• Title/Summary/Keyword: Dominant index

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Effects of Fire on Forest Vegetation in Mt. Samma (산불이 삼마산의 삼림식생에 미치는 영향)

  • Kim, Woen;Park, Jung-Hye;Cho, Young-Ho
    • The Korean Journal of Ecology
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    • v.22 no.3
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    • pp.145-153
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    • 1999
  • Authors report the changes of the community structure and secondary succession after fire in Mt. Samma (333 m). Approximately six ha of the red pine (Pinus densiflora) forest and its floor vegetation were burned and cutted down. The vegetation and soil properties were investigated in the burned and unburned sites from April to October, 1998. The dominant species based on SDR₃ in the burned site were Lespedeza cyrtobotrya (96.87), Quercus serrata (77.90), Cyperus amuricus (46.22) and Miscanthus sinensis var. purpurascens (38.33), whereas the dominant species in the unburned site were Pinus densiflora (100.00) and Q. variabilis (66.10) at the tree layer, Q. serrata (100.00) and Zanthoxylum schinifolium (29.64) at the shrub layer., and Q. serrata (76.30) and M. sinensis var. purpurascens (72.84) at the herb layer. The biological spectra based on SDR₃ were Th-D₁-R/sub 5/-e for the burned and H (M)-D₁-R/sub 5/-e type for the unburned site, respectively. The index of similarity (CCs) between the burned and unburned sites was 0.41. The degree of succession (DS) were 609 for the burned and 1168 for the unburned site, respectively. The species diversity (H) and evenness indices (e) of the burned site were lower than those of the unburned site, but the dominance indices (C) was higher in the burned site. In the analysis of soil properties, pH, the content of NO₃/sup -/-N, available phosphrous, and exchangeable cations (K/sup +/, Ca/sup 2+/, Na/sup +/, Mg/sup 2+/) in the burned site were higher than those in the unburned site, whereas the contents of organic matter, total carbon, total nitrogen and NH₄/sup +/-N were lower in the burned site. The results show that dominant species in the burned site change from Miscanthus-Lespedeza→Lespedeza→Quercus and finally to Quercus forest, and the changes of soil properties also affect the early vegetational succession after fire.

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Ichthyofauna and Fish Community from the Dongjin River System, Korea (동진강 수계의 어류상과 어류군집)

  • Kim, Jong-Ryool;Lee, Chung-Lyeol
    • Korean Journal of Ichthyology
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    • v.13 no.1
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    • pp.40-49
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    • 2001
  • The ichthyofauna and fish community of the Dongjin River system were surveyed at 21 sites from October 1998 to September 1999. We confirmed the presence of 53 species in 14 families belonging to seven orders. Thirty-two species of cyprinid fishes accounted for 60.4% of the total, four species of cobitid and gobiid fishes 7.5% of the total, and two species of bagrid and centrarchid fishes for 3.8% of the total. The dominant species in the Dongjin River system was Zacco platypus (relative abundant 26.0%), the subdominant species was Carassius auratus (14.7%). The dominant and subdominant species in each stream of the Dongjin River system were determined. In the Dongjin River, the dominant species was Z. platypus (40.6%), the subdominant Acheilognathus lanceolatus (20.5%); in Wonpyeong stream, Pseudorasbora parva (22.6%) and Hypomesus olidus (13.2%); in Gobu stream C. auratus (67.5%) and Cyprinnus carpio (15.4%). Fourteen of the 53 species from the the Dongjin River system comprised 28.6% of the total Korean endemic species; seven rare species accounted for less than 0.1% of the total. Four exotic fish species were found: Cyprinus carpio (Islaeli carp), Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus. The species dominance, diversity, and evenness index of the fish community from the Wonpyeong stream were 0.12, 1.08, and 0.91, respectively, indicating better conditions than those of the Dongjin River and the Gobu stream. The fish community of the Wonpyeong stream showed closer relationship to that of the Dongjin River than to that of the Gobu stream.

