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Author Levionnois, Sébastien ; Ziegler, Camille ; Heuret, Patrick ; Jansen, Steven ; Stahl, Clément ; Calvet, Emma ; Goret, Jean-Yves ; Bonal, Damien ; Coste, Sabrina doi  openurl
  Title Is vulnerability segmentation at the leaf‑stem transition a drought resistance mechanism? A theoretical test with a trait‑based model for Neotropical canopy tree species Type Journal Article
  Year 2021 Publication (up) Annals of Forest Science Abbreviated Journal  
  Volume 78 Issue 4 Pages 78-87  
  Keywords Neotropics, bark, canopy, capacitance, drought, drought tolerance, embolism, leaves, models, transpiration, trees, tropical rain forests, xylem  
  Abstract Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stem. However, although it has been intensively investigated these past decades, the extent to which vulnerability segmentation promotes drought resistance is not well understood. Based on a trait-based model, this study theoretically supports that vulnerability segmentation enhances shoot desiccation time across 18 Neotropical tree species. CONTEXT: Leaf-stem vulnerability segmentation predicts lower xylem embolism resistance in leaves than stems thereby preserving expensive organs such as branches or the trunk. Although vulnerability segmentation has been intensively investigated these past decades to test its consistency across species, the extent to which vulnerability segmentation promotes drought resistance is not well understood. AIMS: We investigated the theoretical impact of the degree of vulnerability segmentation on shoot desiccation time estimated with a simple trait-based model. METHODS: We combined data from 18 tropical rainforest canopy tree species on embolism resistance of stem xylem (flow-centrifugation technique) and leaves (optical visualisation method). Measured water loss under minimum leaf and bark conductance, leaf and stem capacitance, and leaf-to-bark area ratio allowed us to calculate a theoretical shoot desiccation time (tcᵣᵢₜ). RESULTS: Large degrees of vulnerability segmentation strongly enhanced the theoretical shoot desiccation time, suggesting vulnerability segmentation to be an efficient drought resistance mechanism for half of the studied species. The difference between leaf and bark area, rather than the minimum leaf and bark conductance, determined the drastic reduction of total transpiration by segmentation during severe drought. CONCLUSION: Our study strongly suggests that vulnerability segmentation is an important drought resistance mechanism that should be better taken into account when investigating plant drought resistance and modelling vegetation. We discuss future directions for improving model assumptions with empirical measures, such as changes in total shoot transpiration after leaf xylem embolism.  
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  Publisher Springer Link Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 1034  
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Author Lang, G.; Marcon, E.; Puech, F. doi  openurl
  Title Distance-based measures of spatial concentration: introducing a relative density function Type Journal Article
  Year 2020 Publication (up) Annals of Regional Science Abbreviated Journal Ann. Reg. Sci.  
  Volume 64 Issue 2 Pages 243-265  
  Keywords Agglomeration; Aggregation; Economic geography; Point patterns; Spatial concentration; accuracy assessment; econometrics; economic activity; economic geography; industrial agglomeration; industrial location; location decision; spatial analysis; spatial distribution  
  Abstract For more than a decade, distance-based methods have been widely employed and constantly improved in spatial economics. These methods are a very useful tool for accurately evaluating the spatial distribution of economic activity. We introduce a new distance-based statistical measure for evaluating the spatial concentration of industries. The m function is the first relative density function to be proposed in economics. This tool supplements the typology of distance-based methods recently drawn up by Marcon and Puech (J Econ Geogr 3(4):409–428, 2003). By considering several simulated and real examples, we show the advantages and the limits of the m function for detecting spatial structures in economics. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.  
  Address RITM, Univ. Paris-Sud, Université Paris-Saclay and CREST, Sceaux, France  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 05701864 (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 976  
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Author Cachet, N.; Hoakwie, F.; Bertani, S.; Bourdy, G.; Deharo, E.; Stien, D.; Houel, E.; Gornitzka, H.; Fillaux, J.; Chevalley, S.; Valentin, A.; Jullian, V. openurl 
  Title Antimalarial Activity of Simalikalactone E, a New Quassinoid from Quassia amara L. (Simaroubaceae) Type Journal Article
  Year 2009 Publication (up) Antimicrobial Agents and Chemotherapy Abbreviated Journal Antimicrob. Agents Chemother.  
