• ALGAE
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• 제34권4호
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• pp.289-301
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• 2019

Mixotrophy in marine organisms is an important aspect of ecology and evolution. The discovery of mixotrophic abilities in phototrophic dinoflagellates alters our understanding of the dynamics of red tides. In the phototrophic dinoflagellate genus Alexandrium, some species are mixotrophic, but others are exclusively autotrophic. There are differences in the ecological roles of autotrophic and mixotrophic Alexandrium in marine food webs. However, of the 34 known Alexandrium species, the mixotrophic ability of >20 species has yet to be explored. In this study, the mixotrophic capabilities of Alexandrium insuetum CCMP2082, Alexandrium mediterraneum CCMP3433, Alexandrium pacificum CCMP3434, Alexandrium tamutum ATSH1609, and Alexandrium margalefii CAWD10 were investigated by providing each species with 22 diverse prey items including bacterium-sized microbeads (1 ㎛), the cyanobacterium Synechococcus sp., algal prey species, and the ciliate Mesodinium rubrum. None of the 5 Alexandrium species fed on any of the prey items. These results increase the number of Alexandrium species lacking mixotrophic abilities to 9, compared to the 7 known mixotrophic Alexandrium species. Furthermore, the Alexandrium phylogenetic tree based on the large subunit ribosomal DNA contained 3 large clades, each of which had species with and without mixotrophic abilities. Thus, the acquisition or loss of mixotrophic abilities in Alexandrium might readily occur.

• 한국응용곤충학회지
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• 제42권3호
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• pp.269-277
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• 2003

최근 들어 벼, 田作物, 과수 등에서 노린재류에 의한 피해가 증가하고 있는 상황에서 지금까지 우리 나라에서 이루어진 연구내용을 조사$.$정리할 필요가 있어서, 우리 나라에서 출판되는 각종 학술지에 게재되어 있는 벼를 제외한 작물, 과수, 잡초를 가해하는 노린재류에 관한 논문을 수집하여 분야별(\circled1 분류 및 형태, \circled2 발육과 성장, \circled3 곤충상, \circled4 피해수준, \circled5 발생소장, \circled6 방제, \circled7식물병 매개)로 정리하였다. \circled1에서는 한국산 노린재류의 종류와 명아주노린재과에 속하는 Piesma spp.의 난과 약충의 형태, 억새노린재의 외부생식기의 형태, 홍줄노린재와 주둥이노린재의수정방의 형태에 관한 연구를 간략히 정리하였다. \circled2에서는 명아주노린재, 장수허리노런재, 큰허리노린재의 온도별 발육과 성장분석에 대한 보고를 요약하였다. \circled3에서는 콩, 단감, 유자, 감귤, 포도, 국화, 백하수오 등의 작물과 참쑥, 망초 등의 잡초에 발생하는 노린재류에 관한 문헌을 정리하고, 계룡산과 경기도 수원시 여기산 지역의 노린재류 상에 관한 조사보고를 소개하였다. \circled4에서는 콩, 단감, 유자, 포도 등에서 노린재류에 의한 피해정도를 정리하였고, \circled5는 단감원에 발생하는 노린재류, 국화의 주요 해충인 애긴노린재,한약재인 백하수오에 발생하는 십자무의긴노린재, 콩 포장에 발생하는 수종의 노린재류의 발생소장에 관한 문헌을 정리하였다. \circled6에서는 단감원, 포도원 및 콩밭에서 실시한 약제방제 효과에 관한 문헌을 조사하였으며, 몇 가지 살충제의 실내 생물검정에 대한 논문도 정리하였다. \circled7마지막으로 오동나무빗자루병의 병원체인 micoplasma-like organism이 썩덩나무노린재와 담배장님노린재에 의해서 일일초로 전파된다는 논문을 소개하였다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.153-156
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• 2008

Comparative analysis of forest fire danger rating on the forest characteristics of thinning area and non-thinning area on forest fire burnt area was studied in this work. To investigate the effect of thinning slash in forest fire, Gangneung-si Wangsan-myeon, Ulgin-gun Wonnam-Myeon, Samchok-si Gagok-Myeon, in which forest fire broke out, were selected. As a result that investigated forest fire danger ratio between thinning slash and non-thinning slash, leeward scorching ratio(36%), crown damage ratio(29%), mortality of branch at the former are higher than those at the latter, leeward scorching ratio of tree, where thinning slash is around, is 10%-20% higher than that of independent tree. So I estimate that thinning slash has a some effect on the intensity of forest fire. And the result to investigate damage of forest fire according to tree species shows that leeward scorching ratio of conifer is 5% higher than that of non-conifer, and mortality of branch of the former is 19% higher than that of the latter. It is considered that forest fire may affect directly to a tree trunk if it diffuse to piled thinning tree because there was no space between thinning trees and trees. Furthermore, it was found that re-ignition had a chance to occur due to lots of piled thinning trees.

