Author
Edward A. D. Mitchell
Other affiliations: University of Franche-Comté, University of the West of England, Swiss Tropical and Public Health Institute ...read more
Bio: Edward A. D. Mitchell is an academic researcher from University of Neuchâtel. The author has contributed to research in topics: Testate amoebae & Sphagnum. The author has an hindex of 58, co-authored 218 publications receiving 13439 citations. Previous affiliations of Edward A. D. Mitchell include University of Franche-Comté & University of the West of England.
Topics: Testate amoebae, Sphagnum, Peat, Arcellinida, Bog
Papers published on a yearly basis
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Dalhousie University1, University of Saskatchewan2, University of Rhode Island3, Sewanee: The University of the South4, Natural History Museum5, New York State Department of Health6, University of British Columbia7, Kaiserslautern University of Technology8, Charles University in Prague9, University of Guelph10, Le Moyne College11, Georgia College & State University12, University of Colorado Boulder13, University of Geneva14, Edinburgh Napier University15, University of Arkansas16, Saint Petersburg State University17
TL;DR: This revision of the classification of eukaryotes retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees.
Abstract: This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.
1,414 citations
Utrecht University1, Université catholique de Louvain2, Institut national de la recherche agronomique3, Centre national de la recherche scientifique4, Université du Québec à Montréal5, Royal Society for the Protection of Birds6, University of Cambridge7, University of Padua8, University of Sussex9, Natural Resources Canada10, Purdue University11, Helmholtz Centre for Environmental Research - UFZ12, Smithsonian Institution13, University of Neuchâtel14, University of Saskatchewan15, Washington State University16, University of Bergen17, University of Stirling18
TL;DR: In this paper, a review of the global literature explores these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
Abstract: Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.
1,131 citations
TL;DR: There is strong evidence that soils, waterways, and plants in agricultural environments and neighboring areas are contaminated with variable levels of neonicotinoids or fipronil mixtures and their metabolites, and this provides multiple routes for chronic exposure of nontarget animals.
Abstract: Systemic insecticides are applied to plants using a wide variety of methods, ranging from foliar sprays to seed treatments and soil drenches. Neonicotinoids and fipronil are among the most widely used pesticides in the world. Their popularity is largely due to their high toxicity to invertebrates, the ease and flexibility with which they can be applied, their long persistence, and their systemic nature, which ensures that they spread to all parts of the target crop. However, these properties also increase the probability of environmental contamination and exposure of nontarget organisms. Environmental contamination occurs via a number of routes including dust generated during drilling of dressed seeds, contamination and accumulation in arable soils and soil water, runoff into waterways, and uptake of pesticides by nontarget plants via their roots or dust deposition on leaves. Persistence in soils, waterways, and nontarget plants is variable but can be prolonged; for example, the half-lives of neonicotinoids in soils can exceed 1,000 days, so they can accumulate when used repeatedly. Similarly, they can persist in woody plants for periods exceeding 1 year. Breakdown results in toxic metabolites, though concentrations of these in the environment are rarely measured. Overall, there is strong evidence that soils, waterways, and plants in agricultural environments and neighboring areas are contaminated with variable levels of neonicotinoids or fipronil mixtures and their metabolites (soil, parts per billion (ppb)-parts per million (ppm) range; water, parts per trillion (ppt)-ppb range; and plants, ppb-ppm range). This provides multiple routes for chronic (and acute in some cases) exposure of nontarget animals. For example, pollinators are exposed through direct contact with dust during drilling; consumption of pollen, nectar, or guttation drops from seed-treated crops, water, and consumption of contaminated pollen and nectar from wild flowers and trees growing near-treated crops. Studies of food stores in honeybee colonies from across the globe demonstrate that colonies are routinely and chronically exposed to neonicotinoids, fipronil, and their metabolites (generally in the 1–100 ppb range), mixed with other pesticides some of which are known to act synergistically with neonicotinoids. Other nontarget organisms, particularly those inhabiting soils, aquatic habitats, or herbivorous insects feeding on noncrop plants in farmland, will also inevitably receive exposure, although data are generally lacking for these groups. We summarize the current state of knowledge regarding the environmental fate of these compounds by outlining what is known about the chemical properties of these compounds, and placing these properties in the context of modern agricultural practices.
