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Author Vincent, G.; Sabatier, D.; Blanc, L.; Chave, J.; Weissenbacher, E.; Pélissier, R.; Fonty, E.; Molino, J.-F.; Couteron, P. url  openurl
  Title Accuracy of small footprint airborne LiDAR in its predictions of tropical moist forest stand structure Type Journal Article
  Year 2012 Publication Remote Sensing of Environment Abbreviated Journal Remote Sens. Environ.  
  Volume 125 Issue Pages 23-33  
  Keywords Basal area; Lidar; Tropical moist forest  
  Abstract We predict stand basal area (BA) from small footprint LiDAR data in 129 one-ha tropical forest plots across four sites in French Guiana and encompassing a great diversity of forest structures resulting from natural (soil and geological substrate) and anthropogenic effects (unlogged and logged forests). We use predictors extracted from the Canopy Height Model to compare models of varying complexity: single or multiple regressions and nested models that predict BA by independent estimates of stem density and quadratic mean diameter. Direct multiple regression was the most accurate, giving a 9.6% Root Mean Squared Error of Prediction (RMSEP). The magnitude of the various errors introduced during the data collection stage is evaluated and their contribution to MSEP is analyzed. It was found that these errors accounted for less than 10% of model MSEP, suggesting that there is considerable scope for model improvement. Although site-specific models showed lower MSEP than global models, stratification by site may not be the optimal solution. The key to future improvement would appear to lie in a stratification that captures variations in relations between LiDAR and forest structure. © 2012 Elsevier Inc.  
  Address ONF, Direction régionale de la Guyane, Cayenne, 97300 France  
  Corporate Author Thesis  
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  Series Volume Series Issue Edition  
  ISSN (down) 00344257 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 9 August 2012; Source: Scopus; Article in Press; Coden: Rseea; doi: 10.1016/j.rse.2012.06.019; Language of Original Document: English; Correspondence Address: Vincent, G.; IRD AMAP CIRAD, TA A-51/PS2, 34398 Montpellier cedex 5, Franceemail: gregoire.vincent@ird.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 418  
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Author Croft, H.; Chen, J.M.; Wang, R.; Mo, G.; Luo, S.; Luo, X.; He, L.; Gonsamo, A.; Arabian, J.; Zhang, Y.; Simic-Milas, A.; Noland, T.L.; He, Y.; Homolová, L.; Malenovský, Z.; Yi, Q.; Beringer, J.; Amiri, R.; Hutley, L.; Arellano, P.; Stahl, C.; Bonal, D. url  doi
openurl 
  Title The global distribution of leaf chlorophyll content Type Journal Article
  Year 2020 Publication Remote Sensing of Environment Abbreviated Journal Remote Sens. Environ.  
  Volume 236 Issue 111479 Pages  
  Keywords  
  Abstract Leaf chlorophyll is central to the exchange of carbon, water and energy between the biosphere and the atmosphere, and to the functioning of terrestrial ecosystems. This paper presents the first spatially-continuous view of terrestrial leaf chlorophyll content (ChlLeaf) at the global scale. Weekly maps of ChlLeaf were produced from ENVISAT MERIS full resolution (300 m) satellite data using a two-stage physically-based radiative transfer modelling approach. Firstly, leaf-level reflectance was derived from top-of-canopy satellite reflectance observations using 4-Scale and SAIL canopy radiative transfer models for woody and non-woody vegetation, respectively. Secondly, the modelled leaf-level reflectance was input into the PROSPECT leaf-level radiative transfer model to derive ChlLeaf. The ChlLeaf retrieval algorithm was validated using measured ChlLeaf data from 248 sample measurements at 28 field locations, and covering six plant functional types (PFTs). Modelled results show strong relationships with field measurements, particularly for deciduous broadleaf forests (R2 = 0.67; RMSE = 9.25 microg cm-2; p < 0.001), croplands (R2 = 0.41; RMSE = 13.18 microg cm-2; p < 0.001) and evergreen needleleaf forests (R2 = 0.47; RMSE = 10.63 microg cm-2; p < 0.001). When the modelled results from all PFTs were considered together, the overall relationship with measured ChlLeaf remained good (R2 = 0.47, RMSE = 10.79 microg cm-2; p < 0.001). This result is an improvement on the relationship between measured ChlLeaf and a commonly used chlorophyll-sensitive spectral vegetation index; the MERIS Terrestrial Chlorophyll Index (MTCI; R2 = 0.27, p < 0.001). The global maps show large temporal and spatial variability in ChlLeaf, with evergreen broadleaf forests presenting the highest leaf chlorophyll values, with global annual median values of 54.4 microg cm-2. Distinct seasonal ChlLeaf phenologies are also visible, particularly in deciduous plant forms, associated with budburst and crop growth, and leaf senescence. It is anticipated that this global ChlLeaf product will make an important step towards the explicit consideration of leaf-level biochemistry in terrestrial water, energy and carbon cycle modelling.  
