• Journal of Korea Water Resources Association
• /
• v.54 no.11
• /
• pp.875-889
• /
• 2021

This study compares and analyzes the Soil and Water Assessment Tool (SWAT) and Terra MODIS (Moderate Resolution Imaging Spectroradiometer) as coniferous, deciduous and mixed forest with Yongdam Dam upstream (904.4 km²). The hydrologic evaluation period was set to 10 years from 2010 to 2019, and the applicability of the 8-day MOD15A2 Leaf Area Index (LAI) data, 3 TDR (Time Domain Reflectometry) (GB, JC, CC), and 1 Flux Tower (DU) evaporation volume (YDD) data was simulated. As a result, the R² of coniferous forest, deciduous forest and mixed forest are 0.95, 0.89, 0.90, soil moisture and evaportranspiration stations R² were analyzed at 0.50 to 0.55 and 0.51, respectively, with R² at 0.74, RMSE 2.75 mm/day, NSE 0.70 and PBIAS 14.3% for Yongdam inflow. Based on the calibrated and validated watersheds, the annual average evaportranspiration was calculated as coniferous 469.7 mm, deciduous 501. mm and 511.5 mm mixed forest, total runoff were estimated at coniferous 909.8 mm, deciduous 860.6 mm and 864.2 mm mixed forest. In the case of annual average evaportranspiration, it was evaluated that deciduous were high, but in the case of streamflow, it was evaluated that coniferous were high. Unlike other hydrologic with similar patterns throughout the year, the average annual evapotranspiration was about 7% higher than coniferous due to the higher evapotranspiration of deciduous with high leaf area index in summer and fall. In addition, deciduous were 9% and 6% higher for surface runoff and lateral flow, but the groundwater of coniferous was 77% higher. Therefore, it was confirmed that the total runoff was in order of coniferous, mixed forest, and deciduous.

• Journal of Ecology and Environment
• /
• v.31 no.2
• /
• pp.153-159
• /
• 2008

The timing of the canopy phenology onset (CPO hereafter) indicates the initiation of the growing season, with rapid increases in exchange rates of carbon dioxide and water vapor between vegetation and atmosphere. The CPO is regarded as a potential indicator of ecosystem responses to global warming, but the CPO shows considerable spatial variation depending on the species composition and local temperature regime. at a given geographic location. In this study, we evaluated the utility of satellite observation data for detection of the timing of the CPO. Leaf area indices (LAI) obtained from the Moderate Resolution Imaging Spectrora-diometer (MODIS) were utilized to detect and map the onset dates from 2001 to 2006. The reliability of MODIS-based onset dates was evaluated with ground measured cherry blossom flowering data from national weather stations. The MODIS onset dates preceded the observed flowering dates by 8 days and were linearly related with a correlation coefficient of 0.58 (p < 0.05). In spite of the coarse spatial (1 km) and temporal (8 days) resolutions of MODIS LAI, the MODIS-based onset dates showed reasonable ability to predict flowering dates.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.22 no.1
• /
• pp.13-19
• /
• 2020

This study compared RGB color images with canopy light interception (LI) and leaf area index (LAI) measurements for low cost and low labor. LAI and LI were measured from vertical gap fraction derived from top of digital image in soybean canopy cover (cv Daewonkong, Deapongkong and Pungsannamulkong). RGB color images, LAI, and LI were collected from V4.5 stage to R5stage. Image segmentation was based on excess green minus excess red index (ExG-ExR). There was a linear relationship between LAI measured with LI (r²=0.84). There was alinear relation ship between LI measured with canopy cover on image (CCI) (r²=0.94). There was a significant positive relationship(r²=0.74) between LAI and CCI at all grow ingseason. Therefore, it is expected that in the future, the RGB color image could be able to easily measure the LAI and the LI at low cost and low labor.

• Proceedings of the KSRS Conference
• /
• 2004.10a
• /
• pp.638-641
• /
• 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.

