RESUMEN
The term rheophyte describes a biological group of flood-tolerant plants that are confined to the beds of swift-running streams and rivers in nature and grow up to flood level, but not beyond the reach of regularly occurring flash floods. Although over 35 yr have passed since the first global census of rheophytes, no updates have been recorded regarding the number of taxa in this biological group in seed plants. Therefore, the present work aimed to (1) review the main topics associated with rheophytism (e.g., morphological characteristics, genetic studies, geographic distribution, conservation, and evolutionary aspects); (2) provide an updated checklist of rheophytes distributed around the world considering the two main groups in seed plants (gymnosperms and angiosperms); (3) demonstrate the distribution of rheophytism in the angiosperm phylogeny; and (4) estimate the geographical distribution and richness of selected taxa on the world map for the first time. All data compiled for the present study originated from a search of peer-reviewed articles, secondary literature (theses, dissertations, reports, books, and floras), and electronic facilities. We compiled a data set composed of four taxa in gymnosperms (Podocarpaceae family) and 1,368 taxa (including obligate, facultative, and unclassified rheophytes) distributed in 114 families and 508 genera in angiosperms. Most of the studied taxa belong to eudicotyledons (72.81%), while 1.46% belong to magnoliids, and 25.73% belong to monocotyledons. The families with the highest number of taxa in descending order are Podostemaceae, Araceae, Myrtaceae, Rubiaceae, Asteraceae, Apocynaceae, Arecaceae, Fabaceae, Phyllanthaceae, and Poaceae. Of the 114 families plotted in angiosperm phylogeny, at least 80 harbor obligate rheophytes. The geographical distribution of rheophytes in angiosperms, as expected based on the first census of this biological group, is mainly in the tropical and subtropical regions. The high richness of rheophytic taxa was mostly found in southern Mexico, southern China, Borneo, and northern and eastern Australia. In contrast, the geographical distribution of rheophytes in gymnosperms is restricted to New Caledonia and Tasmania. The present study will help to advance knowledge regarding the diversity of rheophytes in angiosperms and gymnosperms while drawing attention to this biological group, which has often been overlooked. There are no copyright restrictions. Please cite this data paper when the data are used in publications and teaching events.
Asunto(s)
Cycadopsida , Magnoliopsida , Australia , Borneo , China , Cycadopsida/genética , Humanos , México , Filogenia , TasmaniaRESUMEN
Forest dynamics are driven by top-down changes in climate and bottom-up positive (destabilizing) and negative (stabilizing) biophysical feedbacks involving disturbance and biotic interactions. When positive feedbacks prevail, the resulting self-propagating changes can potentially shift the system into a new state, even in the absence of climate change. Conversely, negative feedbacks help maintain a dynamic equilibrium that allows communities to recover their pre-disturbance characteristics. We examine palaeoenvironmental records from temperate forests to assess the nature of long-term stability and regime shifts under a broader range of environmental forcings than can be observed at present. Forest histories from northwestern USA, Patagonia, Tasmania and New Zealand show long-term trajectories that were governed by (i) the biophysical template, (ii) characteristics of climate and disturbance, (iii) historical legacies that condition the ecological capacity to respond to subsequent disturbances, and (iv) thresholds that act as irreversible barriers. Attention only to current forest conditions overlooks the significance of history in creating path dependency, the importance of individual extreme events, and the inherent feedbacks that force an ecosystem into reorganization. A long-time perspective on ecological resilience helps guide conservation strategies that focus on environmental preservation as well as identify vulnerable species and ecosystems to future climate change. This article is part of the theme issue 'Climate change and ecosystems: threats, opportunities and solutions'.