  Volume 53 Issue 10 Pages 4393-4398  
  Keywords  
  Abstract We report the isolation and identification of a new quassinoid named simalikalactone E (SkE), extracted from a widely used Amazonian antimalarial remedy made out of Quassia amara L. (Simaroubaceae) leaves. This new molecule inhibited the growth of Plasmodium falciparum cultured in vitro by 50%, in the concentration range from 24 to 68 nM, independently of the strain sensitivity to chloroquine. We also showed that this compound was able to decrease gametocytemia with a 50% inhibitory concentration sevenfold lower than that of primaquine. SkE was found to be less toxic than simalikalactone D (SkD), another antimalarial quassinoid from Q. amara, and its cytotoxicity on mammalian cells was dependent on the cell line, displaying a good selectivity index when tested on nontumorogenic cells. In vivo, SkE inhibited murine malaria growth of Plasmodium vinckei petteri by 50% at 1 and 0.5 mg/kg of body weight/day, by the oral or intraperitoneal routes, respectively. The contribution of quassinoids as a source of antimalarial molecules needs therefore to be reconsidered.  
  Address [Cachet, N.; Hoakwie, F.; Bourdy, G.; Deharo, E.; Chevalley, S.; Valentin, A.; Jullian, V.] Univ Toulouse, UPS, Lab Pharmacochim Subst Nat & Pharmacophores Redox, UMR 152, F-31062 Toulouse 9, France, Email: jullian@cict.fr  
  Corporate Author Thesis  
  Publisher AMER SOC MICROBIOLOGY Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0066-4804 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000270020600047 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 103  
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Author Seipke, R.F.; Barke, J.; Ruiz-Gonzalez, M.X.; Orivel, J.; Yu, D.W.; Hutchings, M.I. url  openurl
  Title Fungus-growing Allomerus ants are associated with antibiotic-producing actinobacteria Type Journal Article
  Year 2012 Publication (up) Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology Abbreviated Journal Antonie Van Leeuwenhoek Int. J. Gen. Mol. Microbiol.  
  Volume 101 Issue 2 Pages 443-447  
  Keywords Allomerus ants; Amycolatopsis; Ant-bacteria symbioses; Fungus-growing ants; Insect fungiculture; Streptomyces  
  Abstract Fungus-growing attine ants use natural-product antibiotics produced by mutualist actinobacteria as 'weedkillers' in their fungal gardens. Here we report for the first time that fungus-growing Allomerus ants, which lie outside the tribe Attini, are associated with antifungal-producing actinobacteria, which offer them protection against non-cultivar fungi isolated from their ant-plants. © 2011 Springer Science+Business Media B.V.  
  Address State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, China  
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  ISSN 00036072 (Issn) ISBN Medium  
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  Notes Export Date: 21 March 2012; Source: Scopus; Coden: Aljma; doi: 10.1007/s10482-011-9621-y; Language of Original Document: English; Correspondence Address: Hutchings, M.I.; School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom; email: m.hutchings@uea.ac.uk Approved no  
  Call Number EcoFoG @ webmaster @ Serial 385  
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Author Aimene, Y.; Dorville, R.; Omrane, A. url  openurl
  Title Optimal control for trees trunk diameter estimation in rain forest ecology Type Journal Article
  Year 2013 Publication (up) Applied Mathematical Sciences Abbreviated Journal  
  Volume 7 Issue 17-20 Pages 807-816  
  Keywords Missing data; Optimal control; Tree trunk diameter  
  Abstract We study the optimal control question for an important mechanical problem related to tree trunk diameter variation in tropical forest ecology where some data are missing. Within a cost function, the control problem is formulated with a mechanical model that requires boundary conditions tosolve all equations. We give a characterization of the optimal measurement function for the tree trunk problem.  
  Address Laboratoire CEREGMIA EA 2440, Université Antilles-Guyane, I.E.S.G Campus de Trou-Biran, Route de Baduel, 97337 Cayenne, French Guiana  
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  Notes Export Date: 21 February 2013; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 469  
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Author Schimann, H.; Joffre, R.; Roggy, J.C.; Lensi, R.; Domenach, A.M. openurl 
  Title Evaluation of the recovery of microbial functions during soil restoration using near-infrared spectroscopy Type Journal Article
  Year 2007 Publication (up) Applied Soil Ecology Abbreviated Journal Appl. Soil Ecol.  
  Volume 37 Issue 3 Pages 223-232  
  Keywords NIRS; microbial activities; respiration; denitrification; carbon; nitrogen; soil functioning; restoration  
  Abstract Microbial-based indicators, such as C and N contents or microbial functions involved in C and N cycles, are currently used to describe the status of soils in disturbed areas. Microbial functions are more accurate indicators but their measurement for studies at the ecosystem level remains problematical because of the huge spatial variability of these processes and, consequently, of the large number of soil samples which must be analyzed. Our goal was to test the capacity of near-infrared reflectance spectroscopy (NIRS) to predict respiration and denitrification but also carbon and nitrogen contents of soils submitted to various procedures of restoration. To achieve this objective, we took advantage of an experiment conducted on a reforestation system established after open-cast gold mining in French Guiana. In this experimental station, plantations of various ages and various soil textures were at our disposal. Our results showed that both plantations and soil texture had a strong impact on the recovery of soil functioning: carbon and nitrogen contents, respiration and denitrification increased with age of plantation and clay content. Calibrations were performed between spectral data and microbial-based indicators using partial least squares regression (PLS). The results showed that C and N contents were accurately predicted. Microbial functions were less precisely predicted with results more accurate on clayey soils than on sandy soils. In clayey soils, perturbed or restored soils and the year of plantation were discriminated very efficiently through principal component analyses of spectral signatures (over 80% of variance explained on the first two axes). Near-infrared spectroscopy may thus be extended to the prediction of functional soil parameters, but the capacity of this method must be strengthened by expending the databases with other soils in other contexts. The possibility of using NIRS provides many opportunities for understanding both the temporal dynamics and the spatial variability of the recovery of key microbial functions during soil restoration. (c) 2007 Elsevier B.V. All rights reserved.  
  Address UMR EcoFoG, Kourou 97387, French Guiana, Email: heidy.schimann@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 0929-1393 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000250668000006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 154  
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Author Maggia, Marie-Eugénie ; Decaëns, Thibaud ; Lapied, Emmanuel ; Dupont, Lise ; Roy, Virginie ; Schimann, Heidy ; Orivel, Jérome ; Murienne, Jérôme ; Baraloto, Christophier ; Cottenie, Karl ; Steinke, Dirk doi  openurl
  Title At each site its diversity: DNA barcoding reveals remarkable earthworm diversity in neotropical rainforests of French Guiana Type Journal Article
  Year 2021 Publication (up) Applied Soil Ecology Abbreviated Journal  
  Volume 164 Issue Pages 103932  
  Keywords DNA barcoding Tropical rainforest Community ecology Diversity level Sampling methods  
  Abstract Despite their recognized essential role in soil, earthworms in tropical environments are still understudied. The aim of this study was to re-evaluate the diversity at the regional scale, as well as to investigate the environmental and spatial drivers of earthworm communities. We sampled earthworm communities across a range of habitats at six localities in French Guiana using three different sampling methods. We generated 1675 DNA barcodes and combined them with data from a previous study. Together, all sequences clustered into 119 MOTUs which were used as proxy to assess species richness. Only two MOTUs were common between the six localities and 20.2% were singletons, showing very high regional species richness and a high number of rare species. A canonical redundancy analysis was used to identify key drivers of the earthworm community composition. The RDA results and beta-diversity calculations both show strong species turnover and a strong spatial effect, resulting from dispersal limitations that are responsible for the current community composition. Sampling in different microhabitats allowed the discovery of 23 MOTUs that are exclusively found in decaying trunks and epiphytes, highlighting hidden diversity of earthworms outside of soil.  
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  Publisher Elsevier B.V. Place of Publication Editor  
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  ISSN 0929-1393 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 1055  
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Author Herault, B.; Honnay, O. openurl 
  Title Using life-history traits to achieve a functional classification of habitats Type Journal Article
  Year 2007 Publication (up) Applied Vegetation Science Abbreviated Journal Appl. Veg. Sci.  
  Volume 10 Issue 1 Pages 73-80  
  Keywords forest connectivity; functional group; habitat typology; land-use history; riverine forest; species functional unity  
  Abstract Question: To establish a habitat classification based on functional group co-occurrence that may help the drawing up of conservation plans. Location: Riverine forest fragments in the Grand-duche de Luxembourg, Europe. Methods: Forest fragments were surveyed for their abundance of vascular plants. These were clustered into emergent groups according to 14 life-traits related to plant dispersal, establishment and persistence. Forest fragments were classified according to similar distribution of the identified emergent groups. Environmental factors were related to the emergent group richness in each forest type using generalized linear models. Results: Contrary to former species centred classifications, only two groups of forests, each with clearly different emergent group composition and conservation requirements, were detected: (1) swamp forests characterized by anemogamous perennials, annuals and hydrochorous perennials and (2) moist forests characterized by barochorous perennials, small geophytes and zoochorous phanerophytes. From a conservation point of view, priority should be given to large swamp forest with intact flooding regimes. This is in accordance with the high wind and water dispersal capacities of their typical emergent groups. For the moist forests, conservation priorities should be high forest connectivity and historical continuity since dispersal and establishment of their characteristic emergent groups are highly limited. Conclusions: The described methodology, situated at an intermediate integration level between the individual species and whole community descriptors, takes advantage of both conservation plans built for single species and the synthetic power of broad ecological measures.  
