585 resultados para Prosopis flexuosa
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O objetivo deste estudo foi avaliar a atividade antibacteriana in vitro e cicatrizante do óleo de buriti (M. flexuosa) em feridas realizadas em ratos (Rattus norvegicus albinus). Para a avaliação antibacteriana in vitro, foram utilizados cinco patógenos bacterianos incluindo espécies gram-positivas e espécies gram-negativas mediante o uso do método de difusão em ágar. Para a avaliação da atividade cicatrizante, foram utilizados 40 ratos da linhagem Wistar, divididos em dois grupos: o grupo I, composto por 20 ratos com feridas cutâneas, tratados com aplicação tópica do creme base com 10% de óleo de buriti, e o grupo II, controle, com o mesmo número de animais que receberam a aplicação tópica do creme base. A aplicação do produto foi realizada em feridas padronizadas, circulares de 1cm de diâmetro na região dorsolombar. As avaliações clínica, morfométrica e histopatológica das feridas foram realizadas no 3°, 7°, 14° e 21° dias. Em relação à avaliação da atividade antibacteriana, os resultados mostraram que houve inibição do crescimento bacteriano em quatro dos cinco patógenos testados. Em relação à área da ferida, foi observada redução significativa da área no 14o dia e maior percentual de contração das feridas do grupo tratado em relação ao controle. No décimo quarto dia, as feridas tratadas com o óleo do buriti apresentavam aumento significativo na contagem de fibroblastos e fibras colágenas, além de completo processo de reepitelização, enquanto o grupo controle necessitava de mais tempo para resolução do processo cicatricial
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Rhodnius neglectus Lent, 1954 {Rn}e Psammolestes tertius Lent & Jurberg, 1965 {Pt} são triatomíneos que ocorrem em ninhos de aves, principalmente da família Furnariidae. O ciclo biológico dessas espécies é conhecido em condições de laboratório, sendo poucos estudos em ecótopos silvestres. Para analisar a infestação e estrutura de populações de Rn e Pt em ninhos de aves presentes na palmeira Mauritia flexuosa Linnaeus, em duas estações climáticas do Brasil Central, foram amostradas 41 palmeiras com evidências de nidificação dePhacellodomus ruber Vieillot, 1817 (22 na estação chuvosa e 19 na estação seca) em quatro áreas do Distrito Federal. Os insetos foram capturados usando-se coleta manual na copa da palmeira, identificados morfologicamente, separados por sexo e estádio ninfal. Fezes e glândulas salivares de Rn foram examinadas para verificar infecção por Trypanosoma cruzi Chagas, 1909 e/ou T. rangeli Tejera, 1920. Trinta e cinco palmeiras com ninhos de P. ruber estavam infestadas por Rn (85%) e 22 por Pt (53%). 442 indivíduos foram coletados na estação seca (200 Rn e 242 Pt) e 267 na estação chuvosa (136 Rn e 131 Pt). O único fator relacionado significativamente com a densidade de triatomíneos nas palmeiras foi a área. A estrutura etária das populações mostrou: a) maior abundância de adultos nas populações de Pt, b) maior abundância de machos em ambas as espécies e c) presença de fêmeas ovipondo em ambas as estações. Nenhum dos 177 triatomíneos examinados estava infectado por T. cruzi ou T. rangeli. A estrutura etária das populações de Rn e Pt não diferiu significativamente entre as estações amostradas, indicando ausência de marcada sazonalidade para essas espécies. _______________________________________________________________________________________ ABSTRACT
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Artrópodos associados à copa de árvores, principalmente palmeiras, são pouco conhecidos no Cerrado. Para descrever a estrutura da comunidade de artrópodos à copa de Mauritia flexuosa (Arecaceae) foram amostradas 150 palmeiras em seis veredas” do Distrito Federal, de áreas silvestres, rurais e periurbanas na estação chuvosa. Os artrópodos presentes nos ninhos abandonados de aves, refúgios de mamíferos, folhas e matéria orgânica foram coletados manualmente, fixados em etanol 70% e separados em ordem, família, morfoespécie e guildas alimentares. As características das palmeiras medidas foram altura da estipe, diâmetro da copa, número de folhas e de ninhos de aves nas palmeiras. Foram coletados 3.862 indivíduos, pertencentes a 15 ordens, 45 famílias e 135 morfoespécies. As ordens mais abundantes foram Coleoptera (28,6%), Blattodea (21,8%), Collembola (11,4%) e Hemiptera (10,2%). As famílias Blaberidae, Tenebrionidae, Entomobryidae, Reduviidae, Oniscidae, Staphylinidae, Carabidae e Formicidae representaram 82,1% de todos os indivíduos coletados. A maioria das morfoespécies foi pouco abundante, 71 (52,6%) apresentaram uma abundância média igual ou menor que 1 indivíduo/palmeira. Coleoptera compreendeu o maior número de morfoespécies (43,7%) seguida de Araneae (20,0%). A análise das guildas alimentares mostrou prevalência de predadores e hematófagos (36,0%). A riqueza e a abundância de artrópodos foram menores no ambiente periurbano. O número de ninhos de aves apresentou correlação positiva com abundância e riqueza, o que não ocorreu com as medidas das palmeiras. A importância de M. flexuosa para a manutenção da artropodofauna nas “veredas” no bioma Cerrado é discutida. _______________________________________________________________________________________ ABSTRACT