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Community Analysis of Oribatid Mites (Acari : Oribatida) in the Process of Needle Leaf Decomposition in Korean Pine (Pinus koraiensis) Forest of Namsan and Kwangreung (남산과 광릉지역의 잣나무림에서 낙엽분해과정에 관련된 날개응애 군집분석)

  • 배윤환
    • The Korean Journal of Soil Zoology
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    • v.6 no.1_2
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    • pp.25-31
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    • 2001
  • Oribatid mite communities in the process of litter decomposition were analyzed In Korean pine (Pinus koraiensis) forests of Namsan and Kwangreung, which were supposed to be under different environmental selective pressures. Oribatid mites were collected bimonthly from the litter bags (mesh size 0.4 mm, 1.7 mm) which was set up in the forest floor of study sites. This study had been carried out from Jan., 1997 to Sept., 1998. Species abundance of Kwangreung (mesh size 1.7 mm) was significantly higher than that of Namsan (mesh size 1.7 mm), but total no. of species did not exceed 30 species in all study sites. Concerning body length, medium sized oribatid mites (0.3-0.7mm) were more abundant than small ( < 0.3 mm) and large ( > 0.7 mm) sized mites. In Kwangreung, species whose body lengths were 0.2 mm to 0.5 mm were major group. However, a little larger species than Kwangreung's major group were dominant in Namsan. Sorenson similarity index and cluster analysis suggested that there were qualitative and quantitative differences in species composition in Namsan and Kwangreung. More species were collected in May through September than the other sampling times, but the pattern was rather different between first year and second year. Newly immigrant species were high in May in the first year and many of them regained on next year. Diversity indices suggested that species diversity of Kwangreung was higher than that of Namsan. Nearly 70% of total individual abundance was occupied by several dominant species in Namsan and Kwangreung . In the litter bags of mesh size 1.7 mm, the most dominant species was Trichogalumna nipponica in Namsan and Kwangreung, but in the litter bags of mesh size 0.4 mm in Kwangreung it was Ramusella sengbuschi which is smaller than T. nipponica. And important species related to litter decomposition were selected as follows; T. nipponica, Epidamaeus coreanus, Scheloribates latipes, Ceratozetes japonicus, Ramusella sengbuschi, Eohypochthonius crassisetiger, and Cultroribula lata.

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Temporal and Spatial Variability of Phytoplankton Communities in the Nakdong River Estuary and Coastal Area, 2011-2012 (2011-2012년 낙동강 하구 및 연안역에서 식물플랑크톤 군집의 시·공간적 변화)

  • Chung, Mi Hee;Youn, Seok-Hyun
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.18 no.4
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    • pp.214-226
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    • 2013
  • To understand the changing patterns in phytoplankton communities, we conducted 12 surveys along the Nakdong River, its estuary, and adjacent coastal areas between January 2011 and October 2012 (during the period of barrage construction and sediment dredging). Monthly precipitation ranged from 0 to 502 mm during the survey period, and salinity ranged between 0.1 psu and 0.3 psu in the Nakdong River, regardless of the depth, indicating no seawater influence, while salinity showed large seasonal fluctuations in the estuarine and coastal station, ranging from 0.1 psu to 34.8 psu. A total of 402 phytoplankton species were identified, 178 species from the river and 331 species from the estuary and coastal areas. Phytoplankton standing crop increased in 2012 compared to that in 2011, and was found to be highest in the river, followed by the estuary and coastal areas. Among the top 20 species in frequency of occurrence and dominance, Stephanodiscus spp., Aulacoseira granulata, and Aulacoseira granulata var. angustissima and Pseudo-nitzschia spp. were important species along the river-estuary-coastal areas. Diatoms were the major taxonomic group inhabiting the Nakdong river-estuary-coastal areas. A comparison of seasonal dominant phytoplankton species revealed a slight decrease over the years, from 13 species in 2011 to 10 species in 2012. However, no significant difference was found in the diversity of phytoplankton species between the two survey years, although lightly greater diversity was observed in the coastal areas than in the river and estuary. Cluster analysis with community composition data revealed that the community structure varied significantly in 2011 depending on the time of survey, while in 2012, it hardly showed any variation and was simpler. An increase in the phytoplankton standing crop, fewer dominant species, and simpler community structure in 2012 compared to those in 2011 are probably due to the rapid environmental changes along the Nakdong River. To investigate these ecological relationships, it is necessary to conduct further studies focusing on integrated analyses of biocenosis, including phytoplankton with respect to the changes in nutrient distribution, variation of freshwater discharge, and effect area of freshwater in the Nakdong estuary and adjacent coastal areas.