  Address UMR EEF, INRA Université de Lorraine, Champenoux54280, France  
  Corporate Author Thesis  
  Publisher Elsevier Inc. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 00344257 (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 898  
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Author Vantaux, A.; Roux, O.; Magro, A.; Orivel, J. url  openurl
  Title Evolutionary perspectives on myrmecophily in ladybirds Type Journal Article
  Year 2012 Publication Psyche Abbreviated Journal Psyche  
  Volume 591570 Issue Pages 1-7  
  Keywords  
  Abstract Myrmecophiles are species that usually have developed specialized traits to cope with the aggressiveness of ants enabling them to live in their vicinity. Many coccinellid species are predators of Hemiptera; the latter is also often protected by ants. Therefore these ladybirds frequently interact with ants, and some species have become myrmecophilous. In this paper, we aim to provide an overview of the evolution of myrmecophilous traits in ladybirds. We then discuss the costs and benefits of myrmecophily and the dietary shift to myrmecophagy observed in a few species. Copyright © 2012 Amélie Vantaux et al.  
  Address CNRS, UMR EcoFoG-Ecologie des Forêts de Guyane, Campus Agronomique, BP 316, 97379 Kourou Cedex, France  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN (down) 00332615 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 28 March 2012; Source: Scopus; Art. No.: 591570; doi: 10.1155/2012/591570; Language of Original Document: English; Correspondence Address: Vantaux, A.; Entomology Laboratory, Zoological Institute, Catholic University of Leuven, Naamsestraat 59, 3000 Leuven, Belgium; email: amelie.vantaux@gmail.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 388  
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Author Lacau, S.; Groc, S.; Dejean, A.; Oliveira, M.L.D.; Delabie, J.H.C. pdf  url
openurl 
  Title Tatuidris kapasi sp. nov.: A new armadillo ant from French Guiana (Formicidae: Agroecomyrmecinae) Type Journal Article
  Year 2012 Publication Psyche Abbreviated Journal Psyche  
  Volume 926089 Issue Pages 1-6  
  Keywords  
  Abstract Tatuidris kapasi sp. nov. (Formicidae: Agroecomyrmecinae), the second known species of “armadillo ant”, is described after a remarkable specimen collected in French Guiana. This species can be easily distinguished from Tatuidris tatusia by characters related to the shape of the mesosoma and petiole as well as to the pilosity, the sculpture, and the color. Copyright © 2012 Sébastien Lacau et al.  
  Address Laboratório de Mirmecologia, CEPLAC/CEPEC/SECEN, CP 07, km 22, Rodovia, Ilhéus-Itabuna, 45600-970 Itabuna, BA, Brazil  
  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
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  ISSN (down) 00332615 (Issn) ISBN Medium  
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  Notes Export Date: 28 March 2012; Source: Scopus; Art. No.: 926089; doi: 10.1155/2012/926089; Language of Original Document: English; Correspondence Address: Lacau, S.; Laboratório de Biossistemática Animal, Universidade Estadual Do Sudoeste da Bahia, UESB/DEBI, 45700-000 Itapetinga, BA, Brazil; email: slacau@cepec.gov.br Approved no  
  Call Number EcoFoG @ webmaster @ Serial 389  
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Author Freycon, V.; Krencker, M.; Schwartz, D.; Nasi, R.; Bonal, D. openurl 
  Title The impact of climate changes during the Holocene on vegetation in northern French Guiana Type Journal Article
  Year 2010 Publication Quaternary Research Abbreviated Journal Quat. Res.  
