• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.72-74
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• 2003

Forest canopy density is an ideal representative of the forest habitat situations. It can directly or indirectly depict the canopy structure and gap size in the forestland, thus could be applied to assessment of wildlife’s diversit y. Since population survey of vegetation and wildlife diversities is a key issue for sustainable forest ecosystem management, many research efforts have been focused on forest canopy density using multispectral data in the last two decades. Unfortunately, prediction of canopy density using large scaling remote sensing data remains a challenging issue. Due to recent advances in hyperspectral image sensors hyperspectral imagery is now available for environmental monitoring. In this paper, we conduct experiments to monitor complicated environments of forestland that can be captured by using hyperspectral imagery and further be analyzed to test a prediction model of forest canopy density. The results show that 95% of canopy density could be well described by using 2 difference vegetation indices (DVIs), which are difference of blue and green reflectances rband_100-rband_150 and difference of 2 short wave infrared reflectancse rband_406-rband_410 With the wavelengths of band no. 100, 150, 406, and 410 specified by 462.39 nm, 534.40 nm, 918.22 nm and 924.41 nm respectively.

• Korean Journal of Remote Sensing
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• v.16 no.4
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• pp.327-338
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• 2000

The forest conditions of North Korea has been a great concern since it was known to be closely related to many environmental problems of the disastrous flooding, soil erosion, and food shortage. To assess the long-term changes of forest area as well as the canopy conditions, several sources of multitemporal satellite data were applied to the study area near Kaesung. KOMPSAT-1 EOC data were overlaid with 1981 topographic map showing the boundaries of forest to assess the deforestation area. Delineation of the cleared forest was performed by both visual interpretation and unsupervised classification. For analyzing the change of forest canopy condition, multiple scenes of Landsat and SPOT data were selected. After preprocessing of the multitemporal satellite data, such as image registration and normalization, the normalized difference vegetation index (NDVI) was derived as a representation of forest canopy conditions. Although the panchromatic EOC data had radiometric limitation to classify diverse cover types, they can be effectively used t detect and delineate the deforested area. The results showed that a large portion of forest land has been cleared for the urban and agricultural uses during the last twenty years. It was also found that the canopy condition of remaining forests has not been improved for the last twenty years. It was also found that the canopy condition of remaining forests has not been improved for the last twenty years. Possible causes of the deforestation and the temporal pattern of canopy conditions are discussed.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.1055-1066
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• 2018

Vegetation indices on the basis of optical characteristics of vegetation can represent various conditions such as canopy biomass and physiological activity. Those have been mostly developed with the large-scaled applications of multi-band optical sensors on-board satellites. However, the sensitivity of vegetation indices for detecting vegetation features will be different depending on the spatial scales. Therefore, in this study, the investigation of photochemical reflectance index (PRI), known as one of useful vegetation indices for detecting photosynthetic ability and vegetation stress, under the three spatial scales was conducted using multi-spectral camera installed in unmanned aerial vehicle (UAV),field spectrometer, and leaf reflectometer. In the leaf scale, diurnal PRI had minimum values at different local-time according to the compass direction of leaf face. It meant that each leaf in some moment had the different degree of light use efficiency (LUE). In early growth stage of crop, $PRI_{leaf}$ was higher than $PRI_{stands}$ and $PRI_{canopy}$ because the leaf scale is completely not governed by the vegetation cover fraction.In the stands and canopy scales, PRI showed a large spatial variability unlike normalized difference vegetation index (NDVI). However, the bias for the relationship between $PRI_{stands}$ and $PRI_{canopy}$ is lower than that in $NDVI_{stands}$ and $NDVI_{canopy}$. Our results will help to understand and utilize PRIs observed at different spatial scales.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.328-330
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• 2003

The land cover of burned area has changed dramatically since Daxinganling forest fire in Northeastern China during May 6 ? June 4, 1987. This research focused on determining the burn severity and assessment of forest recovery. Burned severity was classified into three levels from June 1987 Landsat TM data acquired just after the fire. A regression model was established between the forest canopy closure from 1999 forest stand map and the NDVI values from June 2000 Landsat ETM+ data. The map of canopy closure was got according to the regression model. And vegetation cover was classified into four types according to forest closure density. The change matrix was built using the classified map of burn severity and vegetation recovery. Then the change conversions of every forest type were analyzed. Results from this research indicate: forest recovery status is well in most of burned scars; and vegetation change detection can be accomplished using postclassification comparison method.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.7-10
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• 2005