Species Composition of the Catches collected by a Bottom Trawl in the Southern Waters of Korea in Summer, 2004 (2004년 하계 한국 남해에 있어서 저층 트롤 어획물의 종조성)

  • Jeong, Sun-Beom;Hwang, Doo-Jin;Kim, Young-Ju;Shin, Hyeong-Ho;Son, Yong-Uk
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.1
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    • pp.35-45
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    • 2005
  • The experiment was conducted to investigate the species composition of catches collected by the bottom trawl on June 24 to 26, 2004 in the southern waters of Korea using a trawler "DONGBAEK" belongs to Yosu National University. The investigation was carried out at the 5 stations and the towing speed was 3.4${\sim}$3.7k't. The catches were composed of 46 species from 37 families, 10 orders and 2 classes for fishes and 2 species, 2 families and 2 orders for Chondrichthyes and 44 species, 35 familes, 8 orders for Osteichthyes. The catches of Perciforms were the highest as 24 species and 18 families for fishes. The catches of Spear squid, Loli해 bleekeri and Red banded lobster, Metanephrops thomsoni were also the highest for mollusca and crustacea as 1 class, 3 species, 3 families, 2 orders, 1 class and 7 species, 5 families, 1 order, 1 class respectively. In the 5 stations, number of individuals and biomass were 1,144 and 376.0kg at ST-1, 908 and 240.3kg at ST-2, 666 and 90.1kg at ST-3, 2,050 and 300..4kg at ST-4 and 561 and 24.7kg at ST-5. The diversity index of each stations ranged between 1.49 and it showed the richness index of 2.13${\sim}$3.48, the evenness index of 0.48${\sim}$0.77 and the dominance index of 0.43${\sim}$0.8. Body length distributio of the dominant specise were 9${\sim}$32cm(fork length) for Japanese horse mackerel, Trachurus japonicus, 7${\sim}$23cm(mantle length) for Common squid, Todarodes pacificus, 9${\sim}$43cm(mantle length) for Spear squid, Loli해 bleekeri, 23${\sim}$36cm(total length) for File fish, Thamnaconus modestus, 10${\sim}$28cm(fork length) for Yellow porgy, Dentex tumifrons, 10${\sim}$36cm(fork length) for Target dory, Zeus faber and 8${\sim}$35cm(fork length) for Red seabream, Pagrus major.

A Study on the Rating of the Insureds' Anthropometric Data III. A study on the Modified Broca's Index to Estimate Standard Body Weight of Korean Adults (피보험체계측치(被保險體計測値)의 평가(評價)에 관한 연구(硏究) 제3보(第3報) 한국성인(韓國成人)의 표준체중(標準休重) 산출(算出)을 위한 변형(變形)Broca지수(指數)에 관한 연구(硏究))