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Biodiversidad , Cambio Climático , Conservación de los Recursos Naturales , Incendios , Bosques , Árboles , Argentina , Nueva Zelanda , Noroeste de Estados Unidos , TasmaniaRESUMEN
Background and Aims: Allopolyploids exhibit both different levels and different patterns of genetic variation than are typical of diploids. However, scant attention has been given to the partitioning of allelic information and diversity in allopolyploids, particularly that among homeologous monoploid components of the hologenome. Sphagnum × falcatulum is a double allopolyploid peat moss that spans a considerable portion of the Holantarctic. With monoploid genomes from three ancestral species, this organism exhibits a complex evolutionary history involving serial inter-subgeneric allopolyploidizations. Methods: Studying populations from three disjunct regions [South Island (New Zealand); Tierra de Fuego archipelago (Chile, Argentina); Tasmania (Australia)], allelic information for five highly stable microsatellite markers that differed among the three (ancestral) monoploid genomes was examined. Using Shannon information and diversity measures, the holoploid information, as well as the information within and among the three component monoploid genomes, was partitioned into separate components for individuals within and among populations and regions, and those information components were then converted into corresponding diversity measures. Key Results: The majority (76 %) of alleles detected across these five markers are most likely to have been captured by hybridization, but the information within each of the three monoploid genomes varied, suggesting a history of recurrent allopolyploidization between ancestral species containing different levels of genetic diversity. Information within individuals, equivalent to the information among monoploid genomes (for this dataset), was relatively stable, and represented 83 % of the grand total information across the Holantarctic, with both inter-regional and inter-population diversification each accounting for about 5 % of the total information. Conclusions: Sphagnum × falcatulum probably inherited the great majority of its genetic diversity at these markers by reticulation, rather than by subsequent evolutionary radiation. However, some post-hybridization genetic diversification has become fixed in at least one regional population. Methodology allowing statistical analysis of any ploidy level is presented.
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Evolución Biológica , Hibridación Genética , Sphagnopsida/genética , Triploidía , Alelos , Argentina , Australia , Chile , Variación Genética , Genoma de Planta , Repeticiones de Microsatélite , Nueva Zelanda , TasmaniaRESUMEN
BACKGROUND: Seamount-associated faunas are often considered highly endemic but isolation and diversification processes leading to such endemism have been poorly documented at those depths. Likewise, species delimitation and phylogenetic studies in deep-sea organisms remain scarce, due to the difficulty in obtaining samples, and sometimes controversial. The phylogenetic relationships within the precious coral family Coralliidae remain largely unexplored and the monophyly of its two constituent genera, Corallium Cuvier and Paracorallium Bayer & Cairns, has not been resolved. As traditionally recognized, the diversity of colonial forms among the various species correlates with the diversity in shape of their supporting axis, but the phylogenetic significance of these characters remains to be tested. We thus used mitochondrial sequence data to evaluate the monophyly of Corallium and Paracorallium and the species boundaries for nearly all named taxa in the family. Species from across the coralliid range, including material from Antarctica, Hawaii, Japan, New Zealand, Taiwan, Tasmania, the eastern Pacific and the western Atlantic were examined. RESULTS: The concatenated analysis of five mitochondrial regions (COI, 16S rRNA, ND2, and ND3-ND6) recovered two major coralliid clades. One clade is composed of two subgroups, the first including Corallium rubrum, the type species of the genus, together with a small group of Paracorallium species (P. japonicum and P. tortuosum) and C. medea (clade I-A); the other subgroup includes a poorly-resolved assemblage of six Corallium species (C. abyssale, C. ducale, C. imperiale, C. laauense, C. niobe, and C. sulcatum; clade I-B). The second major clade is well resolved and includes species of Corallium and Paracorallium (C. elatius, C. kishinouyei, C. konojoi, C. niveum, C. secundum, Corallium sp., Paracorallium nix, Paracorallium thrinax and Paracorallium spp.). A traditional taxonomic study of this clade delineated 11 morphospecies that were congruent with the general mixed Yule-coalescent (GMYC) model. A multilocus species-tree approach also identified the same two well-supported clades, being Clade I-B more recent in the species tree (18.0-15.9 mya) than in the gene tree (35.2-15.9 mya). In contrast, the diversification times for Clade II were more ancient in the species tree (136.4-41.7 mya) than in the gene tree (66.3-16.9 mya). CONCLUSIONS: Our results provide no support for the taxonomic status of the two currently recognized genera in the family Coralliidae. Given that Paracorallium species were all nested within Corallium, we recognize the coralliid genus Corallium, which includes the type species of the family, and thus consider Paracorallium a junior synonym of Corallium. We propose the use of the genus Hemicorallium Gray for clade I-B (species with long rod sclerites, cylindrical autozooids and smooth axis). Species delimitation in clade I-B remains unclear and the molecular resolution for Coralliidae species is inconsistent in the two main clades. Some species have wide distributions, recent diversification times and low mtDNA divergence whereas other species exhibit narrower allopatric distributions, older diversification times and greater levels of mtDNA resolution.