902 citations
University of Saskatchewan1, Centre for Environment, Fisheries and Aquaculture Science2, Natural History Museum3, University of Rhode Island4, Sewanee: The University of the South5, Academy of Sciences of the Czech Republic6, National Institutes of Health7, Saint Petersburg State University8, University of Salzburg9, Centre national de la recherche scientifique10, Mississippi State University11, Science for Life Laboratory12, Uppsala University13, Charles University in Prague14, Spanish National Research Council15, University of Duisburg-Essen16, Kaiserslautern University of Technology17, University of Oslo18, Dalhousie University19, Pierre-and-Marie-Curie University20, American Museum of Natural History21, University of Michigan22, University of Warsaw23, University of São Paulo24, University of Paris25, University of Guelph26, University of British Columbia27, Royal Botanic Garden Edinburgh28, Kyungpook National University29, University of Geneva30, University of Alabama31, Pompeu Fabra University32, Edinburgh Napier University33, University of Arkansas34, Hosei University35, Oklahoma State University–Stillwater36, Chinese Academy of Sciences37
TL;DR: It is confirmed that eukaryotes form at least two domains, the loss of monophyly in the Excavata, robust support for the Haptista and Cryptista, and suggested primer sets for DNA sequences from environmental samples that are effective for each clade are provided.
Abstract: This revision of the classification of eukaryotes follows that of Adl et al., 2012 [J. Euk. Microbiol. 59(5)] and retains an emphasis on protists. Changes since have improved the resolution of many ...
750 citations
01 Jan 2014
TL;DR: The use of neonicotinoides and fipronil has been extensively studied in the literature as discussed by the authors, with a total of 20,000 tonnes of active in 2010.
Abstract: Depuis leur decouverte dans les annees 1980, les pesticides neonicotinoides sont devenus la classe la plus largement utilisee des insecticides, dans le monde entier, avec des applications a grande echelle allant de la protection des plantes (cultures, legumes, fruits), aux produits veterinaires et aux biocides pour le controle des invertebres parasites en pisciculture. Dans cette revue, nous joignons la fipronil, un phenylpyrazole, aux neonicotinoides en raison de la similitude de leur toxicite, des profils physico-chimiques, et de leur presence dans l'environnement. Les neonicotinoides et le fipronil representent actuellement environ un tiers du marche mondial des insecticides ; la production mondiale annuelle de l'archetype des neonicotinoides, l'imidaclopride, a ete estimee au total a 20 000 tonnes de substance active en 2010. Le succes initial des neonicotinoides et du fipronil est du a plusieurs raisons : (1) il n'y avait pas de resistance connue a ces pesticides chez les ravageurs cibles, principalement en raison de leur developpement recent, (2) leurs proprietes physico-chimiques rassemblaient de nombreux avantages par rapport a celles des generations precedentes d’insecticides (c’est-a-dire, les organophosphores, les carbamates, les pyrethrinoides, etc.), et,(3) ils partagent et supposent des risques reduits pour l’operateur et le consommateur. En raison de leur nature systemique, ils sont absorbes par les racines ou les feuilles et transloques a toutes les parties de la plante, laquelle, a son tour, est effectivement toxique pour les insectes herbivores. La toxicite persiste pendant une periode de temps variable en fonction de la plante, de son stade de croissance, et de la quantite de pesticide appliquee. Une grande variete d'applications sont disponibles, y compris la NON Bonne Pratique Agricole(GAP)prophylactique d’application courante en enrobage de semences. En consequence de leur utilisation extensive et de leurs proprietes physico-chimiques, ces substances peuvent etre trouves dans tous les compartiments environnementaux, y compris le sol, l'eau et l'air. Les neonicotinoides et le fipronil fonctionnent en perturbant la transmission nerveuse dans le systeme nerveux central des invertebres.Les neonicotinoides imitent l'action des neurotransmetteurs, tandis que le fipronil inhibe les recepteurs neuronaux. Ce faisant, les premiers stimulent en permanence les neurones conduisant finalement les invertebres cibles a la mort. Comme pratiquement