| Records |
| Author |
Soong, J.L.; Marañon-Jimenez, S.; Cotrufo, M.F.; Boeckx, P.; Bodé, S.; Guenet, B.; Peñuelas, J.; Richter, A.; Stahl, C.; Verbruggen, E.; Janssens, I.A. |
| Title |
Soil microbial CNP and respiration responses to organic matter and nutrient additions: Evidence from a tropical soil incubation |
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Journal Article |
| Year |
2018 |
Publication |
Soil Biology and Biochemistry |
Abbreviated Journal |
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Volume  |
122 |
Issue |
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Pages |
141-149 |
| Keywords |
13c; Cnp; Microbial stoichiometry; Priming; Soil respiration; Tropics |
| Abstract |
Soil nutrient availability has a strong influence on the fate of soil carbon (C) during microbial decomposition, contributing to Earth's C balance. While nutrient availability itself can impact microbial physiology and C partitioning between biomass and respiration during soil organic matter decomposition, the availability of labile C inputs may mediate the response of microorganisms to nutrient additions. As soil organic matter is decomposed, microorganisms retain or release C, nitrogen (N) or phosphorus (P) to maintain a stoichiometric balance. Although the concept of a microbial stoichiometric homeostasis has previously been proposed, microbial biomass CNP ratios are not static, and this may have very relevant implications for microbial physiological activities. Here, we tested the hypothesis that N, P and potassium (K) nutrient additions impact C cycling in a tropical soil due to microbial stoichiometric constraints to growth and respiration, and that the availability of energy-rich labile organic matter in the soil (i.e. leaf litter) mediates the response to nutrient addition. We incubated tropical soil from French Guiana with a 13C labeled leaf litter addition and with mineral nutrient additions of +K, +N, +NK, +PK and +NPK for 30 days. We found that litter additions led to a ten-fold increase in microbial respiration and a doubling of microbial biomass C, along with greater microbial N and P content. We found some evidence that P additions increased soil CO2 fluxes. Additionally, we found microbial biomass CP and NP ratios varied more widely than CN in response to nutrient and organic matter additions, with important implications for the role of microorganisms in C cycling. The addition of litter did not prime soil organic matter decomposition, except in combination with +NK fertilization, indicating possible P-mining of soil organic matter in this P-poor tropical soil. Together, these results point toward an ultimate labile organic substrate limitation of soil microorganisms in this tropical soil, but also indicate a complex interaction between C, N, P and K availability. This highlights the difference between microbial C cycling responses to N, P, or K additions in the tropics and explains why coupled C, N and P cycle modeling efforts cannot rely on strict microbial stoichiometric homeostasis as an underlying assumption. |
| Address |
INRA, UMR Ecology of Guiana Forests (Ecofog), AgroParisTech, Cirad, CNRS, Université de Guyane, Université des Antilles, Kourou, France |
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Export Date: 16 May 2018 |
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EcoFoG @ webmaster @ |
Serial |
804 |
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Soudani, K.; Hmimina, G.; Delpierre, N.; Pontailler, J.-Y.; Aubinet, M.; Bonal, D.; Caquet, B.; de Grandcourt, A.; Burban, B.; Flechard, C.; Guyon, D.; Granier, A.; Gross, P.; Heinesh, B.; Longdoz, B.; Loustau, D.; Moureaux, C.; Ourcival, J.-M.; Rambal, S.; Saint André, L.; Dufrêne, E. |
| Title |
Ground-based Network of NDVI measurements for tracking temporal dynamics of canopy structure and vegetation phenology in different biomes |
Type |
Journal Article |
| Year |
2012 |
Publication |
Remote Sensing of Environment |
Abbreviated Journal |
Remote Sens. Environ. |
| Volume |
123 |
Issue |
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Pages |
234-245 |
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Crops; Evergreen and deciduous forests; Ground-based NDVI; Herbaceous savanna; NDVI time-series; Phenology; Tropical rain forest |
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Plant phenology characterises the seasonal cyclicity of biological events such as budburst, flowering, fructification, leaf senescence and leaf fall. These biological events are genetically pre-determined but also strongly modulated by climatic conditions, particularly temperature, daylength and water availability. Therefore, the timing of these events is considered as a good indicator of climate change impacts and as a key parameter for understanding and modelling vegetation-climate interactions. In situ observations, empirical or bioclimatic models and remotely sensed time-series data constitute the three possible ways for monitoring the timing of plant phenological events. Remote sensing has the advantage of being the only way of surface sampling at high temporal frequency and, in the case of satellite-based remote sensing, over large regions. Nevertheless, exogenous factors, particularly