 추이행렬(推移行列) 모델의 실제 상황에 대한 적용성을 평가하기 위하여 연구 모델의 단정(假定)과 민감도(敏感度) 역시 고찰하였다. 전반적인 연구 결과가 지적하는 바에 의하면 조사 삼림의 현재 생태적(生態的) 동태(動態)는 인간에 의한 방해와 교란(攪亂)이 있은후 천이가 진행 중임을 반영(反映)한다.

• Journal of the Korean Wood Science and Technology
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• 제4권1호
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• pp.33-37
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• 1976

본 연구(硏究)에서는 합판공장(合板工場) 및 목재공장(木材工場)이면 어디서나 나오는 톱밥을 효율적(效率的)으로 이용(利用)하고자 하는 목적(目的)으로 P.b.에 섞어 사용(使用)할 때 P.b.의 곡강도(曲强度), 흡수율, 함수율, 비중에 미치는 영향을 조사하여 분석(分析) 고찰하였다. 결과(結果) 및 고찰에 의해서 얻어진 본연구(本硏究)의 결론(結論)은 다음과 같다. 1) P.b.의 bending strength에 있어서 톱밥을 섞지 않은 것과 비교해서 5% 섞은 것 까지는 차(差)가 없으며 10%, 15%섞으면 곡강도가 떨어졌으며 20% 섞은 것은 현격한 차이(差異)가 생겼다. 2) Absorbility는 톱밥을 섞을 수록 증가하는 경향으로 나타났으며, 20% 섞은 경우는 현격한 증가가 생겼다. 3) 함수율과 비중(比重)은 각 구성간에 차이(差異)가 없었다. 분산(分散) 분석(分析)을 한 결과(結果) 유의성(有意性)이 없었다. 이상과 같이 톱밥을 P.b. 제조시(時)에 5% 정도 섞는 것은 P.b 의 질(質)에 별다른 영향을 주지 않는 것으로 나타났다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 춘계학술발표회 논문집
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• pp.131-138
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• 2011

Currently, many forest residues have been generated by the National Forest Management Operation. Unfortunately, most of the forest residues are supposed to be used as raw materials for burning fuels like wood pellets. Even though the forest biomass must be effectively used for making high value-added products, they may be subject to disposable raw materials for wood pellets. Wood pellets are regarded as burning fuels with less contribution to the decrease in carbon gas emission, compared to raw materials for kraft pulps. In this study, we studied whether or not forest biomass mixed with various ages and, species could be used as raw materials for kraft pulps.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1307-1309
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• 2003

The EO-1 spacecraft, launched November 21, 2000 into a sun synchronous orbit behind Landsat 7, hosts advanced technology demonstration instruments, whose capabilities are currently being assessed by the user community for future missions. A significant part of the EO-1 program is to perform data comparisons between Hyperion, ALI and Landsat 7 ETM+. In this paper, a comparison of forest classification results from Hyperion, ALI, and the ETM+ of Landsat-7 are provided for Wangqing Forest Bureau, Jilin Province, Northeast China. The data have been radiometrically corrected and geometrically resampled. Feature selection and statistical transforms are used to reduce the Hyperion feature space from 86 channels to 14 features. Classes chosen for discrimination included Larch, Spruce, Oak, Birch, Popular and Mixed forest and other landuses. Classification accuracies have been obtained for each sensor. Comparison of the classification results shows : Hyperion classification results were the best, ALI's were much better than ETM+.

• 한국환경복원기술학회지
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• 제13권4호
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• pp.52-64
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• 2010

This study was carried out to analyze the occurrence characteristics and the influence of forest environment factors on the debris flow of 3 national parks in korea. The results obtained from this study were summarized as follows; The total number of debris flow occurrence was 125 areas. The average length of the debris flow scar was 144m, average width was 20m. And the average area and sediment were $2,854m^2$ and $3,959m^3$ respectively. The factors influencing the debris flow were highly occurred in Metamorphic rock, mixed forest type. And also, slope gradient was $30{\sim}35^{\circ}$, aspect was NE, altitude was over 1,000m, vertical and cross slope was concave (凹), soil depth was below 15cm, stream order was 0 order. The variables of cross slope (complex), deciduous tree, soil depth (over 46cm), cross slope (concave), mixed forest type and altitude (801~1200m) in correlation analysis were significant at 1 % level. The landslide of high mountain area highly tend to change the debris flow in stream bed of torrent. The debris flow in national parks mainly occurred in high mountain area with long ridge and steep slope.

• 펄프종이기술
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• 제42권4호
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• pp.64-70
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• 2010

In this study, hemicelluloses were pre-extracted from mixed hardwood chips using sodium hydroxide solution and then they were isolated from pre-extractives by using various solvents. Isolation was conducted by precipitating hemicelluloses with isopropanol, ethanol, 1,4-dioxane, dimethylsulfoxide (DMSO) and potassium hydroxide (KOH), respectively. The precipitate yield on alkali pre-extractives was the highest when hemicelluloses were isolated by DMSO and then precipitated with ethanol. Most precipitates were yellow colored. The efficiency of isolation was evaluated by analysing the characteristics of isolated hemicelluloses. Isolation using DMSO, KOH and 1,4-dioxane ($80^{\circ}C$) showed rather high efficiency. The highest total separation efficiency was about 77% when alkali pre-extractives were reacted with KOH and precipitated with ethanol. The quantity and purity of isolated hemicelluloses were affected by the solvent type.