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| Gargallo-garriga, Albert; Sardans, Jordi; Llusià, Joan; Peguero, Guille; Asensio, Dolores; Ogaya, Romà; Urbina, Ifigenia; Langenhove, Leandro Van; Verryckt, Lore T.; Courtois, Elodie A.; Stahl, Clément; Grau, Oriol; Urban, Otmar; Janssens, Ivan A.; Nolis, Pau; Pérez-trujillo, Miriam; Parella, Teodor; Peñuelas, Josep. |
| Productivity of tropical lowland moist forests is often limited by availability and functional allocation of phosphorus (P) that drives competition among tree species and becomes a key factor in determining forestall community diversity. We used non-target 31P-NMR metabolic profiling to study the foliar P-metabolism of trees of a French Guiana rainforest. The objective was to test the hypotheses that P-use is species-specific, and that species diversity relates to species P-use and concentrations of P-containing compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates and organic polyphosphates. We found that tree species explained the 59% of variance in 31P-NMR metabolite profiling of leaves. A principal component... |
| Tipo: Text |
Palavras-chave: P-31-NMR metabolic profiling; Iceland; Tropical lowland; P-containing compounds; Species-specific P-use niches. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00648/76023/76922.pdf |
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| Van Langenhove, Leandro; Verryckt, Lore T.; Bréchet, Laëtitia; Courtois, Elodie A.; Stahl, Clement; Hofhansl, Florian; Bauters, Marijn; Sardans, Jordi; Boeckx, Pascal; Fransen, Erik; Peñuelas, Josep; Janssens, Ivan A.. |
| Atmospheric deposition is an important component of the nutrient cycles of terrestrial ecosystems, but field measurements are especially scarce in tropical regions. In this study we analysed 15 months of precipitation chemistry collected in an old growth tropical forest located in French Guiana. We measured nutrient inputs via bulk precipitation and throughfall and used the canopy budget model to estimate nutrient fluxes via canopy exchange and dry deposition. Based on this method we quantified net fluxes of macronutrients and compared their contribution to internal cycling rates via litterfall. Our results suggest that while atmospheric deposition of nitrogen was relatively high (13 kg ha−1 year−1), and mainly in organic forms, the N inputs via litterfall... |
| Tipo: Text |
Palavras-chave: Throughfall; Litterfall; Nutrient cycling; Nitrogen; Phosphorus; Potassium. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00629/74123/73572.pdf |
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| Verryckt, Lore T.; Van Langenhove, Leandro; Ciais, Philippe; Courtois, Elodie A.; Vicca, Sara; Peñuelas, Josep; Stahl, Clément; Coste, Sabrina; Ellsworth, David S.; Posada, Juan M.; Obersteiner, Michael; Chave, Jérôme; Janssens, Ivan A.. |
| Measuring leaf gas exchange from canopy leaves is fundamental for our understanding of photosynthesis and for a realistic representation of carbon uptake in vegetation models. Since canopy leaves are often difficult to reach, especially in tropical forests with emergent trees up to 60 m at remote places, canopy access techniques such as canopy cranes or towers have facilitated photosynthetic measurements. These structures are expensive and therefore not very common. As an alternative, branches are often cut to enable leaf gas exchange measurements. The effect of branch excision on leaf gas exchange rates should be minimized and quantified to evaluate possible bias. We compared light‐saturated leaf net photosynthetic rates measured on excised and intact... |
| Tipo: Text |
Palavras-chave: Branch cutting; Canopy physiology; French Guiana; Gas exchange; Photosynthesis; Rainforest; Stomatal conductance. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00613/72466/71949.pdf |
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| Fisher, Matthew C.; Ghosh, Pria; Shelton, Jennifer M. G.; Bates, Kieran; Brookes, Lola; Wierzbicki, Claudia; Rosa, Goncalo M.; Farrer, Rhys A.; Aanensen, David M.; Alvarado-rybak, Mario; Bataille, Arnaud; Berger, Lee; Boell, Susanne; Bosch, Jaime; Clare, Frances C.; Courtois, Elodie A.; Crottini, Angelica; Cunningham, Andrew A.; Doherty-bone, Thomas M.; Gebresenbet, Fikirte; Gower, David J.; Hoglund, Jacob; James, Timothy Y; Jenkinson, Thomas S.; Kosch, Tiffany A.; Lambertini, Carolina; Laurila, Anssi; Lin, Chun-fu; Loyau, Adeline; Martel, An; Meurling, Sara; Miaud, Claude; Minting, Pete; Ndriantsoa, Serge; O'Hanlon, Simon J.; Pasmans, Frank; Rakotonanahary, Tsanta; Rabemananjara, Falitiana C. E.; Ribeiro, Luisa P.; Schmeller, Dirk S.; Schmidt, Benedikt R.; Skerratt, Lee; Smith, Freya; Soto-azat, Claudio; Tessa, Giulia; Toledo, Luis Felipe; Valenzuela-sanchez, Andres; Verster, Ruhan; Voeroes, Judit; Waldman, Bruce; Webb, Rebecca J.; Weldon, Che; Wombwell, Emma; Zamudio, Kelly R.; Longcore, Joyce E.; Garner, Trenton W. J.. |
| Parasitic chytrid fungi have emerged as a significant threat to amphibian species worldwide, necessitating the development of techniques to isolate these pathogens into culture for research purposes. However, early methods of isolating chytrids from their hosts relied on killing amphibians. We modified a pre-existing protocol for isolating chytrids from infected animals to use toe clips and biopsies from toe webbing rather than euthanizing hosts, and distributed the protocol to researchers as part of the BiodivERsA project RACE; here called the RML protocol. In tandem, we developed a lethal procedure for isolating chytrids from tadpole mouthparts. Reviewing a database of use a decade after their inception, we find that these methods have been applied... |
| Tipo: Text |
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| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00442/55317/78944.pdf |
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| Gargallo-garriga, Albert; Sardans, Jordi; Granda, Victor; Llusià, Joan; Peguero, Guille; Asensio, Dolores; Ogaya, Romà; Urbina, Ifigenia; Van Langenhove, Leandro; Verryckt, Lore T.; Chave, Jérome; Courtois, Elodie A.; Stahl, Clément; Grau, Oriol; Klem, Karel; Urban, Otmar; Janssens, Ivan A.; Peñuelas, Josep. |
| Tropical rainforests harbor a particularly high plant diversity. We hypothesize that potential causes underlying this high diversity should be linked to distinct overall functionality (defense and growth allocation, anti-stress mechanisms, reproduction) among the different sympatric taxa. In this study we tested the hypothesis of the existence of a metabolomic niche related to a species-specific differential use and allocation of metabolites. We tested this hypothesis by comparing leaf metabolomic profiles of 54 species in two rainforests of French Guiana. Species identity explained most of the variation in the metabolome, with a species-specific metabolomic profile across dry and wet seasons. In addition to this “homeostatic” species-specific metabolomic... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00625/73686/73151.pdf |
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| Bréchet, Laëtitia; