| |
Records |
Links |
|
Author |
Niamké, F.B.; Amusant, N.; Stien, D.; Chaix, G.; Lozano, Y.; Kadio, A.A.; Lemenager, N.; Goh, D.; Adima, A.A.; Kati-Coulibaly, S.; Jay-Allemand, C. |
|
| |
Title |
4',5'-Dihydroxy-epiisocatalponol, a new naphthoquinone from Tectona grandis L. f. heartwood, and fungicidal activity |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
International Biodeterioration and Biodegradation |
Abbreviated Journal |
Int. Biodeterior. Biodegrad. |
|
| |
Volume |
74 |
Issue |
|
Pages |
93-98 |
|
| |
Keywords |
4',5'-Dihydroxy-epiisocatalponol; Decay resistance; Fungicidal; Heartwood; Naphthoquinone; Tectona grandis |
|
| |
Abstract |
A new naphthoquinone derivative was isolated from the heartwood of the teak stem. The chemical structure of this new compound, 4',5'-dihydroxy-epiisocatalponol, was determined using 1-D and 2-D nuclear magnetic resonance experiments, vibrational circular dichroism, HRMS, and optical rotation. We showed that this new naphthoquinone derivative plays a key role in the variability of decay resistance in teak wood. A high negative correlation was found between its concentration and the mass losses of the wood samples after exposure to the brown rot Antrodia sp., the fungus that is the most virulent against teak (R = -0.9; ρ < 0.0001). In-vitro bioassays allowed us to demonstrate that 4',5'-dihydroxy-epiisocatalponol acted as a fungicide against Trametes versicolor (white rot) at 58 mg ml -1 (0.22 mM). Overall, our results demonstrated that the concentration of 4',5'-dihydroxy-epiisocatalponol could be used as a new tool to evaluate teak wood durability. © 2012 Elsevier Ltd. |
|
| |
Address |
Laboratoire de Biochimie et de Physiologie Végétales, UMR 47 DIADE – Equipe Rhizogenèse, Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex 05, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
09648305 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes  |
Export Date: 27 September 2012; Source: Scopus; Coden: Ibbie; doi: 10.1016/j.ibiod.2012.03.010; Language of Original Document: English; Correspondence Address: Amusant, N.; CIRAD, Department Environments and societies, UMR Ecology forests of French Guiana, BP 732, 97310 Kourou cedex, French Guiana; email: nadine.amusant@cirad.fr |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
435 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Nicolini, E.; Beauchene, J.; De La Vallee, B.L.; Ruelle, J.; Mangenet, T.; Heuret, P. |
|
| |
Title |
Dating branch growth units in a tropical tree using morphological and anatomical markers: The case of Parkia velutina Benoist (Mimosoïdeae) |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Annals of Forest Science |
Abbreviated Journal |
Ann. Forest Sci. |
|
| |
Volume |
69 |
Issue |
5 |
Pages |
543-555 |
|
| |
Keywords |
Crown development; Deciduousness; Dendrochronology; French Guiana; Growth ring; Phenology; Tree architecture; Wood anatomy |
|
| |
Abstract |
• Context In tropical areas, studies based on the retrospective analysis of tree development have focused principally on growth ring research. The interpretation of primary growth markers is overlooked although it opens perspectives to provide long time-series on tree-crown development. • Aims This study focused on Parkia velutina, an emergent tree of neotropical rain forests. Our objectives were (1) to characterize the phenological cycle of this species, and (2) to identify temporally interpretable morphological and anatomical markers. • Methods We collected dominant branches in 14 adult trees and identified growth markers that limit longitudinal and radial increments. We coupled this approach with a 2-year phenological survey of 20 trees. • Results Leaf shedding, growth unit elongation and growth ring formation define the phenological cycle. At tree scale, this cycle is synchronous and affects all axes. At population scale, trees can be desynchronized. This cycle is annual despite some slight variability. Successive growth units and growth rings are easily identifiable. • Conclusion Dating a branch by counting the number of growth units or growth rings is possible in many years with a reasonable error. Nevertheless, estimating their precise month of formation in order to study climatic influences remains difficult. © INRA/Springer-Verlag France 2012. |
|
| |
Address |
INRA, UMR AMAP, TA A-51/PS2, Montpellier 34398, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