tous les insecticides, ils peuvent egalement avoir des effets letaux et subletaux sur les organismes non cibles, y compris les vertebres predateurs d'insectes. En outre, une gamme d’effets synergiques avec d'autres facteurs de stress a ete documentee. Ici, nous passons en revue de facon extensive leurs voies metaboliques, montrant comment les composes specifiques et les metabolites communs, lesquels peuvent eux-memes etre toxiques, forment ensemble deux cas. Ceux-ci peuvent entrainer une toxicite prolongee. Compte tenu de leur large expansion commerciale, leur mode d'action, leurs proprietes systemiques chez les plantes, leur persistance et leur devenir environnemental, couples avec des informations limitees sur les profils de toxicite de ces composes et de leurs metabolites, les neonicotinoides et le fipronil peuvent entrainer des risques importants pour l'environnement. Une evaluation globale des effets collateraux potentiels de leur utilisation est donc opportune. Le present document, et les chapitres suivants dans cette revue de la litterature mondiale, explorent ces risques et montrent une quantite croissante de preuves qui, sur la base de la persistance et de faibles concentrations de ces pesticides, posent de serieux risques d’impacts environnementaux indesirables.
667 citations
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
American Museum of Natural History1, University of Tartu2, University of Colombo3, Royal Netherlands Academy of Arts and Sciences4, University of Florida5, University of Palermo6, Goethe University Frankfurt7, Hobart Corporation8, Nakhon Phanom University9, University of Bamenda10, University of Gothenburg11, Naturalis12, Swedish University of Agricultural Sciences13, Royal Botanic Gardens14, Universiti Malaysia Sabah15, United States Department of Agriculture16, Forest Research Institute Malaysia17, Humboldt State University18, Chinese Academy of Sciences19, Landcare Research20, University of Western Australia21, Estonian University of Life Sciences22, University of Southern Queensland23, Botanic Garden Meise24, Manchester Metropolitan University25, James Cook University26
TL;DR: Diversity of most fungal groups peaked in tropical ecosystems, but ectomycorrhizal fungi and several fungal classes were most diverse in temperate or boreal ecosystems, and manyfungal groups exhibited distinct preferences for specific edaphic conditions (such as pH, calcium, or phosphorus).
Abstract: Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.
2,346 citations
TL;DR: The improvements the SILVA taxonomy has undergone in the last 3 years are described, focusing on the curation process, the various resources used for curation and the comparison of the SILva taxonomy with Greengenes and RDP-II taxonomies.
Abstract: SILVA (from Latin silva, forest, http://www.arb-silva.de) is a comprehensive resource for up-to-date quality-controlled databases of aligned ribosomal RNA (rRNA) gene sequences from the Bacteria, Archaea and Eukaryota domains and supplementary online services. SILVA provides a manually curated taxonomy for all three domains of life, based on representative phylogenetic trees for the small- and large-subunit rRNA genes. This article describes the improvements the SILVA taxonomy has undergone in the last 3 years. Specifically we are focusing on the curation process, the various resources used for curation and the comparison of the SILVA taxonomy with Greengenes and RDP-II taxonomies. Our comparisons not only revealed a reasonable overlap between the taxa names, but also points to significant differences in both names and numbers of taxa between the three resources.
2,187 citations
01 Dec 2010
TL;DR: In this article, the authors suggest a reduction in the global NPP of 0.55 petagrams of carbon, which would not only weaken the terrestrial carbon sink, but would also intensify future competition between food demand and biofuel production.
Abstract: Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.
1,780 citations
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01 Jan 1944
TL;DR: The only previously known species of Myrsidea from bulbuls, M. warwicki ex Ixos philippinus, is redescribed and sixteen new species are described; they and their type hosts are described.
Abstract: We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.
1,756 citations