• 한국산림과학회지
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• 제111권3호
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• pp.435-449
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• 2022

대면적 산림의 정확한 임분고 측정은 산림경영, 산림 탄소량 추정, 산림 생태계 관리를 위한 필수적인 지표인자로 다수의 국가에서 주기적인 현장조사를 수행하고 있다. 하지만, 현장조사는 많은 비용 및 시간 소요, 접근의 용이성이 낮은 지역의 조사의 기술적 한계성을 가지고 있다. 이를 극복하기 위한 대안으로 원격탐사 기술을 이용한 수고 및 임분고 추정 연구가 활발하다. 이에 본 논문에서는 해외 및 국내의 다양한 원격탐사기반 수고 및 임분고 추정 연구 사례를 분석하여 원격탐사기반 임분고 추정 연구의 동향을 크게 LiDAR기반, Stereo 및 SAR 이미지 점군(Image-based Point Clouds)기반, 원격탐사자료 융합기반 임분고 추정 모델로 나누어 살펴보았다. 또한, 대면적의 전국단위 산림 임분고 추정을 위한 원격탐사자료의 업스케일링(Upscaling) 기법의 사례 분석을 통해 향후 국내 산림환경 및 현황에 적합한 원격탐사기반 전국단위 산림 임분고 추정을 위한 방법의 발전 방향성을 고찰하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.638-641
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• 2004

Returned laser pulse has certain relationship with vegetation canopy structure (canopy closure, height, LAI, biomass). This study attempts to analyze the characteristics of airborne laser scanner data over very dense forest canopy. Discrete pulse laser scanner data were obtained on April 25, 2004 along with digital aerial color imagery. Using forest stand maps, 14 sample stands of 7 species groups were selected and the elevations from the first and last laser return were compared. From the preliminary analysis, we found that the difference between the first and last return was higher with deciduous forest stand than in coniferous stand. Although difference between the first and the last laser returns often corresponds to tree height, it would not be the case for the forest site having very dense canopy structure.

• 대한원격탐사학회지
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• 제28권3호
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• pp.307-318
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• 2012

To understand forest structures, the Geoscience Laser Altimeter System (GLAS) instrument have been employed to measure and monitor forest canopy with feasibility of acquiring three dimensional canopy structure information. This study tried to examine the potential of GLAS dataset in measuring forest canopy structures, particularly maximum canopy height estimation. To estimate maximum canopy height using feasible GLAS dataset, we simply used difference between signal start and ground peak derived from Gaussian decomposition method. After estimation procedure, maximum canopy height was derived from airborne Light Detection and Ranging (LiDAR) data and it was applied to evaluate the accuracy of that of GLAS estimation. In addition, several influences, such as topographical and biophysical factors, were analyzed and discussed to explain error sources of direct maximum canopy height estimation using GLAS data. In the result of estimation using direct method, a root mean square error (RMSE) was estimated at 8.15 m. The estimation tended to be overestimated when comparing to derivations of airborne LiDAR. According to the result of error occurrences analysis, we need to consider these error sources, particularly terrain slope within GLAS footprint, and to apply statistical regression approach based on various parameters from a Gaussian decomposition for accurate and reliable maximum canopy height estimation.

• 환경영향평가
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• 제17권5호
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• pp.279-288
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• 2008

Vertical forest distribution is one of the important factors to understand various ecological mechanism such as succession, disturbance and environmental effects. LiDAR data provide information, both the horizontal and vertical distribution of forest structure. The laser scanner survey provided a point cloud, in which the x, y, and z coordinates of the points are known. The objectives of this study were 1) to analyze factors of forest structure such as individual tree isolation, tree height, canopy closure and tree density using LiDAR data and 2) to compare the forest structure between outer and interior forest. The paper conducted to extract the individual tree using watershed algorithm and to interpolate using the first return of LiDAR data for yielding digital surface model (DSM). The results of the study show characters of edge such as more isolated individual trees, higher density, lower canopy closure, and lower tree height than those of interior forest. LiDAR data is to be useful for analyzing of forest structure. Further study should be undertaken with species for more accurate results.

• 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.

• 대한원격탐사학회지
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• 제36권2_2호
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• pp.325-335
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• 2020