  • Im, Young-Hoon
    • The Journal of the Korean life insurance medical association
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    • v.4 no.1
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    • pp.44-76
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    • 1987
  • Present study was undertaken to establish the modified Broca's indices to estimate standard body weight by using a total of 5,496 insured persons who were medically examined at the Honam Medical Room of Dong Bang Life Insurance Company Ltd. from January, 1983 to January, 1986. The results were as follows: 1. The linear regression equations of body weight to $height^3$ to estimate standard body weight were as follows: In male, for $18{\sim}19$ age group $y=7.272{\times}10^{-6}{\times}x^3+23.560$ for $20{\sim}29$ age group $y=8.187{\times}10^{-6}{\times}x^3+22.031$ for $30{\sim}39$ age group $y=8.627{\times}10^{-6}{\times}x^3+23.169$ for $40{\sim}49$ age group $y=9.561{\times}10^{-6}{\times}x^3+20.994$ for $50{\sim}59$ age group $y=8.604{\times}10^{-6}{\times}x^3+23.081$ and for all ages group $y=7.778{\times}10^{-6}{\times}x^3+25.929$ In female, for $18{\sim}19$ age group $y=8.252{\times}10^{-6}{\times}x^3+18.920$ for $20{\sim}29$ age group $y=7.715{\times}10^{-6}{\times}x^3+22.409$ for $30{\sim}39$ age group $y=8.808{\times}10^{-6}{\times}x^3+21.440$ for $40{\sim}49$ age group $y=9.691{\times}10^{-6}{\times}x^3+21.940$ for $50{\sim}59$ age group $y=12.550{\times}10^{-6}{\times}x^3+11.031$ and for all ages group $y=7.300{\times}10^{-6}{\times}x^3+26.601$ In both sexes, for all ages group $y=8.342{\times}10^{-6}{\times}x^3+22.998$ 2. The modified Broca's index is expressed by formula $\{height(cm)-100\}{\times}K(kg)$. K is obtained from the following formula standard weight to average height estimated $\frac{by\;means\;of\;linear\;regression\;equation(kg)}{\{Average\;height(cm)-100\}{\times}K(kg)}$=1 Author's modified Broca's indices are as follows: In male, for $18{\sim}19$ age group $\{height(cm)-100\}{\times}0.85(kg)$ for $20{\sim}29$ age group $\{height(cm)-100\}{\times}0.90(kg)$ for $30{\sim}39$ age group $\{height(cm)-100\}{\times}0.95(kg)$ for $40{\sim}49$ age group $\{height(cm)-100\}{\times}1.00(kg)$ for $50{\sim}59$ age group $\{height(cm)-100\}{\times}0.95(kg)$ and for all ages group $\{height(cm)-100\}{\times}0.95(kg)$ In female, for $18{\sim}19$ age group $\{height(cm)-100\}{\times}0.90(kg)$ for $20{\sim}29$ age group $\{height(cm)-100\}{\times}0.90(kg)$ for $30{\sim}39$ age group $\{height(cm)-100\}{\times}1.00(kg)$ for $40{\sim}49$ age group $\{height(cm)-100\}{\times}1.05(kg)$ for $50{\sim}59$ age group $\{height(cm)-100\}{\times}1.05(kg)$ and for all ages group $\{height(cm)-100\}{\times}1.00(kg)$ In both sexes, for all age group $\{height(cm)-100\}{\times}0.95(kg)$ 3. Several types of modified Broca's index recommended by author are as follows: I. In male, for $18{\sim}29$ age group $\{height(cm)-100\}{\times}0.90(kg)$ and for $30{\sim}59$ age group $\{height(cm)-100\}{\times}0.95(kg)$ In female, for $18{\sim}29$ age group $\{height(cm)-100\}{\times}0.90(kg)$ and for $30{\sim}39$ age group $\{height(cm)-100\}{\times}1.00(kg)$ II. In male, for all ages group $\{height(cm)-100\}{\times}0.95(kg)$ In female, for all ages group $\{height(cm)-100\}{\times}1.00(kg)$ III. In both sexes, for all ages group $\{height(cm)-100\}{\times}0.95(kg)$ Note: The first type of modified Broca's index is the most precise one in estimating standard body weight among several types established by author. 4. Error of estimated standard body weight appearing by applying modified Broca's indices is generally greater in short build persons than in tall build persons and is more dominant especially in female group.

