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Author | Prunier, J.; Maurice, L.; Perez, E.; Gigault, J.; Pierson Wickmann, A.-C.; Davranche, M.; Halle, A.T. | ||||
Title | Trace metals in polyethylene debris from the North Atlantic subtropical gyre | Type | Journal Article | ||
Year | 2019 | Publication | Environmental Pollution | Abbreviated Journal | Environ. Pollut. |
Volume | 245 | Issue | Pages | 371-379 | |
Keywords | metals'accumulation; Microplastic; Plastic debris; Polyethylene; Polymer | ||||
Abstract | Plastic pollution in the marine environment poses threats to wildlife and habitats through varied mechanisms, among which are the transport and transfer to the food web of hazardous substances. Still, very little is known about the metal content of plastic debris and about sorption/desorption processes, especially with respect to weathering. In this study, plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals; as a comparison, new packaging materials were also analyzed. Both the new items and plastic debris showed very scattered concentrations. The new items contained significant amounts of trace metals introduced as additives, but globally, metal concentrations were higher in the plastic debris. The results provide evidence that enhanced metal concentrations increase with the plastic state of oxidation for some elements, such as As, Ti, Ni, and Cd. Transmission electron microscopy showed the presence of mineral particles on the surface of the plastic debris. This work demonstrates that marine plastic debris carries complex mixtures of heavy metals. Such materials not only behave as a source of metals resulting from intrinsic plastic additives but also are able to concentrate metals from ocean water as mineral nanoparticles or adsorbed species. Plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals. Marine plastic debris carry complex mixtures of heavy metals but it is evidence that plastic oxidation favors their adsorption. | ||||
Address | Univ Rennes, Geosciences, UMR CNRS 6118, bat 15, Campus de Beaulieu, Rennes Cedex, 35042, France | ||||
Corporate Author | Thesis | ||||
Publisher | Elsevier Ltd | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
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Series Volume | Series Issue | Edition | |||
ISSN | 02697491 (Issn) | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | Export Date: 3 December 2018; Coden: Enpoe; Correspondence Address: Halle, A.T.; Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III – Paul Sabatier, 118 route de Narbonne, Cedex 09, France; email: ter-halle@chimie.ups-tlse.fr; References: Al-Sid-Cheikh, M., Pedrot, M., Dia, A., Guenet, H., Vantelon, D., Davranche, M., Gruau, G., Delhaye, T., Interactions between natural organic matter, sulfur, arsenic and iron oxides in re-oxidation compounds within riparian wetlands: NanoSIMS and X-ray adsorption spectroscopy evidences (2015) Sci. Total Environ., 515, pp. 118-128; Anderson, A., Andrady, A., Hidalgo-Ruz, V., Kershaw, P.J., Sources, Fate and Effects of Microplastics in the Marine Environment: a Global Assessment; GESAMP Joint Group of Expertts on the Scientific Aspects of Marine Environmental Protection (2015); Ashton, K., Holmes, L., Turner, A., Association of metals with plastic production pellets in the marine environment (2010) Mar. Pollut. Bull., 60, pp. 2050-2055; Bakir, A., Rowland, S.J., Thompson, R.C., Transport of persistent organic pollutants by microplastics in estuarine conditions (2014) Estuar. Coast Shelf Sci., 140, pp. 14-21; Belzile, N., Devitre, R.R., Tessier, A., Insitu collection of diagenetic iron and manganese oxyhydroxides from natural sediments (1989) Nature, 340, pp. 376-377; Brennecke, D., Duarte, B., Paiva, F., Cacador, I., Canning-Clode, J., Microplastics as vector for heavy metal contamination from the marine environment (2016) Estuar. Coast Shelf Sci., 178, pp. 189-195; Bylan, C., (2003) Developments in Colorants for Plastics, 14, p. 85; Carlton, J.T., Chapman, J.W., Geller, J.B., Miller, J.A., Carlton, D.A., McCuller, M.I., Treneman, N.C., Ruiz, G.M., Tsunami-driven rafting: transoceanic species dispersal and implications for marine biogeography (2017) Science, 357, pp. 1402-1405; Cordeiro, F., Baer, I., Robouch, P., Emteborg, H., C.-G, J., Korsten, B., d. l. C, B., IMEP-34: Heavy Metals in Toys According to EN 71-3:1994 (2012), JCR Luxembourg p 58pp; Eerkes-Medrano, D., Thompson, R.C., Aldridge, D.C., Microplastics in freshwater systems: a review of the emerging threats, identification of knowledge gaps and prioritisation of research needs (2015) Water Res., 75, pp. 63-82; (2004) Emission Scenario Document on Plastic Additives, , OECD Environmental Health and Safety Publications Paris; Engler, R.E., The complex interaction between marine debris and toxic chemicals in the ocean (2012) Environ. Sci. Technol., 46, pp. 12302-12315; Eriksen, M., Mason, S., Wilson, S., Box, C., Zellers, A., Edwards, W., Farley, H., Amato, S., Microplastic pollution in the surface waters of the laurentian great lakes (2013) Mar. Pollut. Bull., 77, pp. 177-182; Fakih, M., Davranche, M., Dia, A., Nowack, B., Petitjean, P., Chatellier, X., Gruau, G., A new tool for in situ monitoring of Fe-mobilization in soils (2008) Appl. Geochem., 23, pp. 3372-3383; Gall, S.C., Thompson, R.C., The impact of debris on marine life (2015) Mar. Pollut. Bull., 92, pp. 170-179; Goldstein, M.C., Carson, H.S., Eriksen, M., Relationship of diversity and habitat area in North Pacific plastic-associated rafting communities (2014) Mar. Biol., 161, pp. 1441-1453; Hansen, E., Nilsson, N.H., Lithner, D., Lassen, C., Hazardous Substances in Plastic Materials, COWI and the Danish Technological Institute on Behalf of Thr Norwegian Climate and Pollution Agency. In Oslo (2010), p 150 pp; (2013) Hazardous Substances in Plastic Materials, , COWI Danish Technological Institute; Hirai, H., Takada, H., Ogata, Y., Yamashita, R., Mizukawa, K., Saha, M., Kwan, C., Ward, M.W., Organic micropollutants in marine plastics debris from the open ocean and remote and urban beaches (2011) Mar. Pollut. Bull., 62, pp. 1683-1692; Holmes, L.A., Turner, A., Thompson, R.C., Adsorption of trace metals to plastic resin pellets in the marine environment (2012) Environ. Pollut., 160, pp. 42-48; Holmes, L.A., Turner, A., Thompson, R.C., Interactions between trace metals and plastic production pellets under estuarine conditions (2014) Mar. Chem., 167, pp. 25-32; Imhof, H.K., Laforsch, C., Wiesheu, A.C., Schmid, J., Anger, P.M., Niessner, R., Ivleva, N.P., Pigments and plastic in limnetic ecosystems: a qualitative and quantitative study on microparticles of different size classes (2016) Water Res., 98, pp. 64-74; Jiao, W.T., Chen, W.P., Chang, A.C., Page, A.L., Environmental risks of trace elements associated with long-term phosphate fertilizers applications: a review (2012) Environ. Pollut., 168, pp. 44-53; Lavers, J.L., Bond, A.L., Ingested plastic as a route for trace metals in laysan albatross (phoebastria immutabilis) and bonin petrel (pterodroma hypoleuca) from midway atoll (2016) Mar. Pollut. Bull., 110, pp. 493-500; Law, K.L., Moret-Ferguson, S.E., Goodwin, D.S., Zettler, E.R., De Force, E., Kukulka, T., Proskurowski, G., Distribution of surface plastic debris in the eastern pacific ocean from an 11-year data set (2014) Environ. Sci. Technol., 48, pp. 4732-4738; Lazzeria, A., Zebarjadb, S.M., Parcellac, M., Cavalierd, K., Rosam, R., Filler toughening of plastics. Part 1-The effect of surface interactions on physico-mechanical properties and rheological behaviour of ultrafine CaCO3/HDPE nanocomposites (2005) Polymer, 46, pp. 827-844; Lithner, D., Larsson, A., Dave, G., Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition (2011) Sci. Total Environ., 409, pp. 3309-3324; Marier, C., Calafut, C., Polypropylene: the Definitive User's Guide and Databook. Norwich NY (1998); Massos, A., Turner, A., Cadmium, lead and bromine in beached microplastics (2017) Environ. Pollut., 227, pp. 139-145; Moret-Ferguson, S., Law, K.L., Proskurowski, G., Murphy, E.K., Peacock, E.E., Reddy, C.M., The size, mass, and composition of plastic debris in the western North Atlantic Ocean (2010) Mar. Pollut. Bull., 60, pp. 1873-1878; Murphy, J., Additives for Plastic Handbook (2003), Elsevier Advanced Technology Oxford, UK; Nziguheba, G., Smolders, E., Inputs of trace elements in agricultural soils via phosphate fertilizers in European countries (2008) Sci. Total Environ., 390, pp. 53-57; Rizzotto, M., Chapter 5 Metal complexes as antimicrobial agents (2012) A Search for Antibacterial Agents, p. 73. , V. Bobbarala; Rochman, C.M., Browne, M.A., Halpern, B.S., Hentschel, B.T., Hoh, E., Karapanagioti, H.K., Rios-Mendoza, L.M., Thompson, R.C., Classify plastic waste as hazardous (2013) Nature, 494, pp. 169-171; Rochman, C.M., Hoh, E., Hentschel, B.T., Kaye, S., Long-term field measurement of sorption of organic contaminants to five types of plastic pellets: implications for plastic marine debris (2013) Environ. Sci. Technol., 47, pp. 1646-1654; Rochman, C.M., Kurobe, T., Flores, I., Teh, S.J., Early warning signs of endocrine disruption in adult fish from the ingestion of polyethylene with and without sorbed chemical pollutants from the marine environment (2014) Sci. Total Environ., 493, pp. 656-661; Rochman, C.M., Hentschel, B.T., Teh, S.J., Long-term sorption of metals is similar among plastic types: implications for plastic debris in aquatic environments (2014) PLoS One, 9; RoHS, Restriction of Hazardous Substances, Eu Directive 2002/95/EC (2006), http://www.rohsguide.com/rohs-substances.htm; Schlining, K., von Thun, S., Kuhnz, L., Schlining, B., Lundsten, L., Stout, N.J., Chaney, L., Connor, J., Debris in the deep: using a 22-year video annotation database to survey marine litter in Monterey Canyon, central California, USA (2013) Deep Sea Res. Part 1 Oceanogr. Res. Pap., 79, pp. 96-105; Tanaka, K., Takada, H., Yamashita, R., Mizukawa, K., Fukuwaka, M., Watanuki, Y., Accumulation of plastic-derived chemicals in tissues of seabirds ingesting marine plastics (2013) Mar. Pollut. Bull., 69, pp. 219-222; ter Halle, A., Ladirat, L., Gendre, X., Goudouneche, D., Pusineri, C., Routaboul, C., Tenailleau, C., Perez, E., Understanding the fragmentation pattern of marine plastic debris (2016) Environ. Sci. Technol., 50, pp. 5668-5675; Ter Halle, A., Ladirat, L., Martignac, M., Mingotaud, A.F., Boyron, O., Perez, E., To what extent are microplastics from the open ocean weathered? (2017) Environ. Pollut., 227, pp. 167-174; Turner, A., Heavy metals, metalloids and other hazardous elements in marine plastic litter (2016) Mar. Pollut. Bull., 111, pp. 136-142; Turner, A., Trace elements in fragments of fishing net and other filamentous plastic litter from two beaches in SW England (2017) Environ. Pollut., 224, pp. 722-728; Turner, A., Concentrations and migratabilities of hazardous elements in second-hand children's plastic toys (2018) Environ. Sci. Technol., 52, pp. 3110-3116; Turner, A., Mobilisation kinetics of hazardous elements in marine plastics subject to an avian physiologically-based extraction test (2018) Environ. Pollut., 236, pp. 1020-1026; Turner, A., Solman, K.R., Analysis of the elemental composition of marine litter by field-portable-XRF (2016) Talanta, 159, pp. 262-271; Wang, J.D., Peng, J.P., Tan, Z., Gao, Y.F., Zhan, Z.W., Chen, Q.Q., Cai, L.Q., Microplastics in the surface sediments from the Beijiang River littoral zone: composition, abundance, surface textures and interaction with heavy metals (2017) Chemosphere, 171, pp. 248-258; Wardrop, P., Shimeta, J., Nugegoda, D., Morrison, P.D., Miranda, A., Tang, M., Clarke, B.O., Chemical pollutants sorbed to ingested microbeads from personal care products accumulate in fish (2016) Environ. Sci. Technol., 50, pp. 4037-4044; Wright, S.L., Thompson, R.C., Galloway, T.S., The physical impacts of microplastics on marine organisms: a review (2013) Environ. Pollut., 178, pp. 483-492; Zettler, E.R., Mincer, T.J., Amaral-Zettler, L.A., Life in the “plastisphere”: microbial communities on plastic marine debris (2013) Environ. Sci. Technol., 47, pp. 7137-7146 | Approved | no | ||
Call Number | EcoFoG @ webmaster @ | Serial | 840 | ||
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Author | Melieres, M.A.; Pourchet, M.; Charles-Dominique, P.; Gaucher, P. | ||||
Title | Mercury in canopy leaves of French Guiana in remote areas | Type | Journal Article | ||
Year | 2003 | Publication | Science of the Total Environment | Abbreviated Journal | Sci. Total Environ. |
Volume | 311 | Issue | 1-3 | Pages | 261-267 |
Keywords | mercury; canopy; rainforest; Hg atmosphere soil transfer | ||||