  Address Univ Liege, Dept Environm Sci & Management, B-6700 Arlon, Belgium, Email: bruno.herault@cirad.fr  
  Corporate Author Thesis  
  Publisher OPULUS PRESS UPPSALA AB Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN 1402-2001 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000245934700009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 218  
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Author Sist, P.; Rutishauser, E.; Peña-Claros, M.; Shenkin, A.; Herault, B.; Blanc, L.; Baraloto, C.; Baya, F.; Benedet, F.; da Silva, K.E.; Descroix, L.; Ferreira, J.N.; Gourlet-Fleury, S.; Guedes, M.C.; Bin Harun, I.; Jalonen, R.; Kanashiro, M.; Krisnawati, H.; Kshatriya, M.; Lincoln, P.; Mazzei, L.; Medjibé, V.; Nasi, R.; d'Oliveira, M.V.N.; de Oliveira, L.C.; Picard, N.; Pietsch, S.; Pinard, M.; Priyadi, H.; Putz, F.E.; Rodney, K.; Rossi, V.; Roopsind, A.; Ruschel, A.R.; Shari, N.H.Z.; Rodrigues de Souza, C.; Susanty, F.H.; Sotta, E.D.; Toledo, M.; Vidal, E.; West, T.A.P.; Wortel, V.; Yamada, T. url  openurl
  Title The Tropical managed forests Observatory: A research network addressing the future of tropical logged forests Type Journal Article
  Year 2015 Publication (up) Applied Vegetation Science Abbreviated Journal Appl. Veg. Sci.  
  Volume 18 Issue 1 Pages 171-174  
  Keywords Biodiversity; Carbon cycle; Climate change; Ecosystem resilience; Logging; Silviculture; Tropical forests; Tropical managed forests Observatory  
  Abstract While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921 ha of forest inventories. To improve our knowledge of the resilience of tropical logged forests, 20 research institutes are now collaborating on studies on the effects of logging on forest structure, productivity, biodiversity and carbon fluxes at large spatial and temporal scales. These studies are carried out in the Tropical managed Forests Observatory (TmFO), an international network including 24 sites and 490 permanent sample plots across South America, Africa and South East Asia.  
  Address Duke University's Nicholas School of the EnvironmentNorth Carolina, United States  
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  Publisher Wiley-Blackwell Place of Publication Editor  
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  ISSN 14022001 (Issn) ISBN Medium  
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  Notes Export Date: 12 December 2014; Coden: Avscf; Correspondence Address: Sist, P.; Cirad, UR 105 TA/10CFrance Approved no  
  Call Number EcoFoG @ webmaster @ Serial 571  
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Author Dézerald, O.; Leroy, C.; Corbara, B.; Dejean, A.; Talaga, S.; Céréghino, R. url  doi
openurl 
  Title Tank bromeliads sustain high secondary production in neotropical forests Type Journal Article
  Year 2018 Publication (up) Aquatic Sciences Abbreviated Journal  
  Volume 80 Issue 14 Pages  
  Keywords Biomass turnover; Epiphytes; Food webs; Functional traits; Invertebrates; Rainforests  
  Abstract In neotropical landscapes, a substantial fraction of the still waters available is found within tank bromeliads, plants which hold a few milliliters to several litres of rainwater within their leaf axils. The bromeliad ecosystem is integrated into the functioning of rainforest environments, but no study has ever estimated the secondary production, nor the biomass turnover rates of bromeliad macroinvertebrates in relation to other functional traits. We estimated secondary production at invertebrate population to metacommunity level in bromeliads of French Guiana. Coleoptera, Diptera and Crustacea with traits that confer resistance to drought had lower biomass turnover, longer generation times, and slower individual growth than species without particular resistance traits, suggesting convergent life history strategies in phylogenetically distant species. Detritivores and predators accounted for 87% and 13% of the overall annual production, respectively, but had similar production to biomass ratios. An average bromeliad sustained a production of 23.93 g dry mass m−2 year−1, a value which exceeds the medians of 5.0–14.8 g DM m−2 year−1 for lakes and rivers worldwide. Extrapolations to the total water volumes held by bromeliads at our field site yielded secondary production estimates of 226.8 ± 32.5 g DM ha−1 year−1. We conclude that the ecological role of tank bromeliads in neotropical rainforests may be as important as that of other freshwater ecosystems. © 2018, Springer International Publishing AG, part of Springer Nature.  
  Address Université de Guyane, UMR Écologie des Forêts de Guyane (AgroParisTech, CIRAD, CNRS, INRA, Université des Antilles), Campus Agronomique, BP 316, Kourou cedex, France  
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  Notes Export Date: 29 January 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 790  
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