• The Korean Journal of Quaternary Research
• /
• v.17 no.2
• /
• pp.163-163
• /
• 2003

The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest zone. At the old-growth deciduous forest near Soribong-peak (533.1m) in KEF, we have established a permanent plot and a flux tower, and the site was registered as a KLTER site and also a KoFlux site. In this study, we aimed to present basic ecological characteristics and synthetic data of carbon budgets and flows, and some monitoring data which are essential for providing important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function. We made a stemmap of trees in 1 ha plot and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area 28.0 m2/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66cm. Soil texture is loam or sandy loam, and its pH was from 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the l.2m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. Litterfall was collected in circular littertraps (collecting area： 0.25m2) and mass loss rates and nutrient release patterns in decomposing litter were estimated using the litterbag technique employing 30cm30cm nylon bags with l.5mm mesh size. Total annual litterfall was 5,627 kg/ha/year and leaf litter accounted for 61% of the litterfall. The leaf litter quantity was highest in Quercus serrata, followed by Carpinus laxiflora and C. cordata, etc. Mass loss from decomposing leaf litter was more rapid in C. laxiflora and C. cordata than in Q. serrata litter. About 77% of C. laxiflora and 84% of C. cordata litter disappeared, while about 48% in Q. serrata litter lost over two years. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. And then we have drawn a schematic diagram of carbon budgets and flows in each compartment of the KEF site.

• Korean Journal of Plant Taxonomy
• /
• v.52 no.4
• /
• pp.255-261
• /
• 2022

Clerodendrum ervatamioides C. Y. Wu was described in 1977 with its type locality in Yunnan, China. During our floristic investigation in the Muong Nhe Nature Reserve of Vietnam of Dien Bien province and in the Muong Te district of the Lai Chau province, we collected several specimens of Clerodendrum ervatamioides, marking the first record of its occurrence in Vietnam. In this paper, details of the morphological features, distribution, ecology, photo plates, and a table comparing the morphological features with its ally Clerodendrum garrettianum Craib are provided.

• Korean Journal of Remote Sensing
• /
• v.33 no.5_1
• /
• pp.571-585
• /
• 2017

The number of spaceborne optical sensors including red-edge band has been increasing since red-edge band is known to be effective to enhance the information content on biophysical characteristics of vegetation. Considering that the Agriculture and Forestry Satellite is planning to carry an imaging sensor having red-edge band, we tried to analyze the current status and potential of red-edge band. As a case study, we analyzed the effect of using red-edge band and tried to find the optimum band width and wavelength region of the red-edge band to estimate leaf area index (LAI) of very dense tree canopy. Field spectral measurements were conducted from April to October over two tree species (white oak and pitch pine) having high LAI. Using the spectral measurement data, total 355 red-edge bands reflectance were simulated by varying five band width (10 nm, 20 nm, 30 nm, 40 nm, 50 nm) and 71 central wavelength. Two red-edge based spectral indices(NDRE, CIRE) were derived using the simulated red-edge band and compared with the LAI of two tree species. Both NDRE and CIRE showed higher correlation coefficients with the LAI than NDVI. This would be an alternative to overcome the limitation of the NDVI saturation problem that NDVI has not been effective to estimate LAI over very dense canopy situation. There was no significant difference among five band widths of red-edge band in relation to LAI. The highest correlation coefficients were obtained at the red-edge band of center wavelength near the 720 nm for the white oak and 710 nm for the pitch pine. To select the optimum band width and wavelength region of the red-edge band, further studies are necessary to examine the relationship with other biophysical variables, such as chlorophyll, nitrogen, water content, and biomass.

• Korean Journal of Ecology and Environment
• /
• v.46 no.4
• /
• pp.561-569
• /
• 2013

This study examines locational environment factors that may affect the vegetation structure in the forests of Naejang National Park. To that end, we selected LAI (Leaf Area Index), diameter at breast height, and tree height as structural variables as well as altitude above sea level, gradient, slope direction, soil moisture, topographic location, and amount of solar radiation as locational environment factors, using the method of canonical correlation analysis in order to find out correlation between them. As to the simple correlation between the locational environment factors and structural variables, the correlation coefficient was relatively low (0.6). The values of LAI, measured along the ridge with higher altitudes, decreased as the soil moisture and solar radiation increased. However, LAI increased as the gradient increased and the slope direction faced the north (farther from the east). In respect of the diameter at breast height, the diameter decreased as the altitude and gradient increased. But the diameter increased as the moisture and solar radiation increased. The tree height decreased as the moisture increased and the site was closer to the ridge. These various correlations show a variety of locational environment factors in the national park, implying that the structural variables are affected by complex locational environment factors. This study conducted a canonical correlation analysis on locational environment factors which may affect the vegetation structure, and the result showed that LAI increased and tree height & diameter at breast height decreased as the solar radiation & moisture decreased and altitude increased. Although more factors that may affect vegetation structure (e.g. climate) should be taken into account, this study is significant in that the vegetation structure, which can adapt to more unfavorable conditions in terms of solar radiation, moisture, and higher altitudes, could be inferred in a statistical way. The results of this study, especially the locational environment factors based on DEM, can be used for assessing diversity of vegetation structure in a forest and for monitoring the structure in a national park on a regular basis so as to establish more effective maintenance plans of a park.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.9
• /
• pp.167-179
• /
• 2022

The study aims to determine the influencing factors and their impact on the management of the forest land used for production allotted to peasant households and proposes solutions to improve its management. Secondary data was calculated until the end of 2019 at state agencies. The primary data was collected through 2 steps. To determine the factors influencing forest land management for production, step one involved a survey of 100 households that were given access to forest land. Step 2 involved a survey of 215 households to determine how factors impacted the Likert scale's five levels. The study also used a multivariate regression model and SPSS24.0 software to determine the impact rates of factor groups. The study indicated 43 factors that belong to 11-factor groups affecting the management of forest land for production. The policy and legal factors group is the most influential, with an impact rate of 12.72%, followed by 10 other factor groups with impact rates ranging from 4.08% to 11.74%. The solutions include improving policies and laws, strengthening the dissemination of policies and laws; encouraging investment, completing cadastral work, intensifying inspection, examination, and sanctioning of administrative violations of land, upgrading the infrastructure system, and ensuring enough human resources to manage forest land.

• Journal of Korean Society of Forest Science
• /
• v.96 no.4
• /
• pp.438-447
• /
• 2007

The purpose of this study was to understand the ecosystem structure and function and soil water changes in Tricholoma matsutake producing pine stands. The investigated stands were pine forest in Sogrisan National Park in Chungbuk-do of Korea. For the purpose we investigated main vegetation, leaf area index(LAI) as ecosystem structural factors and measured photosynthesis, transpiration, xylem water potential, and soil water changes as ecosystem functional factors. Vertical vegetation structure of the site was composed of Pinus densiflora as a overstory species, Quercus mongolica as midstory, Rhododendron mucronulatum, R. schlippenbachii and Fraxinus sieboldiana as understory ones. In the stands LAI was 3.8 during June to September, 2.6 in October and 2.1 during November to April. Photosyntheses of the trees were 6.0 to $7.0{\mu}mol\;CO_2/m^2/s$ in August, and for P. densiflora about $4.0{\mu}mol\;CO_2/m^2/s$ and for Q. mongolica $2.0{\mu}mol\;CO_2/m^2/s$ in mid October. However, R. mucronulatum stopped fixing $CO_2$ and F. sieboldiana shed off the leaves already in mid October. Transpirations were 2.5 to $3.5mmol\;H_2O/m^2/s$ in late August and about $1.0mmol/H_2O/m^2/s$ in mid October. Plant water potentials were -10 to -22 bars for P. densiflora and -5 to -12 bars for the other woody species. The lowest potentials was in late August and highest in late October. Soil water in the stand was closely related to topography. Soil water contents were 7 to 11% at the ridge, 8 to 15% at the hillside and 11 to 19% at the base. Soil temperatures were 0.2 to $0.4^{\circ}C$ higher in T. matustuake colony than noncolony. Mid September soil temperature decreased to $19^{\circ}C$ at which T. matsutake forms primordia. In T. matsutake colony soil moisture was 0.5 to 2.0% lower due to metabolism for consuming water. We suggest that the complicate relationships between ecosystem structure and function in Tricholoma matsutake producing pine stand need to be further investigated.