• Title/Summary/Keyword: Vegetation Density

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Monitoring of Agro-Ecological Environments at Small Watershed (농업유역의 생태환경 모니터링 기법 연구)

  • 박승우;윤광식
    • Journal of Korean Society of Rural Planning
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    • v.2 no.2
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    • pp.91-102
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    • 1996
  • Monitoring techniques for afro-ecological environments were studied, Hydrologic and ecological components in conjunction with water quality were monitored in the Balkan watershed. The hydrologic monitoring program consists of four water level gauging stations along creeks and stream at the watershed having 26.5 km2. Stage - storage relationship of reservoir, rainfall amount of the watershed, and rating curve of the stream gauging stations were established. Soil type, land use, hydrologic soil group, population and economic activities within the watershed were surveyed. Water quality data from the streams were sampled weekly and chemical analysis was conducted. Temporal variations of water quality were investigated and water quality map of each reach of stream was made to identify spatial variations. Seasonal and spatial variations of vegetation densities along stream in the watershed were investigated using grid, Density variations of insect species such as arthropod, flying insect, spider spices, rice insects were also monitored to determine seansonal surveying density. These monitored data will be used to develop monitoring techi%ues and afro - ecological environment models.

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Regeneration of Seedlings under Different Vegetation Types and Effects of Allelopathy on Seedling Establishment of Abies koreana in the Banyabong Peak, Mt. Chiri (지리산(智異山) 구상나무림(林)에서 타감작용(他感作用)이 치수형성(稚樹形成)에 미치는 영향(影響))

  • Kim, Goon Bo;Lee, Kyung Joon;Hyun, Jung Oh
    • Journal of Korean Society of Forest Science
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    • v.87 no.2
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    • pp.230-238
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    • 1998
  • This study was conducted to compare the regeneration of the seedlings under different vegetation types and to identify the presence of allelopathy in Abies koreana(Ak) natural forest in Banyabong Peak(elevation, 1715m), of Mt. Chiri. Twenty quadrats($10m{\times}10m$) were placed in May, 1996 to classify vegetation structure using TWINSPAN. Water-soluble extracts from leaves and soil humus of different vegetation types were collected to test their effects on both seed germination of Ak and mycelial growth of ectomycorrhizal fungi. Phenolic compounds from soil humus were quantified using HPLC. Among the four vegetation types, Sasa borealis(Sb) was found in both Ak-Quercus mongolica(Qm) and Ak-Rhododendron schlippenbachii(Rs) communities. Natural seeding of Ak was $230,000{\pm}90,000seeds/ha$ in 1995 and their germination rate was 25% in an ideal laboratory condition. Density of Ak seedlings less than 5cm in height was 52,000/ha in 1996, while that of seedlings taller than 5cm in height was only 4,000/ha. In the case of Ak-Qm community, density of Ak seedlings with Sb understory was only 7% of the density of seedlings with Rs understary, suggesting the inhibitory effect of Sb. The germination rate of Ak seeds was significantly reduced by leaf extracts of Sb, and Rhododendron mucronulatum var. ciliatum(Rm) and Ak. Soil humus extract of Ak-Qm-Sb subcommunity reduced germination of Ak seeds by 81% and also reduced by 19% the respiration of mycelia of ectomycorrhizal fumgus, Lactarius sp. Among the seven phenolic compounds identified from the soil humus, extract, Ak-Qm-Sb subcommunity contained significantly high content of p-hydroxybenzoic acid, vanillic acid, and syringic acid. Particularly, p-hydroxybenzoic acid was present at 4.2ppm in the Sb roots and at 16.5ppm in the Sb humus, suggesting that it could be the primary allelopathic compound in Abies koreana forests with Sasa borealis understory.