Abstract | A study of total Hg concentration in the foliage of the canopy was carried out in two remote areas in French Guiana. The sampled canopy is representative of the French Guiana canopy. The concentration in the foliage, 64+/-14 ng g(-1) (dry wt.), is used to estimate the annual input of total Hg to the soil through the litterfall, found to be 45+/-10 mug m(-2) y(-1). As translocation is negligible, mercury in the canopy originates mainly from atmospheric uptake by the leaves and this litterfall deposit represents a direct atmospheric input from the background atmospheric load into the soil. (C) 2003 Elsevier Science B.V. All rights reserved. | ||||
Address | Univ Grenoble 1, CNRS, Lab Glaciol & Geophys Environm, F-38402 St Martin Dheres, France, Email: melieres@glaciog.ujf-grenobic.fr | ||||
Corporate Author | Thesis | ||||
Publisher | ELSEVIER SCIENCE BV | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0048-9697 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000184091300019 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 271 | ||
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Author | Coutand, C.; Chevolot, M.; Lacointe, A.; Rowe, N.; Scotti, I. | ||||
Title | Mechanosensing of stem bending and its interspecific variability in five neotropical rainforest species | Type | Journal Article | ||
Year | 2010 | Publication | Annals of Botany | Abbreviated Journal | Ann. Bot. |
Volume | 105 | Issue | 2 | Pages | 341-347 |
Keywords | Mechanosensing; interspecific variability; trees; lianas; rain forest; neotropical species; bending; biomechanics; Bauhinia; Eperua; Symphonia; Tachigali | ||||
Abstract | In rain forests, sapling survival is highly dependent on the regulation of trunk slenderness (height/diameter ratio): shade-intolerant species have to grow in height as fast as possible to reach the canopy but also have to withstand mechanical loadings (wind and their own weight) to avoid buckling. Recent studies suggest that mechanosensing is essential to control tree dimensions and stability-related morphogenesis. Differences in species slenderness have been observed among rainforest trees; the present study thus investigates whether species with different slenderness and growth habits exhibit differences in mechanosensitivity. Recent studies have led to a model of mechanosensing (sum-of-strains model) that predicts a quantitative relationship between the applied sum of longitudinal strains and the plant's responses in the case of a single bending. Saplings of five different neotropical species (Eperua falcata, E. grandiflora, Tachigali melinonii, Symphonia globulifera and Bauhinia guianensis) were subjected to a regimen of controlled mechanical loading phases (bending) alternating with still phases over a period of 2 months. Mechanical loading was controlled in terms of strains and the five species were subjected to the same range of sum of strains. The application of the sum-of-strain model led to a dose-response curve for each species. Dose-response curves were then compared between tested species. The model of mechanosensing (sum-of-strain model) applied in the case of multiple bending as long as the bending frequency was low. A comparison of dose-response curves for each species demonstrated differences in the stimulus threshold, suggesting two groups of responses among the species. Interestingly, the liana species B. guianensis exhibited a higher threshold than other Leguminosae species tested. This study provides a conceptual framework to study variability in plant mechanosensing and demonstrated interspecific variability in mechanosensing. | ||||
Address | [Coutand, Catherine; Lacointe, Andre] Univ Clermont Ferrand, INRA, PIAF, UMR 547, F-63000 Clermont Ferrand, France, Email: coutand@clermont.inra.fr | ||||
Corporate Author | Thesis | ||||
Publisher | OXFORD UNIV PRESS | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
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ISSN | 0305-7364 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000274347000025 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 71 | ||
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Author | Almeras, T.; Fournier, M. | ||||
Title | Biomechanical design and long-term stability of trees: Morphological and wood traits involved in the balance between weight increase and the gravitropic reaction | Type | Journal Article | ||
Year | 2009 | Publication | Journal of Theoretical Biology | Abbreviated Journal | J. Theor. Biol. |