  Volume 73 Issue 2 Pages 220-225  
  Keywords Holocene; Vegetation change; French Guiana; Carbon isotope composition; Soil organic matter  
  Abstract The impact of climatic changes that occurred during the last glacial maximum and the Holocene on vegetation changes in the Amazon Basin and the Guiana Shield are still widely debated. The aim of our study was to investigate whether major changes in vegetation (i.e. transitions between rainforests and C-4 savannas) occurred in northern French Guiana during the Holocene. We measured variations in the delta C-13 of soil organic matter at eight sites now occupied by forest or savannah. The forest sites were selected to cover two regions (forest refugia and peneplains) which are thought to have experienced different intensities of disturbance during the latest Pleistocene and the Holocene. We found that none of the forest sites underwent major disturbances during the Holocene, i.e. they were not replaced by C-4 savannahs or C-4 forest savannahs for long periods. Our results thus suggest that tropical rainforests in northern French Guiana were resilient to drier climatic conditions during the Holocene. Nevertheless, geographical and vertical variations in the C-13 of SOM were compatible with minor changes in vegetation, variations in soil processes or in soil physical properties. (C) 2009 University of Washington. Published by Elsevier Inc. All rights reserved.  
  Address [Freycon, Vincent] CIRAD, UR Dynam Forestiere, F-34398 Montpellier 5, France, Email: vincent.freycon@cirad.fr  
  Corporate Author Thesis  
  Publisher ACADEMIC PRESS INC ELSEVIER SCIENCE Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 0033-5894 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000275246700007 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 66  
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Author Lipshutz, B.H.; Taft, B.R.; Abela, A.R.; Ghorai, S.; Krasovskiy, A.; Duplais, C. pdf  url
openurl 
  Title Catalysis in the service of green chemistry: Nobel prize-winning palladium-catalysed cross-couplings, run in water at room temperature Type Journal Article
  Year 2012 Publication Platinum Metals Review Abbreviated Journal Platinum Met. Rev.  
  Volume 56 Issue 2 Pages 62-74  
  Keywords  
  Abstract Palladium-catalysed cross-couplings, in particular Heck, Suzuki-Miyaura and Negishi reactions developed over three decades ago, are routinely carried out in organic solvents. However, alternative media are currently of considerable interest given an increasing emphasis on making organic processes 'greener'; for example, by minimising organic waste in the form of organic solvents. Water is the obvious leading candidate in this regard. Hence, this review focuses on the application of micellar catalysis, in which a 'designer' surfactant enables these award-winning coupling reactions to be run in water at room temperature. © 2012 Johnson Matthey.  
  Address UMR-CNRS Ecofog, Institut Pasteur de la Guyane, 23 Avenue Pasteur, 97306 Cayenne, France  
  Corporate Author Thesis  
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  ISSN (down) 00321400 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Cited By (since 1996): 1; Export Date: 15 May 2012; Source: Scopus; Coden: Ptmra; doi: 10.1595/147106712X629761; Language of Original Document: English; Correspondence Address: Lipshutz, B.H.; Department of Chemistry, University of California, Santa Barbara, CA 93106, United States; email: lipshutz@chem.ucsb.edu Approved no  
  Call Number EcoFoG @ webmaster @ Serial 400  
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Author Bréchet, L.; Ponton, S.; Alméras, T.; Bonal, D.; Epron, D. url  openurl
  Title Does spatial distribution of tree size account for spatial variation in soil respiration in a tropical forest? Type Journal Article
  Year 2011 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 347 Issue 1 Pages 293-303  
  Keywords Forest structure; Litterfall; Root mass; Soil respiration; Spatial variation; Tropical forest; aboveground production; forest inventory; litterfall; range size; size distribution; soil respiration; spatial distribution; spatial variation; stand dynamics; tropical forest  
  Abstract We explored the relationship between soil processes, estimated through soil respiration (Rsoil), and the spatial variation in forest structure, assessed through the distribution of tree size, in order to understand the determinism of spatial variations in Rsoil in a tropical forest. The influence of tree size was examined using an index (Ic) calculated for each tree as a function of (1) the trunk cross section area and (2) the distance from the measurement point. We investigated the relationships between Ic and litterfall, root mass and Rsoil, respectively. Strong significant relationships were found between Ic and both litterfall and root mass. Rsoil showed a large range of variations over the 1-ha experimental plot, from 1. 5 to 12. 6 gC m-2 d-1. The best relationship between Ic and Rsoil only explained 17% of the spatial variation in Rsoil. These results support the assumption that local spatial patterns in litter production and root mass depend on tree distribution in tropical forests. Our study also emphasizes the modest contribution of tree size distribution-which is mainly influenced by the presence of the biggest trees (among the large range size of the inventoried trees greater than 10 cm diameter at 1. 30 m above ground level or at 0. 5 m above the buttresses)-in explaining spatial variations in Rsoil. © 2011 Springer Science+Business Media B.V.  