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Analysis of Benthic Macroinvertebrate Community Structure and Stability in Major Inflow Streams of Lake Andong and Lake Imha (안동·임하호 주요 유입지천의 저서성 대형무척추동물 군집구조 및 군집안정성 분석)

  • You, Hyuk;Lee, Mi Jin;Seo, Eul Won;Lee, Jong Eun
    • Korean Journal of Environmental Biology
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    • v.34 no.4
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    • pp.320-328
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    • 2016
  • This study was conducted to provide important basic information about effective management of the marine environment at major inflow streams in Lake Andong and Lake Imha. The investigation was conducted 8 times from May, 2015 (AD1, AD2, IH1, IH2) to September, 2016 (AD3, AD4, IH3, IH4), and 8 surveyed sites were selected at Lake Andong (4 sites) and Lake Imha (4 sites). The inquiry identified 114 species, $59,913.7inds.\;m^{-2}$ in Lake Andong and 112 species, $39,038.4inds.\;m^{-2}$ in Lake Imha. The results indicate that the number of species and individuals in Lake Andong is more than that in Lake Imha, because Lake Andong has a variety of riparian vegetation and a richness of organic materials. Community analysis at Lake Imha revealed a dominant index of 0.57 (${\pm}0.18$), a diversity index of 2.87 (${\pm}0.31$), an evenness index of 0.73 (${\pm}0.04$), and a richness index of 4.17 (${\pm}0.71$). The results of functional feeding group analysis showed that a high proportion of species and individuals are gathering collectors. The results of functional habitat group analysis showed that a high proportion of species and individuals are clingers. The result of a physico-chemical water assay and dissolved oxygen and electric conductivity tests revealed that these measures increased when the water temperature decreased. The result of Pearson's correlation analysis by biological factors and physico-chemical factors showed that species and electric conductivity are highly correlated with one another. Major inflow streams of Lake Andong and Lake Imha were exposed to various point pollution sources and non-point pollution sources. This implies a necessity for continuous monitoring of the aquatic ecosystems in order to effect systematic water quality management of Lake Andong and Lake Imha.

Distribution Characteristics Analysis of Pine Wilt Disease Using Time Series Hyperspectral Aerial Imagery (소나무재선충병 발생시기별 피해목 탐지를 위한 시계열 초분광 항공영상의 활용)

  • Kim, So-Ra;Kim, Eun-Sook;Nam, Youngwoo;Choi, Won Il;Kim, Cheol-Min
    • Korean Journal of Remote Sensing
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    • v.31 no.5
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    • pp.385-394
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    • 2015
  • Pine wilt disease has greatly damaged pine forests not only in East Asia including South Korea and China, but also in European region. The damage caused by pine wood nematode (Bursaphelenchus xylophilus) is expressed in bundles within stands and rapidly spreading, however, present field survey methods have limitations to detecting damaged trees at regional level. This study extracted the damaged trees by pine wilt disease using time series hyperspectral aerial photographs, and analyzed their distribution characteristics. Hyperspectral aerial photographs of 1 meter spatial resolution were obtained in June, September, and October. Damaged trees by pine wilt disease were extracted using Normalized Difference Vegetation Index (NDVI) and Vegetation Index green (VIgreen) of the September photograph. Among extracted damaged trees, dead trees with leaves and without leaves were classified, and the spectral reflectance values from the photographs obtained in June, September, and October were compared to extract new outbreaks in September and October. Based on the time series dispersion of extracted damaged trees, nearest neighbor analysis was conducted to analyze distribution characteristics of the damaged trees within the region where hyperspectral aerial photographs were acquired. As a result, 2,262 damaged trees were extracted in the study area, and 604 dead trees (dead trees in last year) with leaves in relation to the damaged time and 300 and 101 newly damaged trees in September and October were classified. The result of nearest neighbor analysis using the data shows that aggregated distribution was the dominant pattern both previous and current year in the study area. Also, 80% of the damaged trees in current year were found within 60 m of dead trees in previous year.