Volume | 256 | Issue | 3 | Pages | 370-381 |
Keywords | Mechanical design; Gravitropism; Bending stresses; Allometry; Reaction wood | ||||
Abstract | Studies on tree biomechanical design usually focus on stem stiffness, resistance to breakage or uprooting, and elastic stability. Here we consider another biomechanical constraint related to the interaction between growth and gravity. Because stems are slender structures and are never perfectly symmetric, the increase in tree mass always causes bending movements. Given the current mechanical design of trees, integration of these movements over time would ultimately lead to a weeping habit unless some gravitropic correction occurs. This correction is achieved by asymmetric internal forces induced during the maturation of new wood. The long-term stability of a growing stem therefore depends on how the gravitropic correction that is generated by diameter growth balances the disturbance due to increasing self weight. General mechanical formulations based on beam theory are proposed to model these phenomena. The rates of disturbance and correction associated with a growth increment are deduced and expressed as a function of elementary traits of stem morphology, cross-section anatomy and wood properties. Evaluation of these traits using previously published data shows that the balance between the correction and the disturbance strongly depends on the efficiency of the gravitropic correction, which depends on the asymmetry of wood maturation strain, eccentric growth, and gradients in wood stiffness. By combining disturbance and correction rates, the gravitropic performance indicates the dynamics of stem bending during growth. It depends on stem biomechanical traits and dimensions. By analyzing dimensional effects, we show that the necessity for gravitropic correction might constrain stem allometric growth in the long-term. This constraint is compared to the requirement for elastic stability, showing that gravitropic performance limits the increase in height of tilted stem and branches. The performance of this function may thus limit the slenderness and lean of stems, and therefore the ability of the tree to capture light in a heterogeneous environment. (c) 2008 Elsevier Ltd. All rights reserved. | ||||
Address | [Almeras, T.; Fournier, M.] INRA, UMR Ecol Forets Guyane, F-97310 Kourou, France, Email: t_almeras@hotmail.com | ||||
Corporate Author | Thesis | ||||
Publisher | ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0022-5193 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000263077100008 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 123 | ||
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Author | Blanc, L.; Dick, J.M. | ||||
Title | Errors in repeated measurements of soil water content in pots using a ThetaProbe | Type | Journal Article | ||
Year | 2003 | Publication | Soil Use and Management | Abbreviated Journal | Soil Use Manage. |
Volume | 19 | Issue | 1 | Pages | 87-88 |
Keywords | measurement; soil water content; probes | ||||
Abstract | The accuracy of a ThetaProbe (Delta-T Devices Ltd, UK) to obtain repeated measures of soil water content in pot plants was tested. This alternative to balance determinations led to a large underestimation of water content, varying from 12.2 to 21.8% of the total water content, depending on soil type. | ||||
Address | Ctr Ecol & Hydrol Edinburgh, Penicuik EH26 0QB, Midlothian, Scotland | ||||
Corporate Author | Thesis | ||||
Publisher | C A B I PUBLISHING | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0266-0032 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000181552000013 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 247 | ||
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Author | Almeras, T.; Yoshida, M.; Okuyama, T. | ||||
Title | The generation of longitudinal maturation stress in wood is not dependent on diurnal changes in diameter of trunk | Type | Journal Article | ||
Year | 2006 | Publication | Journal of Wood Science | Abbreviated Journal | J. Wood Sci. |
Volume | 52 | Issue | 5 | Pages | 452-455 |
Keywords | maturation stress; growth stress; cell-wall maturation; continuous lighting; diurnal strains | ||||
