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Author Rowland, L.; Hill, T.C.; Stahl, C.; Siebicke, L.; Burban, B.; Zaragoza-Castells, J.; Ponton, S.; Bonal, D.; Meir, P.; Williams, M.
Title Evidence for strong seasonality in the carbon storage and carbon use efficiency of an Amazonian forest Type Journal Article
Year 2014 Publication Global Change Biology Abbreviated Journal Global Change Biol.
Volume 20 Issue (up) 3 Pages 979-991
Keywords Carbon use efficiency; Dalec; Data assimilation; Ecosystem respiration; French Guiana; Seasonal carbon fluxes; Tropical forest
Abstract The relative contribution of gross primary production and ecosystem respiration to seasonal changes in the net carbon flux of tropical forests remains poorly quantified by both modelling and field studies. We use data assimilation to combine nine ecological time series from an eastern Amazonian forest, with mass balance constraints from an ecosystem carbon cycle model. The resulting analysis quantifies, with uncertainty estimates, the seasonal changes in the net carbon flux of a tropical rainforest which experiences a pronounced dry season. We show that the carbon accumulation in this forest was four times greater in the dry season than in the wet season and that this was accompanied by a 5% increase in the carbon use efficiency. This seasonal response was caused by a dry season increase in gross primary productivity, in response to radiation and a similar magnitude decrease in heterotrophic respiration, in response to drying soils. The analysis also predicts increased carbon allocation to leaves and wood in the wet season, and greater allocation to fine roots in the dry season. This study demonstrates implementation of seasonal variations in parameters better enables models to simulate observed patterns in data. In particular, we highlight the necessity to simulate the seasonal patterns of heterotrophic respiration to accurately simulate the net carbon flux seasonal tropical forest. © 2013 The Authors Global Change Biology Published by John Wiley & Sons Ltd.
Address Research School of Biology, Division of Plant Sciences, Australian National University, Canberra, ACT, 0200, Australia
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ISSN 13541013 (Issn) ISBN Medium
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Notes Cited By (since 1996):1; Export Date: 24 February 2014; Source: Scopus; Language of Original Document: English; Correspondence Address: Rowland, L.; School of Geosciences, University of Edinburgh, Edinburgh, EH9 3JN, United Kingdom; email: lucy.rowland@ed.ac.uk; Funding Details: FT110100457, ARC, Australian Research Council; Funding Details: NE/F002149/1, NERC, Natural Environment Research Council; Funding Details: NE/J011002/1, NERC, Natural Environment Research Council Approved no
Call Number EcoFoG @ webmaster @ Serial 529
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Author Marcon, E.; Scotti, I.; Herault, B.; Rossi, V.; Lang, G.
Title Generalization of the partitioning of Shannon diversity Type Journal Article
Year 2014 Publication PLoS ONE Abbreviated Journal PLoS ONE
Volume 9 Issue (up) 3 Pages e90289
Keywords
Abstract Traditional measures of diversity, namely the number of species as well as Simpson's and Shannon's indices, are particular cases of Tsallis entropy. Entropy decomposition, i.e. decomposing gamma entropy into alpha and beta components, has been previously derived in the literature. We propose a generalization of the additive decomposition of Shannon entropy applied to Tsallis entropy. We obtain a self-contained definition of beta entropy as the information gain brought by the knowledge of each community composition. We propose a correction of the estimation bias allowing to estimate alpha, beta and gamma entropy from the data and eventually convert them into true diversity. We advocate additive decomposition in complement of multiplicative partitioning to allow robust estimation of biodiversity. © 2014 Marcon et al.
Address INRA, UMR 518 Math. Info. Appli, Paris, France
Corporate Author Thesis
Publisher Public Library of Science Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 19326203 (Issn) ISBN Medium
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Notes Export Date: 18 April 2014; Source: Scopus; Art. No.: e90289; Coden: Polnc; Language of Original Document: English Approved no
Call Number EcoFoG @ webmaster @ Serial 538
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Author Hamadi, A.; Borderies, P.; Albinet, C.; Koleck, T.; Villard, L.; Ho Tong Minh, D.; Le Toan, T.; Burban, B.
