• Journal of Korean Society of Forest Science
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• 제108권2호
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• pp.177-188
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• 2019

The aim of our study was to identify the changing trends in the composition, structure, and spatial distribution of forest vegetation in Apsan Park, a representative urban forest in Daegu, South Korea. A vegetation survey was conducted in 1997 and 2016 using phytosociological methods, and a detailed vegetation map was created using the physiognomic dominant species. There were 22 vegetation types in both 1997 and 2016, but two of those types increased and two decreased. The total coverage per unit area ($100m^2$) of the component vegetation species increased from 163% in 1997 to 182% in 2016, and natural vegetation tended to be more than twice that of artificial vegetation. The average number of species decreased by seven from 25 in 1997 to 18 in 2016. Species diversity (H') increased only slightly from 1,654 in 1997 to 1,680 in 2016, while species dominance (D) decreased by 9% from 0.304 in 1997 to 0.276 in 2016. The similarity in the composition of the forest vegetation was about 78%, which was nearly the same. The life form spectrums of vascular plants changed from '$G-R_5-D_4-e$' in 1997 to '$MM-R_5-D_4-e$' in 2016 and the central dormancy type changed from geophytes (G) to megaphanerophytes (MM). The spatial distribution of the forest vegetation was reduced by approximately four times that of artificial vegetation. The number of forest landscape elements (patches) increased from 269 in 1997 to 294 in 2016, while the average area decreased by 12% from 5.8 ha in 1997 to 5.1 ha in 2016.

• Journal of Korean Society on Water Environment
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• 제23권3호
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• pp.348-355
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• 2007

We investigated temporal changes of composition, habitat area, growth rate and elements content of hydrophytes at the artificial vegetation island (AVI) in Kyungan Stream within Lake Paldang. We also assessed nutrient removal rate through cutting off the emergent part of hydrophytes. The kinds of hydrophytes have increased from four species (P. australis, P. japonica, T. angustifolia and the Z. latifolia) at initial stage of installation to more than 29 species for 6-year operation. P. japonica was most dominant species at the AVI in 2006. The habitat area of have increased about 2.5 times compared to the initial planting area, occupying 63% of AVI's vegetation area. The incoming species of S. fluviatilis and B. frondosa have adapted successively and expanded habitat area in the AVI. The relative growth rate of P. japonica and P. australis was highest in spring sprouting period. Their hights and weights have increased until summer, by the time they were cutting off the emergent part. They started regrowth immediately after cutting and continued to grow until September and withered away in November. The carbon contents of P. japonica and P. australis have increased during growth phase, on the contrary, the nitrogen and phosphorus contents have decreased. By cutting off and removing the emergent part (leaves and branches) of hydrophytes twice from AVI, $17.6gN/m^2/y$ of nitrogen and $1.3gP/m^2/y$ of phosphorus was removed from AVI in 2006.

• Korean Journal of Environment and Ecology
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• 제12권3호
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• pp.290-296
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• 1998

Altitudinal changes in the vegetation of Sunginbong(984m) in UIlungdo (Island) were investigated by sample plots(forty l00$\m^2$) along elevation and analyzed by TWINSPAN and DCA techniques. In the results from the analysis of both techniques, altitudinal zonations were divided into 3 groups such as lower 300m area, 400~700m area, and above 800m area. DCA and similarity index analyses of elevational ranges showed discontinuities between lower and middle elevation areas. But there was a vegetation continuum between middle and high elevation areas. In the analysis of species diversity, there was no significant difference due to altitude except for maximum species diversity which was decreased with altitude. The mean tree density of canopy and understory layers in the middle elevation area showed the highest value, and the highest basal area was recorded at the lower elevation area.

• The Korean Journal of Ecology
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• 제15권4호
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• pp.337-344
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• 1992

A study on the secondary succession and species diversity was conducted at burned sites of which pinus densiflora forest and its floor vegetation was almost destroyed by the forest first in the mts. todok, sansong and palgong from 1977 to 1986. The changes of vegetation during period the year to 11th after fire occurred miscanthus sinensis var. purpurascens $\rightarrow$ miscanthus sinensis var. purpurascens-lespedeza cyrtobotyra $\rightarrow$ lespedeza cyrtobotyra $\rightarrow$ lespedeza cyrtobotyra-quercus serrata community. The biological spectra based on $SDR_3$(%) and SP(%) were $H-D_1-R_5-e$ types. The species diversity generally decrease from miscanthus to lespedeza stage and reached minimum at stage of lespedeza, and after that a litter increase for lespedeza-quercus stage. The species distribution curves showed a decrease from miscanthus to lespedeza stage and slight increase at lespedeza-quercus stage in evenness.