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2007
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Although Mauritia flexuosa (Arecaceae) plays a pivotal role in the ecology and economy of the Amazon, and occurs in a variety of habitats, little is known about the influence of habitat on the reproductive biology of this palm. My dissertation focuses on the reproductive biology of M. flexuosa in three habitats in Roraima, Brazil: undisturbed forest, undisturbed forest-savanna ecotone, and savanna disturbed by plantations of the exotic tree, Acacia mangium. First, I calculated sex ratios and linked precipitation patterns with phenology. Sex ratios were female-biased. Precipitation was negatively associated with flowering, and positively associated with fruiting. Habitat appears to have no significant influence on phenology of M. flexuosa, although short-term climate variation may affect phenology of this species. Second, I examined floral biology, observed floral visitors, and performed exclusion experiments to determine the pollination system of M. flexuosa. Fruit set did not differ significantly between the visitor exclusion treatment and the control, but was significantly lowest in the wind + visitor exclusion treatment, suggesting that this dioecious palm is anemophilous, independent of habitat. Third, I identified the abiotic and biotic factors explaining variation in fruit mass, seed mass, seed number per fruit, and total fruit yield among habitats. Soil moisture and flooding during the wet season were the best predictors of fruit and seed output. The number of leaves, diameter at breast height, and height were all accurate predictors of reproductive output, but crown volume did not accurately predict fruit yields. Results re-evaluate traditional assumptions about wind-pollination in the tropics, and highlight abiotic and biotic factors responsible for variation in reproductive output of M. flexuosa, with implications for effective management of this palm. Finally, I interviewed harvesters and vendors to document the traditional knowledge and market dynamics of the fruit of M. flexuosa, buriti. Traditional knowledge corroborated results from scientific studies. Vendors argued that the price of buriti must increase, and must fluctuate with varying supply. With appropriate economic incentives to vendors/harvesters, Roraima may expand its market infrastructure for buriti, effectively stimulating the regional economy and practicing sustainable harvesting.
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Designing practical rules for controlling invasive species is a challenging task for managers, particularly when species are long-lived, have complex life cycles and high dispersal capacities. Previous findings derived from plant matrix population analyses suggest that effective control of long-lived invaders may be achieved by focusing on killing adult plants. However, the cost-effectiveness of managing different life stages has not been evaluated. We illustrate the benefits of integrating matrix population models with decision theory to undertake this evaluation, using empirical data from the largest infestation of mesquite (Leguminosae: Prosopis spp) within Australia. We include in our model the mesquite life cycle, different dispersal rates and control actions that target individuals at different life stages with varying costs, depending on the intensity of control effort. We then use stochastic dynamic programming to derive cost-effective control strategies that minimize the cost of controlling the core infestation locally below a density threshold and the future cost of control arising from infestation of adjacent areas via seed dispersal. Through sensitivity analysis, we show that four robust management rules guide the allocation of resources between mesquite life stages for this infestation: (i) When there is no seed dispersal, no action is required until density of adults exceeds the control threshold and then only control of adults is needed; (ii) when there is seed dispersal, control strategy is dependent on knowledge of the density of adults and large juveniles (LJ) and broad categories of dispersal rates only; (iii) if density of adults is higher than density of LJ, controlling adults is most cost-effective; (iv) alternatively, if density of LJ is equal or higher than density of adults, management efforts should be spread between adults, large and to a lesser extent small juveniles, but never saplings. Synthesis and applications.In this study, we show that simple rules can be found for managing invasive plants with complex life cycles and high dispersal rates when population models are combined with decision theory. In the case of our mesquite population, focussing effort on controlling adults is not always the most cost-effective way to meet our management objective.
