• 대한원격탐사학회지
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• 제22권5호
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• pp.313-323
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• 2006

Forest Canopy Density is a dynamic process mediated by various natural and anthropogenic factors. It can be changed over time and locations in the same forest type and landscape. However, human dimensions are considered as the primary force of landscape change and subsequent forest canopy loss in tropical regions of the world. Many studies have been indicated that roads have a far greater impact on forests than simply allowing access for human use. Similarly, rivers have been used as means of transportation, hence illegal logging and felling further deplete forest canopy density. The main objective of this study was to investigate the spatio-temporal dynamic alterations of Forest Canopy Density (FCD) across with site associated factors such as biophysical, physical and human interferences in tropical region of Nepal from 1988 to 2001. Landsat TM and ETM+ of 1988 and 2001 were used to assess the spatial and temporal dynamic alterations of FCD. This analysis revealed that distance to human settlements at P=<0.01, rivers, human interferences (path and fire) and species composition had a statistically significance at P=<0.05 level. However, other factors did not show any significant relation. So, we concluded that understanding of dynamic alterations of FCD with respect to factors was quite complex phenomena. Other surrounding environment could also playa significant role. A comprehensive analysis could be required to understand such complexities. Therefore, additional factors such as climatic, biophysical, social, and institutional with respect to spatio-temporal variability should be considered for the better understanding of canopy dynamic.

• 한국산림과학회지
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• 제88권1호
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• pp.38-46
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• 1999

독일 중부(Solling Hills)의 가문비림 임관의 구조적인 수분증산 통도특성은 LE와 H의 유동량으로 측정되고, 1996년 6월중 재배열된 Penman-Monteith 식을 이용하여 SVAT 모형을 설계하여 도출하였다. 또한 SLODSVAT 모형을 통한 전체 임관 내 각 침엽의 연속적인 수분통도성을 평가하여 임관기공의 통도성을 비교하였다. 이와 같은 결과에서 나온 임관 표면 통도성과 유동량을 설계하고, SLODSVAT 모형에 의해 설계된 기공 통도성 사이에서 중요한 차이점을 알 수 있었다. 이 차이점은 산림 임관의 범위내에 빗물리적인 요소에 의해 영향을 받았음을 알 수 있으며, 일반적으로 임관 표변의 통도성은 전체 측정 기간 동안 임관 기공 전도력보다 크게 나타났다. 또한 산림의 전체 증발산량에 대한 하층부의 공헌도는 작았고, 임관의 복사에너지 균형에 의존하지는 않는 것으로 나타났다. 하층부 증발산량의 기각은 독일 가문비림에 대한 임관 표면 전도력의 과대 평가로서 나타난 결과이다.

• 대한원격탐사학회지
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• 제22권5호
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• pp.305-311
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• 2006

Although there have been several attempts to estimate forest LAI using optical remote sensor data, there are still not enough evidences whether the NDVI is effective to estimate forest LAI, particularly in fully closed canopy situation. In this study, we have conducted a simple correlation analysis between LAI and spectral reflectance at two different settings: 1) laboratory spectral measurements on the multiple-layers of leaf samples and 2) Landsat ETM+ reflectance in the close canopy forest stands with fieldmeasured LAI. In both cases, the correlation coefficients between LAI and spectral reflectance were higher in short-wave infrared (SWIR) and visible wavelength regions. Although the near-IR reflectance showed positive correlations with LAI, the correlations strength is weaker than in SWIR and visible region. The higher correlations were found with the spectral reflectance data measured on the simulated vegetation samples than with the ETM+ reflectance on the actual forests. In addition, there was no significant correlation between the forest.LAI and NDVI, in particular when the LAI values were larger than three. The SWIR reflectance may be important factor to improve the potential of optical remote sensor data to estimate forest LAI in close canopy situation.