• Journal of Environmental Impact Assessment
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• 제24권5호
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• pp.516-531
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• 2015

In this study, a software module to predict the effectiveness of vegetation buffer strip (VBS) has been developed for using with Chemicals, Agricultural Management and Erosion Losses (CAMEL), a distributed watershed model. Most basic functions for the VBS module are same as CAMEL except functions newly developed to implement sedimentation enhancement by vegetation and level spreaders. For verification of the VBS module, sensitivity analyses for length, roughness, soil and vegetation type of VBS were carried out using a test grid cell. The surface discharge of sediment are highly sensitive to the roughness coefficient of VBS. The removal efficiencies of VBS for the surface discharges of sediment and TP are generally high regardless of environment changes. The surface discharges of TOC and TN are highly sensitive to the length and soil of VBS. The removal efficiencies of VBS for the surface discharges of TOC and TN are generally lower than those of sediment and TP. The newly developed VBS module reasonably simulates the removal efficiencies of surface discharges that vary according to the environment changes. It is expected that this VBS module can be used for evaluating the effectiveness of VBS-based best management practices to be applied to reduce pollution discharges from various non-point sources.

• Proceedings of the Korea Water Resources Association Conference
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• 한국수자원학회 2021년도 학술발표회
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• pp.6-7
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• 2021

Vegetation development in rivers is one of the important issues not only in academic fields such as geomorphology, ecology, hydraulics, etc., but also in river management practices. The problem of river vegetation is directly connected to the harmony of conflicting values of flood management and ecosystem conservation. In Korea, since the 2000s, the issue of river vegetation and land formation has been continuously raised under various conditions, such as the regulating rivers downstream of the dams, the small eutrophicated tributary rivers, and the floodplain sites for the four major river projects. In this background, this study proposes a method for classifying the distribution of vegetation in rivers based on remote sensing data, and presents the results of applying this to the Naeseong Stream. The Naeseong Stream is a representative example of the river landscape that has changed due to vegetation development from 2014 to the latest. The remote sensing data used in the study are images of Sentinel 1 and 2 satellites, which is operated by the European Aerospace Administration (ESA), and provided by Google Earth Engine. For the ground truth, manually classified dataset on the surface of the Naeseong Stream in 2016 were used, where the area is divided into eight types including water, sand and herbaceous and woody vegetation. The classification method used a random forest classification technique, one of the machine learning algorithms. 1,000 samples were extracted from 10 pre-selected polygon regions, each half of them were used as training and verification data. The accuracy based on the verification data was found to be 82~85%. The model established through training was also applied to images from 2016 to 2020, and the process of changes in vegetation zones according to the year was presented. The technical limitations and improvement measures of this paper were considered. By providing quantitative information of the vegetation distribution, this technique is expected to be useful in practical management of vegetation such as thinning and rejuvenation of river vegetation as well as technical fields such as flood level calculation and flow-vegetation coupled modeling in rivers.

• Korean Journal of Remote Sensing
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• 제38권2호
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• pp.179-188
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• 2022

Global warming causes climate change and increases extreme weather events worldwide, and the occurrence of heatwaves and droughts is also increasing in Korea. For the monitoring of extreme weather, various satellite data such as LST (Land Surface Temperature), TCI (Temperature Condition Index), NDVI (Normalized Difference Vegetation Index), VCI (Vegetation Condition Index), and VHI (Vegetation Health Index) have been used. VHI, the combination of TCI and VCI, represents the vegetation stress affected by meteorological factors like precipitation and temperature and is frequently used to assess droughts under climate change. TCI and VCI require historical reference values for the LST and NDVI for each date and location. So, it is complicated to produce the VHI from the recent satellite GK2A (Geostationary Korea Multi-Purpose Satellite-2A). This study examined the retrieval of VHI using GK2A AMI (Advanced Meteorological Imager) by referencing the historical data from VIIRS (Visible Infrared Imaging Radiometer Suite) NDVI and LST as a proxy data. We found a close relationship between GK2A and VIIRS data needed for the retrieval of VHI. We produced the TCI, VCI, and VHI for GK2A during 2020-2021 at intervals of 8 days and carried out the interpretations of recent extreme weather events in Korea. GK2A VHI could express the changes in vegetation stress in 2020 due to various extreme weather events such as heatwaves (in March and June) and low temperatures (in April and July), and heavy rainfall (in August), while NOAA (National Oceanic and Atmospheric Administration) VHI could not well represent such characteristics. The GK2A VHI presented in this study can be utilized to monitor the vegetation stress due to heatwaves and droughts if the historical reference values of LST and NDVI can be adjusted in a more statistically significant way in the future work.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• 제22권3호
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• pp.261-268
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• 2004