Abstract | A hypothetical mechanism for the generation of maturation stress in wood was tested experimentally. The hypothesis was that the maturation stress could partly originate in a physical mechanism related to daily changes in water pressure and associated diurnal strains. The matrix of lignin and hemicellulose, deposited in the cell wall during the night, would be put in compression by the effect of water tension during the next day. The cellulose framework, crystallizing during the day, would be put in tension by the decrease in tension at night and subsequent cell-wall swelling. This was tested on young saplings of sugi and beech. Half of the saplings were submitted to continuous lighting, which canceled diurnal strains. Saplings were tilted 40 degrees, and their uprighting movement was measured. The uprighting movement is directly due to the production of reaction wood and the concomitant development of large longitudinal maturation stress. It occurred in the continuously lighted plants at least as much as in control plants. We conclude that the generation of longitudinal maturation stress in tension or compression wood is not directly related to variations in water pressure and diurnal strains. | ||||
Address | Nagoya Univ, Grad Sch Bioagr Sci, Lab Biomat Phys, Chikusa Ku, Nagoya, Aichi 4648601, Japan, Email: t_almeras@hotmail.com | ||||
Corporate Author | Thesis | ||||
Publisher | SPRINGER TOKYO | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1435-0211 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000241010600012 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 222 | ||
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Author | Roussel, J.-R.; Clair, B. | ||||
Title | Evidence of the late lignification of the G-layer in Simarouba tension wood, to assist understanding how non-G-layer species produce tensile stress | Type | Journal Article | ||
Year | 2015 | Publication | Tree Physiology | Abbreviated Journal | Tree Physiology |
Volume | 35 | Issue | 12 | Pages | 1366-1377 |
Keywords | maturation stress generation; ontogeny; Simarouba amara Aubl.; tension wood cell wall; tree biomechanics | ||||
Abstract | To recover verticality after disturbance, angiosperm trees produce 'tension wood' allowing them to bend actively. The driving force of the tension has been shown to take place in the G-layer, a specific unlignified layer of the cell wall observed in most temperate species. However, in tropical rain forests, the G-layer is often absent and the mechanism generating the forces to reorient trees remains unclear. A study was carried out on tilted seedlings, saplings and adult Simarouba amara Aubl. trees – a species known to not produce a G-layer. Microscopic observations were done on sections of normal and tension wood after staining or observed under UV light to assess the presence/absence of lignin. We showed that S. amara produces a cell-wall layer with all of the characteristics typical of G-layers, but that this G-layer can be observed only as a temporary stage of the cell-wall development because it is masked by a late lignification. Being thin and lignified, tension wood fibres cannot be distinguished from normal wood fibres in the mature wood of adult trees. These observations indicate that the mechanism generating the high tensile stress in tension wood is likely to be the same as that in species with a typical G-layer and also in species where the G-layer cannot be observed in mature cells. © 2015 The Author 2015. Published by Oxford University Press. All rights reserved. | ||||
Address | CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 701, Kourou, France | ||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
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ISSN | ISBN | Medium | |||
Area | Expedition | Conference | |||
Notes | Export Date: 25 March 2016 | Approved | no | ||
Call Number | EcoFoG @ webmaster @ | Serial | 672 | ||
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Author | Gourlet-Fleury, S.; Comu, G.; Jesel, S.; Dessard, H.; Jourget, J.G.; Blanc, L.; Picard, N. | ||||
Title | Using models to predict recovery and assess tree species vulnerability in logged tropical forests: A case study from French Guiana | Type | Journal Article | ||
Year | 2005 | Publication | Forest Ecology and Management | Abbreviated Journal | For. Ecol. Manage. |
