• Title/Summary/Keyword: quadrat analysis

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A Study on the Algal Communities of Odongdo, Southern Coast of Korea (오동도 해조군락에 관한 연구)

  • SOHN Chul Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.16 no.4
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    • pp.368-378
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    • 1983
  • The community structure of intertidal benthic marine algae were studied seasonally at Odongdo, southern coast of Korea, from June 1982 to May 1983. Algal coverage in $50{\times}50\;cm$ quadrat were recorded for each species by line transect method. The vertical zonation investigated by line transects is recognized into three groups : Upper, middle, and lower zones. The representative species are Gelidium divaricatum, Enteromorpha linza, Porphyra yezoensis, Scytosiphon lomentaria, Blidingia nana, Ectocarpus confervoides in the upper, Ulva pertusa, Chondria crassicaulis in the middle, and Sargassum sagamianum, S. thunbergii, Undaria pinnatifida, Gelidium amansii and various other red algae in the lower zone. The number of algal species and coverage were generally highest in April and lowest in August. Species which appear dominant at least once a year were all of the spring type and the others were autumn type. According to the cluster analysis by similarity index community coefficient(SICC) among 5 transects, the algal communities are divided into two groups, i. e. open-sea group and inland-sea group.

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Changes in macroalgal assemblage with sea urchin density on the east coast of South Korea

  • Jeon, Byung Hee;Yang, Kwon Mo;Kim, Jeong Ha
    • ALGAE
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    • v.30 no.2
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    • pp.139-146
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    • 2015
  • Urchin barrens have been a major issue of rocky coastal ecosystems in temperate regions. In South Korea, the east coast and Jeju Island have especially been a focus because the area of barren ground increases in spite of continual efforts to install artificial reefs. This study approached the urchin barrens issue in South Korea, by focusing on a correlational analysis of urchin and macroalgal abundance. Urchin density and algal species coverage were obtained using a quadrat image analysis. Subtidal sites were then classified into three groups according to the average densities of urchins to evaluate the characterization of the macroalgal community: no urchin (NU) zone; transition (TR) zone, $4inds.\;m^{-2};$ and urchin (UR) zone, ${\geq}8inds.\;m^{-2}$. The average urchin density in the study site was $4.7inds.\;m^{-2}$ and 57 macroalgal species were found in the study site. From the NU zone to UR zone, total species number, species diversity index and evenness gradually decreased, whereas the dominance index increased. The algae species with negative correlations were Grateloupia divaricata, Polysiphonia morrowii, Chondracanthus intermedius, Delesseria violacea, Desmarestia viridis; and those with positive correlations were the crustose corallines, Sargassum horneri. Other species were not significantly correlated with urchin density. The significant correlations indicate that the abundance of some macroalgal species is proportionally regulated by sea urchin density. This study also shows how macroalgal vegetation changes in response to an urchin's density gradient in a natural condition; and there is a TR zone that existed with respect to an intermediate level of algal abundance.

Image Analysis of Typhoon Impacts on Soft Coral Community at Munseom in Jeju, Korea (제주도 문섬 조하대에 서식하는 연산호군락의 태풍에 의한 영향 분석)

  • Kang, Do-Hyung;Song, Jun-Im;Choi, Kwang-Sik
    • Ocean and Polar Research
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    • v.27 no.1
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    • pp.25-34
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    • 2005
  • Impacts of Typhoon Maemi on a soft-coral community located on subtidal cliff at Munseom, Jeju were investigated in this study using underwater photography. Typhoon Maemi hit Jeju Island in late September 2003 and its impact was strong enough to destruct most shallow water sessile benthos including soft corals. To estimate numbers and size of soft-coral colonies, a line transect was installed on the cliff at depth from 3 to 9 m and photographs were taken serially by every 1m. From each $1{\times}1m$ underwater photograph, species and size of soft-coral colony was determined. Number of soft-coral colony and its Percent coverage (PC) in each $1m^2$ quadrat was calculated. Soft corals Scleronephthya gracillium, Dendronephthya gigantea, D. spinulosa and D. castanea were identified from the photographs. Dendronephthya sp. was mainly distributed at 3-6m while S. gracillimum was mostly occurred at $6{sim}9m$. A survey conducted before the typhoon showed that number of the soft-coral colonies at $3{\sim}4m,\;4{\sim}5m,\;5{\sim}6m,\;6{\sim}7m,\;7{\sim}8m\;and\;8{\sim}9m$ was 17, 24, 20, 23, 18 and 30 $colonies/m^2$ or 21, 48, 36, 28, 24 and 43%, respectively. After the typhoon, number of soft-coral colonies in the transect increased, 31, 35, 21, 10, 21 and 50 $colonies/m^2$ while PC was remarkably decreased as 21, 23, 21, 5, 9 and 13%, respectively. Our data suggested that the impact was limited in larger colonies; larger soft coral colonies were selectively destroyed and removed while the small colonies underneath the larger colonies remained undestroyed.