Title Temporal coherence of tropical forests at P-band: Dry and rainy seasons Type Journal Article
Year 2015 Publication IEEE Geoscience and Remote Sensing Letters Abbreviated Journal IEEE Geosci. Remote Sens. Lett.
Volume 12 Issue (up) 3 Pages 557-561
Keywords Biomass mission; forest scattering; ground-based experiment; P-band; range impulse response; temporal coherence
Abstract In this letter, the temporal coherence of tropical forest scattering at P-band is addressed by means of a ground-based experiment. The study is based on the TropiScat campaign in French Guiana, designed to support the Biomass mission, which will be the ESA 7th Earth Explorer mission. For Biomass, temporal coherence is a crucial parameter for coherent processing of polarimetric synthetic aperture radar (SAR) interferometry and SAR tomography in repeat-pass acquisitions. During the experiment, data were continuously collected for six months during both the rainy and dry seasons. For the rain-free days in both seasons, the coherence exhibits a daily cycle showing a high decorrelation during daytime, which is likely due to motion in the canopy. Up to a 20-day baseline, the coherence is much higher in the dry season than in the rainy season (> 0.8). From 20 to 40 days, it presents the same order of magnitude in both seasons [0.6, 0.7]. For larger temporal baselines, it becomes lower in the dry season. The results can be used to assess the long-term coherence of repeat-pass observations over a tropical forest. However, an extension of this study to several years and over other forest spots would be necessary to draw more general conclusions.
Address EcoFogKourou, France
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Publisher Institute of Electrical and Electronics Engineers Inc. Place of Publication Editor
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ISSN 1545598x (Issn) ISBN Medium
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Notes Export Date: 21 October 2014; Correspondence Address: Hamadi, A.; Centre d'Etudes Spatiales de la BiosphèreFrance; Funding Details: ESA, European Space Agency Approved no
Call Number EcoFoG @ webmaster @ Serial 563
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Author Wagner, F.; Rossi, V.; Aubry-Kientz, M.; Bonal, D.; Dalitz, H.; Gliniars, R.; Stahl, C.; Trabucco, A.; Herault, B.
Title Pan-tropical analysis of climate effects on seasonal tree growth Type Journal Article
Year 2014 Publication PLoS ONE Abbreviated Journal PLoS ONE
Volume 9 Issue (up) 3 Pages e92337
Keywords
Abstract Climate models predict a range of changes in tropical forest regions, including increased average temperatures, decreased total precipitation, reduced soil moisture and alterations in seasonal climate variations. These changes are directly related to the increase in anthropogenic greenhouse gas concentrations, primarily CO2. Assessing seasonal forest growth responses to climate is of utmost importance because woody tissues, produced by photosynthesis from atmospheric CO2, water and light, constitute the main component of carbon sequestration in the forest ecosystem. In this paper, we combine intra-annual tree growth measurements from published tree growth data and the corresponding monthly climate data for 25 pan-tropical forest sites. This meta-analysis is designed to find the shared climate drivers of tree growth and their relative importance across pan-tropical forests in order to improve carbon uptake models in a global change context. Tree growth reveals significant intra-annual seasonality at seasonally dry sites or in wet tropical forests. Of the overall variation in tree growth, 28.7% was explained by the site effect, i.e. the tree growth average per site. The best predictive model included four climate variables: precipitation, solar radiation (estimated with extrasolar radiation reaching the atmosphere), temperature amplitude and relative soil water content. This model explained more than 50% of the tree growth variations across tropical forests. Precipitation and solar radiation are the main seasonal drivers of tree growth, causing 19.8% and 16.3% of the tree growth variations. Both have a significant positive association with tree growth. These findings suggest that forest productivity due to tropical tree growth will be reduced in the future if climate extremes, such as droughts, become more frequent. © 2014 Wagner et al.