12864560 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 September 2012; Source: Scopus; Coden: Afosf; doi: 10.1007/s13595-011-0172-1; Language of Original Document: English; Correspondence Address: Nicolini, E.; Unité Mixte de Recherche CIRAD-CNRS-INRA-IRD-Université Montpellier 2, BotAnique et BioinforMatique de l'Architecture des Plantes (AMAP), BP 701, Kourou 97387, French Guiana; email: eric-andre.nicolini@cirad.fr |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
436 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Fortunel, C.; Paine, C.E.T.; Fine, P.V.A.; Mesones, I.; Goret, J.; Burban, B.; Cazal, J.; Baraloto, C.; Comita, L. |
|
| |
Title |
There's no place like home: seedling mortality contributes to the habitat specialisation of tree species across Amazonia |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
Ecology Letters |
Abbreviated Journal |
Ecology Letters |
|
| |
Volume |
19 |
Issue |
10 |
Pages |
1256-1266 |
|
| |
Keywords |
Amazon basin; forests habitats; habitat association; herbivory; light availability; plant lineages; rainfall temporal variation; seedling performance; soil fertility; tropical trees |
|
| |
Abstract |
Understanding the mechanisms generating species distributions remains a challenge, especially in hyperdiverse tropical forests. We evaluated the role of rainfall variation, soil gradients and herbivory on seedling mortality, and how variation in seedling performance along these gradients contributes to habitat specialisation. In a 4-year experiment, replicated at the two extremes of the Amazon basin, we reciprocally transplanted 4638 tree seedlings of 41 habitat-specialist species from seven phylogenetic lineages among the three most important forest habitats of lowland Amazonia. Rainfall variation, flooding and soil gradients strongly influenced seedling mortality, whereas herbivory had negligible impact. Seedling mortality varied strongly among habitats, consistent with predictions for habitat specialists in most lineages. This suggests that seedling performance is a primary determinant of the habitat associations of adult trees across Amazonia. It further suggests that tree diversity, currently mostly harboured in terra firme forests, may be strongly impacted by the predicted climate changes in Amazonia. © 2016 John Wiley & Sons Ltd/CNRS |
|
| |
Address |
Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 October 2016 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
698 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Siebicke, L.; Hunner, M.; Foken, T. |
|
| |
Title |
Aspects of CO 2 advection measurements |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Theoretical and Applied Climatology |
Abbreviated Journal |
Theor. Appl. Climatol. |
|
| |
Volume |
109 |
Issue |
1-2 |
Pages |
109-131 |
|
| |
Keywords |
|
|
| |
Abstract |
Observations of vegetation-atmosphere exchange of carbon dioxide (CO 2) by the eddy covariance (EC) technique are limited by difficult conditions such as nighttime and heterogeneous terrain. Thus, advective flux components are included into the net ecosystem exchange (NEE) budget. However, advection measurements are experimentally challenging and do not always help to solve the night flux problem of the EC technique. This study investigates alternative methods for the observation of horizontal advection, in particular horizontal concentration gradients, as well as different approaches to coordinate rotation and vertical advection. Continuous high-frequency measurements of the horizontal CO 2 concentration field are employed and compared to the often used discontinuous sequential sampling. Significant differences were found in the case of 30-min mean concentration values between the conventional discontinuous sampling approach and the complete observation of the time series by continuous sampling. Estimates of vertical advection rely on accurate estimates of vertical wind velocity (W). Therefore, different approaches to the planar fit coordinate rotation have been investigated. Sector-wise rotation was able to eliminate directional dependencies of mean W. Furthermore, the effect of the data set length used for rotation (window length) was investigated and was found to have significant impact on estimates of vertical advection, with larger window lengths yielding about 50% larger vertical advection. A sequential planar fit with controlled window length is proposed to give reproducible results. The different approaches to the measurement and