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Invasive non-native plants have negatively impacted on biodiversity and ecosystem functions world-wide. Because of the large number of species, their wide distributions and varying degrees of impact, we need a more effective method for prioritizing control strategies for cost-effective investment across heterogeneous landscapes. Here, we develop a prioritization framework that synthesizes scientific data, elicits knowledge from experts and stakeholders to identify control strategies, and appraises the cost-effectiveness of strategies. Our objective was to identify the most cost-effective strategies for reducing the total area dominated by high-impact non-native plants in the Lake Eyre Basin (LEB). We use a case study of the ˜120 million ha Lake Eyre Basin that comprises some of the most distinctive Australian landscapes, including Uluru-Kata Tjuta National Park. More than 240 non-native plant species are recorded in the Lake Eyre Basin, with many predicted to spread, but there are insufficient resources to control all species. Lake Eyre Basin experts identified 12 strategies to control, contain or eradicate non-native species over the next 50 years. The total cost of the proposed Lake Eyre Basin strategies was estimated at AU$1·7 billion, an average of AU$34 million annually. Implementation of these strategies is estimated to reduce non-native plant dominance by 17 million ha – there would be a 32% reduction in the likely area dominated by non-native plants within 50 years if these strategies were implemented. The three most cost-effective strategies were controlling Parkinsonia aculeata, Ziziphus mauritiana and Prosopis spp. These three strategies combined were estimated to cost only 0·01% of total cost of all the strategies, but would provide 20% of the total benefits. Over 50 years, cost-effective spending of AU$2·3 million could eradicate all non-native plant species from the only threatened ecological community within the Lake Eyre Basin, the Great Artesian Basin discharge springs. Synthesis and applications. Our framework, based on a case study of the ˜120 million ha Lake Eyre Basin in Australia, provides a rationale for financially efficient investment in non-native plant management and reveals combinations of strategies that are optimal for different budgets. It also highlights knowledge gaps and incidental findings that could improve effective management of non-native plants, for example addressing the reliability of species distribution data and prevalence of information sharing across states and regions.
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Quilpie mesquite (Prosopis velutina) is an invasive woody weed that is believed to have been introduced into south-west Queensland in the 1930s. Following the withdrawal of 2,4,5-T, research on P. pallida resulted in revised recommendations for control of all Prosopis spp. in Queensland. Adoption of many of these recommendations for Quilpie mesquite control produced substandard results. Following a pilot trial, a shade-house experiment was conducted to determine the differences in susceptibility of two species of mesquite, P. velutina and P. pallida, to commonly available herbicides. It was hypothesized that P. velutina was less susceptible than P. pallida, based upon claims that the registered chemical recommendations for Prosopis spp. were not sufficiently effective on P. velutina. Nine foliar herbicide treatments were applied to potted shade-house plants. Treatment effects indicated differing susceptibility between the two species. P. velutina consistently showed less response to metsulfuron, fluroxypyr, 2,4-D/picloram and triclopyr/picloram, compared to the glyphosate formulations, where negligible differences occurred between the two species. The response to glyphosate was poor at all rates in this experiment. Re-application of herbicides to surviving plants indicated that susceptibility can decrease when follow-up application is in autumn and the time since initial application is short. The relationship between leaf structure and the volume of spray adhering to a plant was assessed across species. The herbicide captured by similar-sized plants of each species differed, with P. pallida retaining a greater volume of herbicide.