Address Division of Forest, Nature, and Landscape, KU Leuven, Leuven, Belgium
Corporate Author Thesis
Publisher Public Library of Science Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 19326203 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 30 May 2014; Source: Scopus; Art. No.: e92337; Coden: Polnc; Language of Original Document: English Approved no
Call Number EcoFoG @ webmaster @ Serial 543
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Author Menzel, F.; Orivel, J.; Kaltenpoth, M.; Schmitt, T.
Title What makes you a potential partner? Insights from convergently evolved ant-ant symbioses Type Journal Article
Year 2014 Publication Chemoecology Abbreviated Journal Chemoecology
Volume 24 Issue (up) 3 Pages 105-119
Keywords Aggression; Coevolution; Cuticular hydrocarbons; Formicidae; Interspecific association; Parabiosis; Recognition cues
Abstract Mutualistic, commensalistic or parasitic interactions are unevenly distributed across the animals and plants: in certain taxa, such interspecific associations evolved more often than in others. Within the ants, associations between species of the genera Camponotus and Crematogaster evolved repeatedly and include trail-sharing associations, where two species share foraging trails, and parabioses, where two species share a nest without aggression. Camponotus and Crematogaster may possess life-history traits that favour the evolution of associations. To identify which traits are affected by the association, we investigated a neotropical parabiosis of Ca. femoratus and Cr. levior and compared it to a paleotropical parabiosis and a trail-sharing association. The two neotropical species showed altered cuticular hydrocarbon profiles compared to non-parabiotic species accompanied by low levels of interspecific aggression. Both species occurred in two chemically distinct types. Camponotus followed artificial trails of Crematogaster pheromones, but not vice versa. The above traits were also found in the paleotropical parabiosis, and the trail-following results match those of the trail-sharing association. In contrast to paleotropical parabioses, however, Camponotus was dominant, had a high foraging activity and often fought against Crematogaster over food resources. We suggest three potential preadaptations for parabiosis. First, Crematogaster uses molecules as trail pheromones, which can be perceived by Camponotus, too. Second, nests of Camponotus are an important benefit to Crematogaster and may create a selection pressure for the latter to tolerate Camponotus. Third, there are parallel, but unusual, shifts in cuticular hydrocarbon profiles between neotropics and paleotropics, and between Camponotus and Crematogaster. © 2014 Springer Basel.
Address Department of Animal Ecology and Tropical Biology Biocentre, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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Publisher Birkhauser Verlag AG Place of Publication Editor
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ISSN 09377409 (Issn) ISBN Medium
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Notes Export Date: 10 June 2014; Coden: Chmoe; Correspondence Address: Menzel, F.; Department of Evolutionary Biology, Institute of Zoology, University of Mainz, Johannes-von-Müller-Weg 6, 55099 Mainz, Germany; email: menzelf@uni-mainz.de Approved no
Call Number EcoFoG @ webmaster @ Serial 547
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Author Turcotte, M.M.; Thomsen, C.J.M.; Broadhead, G.T.; Fine, P.V.A.; Godfrey, R.M.; Lamarre, G.P.A.; Meyer, S.T.; Richards, L.A.; Johnson, M.T.J.
