• Title/Summary/Keyword: Vegetation studies

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Vegetation Classification and Biomass Estimation using IKONOS Imagery in Mt. ChangBai Mountain Area (IKONOS 위성영상을 이용한 중국 장백산 일대의 식생분류 및 바이오매스 추정)

  • Cui, Gui-Shan;Lee, Woo-Kyun;Zhu, Wei-Hong;Lee, Jongyeol;Kwak, Hanbin;Choi, Sungho;Kwak, Doo-Ahn;Park, Taejin
    • Journal of Korean Society of Forest Science
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    • v.101 no.3
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    • pp.356-364
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    • 2012
  • This study was to estimate the biomass of Mt. Changbai mountain area using the IKONOS imagery and field survey data. Then, we prepared the regression function using the vegetation index derived from the IKONOS and biomass estimated from field measured data of previous studies, respectively. The five vegetation index which used in the regression model was SAVI, NDVI, SR, ARVI, and EVI. As a result, the rank of the R-square from coefficient of correlation was as follow, SAVI(0.84), NDVI(0.73), SR(0.59), ARVI(0.0036), EVI(0.0026). Finally, we estimated the biomass of non-measured area using the Soil Adjusted Vegetation Index (SAVI). This study can be used as reference methodology for the estimation of carbon sinks of primary forest.

Identification of two common types of forest cover, Pinus densiflora(Pd) and Querqus mongolica(Qm), using the 1st harmonics of a Discrete Fourier Transform

  • Cha, Su-Young;Pi, Ung-Hwan;Yi, Jong-Hyuk;Park, Chong-Hwa
    • Korean Journal of Remote Sensing
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    • v.27 no.3
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    • pp.329-338
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    • 2011
  • The time-series normalized difference vegetation index (NDVI) product has proven to be a powerful tool to investigate the phenological information because it can monitor the change of the forests with very high time-resolution, This study described the application of the DFT analysis over the 9 year MODIS data for the identification of the two types of vegetation cover, Pinus densiflora(Pd) and Querqus mongolica(Qm) which are dominant species of evergreen and broadleaved deciduous forest, respectively, The total number of samples was 5148 reference cycles which consist of 2160 Pd and 2988 Qm. They were extracted from the pixel-based MODIS scenes over the 9 years from 2000 to 2008 of South Korea. The DFT analysis was mainly focused on the 0th and $1^{st}$ harmonic components, each of which represents the mean value and the variation amplitude of the NDVI over the years, respectively. The $0^{th}$ harmonic values of the vegetation Pd and Qm averaged over the 9 years were 0.74 and 0.65, respectively. This implies that Pd has a higher NDVI than Qm. Similarly obtained $1^{st}$ harmonic values of Pd and Qm were 0.19 and 0.27, respectively. This can be intuitively understood considering that the seasonal variation of Qm is much larger than Pd. This distinctive difference of the $1^{st}$ harmonic value has been used to identify evergreen and deciduous forests. Overall agreement between the Fourier analysis-based map and the actal vegetation map has been estimated to be as high as 75%. This study found that the DFT analysis can be a concise and repeatable method to separate and trace the changes of evergreen and deciduous forest using the annual NDVI cycles.

Studies of Vegetation Structure Analysis and Anticipation of Vegetation Change due to Global Warming on Secondary Forest in Ecotone (추이대 2차림의 식생구조 분석과 온난화에 따른 식생의 변화 예측에 대한 연구 - 두륜산을 중심으로 -)

  • Lee, Sung-Je;Ahn, Young-Hee
    • Korean Journal of Environment and Ecology
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    • v.25 no.3
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    • pp.365-377
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    • 2011
  • This study aims at classifying and interpreting on the second forest vegetation located in Mt. Duryun affiliated to the ecotone in southern part of Korea, and foreseeing vegetation change based on component species and dominant species on canopy. The second forest vegetation is classified into 3 community units as Quercus serrata-Quercus variabilis community, Dendropanax morbiferus-Quercus acuta community and Chamaecyparis obtusa plantation. This research is also expatiated on the relationship between the distribution of communities and the environmental conditions. Quercus serrata-Quercus variabilis community will be succession horizontally and gradually from the part where Quercus variabilis is dominated relatively at first to the other part in the community, according to the component species of deciduous broad-leaved forest in the warm-temperate zone and evergreen broad-leaved forest as Camellietea japonicae.