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Antozoos/genética , Evolución Molecular , Variación Genética , Filogenia , Animales , Antozoos/anatomía & histología , Antozoos/clasificación , ADN Intergénico/genética , ADN Mitocondrial/química , ADN Mitocondrial/genética , Complejo I de Transporte de Electrón/genética , Complejo IV de Transporte de Electrones/genética , Hawaii , Japón , Datos de Secuencia Molecular , Nueva Zelanda , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Especificidad de la Especie , Taiwán , Tasmania , Factores de TiempoRESUMEN
The ability of plants to maintain water flow through leaves under water stress-induced tension (assessed as the leaf hydraulic vulnerability; P50(leaf)) is intimately linked with survival. We examined the significance of P50(leaf) as an adaptive trait in influencing the dry-end distributional limits of cool temperate woody angiosperm species. We also examined differences in within-site variability in P50(leaf) between two high-rainfall montane rainforest sites in Tasmania and Peru, respectively. A significant relationship between P50(leaf) and the 5th percentile of mean annual rainfall across each species distribution was found in Tasmania, suggesting that P50(leaf) influences species climatic limits. Furthermore, a strong correlation between P50(leaf) and the minimum rainfall availability was found using five phylogenetically independent species pairs in wet and dry evergreen tree species, suggesting that rainfall is an important selective agent in the evolution of leaf hydraulic vulnerability. Greater within-site variability in P50(leaf) was found among dominant montane rainforest species in Tasmania than in Peru and this result is discussed within the context of differences in spatial and temporal environmental heterogeneity and parochial historical ecology.
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Magnoliopsida/fisiología , Hojas de la Planta/fisiología , Clima , Deshidratación , Sequías , Perú , Filogenia , Transpiración de Plantas , Lluvia , Tasmania , Temperatura , ÁrbolesRESUMEN
A rule-based model was developed to assess climatic risk of European canker (Neonectria galligena), which is a major disease of apple in some temperate zones. A descriptive rule was derived from published observations on climatic conditions favorable for European canker development. Fuzzy set theory was used to evaluate the descriptive rule quantitatively. The amount and frequency of rainfall and the average number of hours between 11 and 16°C/day were used as input variables whose values were matched with terms in the rule, e.g., 'high' or 'low'. The degree of a term, e.g., the state of being high or low, to a given input value was determined using a membership function that converts an input value to a number between 0 and 1. The rule was evaluated by combining the degree of the terms associated with monthly climate data. Monthly risk index values derived using the rule were combined for pairs of consecutive months over 12 months. The annual risk of European canker development was represented by the maximum risk index value for 2 months combined. The membership function parameters were adjusted iteratively to achieve a specified level of risk at Talca (Chile), Loughgall (Northern Ireland), East Malling (UK), and Sebastopol (USA), where European canker risk was known. The rule-based model was validated with data collected from Canada, Ecuador, Denmark, Germany, Norway, Poland, Sweden, the Netherlands, New Zealand, and the Pacific Northwest (USA), where European canker has been reported to occur. In these validation areas, the model's risk prediction agreed with reports of disease occurrence. The rule-based model also predicted high risk areas more reliably than the climate matching model, CLIMEX, which relies on correlations between the spatial distribution of a species and climatic conditions. The combination of a climatic rule and fuzzy sets could be used for other applications where prediction of the geographic distribution of organisms is required for climatic risk assessment.