Title Percentage leaf herbivory across vascular plant species Type Journal Article
Year 2014 Publication Ecology Abbreviated Journal Ecology
Volume 95 Issue (up) 3 Pages 788-788
Keywords
Abstract Herbivory is viewed as a major driver of plant evolution and the most important energy pathway from plants to higher trophic levels. Therefore, understanding patterns of herbivory on plants remains a key focus in evolution and ecology. The evolutionary impacts of leaf herbivory include altering plant fitness, local adaptation, the evolution of defenses, and the diversification of plants as well as natural enemies. Leaf herbivory also impacts ecological processes such as plant productivity, community composition, and ecosystem nutrient cycling. Understanding the impact of herbivory on these ecological and evolutionary processes requires species-specific, as opposed to community-level, measures of herbivory. In addition, species-specific data enables the use of modern comparative methods to account for phylogenetic non-independence. Although hundreds of studies have measured natural rates of leaf consumption, we are unaware of any accessible compilation of these data. We created such a data set to provide the raw data needed to test general hypotheses relating to plant?herbivore interactions and to test the influence of biotic and abiotic factors on herbivory rates across large spatial scales. A large repository will make this endeavor more efficient and robust. In total, we compiled 2641 population-level measures for either annual or daily rates of leaf herbivory across 1145 species of vascular plants collected from 189 studies. All damage measures represent natural occurrences of herbivory that span numerous angiosperm, gymnosperm, and fern species. To enable researchers to explore the causes of variation in herbivory and how these might interact, we added information about the study sites including: geolocation, climate classification, habitat descriptions (e.g., seashore, grassland, forest, agricultural fields), and plant trait information concerning growth form and duration (e.g., annual vs. perennial). We also included extensive details of the methodology used to measure leaf damage, including seasons and months of sampling, age of leaves, and the method used to estimate percentage area missing. We anticipate that these data will make it possible to test important hypotheses in the plant?herbivore literature, including the plant apparency hypothesis, the latitudinal-herbivory defense hypothesis, the resource availability hypothesis, and the macroevolutionary escalation of defense hypothesis.
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Publisher Ecological Society of America Place of Publication Editor
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ISSN 0012-9658 ISBN Medium
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Notes doi: 10.1890/13-1741.1 Approved no
Call Number EcoFoG @ webmaster @ Serial 575
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Author Chang, S.-S.; Quignard, F.; Alméras, T.; Clair, B.
Title Mesoporosity changes from cambium to mature tension wood: A new step toward the understanding of maturation stress generation in trees Type Journal Article
Year 2015 Publication New Phytologist Abbreviated Journal New Phytologist
Volume 205 Issue (up) 3 Pages 1277-1287
Keywords Cell wall maturation; Maturation stress; Mesoporosity; Poplar (Populus deltoides × P. nigra); Tension wood
Abstract In order to progress in the understanding of mechanical stress generation, the mesoporosity of the cell wall and its changes during maturation of poplar (Populus deltoides × P. nigra) tension wood (TW) and opposite wood (OW) were measured by nitrogen adsorption-desorption. Variations in the thickness of the gelatinous layer (G-layer) were also measured to clarify whether the mesoporosity change simultaneously with the deposition of the G-layer in TW. Results show that mesoporous structures of TW and OW were very similar in early development stages before the deposition of G-layers. With the formation of the S2 layer in OW and the G-layer in TW, the mesopore volume decreased steeply before lignification. However, in TW only, the decrease in mesopore volume occurred together with the pore shape change and a progressive increase in pore size. The different patterns observed in TW revealed that pores from G-layers appear with a different shape compared to those of the compound middle lamella, and their size increases during the maturation process until stabilising in mature wood. This observation strongly supports the hypothesis of the swelling of the G-layer matrix during maturation as the origin of maturation stress in poplar tension wood.
Address CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 701Kourou, France
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Notes Export Date: 28 January 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 581
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Author Marcon, E.; Herault, B.
Title Decomposing phylodiversity Type Journal Article
Year 2015 Publication Methods in Ecology and Evolution Abbreviated Journal Methods in Ecology and Evolution
Volume 6 Issue (up) 3 Pages 333-339
Keywords Biodiversity; Entropy; Functional diversity; Phylogenetic diversity
Abstract Measuring functional or phylogenetic diversity is the object of an active literature. The main issues to address are relating measures to a clear conceptual framework, allowing unavoidable estimation-bias correction and decomposing diversity along spatial scales. We provide a general mathematical framework to decompose measures of species-neutral, phylogenetic or functional diversity into α and β components. We first unify the definitions of phylogenetic and functional entropy and diversity as a generalization of HCDT entropy and Hill numbers when an ultrametric tree is considered. We then derive the decomposition of diversity. We propose a bias correction of the estimates allowing meaningful computation from real, often undersampled communities. Entropy can be transformed into true diversity, that is an effective number of species or communities. Estimators of α- and β-entropy, phylogenetic and functional entropy are provided. Proper definition and estimation of diversity is the first step towards better understanding its underlying ecological and evolutionary mechanisms. © 2015 British Ecological Society.