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For many years Australian forest pathologists and other scientists have dreaded the arrival of the rust fungus, Puccinia psidii, commonly known as Myrtle Rust, in Australia. This pathogen eventually did arrive in that country and was first detected in New South Wales in 2010 on Willow Myrtle (Agonis flexuosa). It is generally accepted that it entered the country on an ornamental Myrtales* host brought in by a private nursery. Despite efforts to eradicate the invasive rust, it has already spread widely, now occurring along the east coast of Australia, from temperate areas in Victoria and southern North South Wales to tropical areas in north Queensland.
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Rural population of India constitutes about 70% of the total population and traditional fuels account for 75% of the rural energy needs. Depletion of woodlands coupled with the persistent dependency on fuel wood has posed a serious problem for household energy provision in many parts. This study highlights that the traditional fuels still meet 85-95% of fuel needs in rural areas of Kolar district: people prefer fuel wood for cooking and agriculture residues for water heating and other purposes. However, rapid changes in land cover and land use in recent times have affected these traditional fuels availability necessitating inventorying, mapping and monitoring of bioresources for sustainable management of bioresources. Remote sensing data (Multispectal and Panchromatic), Geographic Information System (GIS), field surveys and non-destructive sampling were used to assess spatially the availability and demand of energy. Field surveys indicate that rural household depends on species such as Prosopis juliflora, Acacia nilotica, Acacia auriculiformis to meet fuel wood requirement for domestic activities. Hence, to take stock of fuel wood availability, mapping was done at species level (with 88% accuracy) considering villages as sampling units using fused multispectral and panchromatic data. (C) 2009 Elsevier Ltd. All rights reserved.
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Microcatchment water harvesting (MCWH) improved the survival and growth of planted trees on heavy soils in eastern Kenya five to six years after planting. In the best method, the cross-tied furrow microcatchments, the mean annual increments (MAI; based on the average biomass of living trees multiplied by tree density and survival) of the total and usable biomass in Prosopis juliflora were 2787 and 1610 kg ha-1 a-1 respectively, when the initial tree density was 500 to 1667 trees per hectare. Based on survival, the indigenous Acacia horrida, A. mellifera and A. zanzibarica were the most suitable species for planting using MCWH. When both survival and yield were considered, a local seed source of the introduced P. juliflora was superior to all other species. The MAI in MCWH was at best distinctly higher than that in the natural vegetation (163307 and 66111 kg ha-1 a-1 for total and usable biomass respectively); this cannot satisfy the fuelwood demand of concentrated populations, such as towns or irrigation schemes. The density of seeds of woody species in the topsoil was 40.1 seeds m-2 in the Acacia-Commiphora bushland and 12.6 seeds m-2 in the zone between the bushland and the Tana riverine forest. Rehabilitation of woody vegetation using the soil seed bank alone proved difficult due to the lack of seeds of desirable species. The regeneration and dynamics of woody vegetation were also studied both in cleared and undisturbed bushland. A sub-type of Acacia-Commiphora bushland was identified as Acacia reficiens bushland, in which the dominant Commiphora species is C. campestris. Most of the woody species did not have even-aged populations but cohort structures that were skewed towards young individuals. The woody vegetation and the status of soil nutrients were estimated to recover in 1520 years on Vertic Natrargid soils after total removal of above-ground vegetation.
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Intra and interspecific variation in frugivore behaviour can have important consequences for seed dispersal outcomes. However, most information comes from among-species comparisons, and within-species variation is relatively poorly understood. We examined how large intraspecific differences in the behaviour of a native disperser, blackbuck antelope Antilope cervicapra, influence dispersal of a woody invasive, Prosopis juliflora, in a grassland ecosystem. Blackbuck disperse P. juliflora seeds through their dung. In lekking blackbuck populations, males defend clustered or dispersed mating territories. Territorial male movement is restricted, and within their territories males defecate on dung-piles. In contrast, mixed-sex herds range over large areas and do not create dung-piles. We expected territorial males to shape seed dispersal patterns, and seed deposition and seedling recruitment to be spatially localized. Territorial males had a disproportionately large influence on seed dispersal. Adult males removed twice as much fruit as females, and seed arrival was disproportionately high on territories. Also, because lek-territories are clustered, seed arrival was spatially highly concentrated. Seedling recruitment was also substantially higher on territories compared with random sites, indicating that the local concentration of seeds created by territorial males continued into high local recruitment of seedlings. Territorial male behaviour may, thus, result in a distinct spatial pattern of invasion of grasslands by the woody P. juliflora. An ex situ experiment showed no beneficial effect of dung and a negative effect of light on seed germination. We conclude that large intraspecific behavioural differences within frugivore populations can result in significant variation in their effectiveness as seed dispersers. Mating strategies in a disperser could shape seed dispersal, seedling recruitment and potentially plant distribution patterns. These mating strategies may aid in the spread of invasives, such as P. juliflora, which could, in turn, negatively influence the behaviour and ecology of native dispersers.