Vegetation Mapping of Hawaiian Coastal Lowland Using Remotely Sensed Data (원격탐사 자료를 이용한 하와이 해안지역 식생 분류)

  • Park, Sun-Yurp
    • Journal of the Korean association of regional geographers
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    • v.12 no.4
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    • pp.496-507
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    • 2006
  • A hybrid approach integrating both high-resolution and hyperspectral data sets was used to map vegetation cover of a coastal lowland area in the Hawaii Volcanoes National Park. Three common grass species (broomsedge, natal redtop, and pili) and other non-grass species, primarily shrubs, were focused in the study. A 3-step, hybrid approach, combining an unsupervised and a supervised classification schemes, was applied to the vegetation mapping. First, the IKONOS 1-m high-resolution data were classified to create a binary image (vegetated vs. non--vegetated) and converted to 20-meter resolution percent cover vegetation data to match AVIRIS data pixels. Second, the minimum noise fraction (MNF) transformation was used to extract a coherent dimensionality from the original AVIRIS data. Since the grasses and shubs were sparsely distributed and most image pixels were intermingled with lava surfaces, the reflectance component of lava was filtered out with a binary fractional cover analysis assuming that tile total reflectance of a pixel was a linear combination of the reflectance spectra of vegetation and the lava surface. Finally, a supervised approach was used to classify the plant species based on tile maximum likelihood algorithm.

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Analysis of area-based optimal capacity design method in vegetation type LID (식생형 LID 시설에서 면적 기반의 적정 용량 설계 방법 연구)

  • Park, Seowon;Gil, Kyungik
    • Journal of Wetlands Research
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    • v.20 no.4
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    • pp.383-389
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    • 2018
  • Recently, it has been reported that water pollution due to non-point pollutants continues. Studies have been actively carried out to prevent such non-point pollutants from flowing into the water system and to prevent water pollution. In this study, to evaluate the adequate design of the LID facilities the rainfall corresponding to 80% of the cumulative rainfall of Yongin city was applied to an SA / CA graph obtained from the analysis of monitoring results of the vegetation type LID facility. As a result, the appropriate SA/CA ratio was 0.6% for stormwater sustain efficiency 80% and the appropriate SA/CA ratio was 0.5% for TSS removal efficiency 80%. The appropriate SA/CA ratio of the vegetation type LID proposed in this study can be used as a basis. for the future vegetation type LID design. If more data of vegetation type LID are added through continuous research, it will be more accurate.

Plant co-occurrence patterns and soil environments associated with three dominant plants in the Arctic

  • Deokjoo Son
    • Journal of Ecology and Environment
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    • v.47 no.1
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    • pp.1-13
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    • 2023
  • Background: The positive effects of Arctic plants on the soil environment and plant-species co-occurrence patterns are known to be particularly important in physically harsh environments. Although three dominant plants (Cassiope tetragona, Dryas octopetala, and Silene acaulis) are abundant in the Arctic ecosystem at Ny-Ålesund, Svalbard, few studies have examined their occurrence patterns with other species and their buffering effect on soil-temperature and soil-moisture fluctuation. To quantify the plant-species co-occurrence patterns and their positive effects on soil environments, I surveyed the vegetation cover, analyzed the soil-chemical properties (total carbon, total nitrogen, pH, and soil organic matter) from 101 open plots, and measured the daily soil-temperature and soil-moisture content under three dominant plant patches and bare soil. Results: The Cassiope tetragona and Dryas octopetala communities increased the soil-temperature stability; however, the three dominant plant communities did not significantly affect the soil-moisture stability. Non-metric multidimensional scaling separated the sampling sites into three groups based on the different vegetation compositions. The three dominant plants occurred randomly with other species; however, the vegetation composition of two positive co-occurring species pairs (Oxyria digyna-Cerastium acrticum and Luzula confusa-Salix polaris) was examined. The plant species richness did not significantly differ in the three plant communities. Conclusions: The three plant communities showed distinctive vegetation compositions; however, the three dominant plants were randomly and widely distributed throughout the study sites. Although the facilitative effects of the three Arctic plants on increases in the soil-moisture fluctuation and richness were not quantified, this research enables a deeper understanding of plant co-occurrence patterns in Arctic ecosystems and thereby contributes to predicting the shift in vegetation composition and coexistence in response to climate warming. This research highlights the need to better understand plant-plant interactions within tundra communities.