• Journal of Ecology and Environment
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• 제43권2호
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• pp.219-225
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• 2019

In order to assess the impacts of drawdown for land-use change on a Sphagnum-marsh, we compared the vegetation and flora of the wetland before and after the drawdown with focusing on the population of Sphagnum palustre L. Remarkable changes in the coverage of S. palustre and the major vegetational components of the wetland were observed. The coverage of S. palustre markedly decreased by about 75% (from approx. 247 ㎥ in 2011 to approx. 62 ㎥ in 2015) after the drawdown. Tree species such as Salix spp. extended (from about 70% to about 83% in the total coverage of the wetland), whereas herbaceous species shrunk after the drawdown. Upland-inhabiting species such as obligate plants for uplands (OBU) increased, whereas wetland-inhabiting species such as facultative plants for wetlands (FACW) and OBW decreased in terms of vegetational coverage. The total number of plant species decreased from 70 species to 62 species after the drawdown, including the disappearance of some wetland-inhabiting species from the wetland. We suggest that the attention for further studies on the abandoned paddy terraces (APTs) and effort for the management and conservation of APTs and APT-inhabiting species that are vulnerable to human-induced disturbances have to be paid more.

• ALGAE
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• 제28권4호
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• pp.307-330
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• 2013

The genus Cryptomonas is easily recognized by having two flagella, green brownish color, and a swaying behavior. They have relatively simple morphology, and limited diagnostic characters, which present a major difficulty in differentiating between species of the genus. To understand species delineation and phylogenetic relationships among Cryptomonas species, the nuclear-encoded internal transcribed spacer 2 (ITS2), partial large subunit (LSU) and small subunit ribosomal DNA (rDNA), and chloroplast-encoded psbA and LSU rDNA sequences were determined and used for phylogenetic analyses, using Bayesian and maximum likelihood methods. In addition, nuclear-encoded ITS2 sequences were predicted to secondary structures, and were used to determine nine species and four unidentified species from 47 strains. Sequences of helix I, II, and IIIb in ITS2 secondary structure were very useful for the identification of Cryptomonas species. However, the helix IV was the most variable region across species in alignment. The phylogenetic tree showed that fourteen species were monophyletic. However, some strains of C. obovata had chloroplasts with pyrenoid while others were without pyrenoid, which used as a key character in few species. Therefore, classification systems depending solely on morphological characters are inadequate, and require the use of molecular data.

• 한국산림과학회지
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• 제104권4호
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• pp.564-577
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• 2015

본 연구는 새만금간척지에서 원지반에 묘포장을 조성할 수 있는지를 검증하고, 내염성수종을 선발하기 위해 실시하였다. 2010년 조성한 군산시 옥구지역 간척지 원지반토에 2012년 2.0 ha의 묘포장을 조성하고 암거배수를 설치했다. 토양 염도는 토심 60 cm이내에서 2010년 4월 평균 35.2 dS/m이었으나, 2013년도에는 강우제염지역에서 5.13 dS/m, 미제염지역에서 8.20 dS/m로 줄었다. 2013년 4월초 1~4년생에 해당하는 36종(22종 교목과 14종 관목)의 조경수 총 3,943본을 이식하였다. 36종 수목의 첫해 가을 생존율은 평균 71.3%로서 간척지에서 양묘가 가능했다. 봄부터 가을까지 주기적으로 조사한 항목 중에서 묘고, 근원경, 잎 길이, 수관폭, 엽록소함량은 내염성을 판정하는 데 활용하지 못했다. 대신 다양한 수종에 공통된 기준으로 생장상태와 내염성을 상호 비교할 수 있는 항목은 신초 생장량, 생존율, 수세(엽량, 가지 고사와 수관 형성 상태) 뿐이었다. 생존율과 수세를 근거로 하여 수종별로 내염성을 최종적으로 판단하였는데, 생존율이 90% 이상이면서 수세가 매우 양호한 3종(위성류, 꾸지뽕나무, 낙상홍)은 "내염성수종"으로 분류하였다. 생존율이 80~89%이면서 수세가 양호한 5종(곰솔, 자귀나무, 쥐똥나무, 해당화, 난쟁이조릿대)은 "간척지 권장수종"으로 분류하였다. 생존율이 70~79%이면서 수세가 보통수준인 9종(느티나무, 무궁화, 보리수나무, 팥배나무, 회화나무, 메타세쿼이아, 상수리나무, 참느릅나무, 아까시나무)는 "간척지 식재가능수종"으로 분류하였다. 원지반에 원지반토, 준설토, 산림토로 50 cm, 혹은 100 cm 성토를 실시한 시험에서는 원지반토(9.95 dS/m)에서 곰솔의 생존율이 50%로 가장 낮고, 준설토(8.45 dS/m)에서 89%, 산림토(0.9 dS/m)에서 95%로 가장 높았다. 김제 광활지역 간척지에서 3~4년간 양묘한 7개 수종을 옥구지역 원지반토에 이식하였는데, 평균 98.2%의 생존율과 양호한 수세를 보여 이미 간척지 환경에 적응한 개체는 내염성을 가지게 됨을 확인하였다.

