• ALGAE
• /
• 제26권4호
• /
• pp.333-342
• /
• 2011

Macroalgae are important primary producers in marine ecosystem. They don't only play an important role as bioindicators but also provide economic resources for humans. Seasonal and vertical variations in seaweed species composition and biomass were examined to determine the ecological status of seaweed beds around Udo, near Jeju Island. We obtained samples at two sites in the high-intertidal to subtidal zones using the quadrat method between June 2010 and May 2011. A total of 262 species were collected, including 31 green, 61 brown, and 170 red algae. The composition of algal species revealed a decrease in species growing in cold water in comparison with the list 20 years ago. The macroalgal mean biomass (g wet wt $m^{-2}$) was 3,476 g and 2,393 g from the two sites, respectively. Ecklonia cava had the greatest biomass at both sites. The seasonal dominant species by biomass at site 1 from the low-intertidal to 1-3 m depth of the subtidal zone was mostly comprised of thick-leathery form, such as Sargassum hemiphyllum, S. coreanum, and Ecklonia cava, whereas site 2 was comprised of the turf form, such as Chondrophycus intermedius, Chondracanthus intermedius, Dictyopteris prolifera, and Gelidium elegans. The current ecological status of the seaweed community in Udo is stable based on diversity and dominance indices.

• 한국수산과학회지
• /
• 제51권5호
• /
• pp.571-578
• /
• 2018

Seasonal variability in algal community structure of the subtidal zone was examined at four study sites on the southeastern coast of Korea from February to November 2016. A total of 81 species of algae (8 green, 12 brown, and 61 red) were indentified. During the study period, the greatest number of species was observed at Sinamri (57 species) followed by Daesongri (50 species), Dongbaekri (47 species) and Gangyangri (42 species). Of the six functional seaweed forms, the coarsely-branched form was the most dominant, accounting for about 43% of the total species at Daesongri. The annual average biomass in wet weight varied from $700.59g/m^2$ at Sinamri to $1,712.45g/m^2$ at Daesongri. The parameters of seaweed community structures were as follows: dominance index (DI), 0.30-0.54; richness index (R), 4.92-7.05; evenness index (J'), 0.54-0.72; and diversity index (H'), 2.05-2.91.

• 한국산림과학회지
• /
• 제87권1호
• /
• pp.90-97
• /
• 1998

이 연구(硏究)는 우리 나라 주요(主要) 낙엽(落葉) 관엽수(關葉樹) 21종(種)에 대하여 수목(樹木)의 줄기, 가지, 분기부분(分技部分)과 정단부(頂端部) 1년생(年生) 주간(主幹)과 측지(側枝) 등의 상대수분통도성(相對水分通導性)을 측정(測定)하여 수분통도성(水分通導性)의 부위별(部位別) 특성(特性)을 비교(比較)하였다. 1. 관엽수(關葉樹) 21종(種)의 상대수분통도성(相對水分通導性)은 $3.18{\times}10^{-15}{\sim}1.23{\times}10^{-10}m^2$의 폭넓은 범위 내에 분포하였고, 수종별(樹種別), 수체(樹體)의 부위별(部位別)로 다르게 나타났다. 2. 산공재(散孔材) 8수종(樹種)의 부위별(部位別) 평균(平均) 상대수분통도성(相對水分通導性)은 줄기가 $3.49{\times}10^{-13}{\sim}6.35{\times}10^{-11}m^2$, 가지가 $4.89{\times}10^{-13}{\sim}2.99{\times}10^{-11}m^2$, 분기부분(分技部分)이 $1.33{\times}10^{-13}{\sim}9.42{\times}10^{-12}m^2$였고, 환공재(環孔材) 13수종(樹種)은 줄기가 $7.14{\times}10^{-13}{\sim}4.76{\times}10^{-11}m^2$, 가지가 $2.93{\times}10^{-13}{\sim}3.91{\times}10^{-11}m^2$, 분기부분(分技部分)이 $1.14{\times}10^{-13}{\sim}9.20{\times}10^{-12}m^2$의 범위를 나타냈다. 3. 줄기의 직경별(直徑別) 상대수분통도성(相對水分通導性)에 있어서, 산공재(散孔材) 8수종(樹種)은 줄기의 직경(直徑) 크기와 상대수분통도성(相對水分通導性)과의 상관관계(相關關係)가 없는 것으로 나타났으며 다릅나무와 들메나무를 제외한 환공재(環孔材) 11수종(樹種)은 모두 줄기의 직경(直徑)이 작아질수록 상대수분통도성(相對水分通導性)이 커지는 경향이 뚜렷하였다. 4. 관엽수(關葉樹) 5종(種)에 있어서 정단부(頂端部) 1년생(年生) 주간(主幹) 및 측지(側枝)의 상대수분통도성(相對水分通導性)은 주간(主幹)이 $4.87{\times}10^{-13}{\sim}8.41{\times}10^{-11}m^2$이고, 측지(側枝)가 $7.93{\times}10^{-14}{\sim}2.01{\times}10^{-11}m^2$의 범위를 보였으며, 정단주간(頂端主幹)(leaders)이 정단측지(頂端側枝)(adjacent laterals)보다 1.5~8배 정도로 크게 나타나, 수목(樹木)의 정단주간(頂端主幹)은 정아우세(頂芽優勢)와 같은 수력(水力) 적(的) 우세(優勢)(hydraulic dominance)를 보였다.