atmospheric conditions, lead to some uncertainties on the seasonal course of surface reflectance and cause bias in the identification of vegetation phenological events. Since 2005, a network of forest and herbaceous sites has been equipped with laboratory made NDVI sensors to monitor the temporal dynamics of canopy structure and phenology at an intra-daily time step. In this study, we present recent results obtained in several contrasting biomes in France, French Guiana, Belgium and Congo. These sites represent a gradient of vegetation ecosystems: the main evergreen and deciduous forest ecosystems in temperate climate region, an evergreen tropical rain forest in French Guiana, an herbaceous savanna ecosystem in Congo, and a succession of three annual crops in Belgium. In this paper, (1) we provide an accurate description of the seasonal dynamics of vegetation cover in these different ecosystems (2) we identify the most relevant remotely sensed markers from NDVI time-series for determining the dates of the main phenological events that characterize these ecosystems and (3) we discuss the relationships between temporal canopy dynamics and climate factors. In addition to its importance for phenological studies, this ground-based Network of NDVI measurement provides data needed for the calibration and direct validation of satellite observations and products. © 2012 Elsevier Inc. |
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INRA, Unité Biogéochimie des Ecosystèmes Forestiers, Champenoux, France |
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00344257 (Issn) |
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Export Date: 16 August 2012; Source: Scopus; Coden: Rseea; doi: 10.1016/j.rse.2012.03.012; Language of Original Document: English; Correspondence Address: Soudani, K.; University of Paris-Sud, CNRS, AgroParisTech, Laboratoire Ecologie Systematique et Evolution, Faculty of Sciences of OrsayFrance; email: kamel.soudani@u-psud.fr |
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EcoFoG @ webmaster @ |
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422 |
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Schmidt, M.; Dejean, A. |
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A dolichoderine ant that constructs traps to ambush prey collectively: convergent evolution with a myrmicine genus |
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Journal Article |
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2018 |
Publication |
Biological Journal of the Linnean Society |
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124 |
Issue |
1 |
Pages |
41-46 |
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Azteca brevis Forel, a dolichoderine ant species, builds along the branches of its host plant galleries that bear numerous holes slightly wider than a worker’s head. We noted that the workers hide, mandibles open, beneath different holes, waiting for arthropod prey to walk by or alight. They seize the extremities of these arthropods and pull backwards, immobilizing the prey, which is then spreadeagled and later carved up or pulled into a gallery before being carved up. The total duration of the capture ranges from a few minutes to several hours. This ambush group hunting permits the capture of insects of a wide range of sizes, with the largest being 48.71 times heavier than the workers, something that we compared with other cases of group hunting by ants and trap use by other arthropods. A convergence with myrmicine ants of the genus Allomerus is shown. Thus, this study also shows that the genus Azteca presents the largest panel of group hunting strategies by ants and that there is polyethism related to polymorphism, as hunting workers are larger than their nestmates. We concluded that these gallery-shaped traps correspond to the notion of ‘extended phenotype’. |
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0024-4066 |
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10.1093/biolinnean/bly028 |
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EcoFoG @ webmaster @ |
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822 |
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Vincent, G.; Sabatier, D.; Blanc, L.; Chave, J.; Weissenbacher, E.; Pélissier, R.; Fonty, E.; Molino, J.-F.; Couteron, P. |
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Accuracy of small footprint airborne LiDAR in its predictions of tropical moist forest stand structure |
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Journal Article |
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2012 |
Publication |
Remote Sensing of Environment |
Abbreviated Journal |
Remote Sens. Environ. |
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125 |
Issue |
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Pages |
23-33 |
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Basal area; Lidar; Tropical moist forest |
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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. |
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ONF, Direction régionale de la Guyane, Cayenne, 97300 France |
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00344257 (Issn) |