Volume | 209 | Issue | 1-2 | Pages | 69-86 |
Keywords | matrix model; individual-based spatially explicit model; regeneration; recruitment; long-term population dynamics | ||||
Abstract | A major challenge for forest managers is to define the optimal cutting cycle to ensure that the resource is sustained in the long term. Matrix models of forest dynamics allow time-projection of diameter-class distributions and thus assessment of the time needed, after logging, to recover a given part of the exploitable stock. They are easy to build and they only require, as input variables, the diameter structure of the population(s) under scope. However, such models are based on a coarse description of tree population dynamics and must be used with caution. In particular, as trees are only described from a diameter threshold (usually 10 cm dbh), recruitment of a new tree cannot be linked with the preceding generation since too much time elapsed between seed dispersal and the installation of a 10-cm recruit. This causes predictions of matrix models to be highly questionable in the long term when ingrowth to larger dbh classes greatly depends on the way recruitment has been modelled. We used a case study from French Guiana to test whether or not a simple matrix model is reliable enough to help forest managers choose between management alternatives. We focused on the major timber species Dicorynia guianensis Amshoff (Caesalpiniaceae) harvested under a selective cutting regime. We compared predictions of D. guianensis stock recovery in the short and long term provided by two models: StoMat, a non-regulated matrix model, and SELVA, a single-tree distance dependent model explicitly simulating the entire species life cycle. Both models were independently calibrated on data from Paracou permanent sample plots. We showed that: (i) the short-term recovery of the exploitable stock predicted by StoMat is reliable for a large range of disturbance conditions; (ii) recruitment implementation in StoMat does not influence projections until the third felling cycle; (iii) for shared initial stand conditions SELVA and StoMat give consistent mid- and long-term predictions: the simple recruitment model used into StoMat could efficiently summarise the regeneration processes of the species under low felling intensity. Our results indicate that the current felling regime used in French Guiana may not be sustainable on a long-term basis. In any case, no more than 60% of the initial stock would be recovered after logging. We conclude that simple models can provide as reliable predictions as more complicated ones. They may be sufficient to assess the recovery of a species' exploitable stock even in the long term, or at least assess the (un)sustainability of particular harvesting regimes. (c) 2005 Elsevier B.V. All rights reserved. | ||||
Address | CIRAD, Dept Forets, F-34398 Montpellier 5, France, Email: sylvie.gourlet-fleury@cirad.fr | ||||
Corporate Author | Thesis | ||||
Publisher | ELSEVIER SCIENCE BV | Place of Publication | Editor | ||
Language | Summary Language | Original Title | |||
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0378-1127 | ISBN | Medium | ||
Area | Expedition | Conference | |||
Notes | ISI:000228504600007 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 257 | ||
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Author | Ezanno, P.; Aubry-Kientz, M.; Arnoux, S.; Cailly, P.; L'Ambert, G.; Toty, C.; Balenghien, T.; Tran, A. | ||||
Title | A generic weather-driven model to predict mosquito population dynamics applied to species of Anopheles, Culex and Aedes genera of southern France | Type | Journal Article | ||
Year | 2015 | Publication | Preventive Veterinary Medicine | Abbreviated Journal | Preventive Veterinary Medicine |
Volume | 120 | Issue | 1 | Pages | 39-50 |
Keywords | Mathematical modelling; Mosquito; Population dynamics; Seasonality; Sensitivity analysis; Surveillance | ||||