Analysis on forest through satellite image data can be obtained from normalized burn ration (NBR) and normalized difference vegetation index (NDVI) from descriptive information of reflection on the earth's surface recorded each waveband. This study focuses on the efficiency of NBR through comparative analysis after obtaining NBR and NDVI of images form 1 you, 2 years and just after the forest fire and the time of forest-preserved of the area before the forest fire in Sacheon myeon, Cangneung City where the forest fro broke out. As a result, it shows dynamic changes with greater range that differences between NBR images rather than differences between NDVI images, which means it would be better to use NBR image for the analysis of the degrees of damages from forest fire or the status of vegetation restoration and also NBR image more distinctly shows both than NDVI image in forest fro damage area.

• Journal of the Korean Society of Environmental Restoration Technology
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• 제16권1호
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• pp.55-69
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• 2013

The phytosocialogical study on the coastal sand dune vegetation of the East Coast was carried out. 180 phytosociological relev$\acute{e}$s of 62 sites in the East Coast were used in this study. In addition, already published syntaxa and the phytosociological hierarchy in Korea and Japan were used and comparative analyses of syntaxonomy, synecology, syngeography, and syndynamics were performed in the study. In this study, the flora was investigated 30 families, 66 genera, 77 taxa and 3 vegetation types were identified : the coastal drift-line annual communities (Calystegio soldanellae-Salsoletum komarovii), the dune glasslands communities (Elymo-Caricetum kobomugi, Carex kobomugi typical community, Elymus mollis community, Calystegia soldanella community, Zoysia macrostachya community, Cynodon dactylon community, Carex pumila community), and the dune shrubs communities (Linario-Viticetum rotundifoliae, Vitex rotundifolia community, Rosa rugosa community). The aspect of transition in the coastal sand dune vegetation of the East Coast were identified as follows : (1) reduced constancy degree and cover degree of Glehnia littoralis in each community; (2) lack of Ischaemum anthephoroides in Linario-Viticetum rotundifoliae (3) simplified species composition in Vitex rotundifolia community. Unstable habitat condition by external interference seemed to has caused the reduction of 2 taxa, Glehnia littoralis and Ischaemum anthephoroides, that usually grow in the second dune. In addition, we found changes in the distribution of the dune shrub communities influenced by rising temperature of the East Coast as results of the global warming. The results on the distribution of the dune shrub communities in this study demonstrated that the limit of the Rosa rugosa community made $0^{\circ}$ 44'N to the North and the vegetative limit of the Vitex rotundifolia community made $0^{\circ}$ 28'N to the North, respectively compared with the previously phytosociological studies. This study investigated the coastal sand dune vegetation, syntaxonomy, habitat condition and human disturbunce of the East Coast, and this will provide important information as basic data for the coastal ecosystem.

• Korean Journal of Environment and Ecology
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• 제36권1호
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• pp.87-101
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• 2022

This study analyzed changes in the vegetation structure of 16 permanent plots (experimental and control) installed in Wando Arboretum in 1996 to monitor the long-term change process of evergreen broad-leaved forests in warm temperate. Especially, this study discusses the effects of trial treatment (selection cutting and plant introduction), introduced as a restoration technique in 1996, on vegetation development. In communities dominated by Quercus acuta in the canopy (permanent plots 1 through 3), this species's mean important percentage (MIP) decreased, and the evergreen broad-leaved species was introduced from outside increased, likely to change the vegetation structure in the future. The expansion of the evergreen broad-leaved species group was also confirmed in Q. acuta-deciduous broad-leaved forests (permanent plots 5 and 7) and Pinus densifloraforests (permanent plots 9 and 10). In the experimental plots where thinning was carried out, the zoochory (the dispersal of seeds by birds), Cinnamomum yabunikkei, Neolitsea sericea, Machilus thunbergii, etc., and the expansion of the influence of evergreen broad-leaved species were remarkable, so it is considered to have effectively promoted the vegetation development in warm temperate forests. Although evergreen broad-leaved species were planted in the experimental plot to change vegetation structure, it seems the effect on the change was weak due to the small amount of planting. Compared to other vegetation types, the change in the vegetative structure of the pine forest to an evergreen broad-leaved forest was clear due to the decline of P. densiflora and P. thunbergii.