• The Korean Journal of Ecology
• /
• 제15권2호
• /
• pp.103-115
• /
• 1992

This dissertation, which has been prepared in the region of cheju(33o31'N, 126o32'E) from may,1987 to appril, 1989, is to elucidate the dominant characteristics of early stages in secondary succession, by examining the life history of erigeron annuus for the seeding depth of a seed was dependent upon the degree of shading. That is, on the area of ocm,the more tense the shading was, the more germination percentage was increased, while, in the case of 1.5cm, it was somewhat increased, when shading bwcame ess and less tense. The rosette of e. annuus, through its relative light intensity was decreased by shading, up to 5% of natural light, showed some strong shade tolerance, which had no difficulty in matter production. The species diversity of mixed-species community was the highest in the middle of April, the lowest in the last of may. The dominance index was the highest in the late may, the lowest in the middle of April. Toward the end of may, the occupation rate of dominance species was the highest. There was a neutral relationship between intraspecific and interspecific, owing to the differentiation of its niche, temporally and spatially. Productive structure of the community revealed a narrow leaf type which was concentratively distributed in the mid part of community height. The relative light intensity of community ground surface was 6.1%, the leaf inclination 60o,the extinction coefficient(k) 0.4, biomass of community 1,045.6 g.d.w./m2,T/Rratio 9.3, C/Frate 7.0 and sumgermanition, shade toarance and community characteristics on erigeron annuus l.in chejumed leaf area index 3.88. through the various life cycles o e.annuus, we can say that it decreases mortality of seeding caused by some stress and disturbance, for germination lasts for a long time at any opportunity available, and it promotes population growth. The strong shade tolerance of a rosette and the variableness of a life from differentiate the niche between intraspecific and interspecific within the community, and avoid the direct competition between them, thus poromoting community growth.

• 한국토양동물학회지
• /
• 제8권1_2호
• /
• pp.32-36
• /
• 2003

상주시에서 위치한 갑장산(805.7 m)을 대상으로 고도 200m부터 800m까지 100m 간격으로 7개의 시험구를 설정하여 2001년 8월부터 2001년 10월까지 당밀을 이용한 pitfall trap를 설치하여 고도별, 계절별 다양도 및 우점도 지수를 알아보았다. 그 결과 먼지벌레와, 딱정벌레과 그리고 송장벌레과에 속한 곤충들이 채집되었고, 전체 6,304개체 중 먼지 벌레과가 6,163개체로 98% 이상을 차지하였다. 고도 200m부터 700m까지 점차적으로 개체수의 증가추세를 보이다가 800m에서 급격하게 감소하였다. 고도 700m에서 심슨의 우점도지수는 0.66으로 가장 높게 나타났으며, 800m에서 0.47로 가장 낮게 나났다. 반면 심슨의 다양도 지수는 800m에서 0.53으로 가장 높게 나타났다. 계절별 우점도 및 다양도 지수는 0.54에서 0.55로 큰 차이를 발견할 수 없었으며, 과 별 다양도지수는 먼지벌레과에서 가장 높았다.