A Feasibility Study on the Application of TVDI on Accessing Wildfire Danger in the Korean Peninsula (한반도 지역 산불 발생 위험도 예측에 TVDI 적용 가능성 고찰)

  • Kim, Kwang Nyun;Kim, Seung Hee;Won, Myoung Soo;Jang, Keun Chang;Choi, Won Jun;Lee, Yun Gon
    • Korean Journal of Remote Sensing
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    • v.35 no.6_3
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    • pp.1197-1208
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    • 2019
  • Wildfire is a major natural disaster affecting socioeconomics and ecology. Remote sensing data have been widely used to estimate the wildfire danger with an advantage of higher spatial resolution. Among the several wildfire related indices using remote sensing data, Temperature Vegetation Dryness Index (TVDI) assesses wildfire danger based on both Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST). Although TVDI has physical advantages by considering both weather and vegetation condition, previous studies have shown TVDI does not performed well compare to other wildfire related indices over the Korean Peninsula. In this study we have attempted multiple modification to improve TVDI performance over the study region. In-situ measured air temperature was employed to increase accuracy, regression line was generated using monthly data to include seasonal effect, and TVDI was calculated at each province level to consider vegetation type and local climate. The modified TVDI calculation method was evaluated in wildfire cases and showed significant improvement in wildfire danger estimation.

Spatial distribution of vegetation along the environmental gradient on the coastal cliff and plateau of Janggi peninsula (Homigot), southeastern Korea

  • Jung, Song Hie;Kim, A Reum;Lim, Bong Soon;Seol, Jae Won;Lee, Chang Seok
    • Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.117-128
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    • 2019
  • Background: Cliffs are a major plant habitat around the coastal area, but in contrast to sand dunes and salt marshes, they have been little investigated in Korea. There are simple descriptions of cliff vegetation in studies on island vegetation, but there is no published paper, which addressed sea cliff vegetation synthetically. Furthermore, the coastal area where this study was carried out was designated as a conservation reserve. Even though, this area is exposed to intense recreational use such as trekking in these days. This study aims to clarify spatial distribution and structure of vegetation along the environmental gradient on coastal cliff and plateau in the Janggi peninsula (Homigot) located on southeastern Korea. Further, this study has also another objective to prepare a restoration plan to protect this conservation reserve from intense human disturbance. Results: Landscape elements were arranged in the order of sea cliff risen directly on the sea, seashore, coastal cliff, and plateau covered with relatively deep soil in a coastal area of the Janggi peninsula (Homigot), southeastern Korea. Vegetation was sampled at 59 plots arranged from the sea cliff through the seashore and coastal cliff to plateau. The sea cliff, seashore, and coastal cliff, which compose the coastal landscape, were dominated by the seashore spatulate aster (Aster spathulifolius Maxim.) community, dwarf sand sedge (Carex pumila Thunb.) community, and seashore spatulate aster (Aster spathulifolius Maxim.) community. On the plateau corresponding to the ridge of the coastal cliff, black pine (Pinus thunbergii Parl.) community, golden rain tree (Koelreuteria paniculata Laxmann) community, east Asian hackberry (Celtis sinensis Pers.) community, sawleaf zelkova (Zelkova serrata Makino) community, and Korean oak (Quercus dentata Thunb.) community were established in the mentioned order along distance from the sea. Stand ordination showed a vegetation sequence from the seashore through the cliff to the plateau, consistent in its overall pattern among sites. This was dominated by topography. There is evidence for the importance also of salinity, drought and of soil depth. Conclusion: The lack of scientific interest in cliffs to date is in striking contrast to the commonness of cliffs around the whole national territory and to the attraction cliffs have had for humans throughout history. Cliffs provide a unique habitat, rarely investigated from an ecological viewpoint. Cliffs may represent an invaluable type of ecosystem, consisting of some of the least disturbed habitats on earth and contributing more to the biodiversity of a region than their surface coverage would indicate. Although this coastal area where this study was carried out was designated as a conservation reserve, this area is in danger of severe disturbance due to excessive recreational use. We recommended a restoration plan to protect this area from such a disturbance.