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Clima , Hypocreales/fisiología , Malus/microbiología , Modelos Biológicos , Enfermedades de las Plantas/microbiología , Calibración , Canadá , Chile , Ecuador , Europa (Continente) , Lógica Difusa , Nueva Zelanda , Lluvia , Riesgo , Tasmania , Factores de Tiempo , Estados UnidosRESUMEN
Months of the year with high risk of European canker (Neonectria galligena) development in areas of the United States, Chile, England, and Northern Ireland were determined from published data. Moving-window analysis of long-term climatic data was used to classify disease risk in these areas in relation to rainfall and temperature conditions using the degree of agreement statistic. Greatest agreement occurred when it both rained on >30% of days/month and there was an average of >8 h/day with temperature of 11 to 16°C. When these thresholds were applied in eight validation areas in New Zealand, Australia, the United States, The Netherlands, and Denmark, areas with reported higher risk of disease tended to be areas where the thresholds were exceeded more often and by greater amounts. Areas at higher latitudes (>52°) with frequent summer rainfall appeared to be most prone to European canker, including the fruit rot phase of the disease, probably because summer temperatures were more favorable than at lower latitudes. The climatic thresholds derived for European canker could be useful for studies of disease establishment risk, surveillance, eradication, climate change impact assessment, and, possibly, for disease risk forecasting. The methods used in this study allowed conditions favorable for disease development to be identified even though quantitative regional disease data were lacking, and they could be useful for similar geoclimatic studies of other diseases.
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Ascomicetos/fisiología , Malus/microbiología , Enfermedades de las Plantas/microbiología , Chile , Clima , Europa (Continente) , Nueva Zelanda , Lluvia , Tasmania , Factores de Tiempo , Estados UnidosRESUMEN
El motivo de éste trabajo es sugerir una legislación para un adecuado manejo de los efluentes líquidos generados en los establecimientos de salud. Se analiza la legislación nacional e internacional sobre el tema y el estado actual de la gestión de los efluentes líquidos domiciliarios en Argentina. Se concluye que, una vez eliminados los residuos patogénicos y peligrosos, los efluentes líquidos de establecimientos de salud y los domiciliarios son de calidad similar. En conclusión, se sugiere un tratamiento centralizado de los efluentes líquidos tanto domiciliarios como de establecimientos de salud, con la condición de que sean volcados a una red cloacal y que, previamente, haya una adecuada eliminación de residuos patogénicos y sustancias peligrosas (AU)
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Hospitales , Instituciones de Salud , Residuos Sanitarios , Eliminación de Residuos Sanitarios/métodos , Aguas Residuales , Eliminación de Residuos Líquidos/métodos , Eliminación de Aguas Residuales , Eliminación de Residuos Peligrosos , Residuos Peligrosos , Eliminación de Residuos Sanitarios/legislación & jurisprudencia , Eliminación de Residuos Líquidos/legislación & jurisprudencia , Argentina , España , Australia , Queensland , TasmaniaRESUMEN
El motivo de éste trabajo es sugerir una legislación para un adecuado manejo de los efluentes líquidos generados en los establecimientos de salud. Se analiza la legislación nacional e internacional sobre el tema y el estado actual de la gestión de los efluentes líquidos domiciliarios en Argentina. Se concluye que, una vez eliminados los residuos patogénicos y peligrosos, los efluentes líquidos de establecimientos de salud y los domiciliarios son de calidad similar. En conclusión, se sugiere un tratamiento centralizado de los efluentes líquidos tanto domiciliarios como de establecimientos de salud, con la condición de que sean volcados a una red cloacal y que, previamente, haya una adecuada eliminación de residuos patogénicos y sustancias peligrosas
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Eliminación de Aguas Residuales , Eliminación de Residuos Líquidos/métodos , Eliminación de Residuos Sanitarios/métodos , Eliminación de Residuos Peligrosos , Instituciones de Salud , Hospitales , Residuos Sanitarios , Aguas Residuales , Argentina , Australia , Eliminación de Residuos Líquidos/legislación & jurisprudencia , Eliminación de Residuos Sanitarios/legislación & jurisprudencia , Residuos Peligrosos , Queensland , España , TasmaniaAsunto(s)