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As restingas do Estado do Rio de Janeiro são áreas de sedimentação predominantemente quaternária, descontínuas geograficamente, formadas em função das mudanças paleoclimáticas, flutuações do nível do mar e transporte longitudinal de sedimentos. A diversidade e a estrutura da vegetação halófila-psamófila presente nestas restingas são os principais focos deste estudo, onde foram analisadas a similaridade florística, as formas de vida e síndrome de dispersão, o padrão de riqueza e diversidade, a distribuição das espécies e os parâmetros de cobertura vegetal, serrapilheira, solo desnudo e salinidade da água do mar. Foram amostradas nove áreas de restinga, a saber, Praia do Sul, Marambaia, Grumari, Marapendi, Maricá, Massambaba, Barra de São João, Jurubatiba e São João da Barra. Foram encontradas 90 espécies, distribuídas em 33 famílias, 69 gêneros, sendo as famílias de maior riqueza específica: Asteraceae (10), Poaceae (9 espécies), Fabaceae (9) e Rubiaceae (6). Foi registrada uma baixa riqueza de espécies nas áreas avaliadas, variando de 25 a 48. Somente 11 espécies ocorreram em todas as áreas (Alternanthera maritima, Blutaparon portulacoides, Canavalia rosea, Cereus fernambucensis, Euphorbia hyssopifolia, Ipomoea imperati, Ipomoea pes-caprae, Panicum racemosum, Remirea maritima, Sporobolus virginicus, Stenotaphrum secundatum), e 12 são dominantes, em uma ou mais áreas (Allagoptera arenaria, Alternanthera maritima, Blutaparon portulacoides, Canavalia rosea, Ipomoea imperati, Ipomoea pes-caprae, Mollugo verticillata, Panicum racemosum, Remirea maritima, Spermacoce capitata, Sporobolus virginicus, Stenotaphrum secundatum), existindo um grande número de espécies raras. O índice de diversidade de Shannon variou de 1,49 a 2,40, e a equabilidade de Pielou de 0,82 a 0,60. O agrupamento formou dois grandes grupos, sendo o primeiro constituído por Barra de São João, Praia do Sul, Marambaia, Grumari e Marapendi, e o segundo por Jurubatiba, São João da Barra, Maricá e Massambaba. As áreas mais similares floristicamente foram Maricá e Massambaba (58%), Grumari e Marapendi (56%), e Barra de São João e Praia do Sul (50%). A vegetação apresenta uma flora característica, com diferença na composição entre as áreas, e similaridade entre áreas geograficamente mais próximas. Um terço das espécies identificadas são caméfitos (34,56%), seguida por fanerófitos (20,98%), geófitos (16,04%), hemicriptófitos (12,34%), terófitos (13,58%) e duas lianas. Na dispersão predomina a autocoria (41,97%), anemocoria (33,33%) e zoocoria (24,69%). O tamanho das áreas perpendicularmente ao mar não está relacionado com aumento da riqueza, nem apresenta o padrão de aumento com o distanciamento do mar. Existem diferenças da riqueza e da diversidade entre as áreas, não havendo uma homogeneidade ao longo do litoral. Há uma zonação, com espécies distribuídas próximas ao mar (Allagoptera arenaria, Alternanthera maritima, Blutaparon portulacoides, Canavalia rosea, Cassytha filiformis, Cereus fernambucensis, Hydrocotyle bonariensis, Ipomoea pes-caprae, Schinus terebinthifolia, Sophora tomentosa, Stenotaphrum secundatum, Cyrtocymura scorpioides), e ao longo do gradiente perpendicular ao mar (Chamaecrista flexuosa, Euphorbia hyssopifolia, Ipomoea imperati, Mollugo verticillata, Panicum racemosum, Paspalum maritimum, Remirea maritima, Sporobolus virginicus). O modelo de série logarítmica é o que melhor representa a vegetação, independente da diversidade ou riqueza. A cobertura vegetal variou entre as áreas. A serrapilheira e o solo desnudo estão estreitamente relacionados com a cobertura vegetal, havendo variação entre as áreas.