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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 |
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EcoFoG @ webmaster @ |
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418 |
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Dejean, A.; Orivel, J.; Leponce, M.; Compin, A.; Delabie, J.H.C.; Azémar, F.; Corbara, B. |
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Ant–plant relationships in the canopy of an Amazonian rainforest: the presence of an ant mosaic |
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Journal Article |
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2018 |
Publication |
Biological Journal of the Linnean Society |
Abbreviated Journal |
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125 |
Issue |
2 |
Pages |
344-354 |
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Using different techniques to access the canopy of an Amazonian rainforest, we inspected 157 tree crowns for arboreal ants. Diversity statistics showed that our study sample was not representative of the tree and ant populations due to their high diversity in Amazonian rainforests, but permitted us to note that a representative part of territorially dominant arboreal ant species (TDAAs) was inventoried. Mapping of TDAA territories and use of a null model showed the presence of an ant mosaic in the upper canopy, but this was not the case in the sub-canopy. Among the TDAAs, carton-nesting Azteca dominated (52.98% of the trees) whereas ant-garden ants (Camponotus femoratus and Crematogaster levior), common in pioneer formations, were secondarily abundant (21.64% of the trees), and the remaining 25.37% of trees sheltered one of 11 other TDAAs. The distribution of the trees forming the upper canopy influences the structure of the ant mosaic, which is related to the attractiveness of some tree taxa for certain arboreal ant species and represents a case of diffuse coevolution. |
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0024-4066 |
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10.1093/biolinnean/bly125 |
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no |
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EcoFoG @ webmaster @ |
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824 |
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Longo, M.; Saatchi, S.; Keller, M.; Bowman, K.; Ferraz, A.; Moorcroft, P.R.; Morton, D.C.; Bonal, D.; Brando, P.; Burban, B.; Derroire, G.; dos-Santos, M.N.; Meyer, V.; Saleska, S.; Trumbore, S.; Vincent, G. |
| Title |
Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests |
Type |
Journal Article |
| Year |
2020 |
Publication |
Journal of Geophysical Research: Biogeosciences |
Abbreviated Journal |
J. Geophys. Res. Biogeosci. |
| Volume |
125 |
Issue |
8 |
Pages |
e2020JG005677 |
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Amazon; drought; ecosystem modeling; evapotranspiration; forest degradation; remote sensing; carbon cycle; deforestation; dry season; evapotranspiration; hydrological cycle; logging (timber); net primary production; remote sensing; sensible heat flux; tropical forest; understory; water stress; Amazon River |
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Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high-resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED-2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED-2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems. ©2020. The Authors. |
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AMAP, Univ Montpellier, IRD, CIRAD, CNRS, INRAE, Montpellier, France |
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Blackwell Publishing Ltd |
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21698953 (Issn) |
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EcoFoG @ webmaster @ |
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957 |
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Houel, E.; Bertani, S.; Bourdy, G.; Deharo, E.; Jullian, V.; Valentin, A.; Chevalley, S.; Stien, D. |
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Quassinoid constituents of Quassia amara L. leaf herbal tea. Impact on its antimalarial activity and cytotoxicity |
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Journal Article |
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2009 |
Publication |
Journal of Ethnopharmacology |
Abbreviated Journal |
J. Ethnopharmacol. |
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126 |
Issue |
1 |
Pages |
114-118 |
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Quassia amara L.; Simaroubaceae; Leaf tea; Antimalarial activity; Cytotoxicity; Simalikalactone D |
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Aim of the study: Our objective was to assess whether it could be contemplated to recommend Quassia amara young leaf tea for treatment against malaria. and if yes. set up a standard protocol for preparing the herbal tea. Materials and methods: The leaf tea was extracted with methylene chloride and the organic extract was fractionated with HPLC. Pure compounds were characterized and their in vitro cytotoxicity and antiplasmodial activity was determined. Results and discussion: We discovered that antimalarial Quassia amara young leaf tea contains several quassinoids: simalikalactone D (SkD. 1), picrasin B (2). picrasin H (3), neoquassin (4), quassin (5), picrasin 1(6) and picrasin J (7). These last two compounds are new. In addition. our experiments demonstrate that both biological activity and cytotoxicity of the remedy may be attributed solely to the presence of SkD. Conclusion: In conclusion, this preparation Should not be recommended for treatment of malaria until a clinical Study in humans is performed with SkD. (C) 2009 Elsevier Ireland Ltd. All rights reserved |