Impact of Environmental Factors on in vitro Interactions and Niche Overlap between Aspergillus ochraceus and other Storage Fungi (Aspergillus ochraceus와 다른 저장균간의 in vitro 상호작용 및 Niche Overlap에 미치는 환경요인의 영향)

  • Lee, Hyang-Burm;Magan, Naresh;Yu, Seung-Hun
    • The Korean Journal of Mycology
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    • v.27 no.4 s.91
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    • pp.283-288
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    • 1999
  • The effect of water activity ($a_w,\;0.9{\sim}0.995$) and temperature ($18{\sim}30^{\circ}$C) on in vitro growth and interactions between ochratoxin-producing Aspergillus ochraceus and six other fungi (Alternaria alternata, Aspergillus candidus, A. flavus, A. niger, Eurotium amstelodami, E. rubrum) isolated from maize grain were investigated. A. ochraceus and each six other species were paired and their interactions given a numerical score to obtain an index of dominance ($I_D$) for each species. Generally A. ochraceus was very competitive and dominant against other fungi. It was, however, dominanted by Alternaria alternata and A. niger at high $a_w\;(0.995\;a_w)$, and mutually antagonistic when paired with E. amstelodami and E. rubrum at low $a_w\;(0.9\;a_w)$. The growth rates of each species were also calculated under the same range of environmental conditions. They were markedly influenced by aw and temperature. At high temperature ($30^{\circ}C$), A. ochraceus grew most rapidly under slightly drier conditions ($0.95\;a_w$), while A. alternata, A. flavus and A. niger did at high water availability level ($0.995\;a_w$). At $18^{\circ}C\;and\;25^{\circ}C$, and high $a_w$ level ($0.995\;a_w$), A. alternata grew fastest, while A. candidus, E. amstelodami and E. rubrum grew very slowly. Using Biolog plates the effect of $a_w$ and temperature on utilization patterns of carbon sources in maize was evaluated. The niche overlap index (NOI) relative to A. ochraceus was determined and compared with that of each interacting species. Under high water available condition ($0.995\;a_w$). the NOI of A. ochraceus was often >0.9, indicative of the coexistence with other interacting species. However, against E. amstelodami and E. rubrum at $18^{\circ}C$, the species had NOI <0.8, indicative of occupation of different niches. At low $a_w\;(0.95\;a_w)$, NOI for A. ochraceus was <0.8 when paired with A. alternata and A. niger also suggested the occupation of different niches.

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The Effect of Water Conveyance of Boryeong Dam on Structural Changes of Benthic Macroinvertebrates Community (보령댐 도수가 저서성 대형무척추동물 군집구조 변화에 미치는 영향)

  • An, Chae-Hui;Han, Jung-Soo;Choi, Jun-Kil;Lee, Hwang-Goo
    • Korean Journal of Environment and Ecology
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    • v.32 no.4
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    • pp.381-391
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    • 2018
  • The purpose of this study is to investigate the influence of artificial disturbances occurring during water conveyance frequency on benthic macro-invertebrate by comparing and analyzing data before and after the construction of Boryeong dam in Boryeong-si, Chungcheongnam-do. We conducted the survey eight times in four points from April 2016 to September 2017. A total of 13,447 individuals from 125 species, 70 families, 19 orders, 7 classes, and 4 phyla were collected. The result of the community analysis showed that the dominant index was 0.55 (${\pm}0.07$) to 0.47 (${\pm}0.08$), diversity index was 2.06 (${\pm}0.26$) to 2.23 (${\pm}0.28$), evenness index was 0.69 (${\pm}0.05$) to 0.70 (${\pm}0.04$), and richness index was 3.43 (${\pm}0.72$) to 4.03 (${\pm}0.91$). After conveyance, the dominance decreased while the diversity, evenness, and richness increased. The result of the functional group analysis showed the portion of scrapers, filtering-collectors increased while that of shredders, gathering-collectors decreased in the functional feeding group and that the proportion of climbers and clingers increased while that of burrowers and sprawlers decreased in the habitat orientation group. The result of analysis of community stability showed that St. 1 and St. 2 decreased resistance and resilience after conveyance and new species appeared in the III characteristics group while St. 3 and St. 4 did not show much difference. The result of multidimensional scaling analysis showed that the variation of similarity was the highest at St. 1 after conveyance, and the variation of similarity at St. 4 was the lowest.