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As extensas pradarias submersas formadas pelas gramas marinhas são importantes habitats da costa, onde ocorrem interações ecológicas entre diversas espécies da vegetação subaquática, invertebrados bentônicos e peixes. As gramas marinhas e algas de deriva são conhecidas como macrófitas marinhas e, por ocuparem o mesmo tipo de substrato, são normalmente encontradas juntas, proporcionando oxigênio, alimento, proteção, abrigo além de sítios de reprodução e pastagem para os animais associados a essas pradarias. Amostras de algas de deriva e de H. wrightii foram coletadas, ao longo de transectos fixos de 50 m paralelos à Ilha do Japonês, a fim de analisar a existência de relações positivas entre as espécies de macrófitas marinhas e sua macrofauna associada, comparar as duas comunidades e avaliar a estruturação da comunidade macrofaunal bêntica do local. Os transectos foram alocados de acordo com a posição do banco de grama marinha. Observou-se que a densidade de eixos e a biomassa de H. wrightii não explicam a variação da biomassa, riqueza de espécies e diversidade (Índice de Simpson) das algas de deriva. A grande movimentação das algas de deriva ao longo do banco de grama marinha faz com que elas se homogeneízem e ocupem diferentes lugares ao acaso na pradaria, muitos desses locais com baixa biomassa de H. wrightii devido à grande variabilidade na distribuição dessa espécie no local de estudo. Os descritores ecológicos da grama marinha também não tiveram relações positivas com sua macrofauna bêntica associada. A comunidade macrofaunal associada às gramas marinhas foi mais densa, rica e diversa do que a comunidade macrofaunal associada às algas de deriva. Os moluscos Anomalocardia flexuosa, Cerithium atratum, Ostrea sp, Tellina lineata e Divalinga quadrissulcata dominaram o ambiente de gramas marinhas. A maior complexidade estrutural das algas de deriva forneceu um habitat protegido mais atrativo para os crustáceos como, Pagurus criniticornis, Cymadusa filosa e Batea catharinensis. A malacofauna associada às algas não foi abundante, mas um novo registro foi a ocorrência do bivalve invasor Lithopaga aristatus, perfurando uma concha de Ostrea sp. As relações entre os descritores da biomassa algal foram comprovadas para a maioria dos descritores de sua fauna associada. As relações das macrófitas marinhas com a macrofauna total associada seguiram o mesmo padrão das relações das algas de deriva. As análises de agrupamento e ordenação mostraram que as comunidades macrofaunais bênticas do local são estruturadas de acordo com os táxons dos organismos associados mais dominantes influenciados pelo tipo de vegetação basibionte (algas de deriva ou grama marinha). Destaca-se com o presente estudo a importância de medidas de maior proteção no local para a preservação e manutenção do ecossistema da Ilha do Japonês, RJ, Brasil
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Ulvacean green seaweeds are common worldwide; they formed massive green tides in the Yellow Sea in recent years, which caused marine ecological problems as well as a social issue. We investigated two major genera of the Ulvaceae, Ulva and Enteromorpha, and collected the plastid rbcL and nuclear ITS sequences of specimens of the genera in two sides of the Yellow Sea and analyzed them. Phylogenetic trees of rbcL data show the occurrence of five species of Enteromorpha (E. compressa, E. flexuosa, E. intestinalis, E. linza and E. prolifera) and three species of Ulva (U. pertusa, U. rigida and U. ohnoi). However, we found U. ohnoi, which is known as a subtropical to tropical species, at two sites on Jeju Island, Korea. Four ribotypes in partial sequences of 5.8S rDNA and ITS2 from E. compressa were also found. Ribotype network analysis revealed that the common ribotype, occurring in China, Korea and Europe, is connected with ribotypes from Europe and China/Japan. Although samples of the same species were collected from both sides of the Yellow Sea, intraspecific genetic polymorphism of each species was low among samples collected worldwide.