| Address |
[Stien, Didier] Univ Antilles Guyane, CNRS, UMR Ecofog, Inst Enseignement Super Guyane, F-97337 Cayenne, France, Email: didier.stien@guyane.cnrs.fr |
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ELSEVIER IRELAND LTD |
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0378-8741 |
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ISI:000271790800015 |
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no |
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EcoFoG @ eric.marcon @ |
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94 |
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Odonne, G.; Bourdy, G.; Castillo, D.; Estevez, Y.; Lancha-Tangoa, A.; Alban-Castillo, J.; Deharo, E.; Rojas, R.; Stien, D.; Sauvain, M. |
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Ta'ta', Huayani: Perception of leishmaniasis and evaluation of medicinal plants used by the Chayahuita in Peru. Part II |
Type |
Journal Article |
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2009 |
Publication |
Journal of Ethnopharmacology |
Abbreviated Journal |
J. Ethnopharmacol. |
| Volume |
126 |
Issue |
1 |
Pages |
149-158 |
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Leishmaniasis; Medicinal plants; Traditional medicine; Chayahuita; Peru |
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Aim of the study v: A knowledge attitude and practice study centred on leishmaniasis and its treatment was performed among the Chayahuita, in Amazonian Peruvian ethnic group living in ail endemic area. This study documents traditional Chayahuita plant's use and disease concepts. Also, activity of some medicinal Plants Used by the Chayahuita is highlighted and discussed. Materials and methods: Ninety-three Chayahuita people were interviewed, following a semi-structured questionnaire focussed oil disease knowledge and perception, personal attitude and healing practices. Simultaneously, a collection of plants was performed in different ecotopes, in order to make ail extensive inventory of the pharmacopoeia. Results: For the Chayahuita, cutaneous (CL) and muco-cutaneous leishmaniasis (MCL) are considered as diseases of their own, with specific names, aetiologics, mode of transmission. Regarding CL, Chayahuita people consider that the humid characteristic of the Skill ulcer is a discriminative fact orienting the diagnostic for Ta'ta' (leishmaniasis). Forty-six different species were designated useful against LC and /or MCL (29 species by means of the questionnaire and 27 species when collecting in different ecotopes). Thirty-seven extracts corresponding to 31 Species used medicinally were screened in vitro against Leishmania amazonensis axenic amastigotes, assessing their viability by the reduction Of tetrazolium salt (MTT). Six species displayed a good activity (10 μg/ml < IC50 < 20 μg/ml): all undetermined hemi-epiphytic Clusiaceae. Cybianthus anthuriophyllus Pipoly (Myrsinaceae), two Piper, Piper sanguineispicum Trel., and Piper loretoanum Trel. (Piperaceae), Desmodium axillare Sw. DC. (Fabaceae), and Clibadium sylvestre (Aubl.) Baill (Asteraceae). Conclusion: Perception of leishmaniasis, attitude. treatments and diet prohibitions still largely reflects traditional Chayahuita cosmovision, even if some tentative of bio-medical re-interpretation is arising. (C) 2009 Elsevier Ireland Ltd. All rights reserved. |
| Address |
[Odonne, G.; Bourdy, G.; Estevez, Y.; Deharo, E.; Sauvain, M.] Univ Toulouse, UPS, UMR 152, Lab Pharmacochim Subst Nat & Pharmacophores Redox, F-31062 Toulouse 9, France, Email: Genevieve.bourdy@ird.fr |
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ELSEVIER IRELAND LTD |
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0378-8741 |
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ISI:000271790800020 |
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EcoFoG @ eric.marcon @ |
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95 |
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Van Langenhove, Leandro ; Depaepe, Thomas ; Verryckt, Lore T. ; Vallicrosa, Helena ; Fuchslueger, Lucia ; Lugli, Laynara F. ; Bréchet, Laëtitia M. ; Ogaya, Roma ; Llusia, Joan ; Urbina, Ifigenia ; Gargallo-Garriga, Albert ; Grau, Oriol ; Richter, Andreas ; Penuelas, Josep ; Van Der Straeten, Dominique ; August Janssens, Ivan A. |
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Impact of Nutrient Additions on Free-Living Nitrogen Fixation in Litter and Soil of Two French-Guianese Lowland Tropical Forests |
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Journal Article |
| Year |
2021 |
Publication |
JGR Biogeosciences |
Abbreviated Journal |
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126 |