  Address Nancy Université, Université Henri Poincaré, UMR 1137, Ecologie et Ecophysiologie Forestières, Faculté des Sciences, 54500 Vandoeuvre les Nancy, France  
  Corporate Author Thesis  
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  ISSN (down) 0032079x (Issn) ISBN Medium  
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  Notes Export Date: 21 October 2011; Source: Scopus; Coden: Plsoa; doi: 10.1007/s11104-011-0848-1; Language of Original Document: English; Correspondence Address: Bréchet, L.; INRA, UMR Ecologie des Forêts de Guyane, Campus Agronomique, BP 709, 97387 Kourou cedex, French Guiana; email: laetitiabrechet@yahoo.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 345  
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Author Van Langenhove, L.; Depaepe, T.; Vicca, S.; van den Berge, J.; Stahl, C.; Courtois, E.; Weedon, J.; Urbina, I.; Grau, O.; Asensio, D.; Peñuelas, J.; Boeckx, P.; Richter, A.; Van Der Straeten, D.; Janssens, I.A. pdf  url
doi  openurl
  Title Regulation of nitrogen fixation from free-living organisms in soil and leaf litter of two tropical forests of the Guiana shield Type Journal Article
  Year 2019 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume Issue Pages  
  Keywords Free-living nitrogen fixation; French Guiana; Molybdenum; Nutrients; Phosphorus; Tropical forest  
  Abstract Background and aims: Biological fixation of atmospheric nitrogen (N 2 ) is the main pathway for introducing N into unmanaged ecosystems. While recent estimates suggest that free-living N fixation (FLNF) accounts for the majority of N fixed in mature tropical forests, the controls governing this process are not completely understood. The aim of this study was to quantify FLNF rates and determine its drivers in two tropical pristine forests of French Guiana. Methods: We used the acetylene reduction assay to measure FLNF rates at two sites, in two seasons and along three topographical positions, and used regression analyses to identify which edaphic explanatory variables, including carbon (C), nitrogen (N), phosphorus (P) and molybdenum (Mo) content, pH, water and available N and P, explained most of the variation in FLNF rates. Results: Overall, FLNF rates were lower than measured in tropical systems elsewhere. In soils seasonal variability was small and FLNF rates differed among topographies at only one site. Water, P and pH explained 24% of the variation. In leaf litter, FLNF rates differed seasonally, without site or topographical differences. Water, C, N and P explained 46% of the observed variation. We found no regulatory role of Mo at our sites. Conclusions: Rates of FLNF were low in primary rainforest on poor soils on the Guiana shield. Water was the most important rate-regulating factor and FLNF increased with increasing P, but decreased with increasing N. Our results support the general assumption that N fixation in tropical lowland forests is limited by P availability. © 2019, The Author(s).  