• 한국산림과학회지
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• 제96권2호
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• pp.227-234
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• 2007

The forest canopy gap has been well known as a substantial process of forest cyclic regeneration and important role in stand structure, dynamics, and biodiversity of the forest ecosystem. Based on 3,600 $5m{\times}5m$ square grids in a 9ha permanent experimental plot, the study was conducted to evaluate the regeneration pattern of woody species by developmental stage {seedlings (<1 m of height), saplingI (>1 m of height, <2 cm of DBH), and saplingII (2 cm$<200m^2$), $201-400m^2$, $400-600m^2$, $601-800m^2$, and $>800m^2$) in the mixed broadleaved-Korean pine forest. The results indicated that the regenerating trees of Populus ussuriensis occurred only in the canopy gap area, considered to be a typical gap-dependent species. The regeneration of Ulmus japonica, Ulmus laciniata, and Maackia amurensis could be generally satisfied with the gap size of $201-600m^2$, Betula costata and Prunus padus with gap size of $401-800m^2$, Picea koraiensis with gap size of $201-800m^2$, Fraxinus mandshurica and Syringa reticulata var. mandshurica with smaller than $800m^2$, respectively. Acer ukurunduense and Acer tegmentosum were likely to have no problem with the gap size to make gap regeneration. Acer mono and Tilia amurensis looked more capable of regenerating in the closed canopy disregarding the upper crown condition. The regeneration of Pinus koraiensis and Abies nephrolepis had no trouble under the canopy condition in less than $800m^2$of gap size. The density of regenerating shrubs was rather high, especially under the closed canopy, considered to be associated with great amount of regeneration production in such shade tolerant species as Lonicera maackii, Corylus mandshurica, Euonymus pauciflorus, and Philadelphus schrenkii under the closed canopy. Pearson correlation coefficient was computed to compare the similarity among non-gap area and five gap size classes by developmental stages for trees and shrubs. The similarity coefficients among closed canopy and the gap size classes were mostly significantly correlated to each other with a few exceptions.

• 한국산림과학회지
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• 제102권2호
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• pp.247-254
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• 2013

본 연구의 목적은 우리나라 주요 침엽수종을 대상으로 수관층 연료특성을 비교 분석하여 수관화 확산 위험성을 평가하고자 하였다. 본 연구에서는 국립산림과학원에서 개발된 바이오매스 추정식과 제 5차 국가산림자원조사자료를 활용하였으며, 이를 통해 임분단위 수관연료량과 지하고를 추정할 수 있는 모델을 개발하였다. 연구 결과에 의하면 잣나무림의 평균 수관연료밀도는 0.34 kg/$m^3$으로 가장 높게 나타났으며, 강원지방소나무림 0.28 kg/$m^3$, 곰솔림 0.15 kg/$m^3$, 리기다소나무림 0.15 kg/$m^3$, 중부지방소나무림 0.12 kg/$m^3$, 일본잎갈나무림 0.09 kg/$m^3$ 순으로 나타났다. 임분단위 수관연료량 추정식 모형의 조정결정계수($R^2_{adj}$)는 0.6321~0.9950, 지하고 추정식 모형의 조정결정계수($R^2_{adj}$)는 0.6390~0.8536의 범위를 보였다.

• 농업과학연구
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• 제50권4호
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• pp.663-673
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• 2023

The purpose of this study was to scientifically activate the forest healing program activities for the elderly. The predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD), which are indices of thermal comfort in the thermal environment, and degree of canopy closure were compared and analyzed. Based on this information, the study objective was to present the appropriate conditions for maintaining the best comfort for the elderly. Six deck road shelters, which are the most active locations in forest healing programs among the National Center for Forest Therapy, were selected as the study sites. The results indicated that in the case of the conditions of 1 clo (clothing insulation value) and 1 met (metabolic rate) at an air temperature of 19 to 21 degrees in September on the measurement date, the PMV values ranged between -1.85 and -0.98 at all sites, and PPD values ranged between 25.60% and 68.68%. On the other hand, in the case of 1.3 clo and 1.6 met conditions, the PMV values ranged between -0.08 and 0.23 for all sites and PPD values ranged between 5.40 and 6.18. As shown above, the difference in thermal environment comfort and satisfaction according to the condition of the amount of metabolism and the amount of clothing could be confirmed. In addition, an analysis of the relation between PPD and canopy closure suggested a significantly positive correlation between them, and it was found that canopy closure was a factor affecting thermal comfort. Studies on effects of forest thermal environmental comfort and canopy closure on forest healing program areas should be conducted extensively according to seasonal conditions to provide information that can be used for more effective forest healing programs.