calculation of horizontal and vertical advection presented are applied to data obtained during the exchange processes in mountainous region experiment at the FLUXNET site Waldstein-Weidenbrunnen (DE-Bay). Estimates of NEE including advection are compared to NEE from turbulent and storage flux alone without advection. NEE including vertical advection with sector-wise planar fit rotation and controlled window length and including horizontal advection from continuous gradient measurements, which were comprehensively bias corrected by a new approach, did compare well with the expected night flux error, with meteorological drivers of the fluxes and with soil chamber measurements. Unrealistically large and noisy values of horizontal advection from the conventional discontinuous sampling approach, which lead to unrealistic values of NEE, could be eliminated by the alternative approaches presented. We therefore suggest the further testing of those approaches at other sites in order to improve the accuracy of advection measurements and, subsequently, estimates of NEE. © 2011 Springer-Verlag. |
|
| |
Address |
Wind Cert Services, TÜV SÜD Industrie Service GmbH, Ludwig-Eckert-Str. 10, 93049 Regensburg, Germany |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0177798x (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 June 2012; Source: Scopus; doi: 10.1007/s00704-011-0552-3; Language of Original Document: English; Correspondence Address: Siebicke, L.; Department of Micrometeorology, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany; email: lukas.siebicke@uni-bayreuth.de |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
406 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Coq, S.; Weigel, J.; Bonal, D.; Hattenschwiler, S. |
|
| |
Title |
Litter mixture effects on tropical tree seedling growth – a greenhouse experiment |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Plant Biology |
Abbreviated Journal |
Plant Biol. |
|
| |
Volume |
14 |
Issue |
4 |
Pages |
630-640 |
|
| |
Keywords |
Amazonian lowland rain forest; Autotoxicity; Belowground/aboveground interactions; Litter decomposition; Plant nutrition; Plant-soil feedback |
|
| |
Abstract |
Decomposing litter provides critical nutrients for plants, particularly in nutrient-poor ecosystems such as tropical forests. We hypothesised that decomposing litter improves the performance of a variety of tropical tree seedlings, and that this litter effect varies depending on the species of litter present in litter mixtures. We addressed these hypotheses with a large pot experiment manipulating a range of different litter mixtures of contrasting quality and using seedlings of four tree species from the Amazonian forest of French Guiana. In contrast to our initial hypothesis, decomposing litter had either neutral or negative impacts on seedling growth, despite strongly different growth rates, biomass allocation patterns and leaf and root traits among tree species. Tree species varied in their responses to litter additions, which were further modified by species identity of the added litter. Our data show litter species-specific effects on growth, biomass allocation and leaf and root traits of tropical tree seedlings. These results suggest that a net nutrient release from decomposing litter does not necessarily improve tree seedling growth, even under nutrient-limiting conditions. In conclusion, litter layer composition may affect seedling establishment and recruitment success beyond litter-derived plant nutrient availability, which may contribute to tree species composition and dynamics in the studied tropical forest. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands. |
|
| |
Address |
INRA, UMR, Écologie et Écophysiologie, Champenoux, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
14358603 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 June 2012; Source: Scopus; Coden: Pbiof; doi: 10.1111/j.1438-8677.2011.00534.x; Language of Original Document: English; Correspondence Address: Coq, S.; Laboratoire d'Ecologie Alpine (LECA), CNRS, Université Joseph Fourier, BP 53, F-38042 Grenoble, Cedex 09, France; email: sylvain.coq@gmail.com |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
407 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Odonne, G.; Houel, E.; Bourdy, G.; Stien, D. |
|
| |
Title |
Treating leishmaniasis in Amazonia: A review of ethnomedicinal concepts and pharmaco-chemical analysis of traditional treatments to inspire modern phytotherapies |