• 한국패류학회지
• /
• 제23권2호
• /
• pp.235-243
• /
• 2007

제주 바다목장조성지인 차귀도 주변해역의 저서 무척추동물에 대한 출현 및 계절적 변동을 파악하기 위해 고산, 용수, 용당, 신창의 4개 해역을 설정하여 2004년 9월과 11월 및 2005년 2월, 4월, 6월, 8월 등 모두 6 차례에 걸쳐 조사 분석을 하였다. 조사기간 중 총 201 종의 저서동물이 출현하였다. 연체동물이 74 종 (37.2%) 으로 가장 높게 나타났다. 이 중 복족류가 28.4%로 가장 우점 하였고, 절지동물 43 종 (19.2%), 자포동물 34 종 (16.7%) 의 순으로 나타났다. 조사해역의 평균 개체밀도와 생물량은 각각 455 개체/$m^2$ (53.9%), 15,565.0g/$m^2$ (64.4%) 로 종류와 마찬가지로 연체동물이 개체수와 생체량에서 가장 높게 출현하였다. 주요 우점종은 Trochus sacellus, Batillus cornutus, Pagurus gracilipes, Cantharus cecillei의 복족류에서 높은 우점률을 보였다. 계절별 출현양상은 하계에 개체수 및 생체량이 증가하다 동계로 갈수록 감소하는 경향을 보였다. 그리고 종 다양도, 균등도, 풍부도의 해역별 변동을 보면 조사해역의 남쪽에 위치해 있는 고산에서 상대적으로 높게 나타난 반면, 북쪽에 위치한 신창에서 가장 낮게 나타나는 경향을 보였다.

• 한국환경과학회지
• /
• 제23권2호
• /
• pp.291-302
• /
• 2014

We have studied characteristics of community structure on the benthic macro-invertebrates at twelve selected sites in upstream, midstream and downstream of Paemsagol, Piagol, Chilseongol and Daeseonggol, major streams of Jirisan Mountain, for three years from April 2008 to September 2010. As a result, 2 phyla, 3 classes, 11 orders, 41 families, 119 species and 4,449 individuals of benthic macro-invertebrates have been collected and classified in this study. Among them EPT group (Ephemeroptera, Plecoptera, Trichoptera), commonly appearing taxa in clean stream ecosystem, was found most frequently. The highest species number of benthic macro-invertebrates were collected in 2008, the year with lower climatic influence including heavy rain. In almost all of survey sites 80% or over of EPT group were counted, and St. 1 scored highest rate of EPT group at 92.59%. Most dominant species was Ecdyonurus kibumensis at 12.83% of dominance index, and subdominant species was Goerodes KUb at 6.81% of dominance index. The investigation of the feeding function group indicated that gathering-collectors were dominant with 26 species and 1,334 individuals, while the number of filtering-collectors was lowest with 11 species and 230 individuals. This result represents that the feeding function group of Jirisan Mountain is mountainous stream-specific one. Both diversity index and richness index were lowest at the midstream of Chilseongol (St. 5), while the midstreams of Daeseonggol (St. 11) and Piagol (St. 8) were highest in diversity and richness indices respectively. The analyses of linear regression and correlation were performed in order to investigate and to predict the appearance aspect of EPT group by altitude. The results showed that the ratio of Plecopteran species number has increased by the elevation of the altitude at 0.05 significance level. Cluster analysis was also carried out for evaluating environmental similarities among survey sites. As a result, upper regions of Paemsagol (St. 1) and Piagol have clustered as most similar sites each other, while the midstream of Piagol (St. 8) has separated with lower similarity value than other sites in species composition.