• 한국산림과학회지
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• 제107권4호
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• pp.412-421
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• 2018

본 연구는 산림시업이 소나무임분의 수관연료특성 변화에 미치는 영향을 예측하고자 하였다. 본 연구에서는 국가산림자원자료 중 시업지 1,085 stands, 비시업지 349 stands의 표본점 자료를 분석에 이용하였으며, Weibull 함수를 사용하여 시간에 따른 임분생장과 수관연료특성에 대해 예측하였다. 산림시업유무에 따른 수관연료특성을 비교해본 결과 비시업지 임분이 시업지 임분에 비해 평균 수관연료량은 약 14% 높게 나타났으며, 연소가능한 수관연료밀도 또한 약 16% 높게 나타났다. Weibull 함수를 사용하여 임령 40년, 50년, 60년의 생장 예측과 수관연료특성 변화를 비교해본 결과, 시업지 임분은 시간이 지남에 따라 중경목, 대경목에 최대임목본수의 증가가 예측된 반면, 비시업지 임분은 소경목, 중경목에서 최대임목본수가 예측되었다. 비시업지 임분이 시업지 임분에 비해 수관연료량, 수관연료밀도의 증가량이 높게 나타나 수관화로의 확산 가능성이 높은 것으로 사료되었다.

• 한국산림과학회지
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• 제89권5호
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• pp.543-551
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• 2000

소나무의 갱신 특성을 구명하기 위하여 강원도 평창군 중왕산 지역 소나무 천연림에서 교란에 의해 형성된 숲틈을 대상으로 line-transect 조사법에 의해 소나무의 수관 architecture 특성을 조사, 분석하였다. 갱신 초기단계에 소나무는 숲틈에서 생장환경에 적응능력을 나타내었고 소개된 임분에서 자라는 소나무에 비해 architecture 특성은 다르게 나타났다. 소나무 천연림내 숲틈에서 소나무의 주 가지의 분지각의 변이폭은 작았고 주 가지의 길이 생장량은 가지 연령이 4~5년생 일 때까지 비교적 크게 나다났고 그 이후에는 점차 작아졌다. 숲틈에서 소나무의 줄기로부터는 주 가지가 평균 5개씩 발생하였고 주가지에서는 잔가지가 평균 4개씩 발생하였다. 줄기에서 발생한 주 가지는 방위별로 균일한 분포양상을 나타내었지만 주가지에서 발생하는 잔가지의 수는 숲틈의 크기가 $100{\sim}120m^2$이하일 때 주로 $S44^{\circ}E{\sim}S90^{\circ}W$ 사이의 방위에 많이 분포하였다.

• 대한원격탐사학회지
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• 제28권3호
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• pp.297-305
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• 2012

This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

• The Korean Journal of Ecology
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• 제18권2호
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• pp.219-230
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• 1995

Although many studies of nutrient cycling in forest ecosystems have reported that clearcutting creates increased organic matter decomposition and nitrogen (N) mineralization in soils, little is known about the change of these factors following various levels of canopy removal. A series of experimental plots with four levels of canopy cover, i.e., clearcut, 25％, 75％, and uncut, was established in northern red oak (Quercus rubra L.) stands in northern Lover Michigan, U.S.A. I examined decomposition of cellulose filter papers and N mineralization using an in situ soil incubation technique in the top 15cm of mineral soil during the second growing season (1992, May-October) following stand manipulation. Mass loss from cellulose filter papers was more rapid in the canopy removal treatments than in the uncut treatment. similarly, net N mineralization was significantly greater in the canopy removal treatments than in the uncut treatment. There was no significant difference in net N mineralization rates among the three levels of canopy removal. Net N mineralization for the growing season was 58 kg/ha for the clearcut, 54 kg/ha for the 25％ canopy cover, 51 kg/ha for the 75％ canopy cover, and 22 kg/ha for the uncut treatment. These results indicated that even only small amounts of canopy removal (leaving 75％ canopy cover) let to substantial increases of cellulose decomposition and the amount of available soil nitrogen.