Antropología Cultural , Cultura , Conducta Exploratoria , Historia Natural , Grupos de Población , Antropología Cultural/historia , Historia del Siglo XVIII , Historia del Siglo XIX , Humanos , Historia Natural/historia , Observación , Grupos de Población/historia , San Vicente y las Grenadinas , Ciencia/historia , TasmaniaRESUMEN
Galaxias maculatus is one of the world's most widely distributed freshwater fish. This species has a marine-tolerant juvenile phase, and a geographical range extending through much of the southern hemisphere. We conducted phylogeographic analyses of 163 control region haplotypes of G. maculatus, including samples from New Zealand (five locations), Tasmania (one location) and Chile (one location). A lack of genetic structure among New Zealand samples suggests that marine dispersal facilitates considerable gene flow on an intra-continental scale. The discovery of a Tasmanian-like haplotype in one of 144 New Zealand samples indicates that inter-continental marine dispersal occurs but is insufficient to prevent mitochondrial DNA differentiation among continents. The sister relationship of Tasmanian and New Zealand clades implies that marine dispersal is an important biogeographical mechanism for this species. However, a vicariant role in the divergence of eastern and western Pacific G. maculatus cannot be rejected.
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Peces/genética , Animales , Secuencia de Bases , Chile , Cartilla de ADN/genética , ADN Mitocondrial/genética , Agua Dulce , Variación Genética , Genética de Población , Haplotipos , Nueva Zelanda , Filogenia , TasmaniaRESUMEN
This is a case study of the processes involved in attaining the status of 'victim' after an industrial accident. In this case a migrant working in the manufacturing industry becomes increasingly 'disabled' and seeks legitimation as a 'victim' who is 'worthy' of financial compensation. The institutional processes involved are the industrial, medical and legal systems. Chronic pain is a condition that often defies an unambiguous diagnosis. Most chronic pain victims are therefore constantly seeking legitimation for their condition as physicians attempt to uncover the aetiology of the pain. Most chronic pain victims also fail to fulfil the expectation of getting well as soon as possible. Physicians can, at best, only give a prognosis that is little better than an 'educated guess'. The conditional nature of the legitimacy gives the chronic pain victims only limited legitimacy for their sick role and this often results in physicians seeking psychological or moral explanations for what began as a relatively simple physical problem. Psychological or psychiatric diagnoses are considerably weaker metaphorically than physiological diagnoses and tend to infer the strong possibility of the victim contributing to her/his condition as a result of hypochondriacal or psychosomatic 'tendencies' or, even worse, 'malingering'. The migrant client can exacerbate this situation through an earnest desire to (over)conform to norms by going along with whatever is recommended by people who hold superior status by virtue of their knowledge and power ('posicíon'). Among some Latin American countries 'over-compliance' has been recognised a socio-medical condition and is termed 'susto'. In the workers' compensation context the shift to overconformity ('susto') results from the uncertainty about receiving (legitimate) acknowledgement and compensation. The desire is to ensure, as far as possible, that a certainty of outcome is achieved (i.e. a return to work or adequate compensation). In other words, concurrent practises within the system (medical-social-legal) produces what it tries to eliminate--the seemingly unjustifiable/illegitimate internalising of the role of victim intent on receiving compensation. 'Susto' is therefore an adaptive response to normative ambiguity and uncertainty about future outcomes. Under conditions of worsening health (physical and mental), and the pressure to continue treatment, the best "solution" for the victim appears to be to "pull the victim out of the medical system", to de-socialise her/him from semi-institutionalisation, and to use social and informal support structures to build up on the victim's independence, self-esteem, personal integrity and sense of control of her/his own life.