• 한국환경보건학회지
• /
• 제45권5호
• /
• pp.426-433
• /
• 2019

Objectives: Zooplankton communities play important roles in aquatic ecosystems as secondary producers that graze on phytoplankton and in turn are preyed upon by planktivorous and juvenile fish. They can shift their distribution, species composition, and abundance in response to environmental changes. Therefore zooplankton communities are important for understanding the energy flow in aquatic ecosystems and can be valuable indicators of environmental conditions. However, zooplankton in streams are still not well-studied, especially in northern Gyeonggi-do Province. This study aims to investigate the zooplankton communities in major streams in northern Gyeonggi-do Province. Methods: Zooplankton is important in the nutrient cycle and energy flow of aquatic ecosystems. Therefore, we surveyed zooplankton and measured temperature, DO, BOD, COD, T-N, T-P, and Chl-a in major streams (Sincheon, Gongneungcheon, Wangsukcheon, and Gapyeongcheon Streams) and stagnant water (Gomoji Reservoir). Results: The water quality in Gapyeongcheon Stream was the highest grade, while that of Gomoji Reservoir was mesoeutrophic and eutrophic during the research period. In the zooplankton community, Nauplius, Rotaria, and Monostyla spp. were dominant in Sincheon, Gongneungcheon, and Wangsukcheon Streams, and the dominance index was also high. In the case of Gapyeongcheon Stream, it was found that water quality and aquatic ecosystem health were good, and the lowest dominance index reflected this. In Gomoji Reservoir, Polyarthra spp., Nauplius, and Bosmina longirostris, which can be easily observed as eutrophication progresses, showed a high dominance rate. Therefore, it is necessary to monitor the progress of eutrophication in further research. Conclusions: We collected data on the zooplankton communities in streams and investigated their characteristics. As a result, specific species were found to be dominant at each survey sites and some of them are known to be observed as eutrophication progresses. Therefore, we should investigate the zooplankton community of streams around us and apply ecological stream management.

• Weed & Turfgrass Science
• /
• 제3권2호
• /
• pp.86-94
• /
• 2014

2013년에 경기 남부지역 벼 재배면적 64.9천ha를 대상으로 약 325 ha당 1점씩을 기준으로 하여 200개 지점에서 답유형, 이앙시기, 농업지대 등으로 구분하여 논잡초 분포를 조사한 결과는 다음과 같다. 발생 논잡초 초종은 화본과 3종, 사초과 5종, 광엽 및 기타 잡초가 11종 등 총 19종으로 2005년 17종에 비해 2종이 증가하였다. 논잡초의 우점도는 올방개> 피> 벗풀> 물달개비> 올챙이고랭이> 가막사리> 순이었으며, 2005년 대비 올방개($30{\rightarrow}21%$), 가막사리($10{\rightarrow}6%$)는 감소하였고, 물달개비(815%), 올챙이고 랭이($2{\rightarrow}9%$), 벗풀($14{\rightarrow}16%$), 피($16{\rightarrow}18%$)는 증가하였다. $m^{-2}$ 당 논잡초 발생량은 2005년 2.83 g 에서 2013년에는 3.51 g으로 0.68 g 증가하였다. 일년생과 다년생잡초의 생활형 비율은 2005년 각각 45.2%: 54.8%에서 2013년에는 각각 45.8%: 54.2%로 나타났다. 논유형별 논잡초 발생분포는 보통답, 습답, 사질답에서 올방개, 염해답에서는 새섬매자기가 최우점 잡초로 나타났다. 이앙기별 논잡초 발생분포는 5월 중순은 올방개, 피, 5월 하순은 물달개비, 올챙이고랭이, 6월 상순은 물달개비, 올방개가 우점하였다. 경운방법별 논잡초 발생분포는 추경은 올방개, 피, 춘경은 올방개, 벗풀이 우점하였으며, 농업지대별 논잡초 발생분포는 남부평야는 올방개, 피, 서부해안은 물달개비, 가막사리, 동부내륙은 올방개, 벗풀이 우점하였다. 농가의 제초제 처리횟수는 2회 이상이 96%로 2005년 62%에 비해 크게 증가하였으며, 적기처리 농가는 89%로 2005년 86%에 비해 소폭 증가하였다. 앞으로 전국적으로 문제가 되고 있는 물달개비, 올챙이고랭이 등 SU계 제초제 저항성 논잡초의 발생 증가가 예상되므로 주기적인 논잡초 발생 모니터링과 아울러 효율적인 방제방법에 대한 연구가 필요한 것으로 생각되었다.

• 한국패류학회지
• /
• 제7권1호
• /
• pp.49-57
• /
• 1991

A study on the distribution and community structure of the benthic macroinvertebrates on the intertidal zones of Gapa and Mara islets were carried out from March to June 1991. The macroinvertebrates collected and identified were composed of 7 phyla, 14 classes, 29 orders, 68 families and 132 speies in Gapa islet and of 7 phyla, 12 classes, 23 orders, 49 familis and 90 species in Maara islet. The first and second dominant species and the community dominance indices of the upper tidal zones of Gapa and Mara islets were Nodilittorina exigua, Pollicipes mitella and 79.01, 69.77 respectively. However, the dominant species of the middle and lower intertidal zones of the two islets were not identities and different among the tidal zones.