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Wildlife Habitat Prediction Model based on Specialist's Experience - A Case Study of Daecheoncheon.Cheongradam - (전문조사원 경험에 의한 야생동물 서식지 예측모형 - 대천천.청라댐 유역을 대상으로 -)

  • Jang, Raeik;Lee, Myoun-Woo
    • Korean Journal of Environment and Ecology
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    • v.28 no.4
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    • pp.393-403
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    • 2014
  • The aim of this study was to use the information deduced from biotopemap in Boryeong, Chungnam province conducted in 2011 and to select the wildlife survey point. The information used for the study was deduced from the knowledge and experience of wildlife specialists and was realized by 6 environmental variables (Outside distance from food vegetation, Outside distance from farm land, Outside distance from forest, Human density, Outside distance from road, Outside distance from water). 6 environmental variables were modeled by map overlay method and the model could deduce the correlation of 94.72% as a result of comparing with occurrence information. The areas predicted to have many occurrences were rural landscapes, forests, and valleys, and they can be used to deduce the quality wildlife survey results in the limit of survey range (area, schedule, and budget). However, it had the limit points such as the inside of forests was excluded, all species did not prefer the same habitat. The following studies are needed for this part in the future.

Estimation of the Random Error of Eddy Covariance Data from Two Towers during Daytime (주간에 두 타워로부터 관측된 에디 공분산 자료의 확률 오차의 추정)

  • Lim, Hee-Jeong;Lee, Young-Hee;Cho, Changbum;Kim, Kyu Rang;Kim, Baek-Jo
    • Atmosphere
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    • v.26 no.3
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    • pp.483-492
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    • 2016
  • We have examined the random error of eddy covariance (EC) measurements on the basis of two-tower approach during daytime. Two EC towers were placed on the grassland with different vegetation density near Gumi-weir. We calculated the random error using three different methods. The first method (M1) is two-tower method suggested by Hollinger and Richardson (2005) where random error is based on differences between simultaneous flux measurements from two towers in very similar environmental conditions. The second one (M2) is suggested by Kessomkiat et al. (2013), which is extended procedure to estimate random error of EC data for two towers in more heterogeneous environmental conditions. They removed systematic flux difference due to the energy balance deficit and evaporative fraction difference between two sites before determining the random error of fluxes using M1 method. Here, we introduce the third method (M3) where we additionally removed systematic flux difference due to available energy difference between two sites. Compared to M1 and M2 methods, application of M3 method results in more symmetric random error distribution. The magnitude of estimated random error is smallest when using M3 method because application of M3 method results in the least systematic flux difference between two sites among three methods. An empirical formula of random error is developed as a function of flux magnitude, wind speed and measurement height for use in single tower sites near Nakdong River. This study suggests that correcting available energy difference between two sites is also required for calculating the random error of EC data from two towers at heterogeneous site where vegetation density is low.

The Characteristics of the Sites and Prospects of the Bear Shelves of Asiatic Black Bear (Ursus Thibetanus) on Jirisan National Park (지리산 반달가슴곰 상사리 입지와 조망 특성)

  • Yu, Jaeshim;Park, Chonghwa;Woo, Donggul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.4
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    • pp.41-49
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    • 2012
  • The objective of this study is to investigate the characteristics of the location and prospects of the bear shelves built by Asiatic black bears in the Jirisan National Park. Previous researchers have been analyzed bear shelves in terms of places for resting and eating, but we are going to analyze based on the prospect-and-refuge theory. Characteristics of the sites of bear shelves are measured through field survey and topographic analysis by using digital elevation model (DEM). The normalized difference vegetation index (NDVI) is used to evaluate the optimum location of bear shelves in terms of crown density. Man-made objects are identified by viewshed analysis based on geographical information system (GIS). Findings of this paper can be summarized as follows. First, most bear trees are located deep inside of the mountainous national park, slopes of 30~40 degrees, altitude of 400~1,200m, and relatively low vegetation density with NDVI value of 0.4~0.6 compared to the average NDVI of the park. Second, the average height of bear shelves is 12.44m, or 74% of the average height of bear trees. They are located at suitable places to observe nearby trails and other park facilities. Third, man-made objects within the 100m radius of bear trees include lodge, bear training center, beekeeping camp, and hiking trails. Thus we may temporarily conclude that one of the main criteria of the bear tree selection in the park has been to identify optimum places for the monitoring of human activities in their habitat.