Plant water deficiency during drought season causes physiological stress and can be a critical indicator of forest fire vulnerability. In this study, we attempt to analyze the spectral characteristics of water stressed vegetation by using the laboratory measurement on leaf samples and the canopy reflectance spectra extracted from satellite hyperspectral image data. Leaf-level reflectance spectra were measured by varying moisture content using a portable spectro-radiometer. Canopy reflectance spectra of sample forest stands of two primary species (pine and oak) located in central part of the Korean peninsula were extracted from EO-l Hyperion imaging spectrometer data obtained during the drought season in 2001 and the normal precipitation year in 2002. The preliminary analysis on the reflectance spectra shows that the spectral characteristics of leaf samples are not compatible with the ones obtained from canopy level. Although moisture content of vegetation can be influential to the radiant flux reflected from leaf-level, it may not be very straightforward to obtain the spectral characteristics that are directly related to the level of canopy moisture content. Canopy spectra form forest stands can be varied by structural variables (such as LAt, percent coverage, and biomass) other than canopy moisture content.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.80-94
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• 2010

The purpose of this study is suggest to restoration model of Pinus thunbergii in Saha-gu, Busan. The result of this study is summarized as follows. As the results of this study, vegetation restoration model is presented by separating community planting and edge planting. In community planting, as a group of canopy, there are 6 species; Pinus thunbergii, Quercus acutissima, Quercus dentata, Quercus serrata, Quercus alienna, Quercus variabilis. As a group of understory, there are 5 species; Platycarya strobilacea, Prunus sargentii, Styrax japonica, Eurya japonica, Morus bombycis. Also as a group of shrub, there were 15 kinds of species; Ulmus pavifolia, Ulmus davidiana, Lindera obtusiloba, Elaeagnus macrophylla, Mallotus japonicus, Ligustrum obtusifolium, Sorbus alnifolia, Rhus trichocarpa, Zanthoxylum schinifolium, Rosa wichuraiana, Rhus chinensis, Viburnum erosum, Rhododendron mucronulatum, Rhododendron yedoense, Indigofera pseudotinctoria. And as a group of edge vegetation, there were 10 kinds of species; Japanese Angelica, Symplocos chinensis, Pittosporum tobira, Lespedeza maximowiczii, Lespedeza bicolor, Rubus coreanus, Rubus idaeus, Vitis thunbergii, Ampelopsis brevipedunculata, Rosa multiflora. Vegetation restoration models of Pinus thunbergii community were calculated the units $400m^2$ for the average populations of the woody layer is 24 in canopy layer, 35 in understory layer, 410 in shrub layer, 34% herbaceous layer ground cover. And the average of breast-high area and canopy area is $10,852cm^2$ in canopy layer, in understory layer $1,546cm^2$, in shrub layer $1,158,660cm^2$. The shortest distance between trees is calculated as 2.0m in canopy layer, 1.9m in understory layer.

• Journal of Fisheries and Marine Sciences Education
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• v.17 no.3
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• pp.404-412
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• 2005

The surface energy budget depends on many factors, such as the type of surface, the soil moisture and the vegetation canopy, the geographical location, daily, monthly and seasonal variations, and weather conditions. In the coastal region, the surface is not homogeneous at various scales for instance water, sand, mud, tall grass, and crops. The energy balance over the vegetation canopy was analyzed with the optical energy balance measuring system. The latent heat flux was more intensive than the sensible heat flux. The sensible heat flux was very small in summer due to the canopy effect and higher in spring and autumn. In summer the development of the atmospheric boundary depended on rather the vertical shear of wind than the sensible heat flux.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.249-259
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• 2019

We investigated the tritrophic interactions associated with elevation and openness of dwarf bamboo (Sasa quelpaertensis Nakai) vegetation on Mt. Halla, Jeju Island. The interactions between dwarf bamboo plants and its consumers were investigated in four study sites with and without canopy along the elevation gradient. The ecological traits of dwarf bamboo included leaf area, water content, nitrogen content and carbon/nitrogen ratio. Arthropods were collected using a sweeping net and they were later divided into three different feeding guilds: herbivorous, omnivorous and predators. We found that the elevation and canopy openness on dwarf bamboo vegetation was positively related and as elevation increased and canopy opened, the bamboo densities and C/N ratio increased. However, the leaf area, water content and the N content decreased. The study sites with closed canopy indicated a relatively higher species richness of arthropods including insects. We concluded that the tritrophic interactions is closely related to the ecological characteristics of the dwarf bamboos, which is affected by elevation and canopy openness.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.86-92
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• 1999

Evapotranspiration is one of important variables affecting ecosystem processes such as vegetation distribution and growth. It acts as a limiting factor for natural water resource management. The transpiration of vegetation is mainly determined by climatic factors. The lower slope of the study area was densely forested with Pinus densiflora S. et Z. of 8 m height, and the upper slope was covered with poorly grown Pinus densiflora S. et Z. and Quercus trees. The amount of evapotranspiration was estimated to 590.3 mm/yr by annual water budget method. The canopy resistance of Penman-Monteith model was determined as 99 s/m. Seasonal evapotranspiration can be estimated with the calculated evaporation and the canopy resistance. The amount of evapotranspiration peaked in May. That is considered from both the direct evaporation of intercepted rainfall and the transpiration of vegetation during the dry spring season.

• Proceedings of the KSRS Conference
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• 2004.10a
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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.