Type |
Journal Article |
| |
Year |
2017 |
Publication |
Journal of Ethnopharmacology |
Abbreviated Journal |
Journal of Ethnopharmacology |
|
| |
Volume |
199 |
Issue |
|
Pages |
211-230 |
|
| |
Keywords |
Amazonia; Distribution indexes; Ethnomedecine; Interculturality; Leishmaniasis; Medicinal plants; Traditional medicine |
|
| |
Abstract |
Ethnopharmacological relevance Cutaneous and mucocutaneous leishmaniasis are neglected tropical diseases that occur in all intertropical regions of the world. Amazonian populations have developed an abundant knowledge of the disease and its remedies. Therefore, we undertook to review traditional antileishmanial plants in Amazonia and have developed new tools to analyze this somewhat dispersed information. Material and methods A literature review of traditional remedies for cutaneous/mucocutaneous leishmaniasis in the Amazon was conducted and the data obtained was used to calculate distribution indexes designed to highlight the most relevant uses in Amazonia. The cultural distribution index represents the distribution rate of a given taxon among different cultural groups and was calculated as the ratio of the number of groups using the taxon to the total number of groups cited. The geographical distribution index allowed us to quantify spatial distribution of a taxon's uses in Amazonia and was calculated geometrically by measuring the average distance between the points where uses have been reported and the barycenter of those points. The general distribution index was defined as an arithmetic combination of the previous two and provides information on both cultural and spatial criteria. Results 475 use reports, concerning 291 botanical species belonging to 83 families have been gathered depicted from 29 sources. Uses concern 34 cultural groups. While the use of some taxa appears to be Pan-Amazonian, some others are clearly restricted to small geographical regions. Particular attention has been paid to the recipes and beliefs surrounding treatments. Topical application of the remedies dominated the other means of administration and this deserves particular attention as the main treatments against Neotropical leishmaniasis are painful systemic injections. The data set was analyzed using the previously defined distribution indexes and the most relevant taxa were further discussed from a phytochemical and pharmacological point of view. Conclusions The Amazonian biodiversity and cultural heritage host a fantastic amount of data whose systematic investigation should allow a better large-scale understanding of the dynamics of traditional therapies and the consequent discovery of therapeutic solutions for neglected diseases. Distribution indices are indeed powerful tools for emphasizing the most relevant treatments against a given disease and should be very useful in the meta-analysis of other regional pharmacopeia. This focus on renowned remedies that have not yet benefitted from extended laboratory studies, could stimulate future research on new treatments of natural origin for leishmaniasis. © 2017 Elsevier Ireland Ltd |
|
| |
Address |
Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM), Observatoire Océanologique, Banyuls-sur-Mer, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 February 2017 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
737 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Basset, Y.; Cizek, L.; Cuénoud, P.; Didham, R.K.; Guilhaumon, F.; Missa, O.; Novotny, V.; Ødegaard, F.; Roslin, T.; Schmidl, J.; Tishechkin, A.K.; Winchester, N.N.; Roubik, D.W.; Aberlenc, H.-P.; Bail, J.; Barrios, H.; Bridle, J.R.; Castaño-Meneses, G.; Corbara, B.; Curletti, G.; Da Rocha, W.D.; De Bakker, D.; Delabie, J.H.C.; Dejean, A.; Fagan, L.L.; Floren, A.; Kitching, R.L.; Medianero, E.; Miller, S.E.; De Oliveira, E.G.; Orivel, J.; Pollet, M.; Rapp, M.; Ribeiro, S.P.; Roisin, Y.; Schmidt, J.B.; Sørensen, L.; Leponce, M. |
|
| |
Title |
Arthropod diversity in a tropical forest |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Science |
Abbreviated Journal |
|
|
| |
Volume |
338 |
Issue |
6113 |
Pages |
1481-1484 |
|
| |
Keywords |
|
|
| |
Abstract |