Vegetation characteristics, conservation and ecotoursim strategies for water spider(Argyroneta aquatica) in small marsh, Korean Natural Monument (물거미가 서식하는 천연기념물 습지의 식생학적 특성과 보전 및 생태관광화 방안)

  • You, Young-Han;Yi, Hoon-Bok
    • Journal of Wetlands Research
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    • v.11 no.2
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    • pp.99-106
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    • 2009
  • Water spider(Argyroneta aquatica Clerck) is only spider that live under aquatic water. In korea, water spider distributed only in Undari Wetland, Yeochon County, Kyongii Proviance, where it is designated as Natural Monument. I counted the population density, analysed the ecological traits such as actual vegetation map, and suggested conservation strategy and eco-tourism planning for water spider. The population mean density of water spider was one individual/$m^2$ and 8,000 individuals/ha. The wetland inhabited by water spider was characterized by high water level fluctuation between rainy season and dry ones. Wetland plant community was dominated by Phragmites australis and Leersia oryzoides var. japonica with submersed plant, Utricularia japonica. It is need to supply water for inhibiting terrestial succession trend during the dry season and to connect three fragmented wetlands through ecological corridor. Also, It was suggested that ecotourism planning is important for conserving this wetland.

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Forest Community Structure Analysis of Seooreung Area (서오릉의 산림군락구조 분석)

  • Yee, Sun;Lee, Mi-Jeong;Kim, Hyo-Jeong;Kwon, Oh-Won;Song, Ho-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.2
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    • pp.62-67
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    • 2004
  • Forest community structure analysis in the Seooreung area, Goyang-si was carried out to supply basic data for reasonable management and conservation. The forest vegetation of the Seooreung area was classified into Alnus japonica community, Quercus mongolica - Carpinus laxiflora community, Quercus serrata community, and Pinus densiflora community. The dominant species in the area were in the order of Quercus mongolica, Quercus serrata, Robinia pseudoacacia, Quercus variabilis, Quercus aliena, Styrax japonica, Pinus rigida, and Alnus hirsuta. According to the DBH analysis result, Pinus densiflora was dominance species in Tomb area. Pinus rigida had a density of normal distribution style in the entire forests, therefore, their dominance are expected to continue for now. However, Quercus serrata is expected to extend their influence in the future in competition with Pinus rigida. Quercus mongolica had a density of normal distribution style in the Quercus mongolica - Carpinus laxiflora community, therefore, their dominance are expected to continue for now. Carpinus laxiflora is expected to extend their influence in the future in competition with Quercus mongolica. The relationship between the distribution of dominant species of forest vegetation and soil condition in Seooreung area was investigated by analyzing soil nutrition and moisture gradient. Alnus hirsuta community was distributed in the mesic and medium nutrition area and Quercus mongolica - Carpinus laxiflora community in the serix and relative good nutrition area. Pinus densiflora community was distributed in the serix and poor nutrition area and Quercus serrata community in the subserix and medium nutrition area.

Comparison of Accuracy between Analysis Tree Detection in UAV Aerial Image Analysis and Quadrat Method for Estimating the Number of Treesto be Removed in the Environmental Impact Assessment (환경영향평가의 훼손수목량 추정을 위한 드론영상 분석법과 방형구법의 정확성 비교)

  • Park, Minkyu
    • Journal of Environmental Impact Assessment
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    • v.30 no.3
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    • pp.155-163
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    • 2021
  • The number of trees to be removed trees (ART) in the environmental impact assessment is an environmental indicator used in various parts such as greenhouse gas emissions and waste of forest trees calculation. Until now, the ART has depended on the forest tree density of the vegetation survey, and the uncertainty of estimating the amount of removed trees has increased due to the sampling bias. A full-scale survey can be offered as an alternative to improve the accuracy of ART, but the reality is that it is impossible. As an alternative, there is an individual tree detection using aerial image (ITD), and in this study, we compared the ARTs estimated by full-scale survey, sample survey, and ITD. According to the research results, compared to the result of full-scale survey, the result of ITD was overestimated by 25. While 58 were overestimated by the sample survey (average). However, as the sample survey is an estimate based on random samples, ART will be overestimated or underestimated depending on the number and size of quadrats.