Abstract | An accurate understanding and prediction of mosquito population dynamics are needed to identify areas where there is a high risk of mosquito-borne disease spread and persistence. Simulation tools are relevant for supporting decision-makers in the surveillance of vector populations, as models of vector population dynamics provide predictions of the greatest risk periods for vector abundance, which can be particularly helpful in areas with a highly variable environment. We present a generic weather-driven model of mosquito population dynamics, which was applied to one species of each of the genera Anopheles, Culex, and Aedes, located in the same area and thus affected by similar weather conditions. The predicted population dynamics of Anopheles hyrcanus, Culex pipiens, and Aedes caspius were not similar. An. hyrcanus was abundant in late summer. Cx. pipiens was less abundant but throughout the summer. The abundance of both species showed a single large peak with few variations between years. The population dynamics of Ae. caspius showed large intra- and inter-annual variations due to pulsed egg hatching. Predictions of the model were compared to longitudinal data on host-seeking adult females. Data were previously obtained using CDC-light traps baited with carbon dioxide dry ice in 2005 at two sites (. Marais du Viguerat and Tour Carbonnière) in a favourable temperate wetland of southern France (Camargue). The observed and predicted periods of maximal abundance for An. hyrcanus and Cx. pipiens tallied very well. Pearson's coefficients for these two species were over 75% for both species. The model also reproduced the major trends in the intra-annual fluctuations of Ae. caspius population dynamics, with peaks occurring in early summer and following the autumn rainfall events. Few individuals of this species were trapped so the comparison of predicted and observed dynamics was not relevant. A global sensitivity analysis of the species-specific models enabled us to identify the parameters most influencing the maximal abundance of mosquitoes. These key parameters were almost similar between species, but not with the same contributions. The emergence of adult mosquitoes was identified as a key process in the population dynamics of all of the three species considered here. Parameters associated with adult emergence therefore need to be precisely known to achieve accurate predictions. Our model is a flexible and efficient tool that predicts mosquito abundance based on local environmental factors. It is useful to and already used by a mosquito surveillance manager in France. © 2015 Elsevier B.V. | ||||
Address | Université des Antilles et de la Guyane, UMR 'Ecologie des Forêts de Guyane'Kourou, France | ||||
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Notes | Cited By :1; Export Date: 18 May 2015 | Approved | no | ||
Call Number | EcoFoG @ webmaster @ | Serial | 603 | ||
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Author | Campillo, F.; Rakotozafy, R.; Rossi, V. | ||||
Title | Parallel and interacting Markov chain Monte Carlo algorithm | Type | Journal Article | ||
Year | 2009 | Publication | Mathematics and Computers in Simulation | Abbreviated Journal | Math. Comput. Simul. |
Volume | 79 | Issue | 12 | Pages | 3424-3433 |
Keywords | Markov chain Monte Carlo method; Interacting chains; Hidden Markov model | ||||
Abstract | In many situations it is important to be able to propose N independent realizations of a given distribution law. We propose a strategy for making N parallel Monte Carlo Markov chains (MCMC) interact in order to get an approximation of an independent N-sample of a given target law. In this method each individual chain proposes candidates for all other chains. We prove that the set of interacting chains is itself a MCMC method for the product of N target measures. Compared to independent parallel chains this method is more time consuming. but we show through examples that it possesses many advantages. This approach is applied to a biomass evolution model. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved. | ||||
Address | [Rossi, Vivien] CIRAD, Res Unit, Montpellier, France, Email: Fabien.Campillo@inria.fr | ||||
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Publisher | ELSEVIER SCIENCE BV | Place of Publication | Editor | ||
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ISSN | 0378-4754 | ISBN | Medium | ||
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Notes | ISI:000269289100006 | Approved | no | ||
Call Number | EcoFoG @ eric.marcon @ | Serial | 197 | ||
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