식생 높이는 높이-탄소식생량 추정 모델을 이용하여 식생탄소량은 측정하는데 사용된다. 접근이 힘든 지역의 망그로브 생태는 현장 자료를 취득하는데 어려움이 있으며, 제한적인 현장 자료로부터 대규모 식생량 및 탄소양모델을 연구하는데 한계점이 있다. 능동형과 수동형 원격탐사 기법이 망그로브 식생 연구에 활용되고 있으나, 공간 해상도의 한계로 인해 작은 규모의 특징을 감지하는데 문제가 있다. 이 논문에서는 TanDEM-X 자료를 이용하여 SRF 지역 12 m 공간 해상도 망그로브 식생 높이 분포를 측정하였다. 단일 편파를 사용하였지만, 수면과 망그로브 식생 사이에서 일어나는 이중 반사 현상을 이용하여 망그로브 숲 지역의 수면의 높이를 측정하여 식생 높이를 측정하는 새로운 인버젼 모델을 사용하였다. TanDEM-X 식생 높이 결과를 모자이크하여 SRF 전 지역의 대규모 식생 높이 지도를 제작하였다. 현장 자료와 검증한 결과 상관계수 0.83, RMSE 0.84 m로 나타났다. 전 세계를 관측한 TanDEM-X 자료를 이용하면, 고해상도 글로벌 망그로브 식생 높이 지도 제작이 가능함을 보여주었다. 이러한 결과들은 망그로브 식생탄소량 및 탄소 순환을 이해하는데 중요한 역할을 할것으로 기대된다.

• 한국산림과학회지
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• 제94권5호통권162호
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• pp.321-329
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• 2005

Based on the data representing four typical Korean pine forest types, the age structure, DBH distribution, species composition, and forking rule were systemically analyzed for old-growth Korean pine forest in Liangshui Nature Reserve, northeast China. The age structure of Korean pine trees was strongly uneven-aged with one dominated peak following normal distribution, and age of trees varied from 100 to 180 years within a stand. The DBH and height differences in same age class (20 years) varied from 28 cm~64 cm and 5 to 20 m, respectively. Many conifer and hard wood species, such as spruce, fir, costata birch, basswood, oak, and elm, were mixed with dominated trees of Korean pine. The canopy of the old-growth Korean pine forest can be divided into two layers, and differences of mean age and height between Layer I and Layer II were ranged 80~150 years and 7~13 m, respectively. The Weibull function was used to model the diameter distribution and performed well to describe size-class distribution either with a single peak in over-story canopy and inverse J-shape in under-story canopy for old-growth Korean pine stands. The forking height of Korean pine trees ranged from 16m to 24 m (mean 19.4 m) and tree age about 120 to 160 years old. The results will provide a scientific basis to protect and recover the ecosystem of natural old-growth Korean pine and also provide the model in management of Korean pine plantation.

• 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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• 제97권5호
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• pp.540-546
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• 2008

Enrichment planting has been used as one of the promising restoration techniques to accelerate the natural restoration process of secondary forests or logged-over forests in Myanmar, The objectives of this study were to examine the growth performances of two commercial species such as Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) in response to different canopy opening treatments and to examine the suitability of these species in enrichment planting activities for the restoration of degraded tropical forests in Myanmar. In this study, split plot design was applied, and three levels of canopy openings were experimented. The survival rate and height growth of two species were measured four times with 6 month interval. The root collar diameter (RCD) was also measured in the last assessment. Although the survival rate of seedlings was not significantly different among the three treatments (p>0.05) as well as between two species (p>0.05) for all consecutive measurements, height (p<0.05) and RCD were significantly different (p<0.001) among the treatments, T. grandis seedlings thrived best under complete canopy opening (i.e., 5 m width canopy opening with strip-clear cutting) while P. macrocarpus seedlings under partial canopy opening (without felling of marketable tree species). Because this study is concerned with only for young stage of seedlings, continuous assessment and follow-up tending activities are needed to verify the species suitability and optimum width of canopy opening for enrichment planting activities in restoration of degraded forests of Myanmar.

• Journal of Ecology and Environment
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• 제41권1호
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• pp.1-8
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• 2017

Background: Though the biomass of floral vegetation in understory plant communities in a forested ecosystem only accounts for less than 1% of the total biomass of a forest, they contain most of the floral resources of a forest. The diversity of understory honey plants determines visitation rate of pollinators such as honey bee (Apis mellifera) as they provide rich food resources. Since the flower visitation and foraging activity of pollinators lead to the provision of pollination service, it also means the enhancement of plant-pollinator relationship. Therefore, an appropriate management scheme for understory vegetation is essential in order to conserve pollinator population that is decreasing due to habitat destruction and disease infection. This research examined the diversity of understory honey plant and studied how it is related to environmental variables such as (1) canopy density, (2) horizontal heterogeneity of canopy surface height, (3) slope gradient, and (4) distance from roads. Vegetation survey data of 39 plots of mixed forests in Chuncheon, Korea, were used, and possible management practices for understory vegetation were suggested. Results: This study found that 113 species among 141 species of honey plant of the forests were classified as understory vegetation. Also, the understory honey plant diversity is significantly positively correlated with distance from the nearest road and horizontal heterogeneity of canopy surface height and negatively correlated with canopy density. Conclusions: The diversity of understory honey plant vegetation is correlated to vegetation structure and human impact. In order to enhance the diversity of understory honey plant, management of density and height of canopy is necessary. This study suggests that improved diversity of canopy cover through thinning of overstory vegetation can increase the diversity of understory honey plant species.