• Journal of Ecology and Environment
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• 제44권4호
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• pp.241-255
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• 2020

Background: The stem exclusion stage is a stage of forest development that is important for understanding the subsequent understory reinitiation stage and maturation stage during which horizontal heterogeneity is formed. Over the past 11 years (2009-2019), we observed a deciduous broad-leaved forest in the Albongbunji Basin in Ulleungdo, South Korea in its stem exclusion stage, where Fagus engleriana (Engler's beech) is the dominant species, thereby analyzing the changes in the structure (density and size distributions), function (biomass and species richness), and demographics. Results: The mean stem density data presented a bell-shaped curve with initially increasing, peaking, and subsequently decreasing trends in stem density over time, and the mean biomass data showed a sigmoidal pattern indicating that the rate of biomass accumulation slowed over time. Changes in the density and biomass of Fagus engleriana showed a similar trend to the changes in density and biomass at the community level, which is indicative of the strong influence of this species on the changing patterns of forest structure and function. Around 2015, a shift between recruitment and mortality rates was observed. Deterministic processes were the predominant cause of tree mortality in our study; however, soil deposition that began in 2017 in some of the quadrats resulted in an increase in the contribution of stochastic processes (15% in 2019) to tree mortality. The development of horizontal heterogeneity was observed in forest gaps. Conclusions: Our observations showed a dramatic shift between the recruitment and mortality rates in the stem exclusion stage, and that disturbance increases the uncertainty in forest development increases. The minor changes in species composition are likely linked to regional species pool and the limited role of the life-history strategy of species such as shade tolerance and habitat affinity. Our midterm records of ecological succession exhibited detailed demographic dynamics and contributed to the improvement of an ecological perspective in the stem exclusion stage.

• Journal of Forest and Environmental Science
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• 제8권1호
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• pp.51-66
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• 1992

This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

• Journal of Ecology and Environment
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• 제38권1호
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• pp.47-56
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• 2015

Ailanthus altissima, which is recognized as an invasive tree in the Western world, has been widely observed in Japan. To investigate how A. altissima expanded within-population and to new populations within a region, 446 A. altissima trees were sampled from three separate sites (A, B, and C) including 35 distantly positioned patches, with three chloroplast DNA markers and nine nuclear microsatellite markers. We detected 2, 2, and 3 chloroplast haplotypes in sites A, B, and C, respectively. In addition, 271, 40, and 41 nuclear genotypes were detected in sites A, B, and C, respectively. The clonal richness value was 0.85, 0.78, and 0.53 in sites A, B, and C, respectively. Most trees with the same genotypes were distributed in the same patch, indicating that range expansion by asexual reproduction was limited to a maximum of 45 meters. According to autocorrelation analysis, the extent of nonrandom spatial genetic structure was approximately 0-2 km in sites A and C. KINGROUP analyses showed that 812, 74, and 111 nuclear genotype pairs were detected to have kinship in sites A, B, and C, respectively. Most nuclear genotype pairs were detected within the same patches or sites. These results indicate that the number of A. altissima trees gradually increased from seeds, some of which were produced by trees within sites, meaning that this species could regenerate naturally. This shows the need for the future management of A. altissima as an invasive species in Japan.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.131-137
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• 2006

This study was investigated the contents of heavy metals in plants at Dalcheun mine area, in order to offer basic data for phytoremedation on soil contamination by heavy metals. As the results of this study, the contents of Ni, As, Cd in plants were the highest at the west area of Dalcheun mine area. But the content of Zn was similar in all of Dalcheun mine area. For the herbaceous plants, the contents of heavy metals were higher in plants which were included in Gramineae and Compositae than any other families. And then the contents of Ni, Zn, Cd in root were higher $1.4{\sim}1.8$ times than stem, especially the content of As was higher 4 times. For the trees, the contents of heavy metals were usually high in Zanthoxylum piperitum, Pine tree, Chestnut tree, Quercus acutissima and Lindera obtusiloba. The contents of heavy metals with parts of tree were almost same range. All experimental result, we paid attention on two conclusions. First, the contents of heavy metals in herbs was higher than in trees. And second, if there were some spices that the content of heavy metal in leave were higher than in root, they could accumulate that kind of heavy metal. Therefore, It is above 2 times which the content of heavy metal in the leave is higher than in the root about herbs, that kind of plants was regarded as a accumulation species. According as the heavy metals, accumulation species were selected. We think that the accumulation species are able to absorb the heavy metals from the soil, they will make use of phytoremedation on contaminated soil by heavy metals.