Vegetation Classification and Distributional Pattern in Damyang Riverine Wetland (담양하천습지의 식생유형과 분포양상)

  • Ahn, Kyunghwan;Lim, Jeongcheol;Lee, Youlkyung;Choi, Taebong;Lee, Kwangseok;Im, Myoungsoon;Go, Youngho;Suh, Jaehwa;Shin, Youngkyu;Kim, Myungjin
    • Journal of Environmental Impact Assessment
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    • v.25 no.2
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    • pp.89-102
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    • 2016
  • Damyang riverine wetland was designated as a wetland protected area in 2004; that is located in the Yeongsan river mainstream. Total 30 phytosociological releves at field studies were classified with 22 vegetation types including of 101 species (unidentified 1 species). Legends of actual vegetation map were separated by 6 types; riparian forest, substitute vegetation, synanthropic vegetation, wet meadow vegetation, open water, an area of wetland vegetation is about 35 % ($386,841.86m^2$). Results of this study area as follows. The plant society of Damyang riverine wetland was conjectured that it was formed by rapidly water environment change with installed weir on the upstream of protected area and operating of Damyang dam on top of the basin. Until recently, the terrace land on the river was used to cultivate, but that would be formed fallow vegetation scenery on riverfront caused by no cultivation after designated protected area. Paspalum distichum var. indutum community designated as invasive alien plant by Korea Ministry of Environment was widely developed and Myriophyllum spicatumunrecorded in the country as newly alien species was discovered in the study zone. The plants as lapped over developing environment for Leersia japonica must be occupied habitat of native plant species having similar niche. The various plant society in Damyang riverine wetland should be developed because of environmental changes, disturbances and damages of stream.

Modeling the Spatial Distribution of Roe Deer (Capreolus pygargus) in Jeju Island (제주 노루(Capreolus pygargus)의 서식지 선호도 분석)

  • KIM, A-Reum;LEE, Jae-Min;JANG, Gab-Sue
    • Journal of the Korean Association of Geographic Information Studies
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    • v.20 no.4
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    • pp.139-151
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    • 2017
  • The habitat preference of roe deers(Capreolus pygargus) in Jeju island, South Korea was analyzed by using their occurrence probability in MaxEnt model in this study. Totally 490 surveying data were gathered and 15 environmental variables were chosen for the model in which 6 variables out of 15 ones were filtered and finally removed because of there being higher correlation(over 0.7 in correlation coefficient). According to the modeling, roe deers were known to prefer the area ranging from 200 to 700 meter and over 1,500 meter in sea level, where there were not many dominant tree and/or dominant vegetation with low density so that understory vegetation can grow well with plentiful sunlight and can be used as a food of herbivore like roe deers. Otherwise, the region ranging from 700 to 1,500 meter was mostly covered with high density vegetation which cut off sunlight trying to penetrate through the dominant vegetation. It can cause a lower density of vegetation on surface, which can not attract to roe deers.