Issue |
7 |
Pages |
e2020JG006023 |
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In tropical forests, free-living Biological nitrogen (N) fixation (BNF) in soil and litter tends to decrease when substrate N concentrations increase, whereas increasing phosphorus (P) and molybdenum (Mo) soil and litter concentrations have been shown to stimulate free-living BNF rates. Yet, very few studies explored the effects of adding N, P, and Mo together in a single large-scale fertilization experiment, which would teach us which of these elements constrain or limit BNF activities. At two distinct forest sites in French Guiana, we performed a 3-year in situ nutrient addition study to explore the effects of N, P, and Mo additions on leaf litter and soil BNF. Additionally, we conducted a short-term laboratory study with the same nutrient addition treatments (+N, +N+P, +P, +Mo, and +P+Mo). We found that N additions alone suppressed litter free-living BNF in the field, but not in the short-term laboratory study, while litter free-living BNF remained unchanged in response to N+P additions. Additionally, we found that P and P+Mo additions stimulated BNF in leaf litter, both in the field and in the lab, while Mo alone yielded no changes. Soil BNF increased with P and P+Mo additions in only one of the field sites, while in the other site soil BNF increased with Mo and P+Mo additions. We concluded that increased substrate N concentrations suppress BNF. Moreover, both P and Mo have the potential to limit free-living BNF in these tropical forests, but the balance between P versus Mo limitation is determined by site-specific characteristics of nutrient supply and demand. |
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American Geophysical Union |
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EcoFoG @ webmaster @ |
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1040 |
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Schmitt, S.; Hérault, B.; Ducouret, É.; Baranger, A.; Tysklind, N.; Heuertz, M.; Marcon, É.; Cazal, S.O.; Derroire, G. |
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Topography consistently drives intra- and inter-specific leaf trait variation within tree species complexes in a Neotropical forest |
Type |
Journal Article |
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2020 |
Publication |
Oikos |
Abbreviated Journal |
Oikos |
| Volume |
129 |
Issue |
10 |
Pages |
1521-1530 |
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intraspecific variability; leaf traits; Paracou; species complex; syngameon; tropical forests; Bayesian analysis; coexistence; divergence; genetic variation; hierarchical system; leaf area; local adaptation; niche overlap; species diversity; topography; tropical forest; Guyana Shield |
| Abstract |
Tropical forests shelter the highest species diversity worldwide, although genus diversity is lower than expected. In the species-rich genera, species complexes are composed of closely-related species that share large amounts of genetic variation. Despite the key role of species complexes in diversification, evolution and functioning of ecological communities, little is known on why species complexes arise and how they are maintained in Neotropical forests. Examining how individual phenotypes vary along environmental gradients, within and among closely-related species within species complexes, can reveal processes allowing species coexistence within species complexes. We examined leaf functional trait variation with topography in a hyperdiverse tropical forest of the Guiana Shield. We collected leaf functional traits from 766 trees belonging to five species in two species complexes in permanent plots encompassing a diversity of topographic positions. We tested the role of topography on leaf functional trait variation with a hierarchical Bayesian model, controlling for individual tree diameter effect. We show that, mirroring what has been previously observed among species and communities, individual leaf traits covary from acquisitive to conservative strategy within species. Moreover, decreasing wetness from bottomlands to plateaus was associated with a shift of leaf traits from an acquisitive to a conservative strategy both across and within closely-related species. Our results suggest that intraspecific trait variability widens species’ niches and converges at species’ margins where niches overlap, potentially implying local neutral processes. Intraspecific trait variability favors local adaptation and divergence of closely-related species within species complexes. It is potentially maintained through interspecific sharing of genetic variation through hybridization. © 2020 Nordic Society Oikos. Published by John Wiley & Sons Ltd |
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INRAE, UMR EcoFoG (Agroparistech, CNRS, Cirad, Université des Antilles, Univ. de la Guyane), Kourou, French Guiana |
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Blackwell Publishing Ltd |
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00301299 (Issn) |
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EcoFoG @ webmaster @ |
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950 |
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