Correlation Analysis between Forest Community Structure and Environment Factor in Mt. Guryong, Gyeongsangbuk-Do Province (구룡산의 산림군집구조와 환경요인의 상관관계)

  • Lee, Seo-Hui;Kim, Hye-Jin;Yun, Chung-Weon
    • Journal of Korean Society of Forest Science
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    • v.101 no.3
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    • pp.526-537
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    • 2012
  • The study was carried out to classify forest vegetation structure of Mt. Guryong which is located in Bonghwa-gun, Gyeongsangbuk-do province. 72 plots(quadrat) were investigated from July to August in 2010 using phytosociological analysis methodology of Z-M schools. The forest vegetation of the study area was classified as Quercus mongolica community group that was further divided into 5 communities; Pinus densiflora for. erecta community, Acer mono community, Quercus mongolica typical community, Larix leptolepis community and Pinus koraiensis community. Pinus densiflora for. erecta community was subdivided into Quercus variabilis group and Pinus densiflora for. erecta typical group. Acer mono community was also subdivided into Prunus maackii group and Deutzia glabrata group. The vegetation of the study areas could be described as 1 community group, 5 communities and 4 groups and 7 units in total. Classified vegetation units were highly correlated with altitude and topography. It was considered that forest tending operations for maintaining need to be continuously practiced for Quercus spp. with highly relative dominance value in the Pinus densiflora for. erecta community (vegetation units 1, 2).

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.

Characteristics of Wintering Bird Communities in the Moeyungyi Wetland Wildlife Sanctuary, Myanmar

  • Aung, Hsu Sandar;Kim, Hankyu;Lee, Yohan
    • Journal of Forest and Environmental Science
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    • v.38 no.3
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    • pp.195-206
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    • 2022
  • Gaining an understanding of bird communities in different habitat types is essential for the conservation of ecologically important habitats. Wetlands possess different types of habitats and provide an important environment for wintering waterbird communities. This study compares avian communities in five different habitat types in the Moeyungyi Wetland Wildlife Sanctuary (MWWS), Myanmar. From December 2014 to the first week of February in 2015, bird and habitat data were collected from representative areas of five habitat types (i.e., short grassland, tall grassland, lotus fields, open water areas, and rice fields) at MWWS. We established nine sampling plots in each habitat type, and used the point quadrat method to survey habitats and the point count method to survey birds in the habitats. Simple one-way analysis of variance (ANOVA) and post-hoc tests were used to determine differences between bird communities. We made 95 detections during 19 daily visits to each of the five habitat types. During the survey period, we recorded a total of 10,389 individuals belonging to 52 different bird species, based on 7-min observations at each of the 45 point count stations. Furthermore, we detected significant differences by habitat structure (i.e., vegetation coverage, height, and density; water depth; and plant species diversity) as well as bird communities (i.e., species richness, abundance, and diversity indices). In addition, the detailed analysis of 52 avian species revealed significant differences among 45 species with respect to the mean numbers of observed individuals in the survey habitats. The findings of this study revealed significant differences in the structure and composition of waterbird communities among the five assessed habitat types. Because natural marshes provide preferable habitats for a larger number and greater diversity of birds, relative to rice fields, natural marshes should be prioritized for conservation and restoration in Moeyungyi Wetland Wildlife Sanctuary.

Vegetation structure of the Adenophora remotiflora population;Focusing on community Danmoknyeong in Jeombongsan of Gangwon-do (모시대(Adenophora remotiflora) 개체군의 식생구조에 관한 연구;강원도 점봉산 단목령을 중심으로)

  • Choo, Byung-Kil;Ji, Yun-Ui;Moon, Byeong-Cheol;Yoon, Tae-Sook;Chae, Sung-Wook;Kim, Ho-Kyoung
    • Korean Journal of Oriental Medicine
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    • v.14 no.1
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    • pp.117-121
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    • 2008
  • Objectives : This study was carried out to investigate vegetation structure of Adenophora remotiflora population found to be distributed in Jeombongsan Danmokryeong. Methods : From 2007 June until November, $2m{\times}2m$ quadrat was established in Adenophora remotiflora community in order to record a dominants and coverage. Results : 1. The vegetation of Adenophora remotiflora community was classified into Astilbe chinensis subcommunity and Calamagrostis langsdodfii subcommunity. Differential species of community was Angelica deacrusica and Lychnis cognata. The Adenophora remotiflora community was found in south face, high of altitude and low slope degree. 2. The value of species diversity ranged from 5.547152 to 10.077886, euenness ranged from 0.779749 to 0.986358 and dominance ranged from 0.013642 to 0.220251. 3. Aconitum jaluense was located at the higher altitudes than those of other species. Lychnis cognata, Lychnis cognata and Pedicularis resupinata was located at the lower altitudes and slope degree than those of other species. Conclusions : The vegetation of Adenophora remotiflora community was classified into Astilbe chinensis subcommunity and Calamagrostis langsdodfii subcommunity. The value of species diversity was low and community was dominated by a large number species. The Adenophora remotiflora community was found in south face, high of altitude and low slope degree.