Most eukaryotic organisms are arthropods. Yet, their diversity in rich terrestrial ecosystems is still unknown. Here we produce tangible estimates of the total species richness of arthropods in a tropical rainforest. Using a comprehensive range of structured protocols, we sampled the phylogenetic breadth of arthropod taxa from the soil to the forest canopy in the San Lorenzo forest, Panama. We collected 6144 arthropod species from 0.48 hectare and extrapolated total species richness to larger areas on the basis of competing models. The whole 6000-hectare forest reserve most likely sustains 25,000 arthropod species. Notably, just 1 hectare of rainforest yields >60% of the arthropod biodiversity held in the wider landscape. Models based on plant diversity fitted the accumulated species richness of both herbivore and nonherbivore taxa exceptionally well. This lends credence to global estimates of arthropod biodiversity developed from plant models. |
|
| |
Address |
Natural History Museum of Denmark, 2100 Copenhagen, Denmark |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 December 2012; Source: Scopus |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
451 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Mathieu, A.; Letort, V.; Cournède, P.H.; Zhang, B.G.; Heuret, P.; De Reffye, P. |
|
| |
Title |
Oscillations in functional structural plant growth models |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Mathematical Modelling of Natural Phenomena |
Abbreviated Journal |
|
|
| |
Volume |
7 |
Issue |
6 |
Pages |
47-66 |
|
| |
Keywords |
Cecropia trees; Cucumber plant; Dynamic system of plant growth; Functional-structural plant models; GreenLab |
|
| |
Abstract |
The dynamic model of plant growth GreenLab describes plant architecture and functional growth at the level of individual organs. Structural development is controlled by formal grammars and empirical equations compute the amount of biomass produced by the plant, and its partitioning among the growing organs, such as leaves, stems and fruits. The number of organs initiated at each time step depends on the trophic state of the plant, which is evaluated by the ratio of biomass available in plant to the demand of all the organs. The control of the plant organogenesis by this variable induces oscillations in the simulated plant behaviour. The mathematical framework of the GreenLab model allows to compute the conditions for the generation of oscillations and the value of the period according to the set of parameters. Two case-studies are presented, corresponding to emergence of oscillations associated to fructification and branching. Similar alternating patterns are commonly reported by botanists. In this article, two examples were selected: alternate patterns of fruits in cucumber plants and alternate appearances of branches in Cecropia trees. The model was calibrated from experimental data collected on these plants. It shows that a simple feedback hypothesis of trophic control on plant structure allows the emergence of cyclic patterns corresponding to the observed ones. © EDP Sciences, 2012. |
|
| |
Address |
CIRAD, UMR AMAP, Montpellier, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 December 2012; Source: Scopus |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
452 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Molina, L.; Broquet, G.; Imbach, P.; Chevallier, F.; Poulter, B.; Bonal, D.; Burban, B.; Ramonet, M.; Gatti, L.V.; Wofsy, S.C.; Munger, J.W.; Dlugokencky, E.; Ciais, P. |
|
| |
Title |
On the ability of a global atmospheric inversion to constrain variations of CO2 fluxes over Amazonia |
Type |
Journal Article |
| |
Year |
2015 |
Publication |
Atmospheric Chemistry and Physics |
Abbreviated Journal |
Atmospheric Chemistry and Physics |
|
| |
Volume |
15 |
Issue |
14 |
Pages |
8423-8438 |
|
| |
Keywords |
|
|
| |
Abstract |
The exchanges of carbon, water and energy between the atmosphere and the Amazon basin have global implications for the current and future climate. Here, the global atmospheric inversion system of the Monitoring of Atmospheric Composition and Climate (MACC) service is used to study the seasonal and interannual variations of biogenic CO<inf>2</inf> fluxes in Amazonia during the period 2002-2010. The system assimilated surface measurements of atmospheric CO<inf>2</inf> mole fractions made at more than 100 sites over the globe into an atmospheric transport model. The present study adds measurements from four surface stations located in tropical South America, a region poorly covered by CO<inf>2</inf> observations. The estimates of net ecosystem exchange (NEE) optimized by the inversion are compared to an independent estimate of NEE upscaled from eddy-covariance