Changes of Spatial Distribution of Korean Red Pine Forest in Hallasan National Park (한라산국립공원 소나무림의 공간분포 변화)

  • Kim, Jong-Kab;Koh, Jung-Goon;Yim, Hyeong-Taek;Kim, Dong-Soon
    • Korean Journal of Environment and Ecology
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    • v.33 no.5
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    • pp.578-586
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    • 2019
  • The purpose of this study was to investigate the change of spatial distribution of Korean red pine (Pinus densiflora Siebold & Zucc.) in Hallasan National Park by surveying the distribution and crown density and analyzing by the elevation, slope, orientation, and regional habitat in 2006 and 2015. The total area of the Korean red pine forest was 1,259.9 ha in 2015, which increased by 51.4 ha, or 4.1%, compared to 1,208.5 ha in 2006. For the past 10 years, the area of sparse density with crown density of 11% to 40% of Korean red pine increased by 59.8 ha, the area of moderate density with crown density of 41% to 70% increased by 59.0 ha, and the area of dense density with 71% or more crown density increased by 67.3 ha. In terms of the altitude above sea level, the Korean red pine forest area between 1,010 m and 1,400 m was the largest at 1,003.0 ha or 79.6% of the total area in 2015. The area between 1,100 m and 1,300 m increased, and the area of dense density decreased significantly while the areas of moderate density and sparse density increase. There was no notable change according to the land slope, and the area increased from 2006 regardless of the slope. By direction, 56.4% were distributed in the southwest and southeast directions centered on the south-facing slope with the increase of 27.8 ha over the 10 years while the northwest and northeast directions centered on the north-facing slope decreased by 7.6 ha. Regarding the distribution change of the Korean red pine forest by the region, the Yeongsil area showed an increase of 25.5 ha, or 49.6% of the total area increase, in 2006 while the Ibseog-oreum area including the right side on the Sanbeoleum mountain valley increased by 20.4 ha. The distribution in the Gaemideung area that includes Jogeundeule increased by 7.4 ha while that of Sogbat in Sungpanak Trail decreased by 1.9 ha. This study analyzed the changes in the distribution area and crown density of the Korean red pine forest according to the altitude, slope, direction, and regional habitat in Hallasan National Park. The expansion of Korean red pine forest distribution was limited to the areas where the grass and the shrub was the dominating vegetation structure, or the forest gap was created by the disturbance. On the other hand, the distribution area of the Korean red pine forest surrounded by deciduous broad-leaved forests or mixed vegetation structure is considered to result from the change in density more than the area due to competition with deciduous broad-leaved trees.

A Study on the Vegetation Pattern Using Two-Dimensional Spectral Analysis (2 次元 스펙트럼法을 이용한 植生類型에 대한 硏究)

  • Park, Seung Tai
    • The Korean Journal of Ecology
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    • v.13 no.2
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    • pp.83-92
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    • 1990
  • Two-dimensional analysis provides a comprehensive description of the structure, scales of pattern and directional components in a spatial data set. In spectral analysisi, four functions are illustrated,; the autocorrelation, the periodogram, the R-spectrum and the $\theta$ -spectrum. The R-spectrum and $\theta$ -spectrum function respectively summarize the periodogram in term of scale of pattern and directional components. Sampling is measured in the Naejang National Park area where the Daphniphyllum trees grow. 320 contiguous (15$\times$15)m plots are located along the transect and density of all trees over DBH 3 cm recorded respectively. 12 species of vascular plant are recorded in this survey area. The trend surface of density of all plant are estimated using polynomial regression and are exhibited in 3-dimensional graph and density contour map. Transformation to the corresponding polar spectrum from the periodogram emphasized the directional components and the scales to pattern. R-spectrum corresponding to the scale of pattern of periodogram showed a large peak 15.47 in the interval 9$\theta$-spectrum corresponding to directional components have two peaks 8.28 and 11.05 in the interval $35^{\circ}\theta <45^{\circ}and 125^{\circ}\theta< <135^{\circ}, respectively. Programs to compute all the analyses described in this study was obtained from Dr. Ranshow and was translated to BASIC by the author.

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