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Plant Diversity of Qurecus mongolica Forest in Mt. Biryong (비룡산 신갈나무림의 식물 다양성)

  • Kim, Jun-Soo;Hong, Jin-Ki;Kim, Kyung-Soo;Cho, Yong-Chan;Bae, Kwan-Ho
    • Journal of agriculture & life science
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    • v.45 no.3
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    • pp.9-18
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    • 2011
  • This study was performed to investigate species diversity of understory in Mt. Biryong. The quadrat size was installed based on the result of analysis of Species-Area Curve. The vascular plants were enlisted 107 taxa: 47 families, 80 genera, 91 species, 11 varieties, 2 subspecies, and 3 forms. The three taxa such as Carex okamotoi, Philadelphus schrenkii var. schrenkii, and Weigela subsessilis were enlisted from the surveyed sites as the Korean endemic plants. Due to the list from the Korea Forestry Administration, Rhododendron micranthum was enlisted as the rare plant. The growth from was categorized followed by forbs, shrubs and trees, respectively.

A Study on the Spatial Distribution of the Vacant Houses and their Accessibility : Focused on the Vacant Houses in Okcheon-gun, Chungcheongbuk-do (빈집 공간분포 특성 및 접근성에 관한 연구 : 충청북도 옥천군 빈집을 중심으로)

  • Lee, Jong-Soo;Kim, Sun-Duck
    • The Journal of the Korea Contents Association
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    • v.21 no.12
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    • pp.791-802
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    • 2021
  • In Korea, the cities continue to deteriorate, while the vacant houses in the small local towns emerge as a serious social problem. Despite the vacant houses emerge as a serious social problem in the small local towns as well as in the large cities, the basic researches into them are yet to be conducted on a full scale. Thus, in order to know about the spatial distribution of the vacant houses, this study conducted the square analysis and the kernel density analysis. As a result, it was confirmed that the vacant houses in Okcheon-gun had certain crowding forms and characteristics at the level of statistical significance. Next, in order to examine the distribution of the vacant houses in terms of the accessibility to the living SOC facilities, the GIS network analysis was performed, focusing on the major facilities and road networks. As a result, it was found that the better the accessibility to the living SOC facilities such as medical and well-being was, the ratio of the vacant houses was lower. In contrast, it was found that the accessibility to the obligatory facilities such as public administration and educational facilities did not have any important effects on the distribution of the vacant houses. All in all, through this study, the spatial distribution of the vacant houses in the small local town and their accessibility to the major SOC facilities could be analyzed.

The Effect on the Forest Temperature by Reduced Biomass Caused by Natural Forest Thinning (천연림 간벌에 기인한 산림생물량 감소가 산림 내부 온도에 미치는 영향 연구)

  • Kang, Rae-Yeol;Hong, Suk-Hwan
    • Korean Journal of Environment and Ecology
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    • v.32 no.3
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    • pp.303-312
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    • 2018
  • This study was conducted to investigate the relationship between the decrease of forest biomass by forest thinning and the change of temperature in the natural forest by measuring forest biomass and temperature before and after forest thinning in the Pusan National University forest where afforestation had been carried out. We intended to investigate the relationship between the forest biomass, estimated by calculating the Basal area, Crown area and Crown volume using the same formula to the same quadrat before and after forest thinning, and the forest temperature. Temperature measurement was carried out on April 20, 2016 through 28 before forest thinning, July 26, 2016 through November 4 around the time of forest thinning, and April 15, 2017 through May 8 after forest thinning. A temperature data logger was installed to point north at the height of 2.0 m above the ground in the center of the quadrat to record data every 10 minutes during the measurement periods. We used the AWS (Automatic Weather Station) data of the Dongnae-gu area located in the nearby city because it was difficult to set the control group since the whole forest was the subject to the forest thinning. The analysis of the relationship between forest biomass change and temperature showed that the change in temperature inside the forest was the greatest in the midday (12:00 - 15: 00) and was highly correlated with the Crown volume in the forest biomass. The temperature increase was much larger (average $1.91^{\circ}C$) 1 year after forest thinning than immediately after forest thinning (average $0.74^{\circ}C$). The comparison of the decrease rate of Crown volume and the increase in temperature showed that the Pitch pine community, which showed the highest decrease of Crown volume by 15.4%, recorded the highest temperature rise of $1.06^{\circ}C$ immediately after forest thinning and $2.49^{\circ}C$ 1 year after forest thinning. The Pitch pine-Korean red pine community, which showed the lowest Crown volume reduction rates with 5.0%, recorded no significant difference immediately after forest thinning but a temperature rise of $0.92^{\circ}C$ 1 year after forest thinning. The results confirmed that the decrease of forest biomass caused by forest thinning led to a rapid increase of the internal temperature. The fact that the temperature increase was more severe after 1 year than immediately after forest thinning confirmed that the microclimate changes due to the removed biomass cannot be recovered in a short time.