Address Cirad, UMR EcoFoG, BP 709Kourou, French Guiana
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Notes Export Date: 31 March 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 590
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Author Vedel, V.; Cerdan, A.; Martinez, Q.; Baraloto, C.; Petitclerc, F.; Orivel, J.; Fortunel, C.
Title Day-time vs. Night-time sampling does not affect estimates of spider diversity across a land use gradient in the Neotropics Type Journal Article
Year 2015 Publication Journal of Arachnology Abbreviated Journal Journal of Arachnology
Volume 43 Issue (up) 3 Pages 413-416
Keywords Araneae; community; day; night; sampling protocol
Abstract To obtain a reliable description of spider communities, robust sampling protocols are crucial. However, it remains unclear if descriptions of spider communities in tropical habitats require both day and night sampling. Here we tested whether sampling both day and night in high and low vegetation strata would lead to better diversity estimates of spider communities than sampling at only one period of the day. We determined spider taxonomic diversity in a network of 12 plots in French Guiana along a vegetation gradient. We found high alpha diversity of spiders as expected for a tropical area at every site. We showed strong differences in spider alpha and beta diversity between high and low vegetation strata, while they were similar between day and night sampling. Our results suggest that collecting spiders at only one period is sufficient to describe the diversity of spider communities across land use types in the neotropics. © The American Arachnological Society.
Address Department of Biology, University of Maryland, College Park, MD, United States
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Notes Export Date: 10 December 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 641
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Author Bossu, J.; Beauchene, J.; Estevez, Y.; Duplais, C.; Clair, B.
Title New insights on wood dimensional stability influenced by secondary metabolites: The case of a fast-growing tropical species Bagassa guianensis aubl Type Journal Article
Year 2016 Publication PLoS ONE Abbreviated Journal PLoS ONE
Volume 11 Issue (up) 3 Pages e0150777
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Abstract Challenging evaluation of tropical forest biodiversity requires the reporting of taxonomic diversity but also the systematic characterization of wood properties in order to discover new promising species for timber industry. Among wood properties, the dimensional stability is regarded as a major technological characteristic to validate whether a wood species is adapted to commercial uses. Cell structure and organization are known to influence the drying shrinkage making wood density and microfibrils angle markers of choice to predict wood dimensional stability. On the contrary the role of wood extractive content remains unclear. This work focuses on the fast-growing tropical species Bagassa guianensis and we report herein a correlation between heartwood drying shrinkage and extractive content. Chemical extractions and shrinkage experiments were performed on separate wood twin samples to better evaluate correctly how secondary metabolites influence the wood shrinkage behaviour. Extractive content were qualitatively and quantitatively analysed using HPLC and NMR spectroscopy. We found that B guianensis heartwood has a homogeneous low shrinkage along its radius that could not be explained only by its basic density. In fact the low drying shrinkage is correlated to the high extractive content and a corrected model to improve the prediction of wood dimensional stability is presented. Additionally NMR experiments conducted on sapwood and heartwood extracts demonstrate that secondary metabolites biosynthesis occurs in sapwood thus revealing B. guianensis as a Juglans-Type heartwood formation. This work demonstrates that B. guianensis, a fast-growing species associated with high durability and high dimensional stability, is a good candidate for lumber production and commercial purposes. © 2016 Bossu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Address Cirad, UMR EcoFoG, AgroParisTech, CNRS, INRA, Université des Antilles, Université de Guyane, Kourou, France
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Notes Export Date: 18 April 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 673
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