flux measurements in Amazonia. They are also qualitatively evaluated against reports on the seasonal and interannual variations of the land sink in South America from the scientific literature. We attempt at assessing the impact on NEE of the strong droughts in 2005 and 2010 (due to severe and longer-than-usual dry seasons) and the extreme rainfall conditions registered in 2009. The spatial variations of the seasonal and interannual variability of optimized NEE are also investigated. While the inversion supports the assumption of strong spatial heterogeneity of these variations, the results reveal critical limitations of the coarse-resolution transport model, the surface observation network in South America during the recent years and the present knowledge of modelling uncertainties in South America that prevent our inversion from capturing the seasonal patterns of fluxes across Amazonia. However, some patterns from the inversion seem consistent with the anomaly of moisture conditions in 2009. © Author(s) 2015. |
|
| |
Address |
NOAA, Earth System Research Laboratory, Global Monitoring Division, Boulder, CO, United States |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 August 2015 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
615 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Dezerald, O.; Céréghino, R.; Corbara, B.; Dejean, A.; Leroy, C. |
|
| |
Title |
Functional trait responses of aquatic macroinvertebrates to simulated drought in a Neotropical bromeliad ecosystem |
Type |
Journal Article |
| |
Year |
2015 |
Publication |
Freshwater Biology |
Abbreviated Journal |
Freshwater Biology |
|
| |
Volume |
60 |
Issue |
9 |
Pages |
1917-1929 |
|
| |
Keywords |
Food webs; Precipitations; Rainforests; Resistance/resilience; Tipping point |
|
| |
Abstract |
The duration of the dry seasons in south-eastern Amazonia is expected to increase. Little is known of how freshwater assemblages respond to drought in the humid rainforests and of the extent to which they resist the absence of rainfall before the collapse of the system. We manipulated rainshelters over tank-forming bromeliads (i.e. the interlocking leaf axils of these plants form wells that collect rainwater) to simulate an exceptionally long dry period (49 days, compared with a 10-year mean ± SD annual maximum number of 17 ± 5.3 days without rainfall at the study site) and then a rewetting period. By sampling weekly over 3 months, we followed the dynamics of the representation of abundance-weighted traits in invertebrate assemblages in these treatment plants and in a control group. The functional structure of assemblages was drought resistant until the water volume in the bromeliad pools dropped by 90%, when there was a sudden shift in the functional trait structure due to the loss of most populations except the drought-resistant culicids. Traits related to life history, body size and preferred food showed significant responses to drought. There was a convergence in the functional traits of species surviving in dry plants, strengthening the idea that environmental filtering, rather than stochasticity, determines the functional trajectory of aquatic assemblages during drought. At the end of the dry period, samples of the detritus potentially containing drought-resistant eggs/cysts (and eventually live larvae) were taken from the dry plants and rewetted in the laboratory, allowing us to distinguish resistant species from those requiring recolonisation via subsequent oviposition by adults from elsewhere. Patches of water-filled bromeliads persisting in the area provided the most important pool of colonists, and communities returned to the pre-disturbance state within 1-2 weeks of rewetting. Our results suggest that the functional trait structure of invertebrate assemblages in bromeliads could remain stable under scenarios of precipitation change that would triple the duration of current dry periods at a local scale. Future experiments should evaluate how environmental factors might alter the tipping point between resistance to drought and a collapse in ecosystem processes. © 2015 John Wiley & Sons Ltd. |
|
| |
Address |
IRD, UMR AMAP (botAnique et Modélisation de l'Architecture des Plantes et des vegetations), Boulevard de la Lironde, TA A-51/PS2, Montpellier Cedex 5, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 27 August 2015 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
616 |
|
| Permanent link to this record |