  Address Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, 1090, Austria  
  Corporate Author Thesis  
  Publisher Springer International Publishing Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 0032079x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 868  
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Author Van Langenhove, L.; Depaepe, T.; Vicca, S.; van den Berge, J.; Stahl, C.; Courtois, E.; Weedon, J.; Urbina, I.; Grau, O.; Asensio, D.; Peñuelas, J.; Boeckx, P.; Richter, A.; Van Der Straeten, D.; Janssens, I.A. doi  openurl
  Title Regulation of nitrogen fixation from free-living organisms in soil and leaf litter of two tropical forests of the Guiana shield Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 450 Issue 1-2 Pages 93-110  
  Keywords Free-living nitrogen fixation; French Guiana; Molybdenum; Nutrients; Phosphorus; Tropical forest; acetylene; leaf litter; molybdenum; nitrogen fixation; nutrient cycling; phosphorus; rainforest; reduction; soil biota; soil carbon; soil nitrogen; soil water; topographic effect; tropical forest; French Guiana  
  Abstract Background and aims: Biological fixation of atmospheric nitrogen (N2) is the main pathway for introducing N into unmanaged ecosystems. While recent estimates suggest that free-living N fixation (FLNF) accounts for the majority of N fixed in mature tropical forests, the controls governing this process are not completely understood. The aim of this study was to quantify FLNF rates and determine its drivers in two tropical pristine forests of French Guiana. Methods: We used the acetylene reduction assay to measure FLNF rates at two sites, in two seasons and along three topographical positions, and used regression analyses to identify which edaphic explanatory variables, including carbon (C), nitrogen (N), phosphorus (P) and molybdenum (Mo) content, pH, water and available N and P, explained most of the variation in FLNF rates. Results: Overall, FLNF rates were lower than measured in tropical systems elsewhere. In soils seasonal variability was small and FLNF rates differed among topographies at only one site. Water, P and pH explained 24% of the variation. In leaf litter, FLNF rates differed seasonally, without site or topographical differences. Water, C, N and P explained 46% of the observed variation. We found no regulatory role of Mo at our sites. Conclusions: Rates of FLNF were low in primary rainforest on poor soils on the Guiana shield. Water was the most important rate-regulating factor and FLNF increased with increasing P, but decreased with increasing N. Our results support the general assumption that N fixation in tropical lowland forests is limited by P availability. © 2019, The Author(s).  
  Address Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, 1090, Austria  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 0032079x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 971  
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Author Urbina, I.; Grau, O.; Sardans, J.; Ninot, J.M.; Peñuelas, J. doi  openurl
  Title Encroachment of shrubs into subalpine grasslands in the Pyrenees changes the plant-soil stoichiometry spectrum Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume 448 Issue 1-2 Pages 37-53  
  Keywords Nutrient stocks; Plant strategy; Plant-soil stoichiometry; Shrub encroachment; Subalpine grassland succession; aboveground biomass; biogeochemical cycle; carbon sequestration; ectomycorrhiza; fungus; grass; nitrogen; nutrient uptake; shrub; soil-vegetation interaction; stoichiometry; subalpine environment; succession; Europe; Pyrenees; Fungi  
  Abstract Aims: Shrub encroachment has been reported over a large proportion of the subalpine grasslands across Europe and is expected to have an important impact on the biogeochemical cycle of these ecosystems. We investigated the stoichiometric changes in the plant-soil system along the succession (e.g. increase in encroachment from unencroached grassland to mature shrubland) at two contrasting sites in the Pyrenees. Methods: We analyzed the chemical composition (C, N,15N, P, K, Ca, Mg and Fe) in the soil and in the aboveground plant compartments (leaves, leaf-litter and stems) of the main herbaceous species and shrubs at three contrasting stages of the succession: unencroached grassland, young shrubland and mature shrubland. Results: The plant-soil stoichiometry spectrum differed between the successional stages. Shrub encroachment generally increased the concentration of C and Ca and the C:N ratio and often reduced to concentrations of N, P and K in the leaves and leaf-litter, while several soil nutrient concentrations (N, P, K Ca and Mg) decreased. The stocks of C, N, P, Ca, and Mg in the total aboveground biomass increased with encroachment. Conclusions: Shrub encroachment favored the dominance of long-lived species with low concentrations of N and P in the plant-soil compartments, high C:nutrient ratios in the aboveground biomass and increase the uptake of N through ericoid or ectomycorrhizal fungi. We highlight the role of shrubs in the sequestration of C and nutrients through the allocation to the aboveground biomass. The changes in plant-soil elemental composition and stocks suggest a slowdown of the biogeochemical cycles in the subalpine mountain areas where shrub encroachment occurred. © 2020, Springer Nature Switzerland AG.  
  Address Biodiversity Research Institute (IRBio) and Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Catalonia, Spain  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN (down) 0032079x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 983  
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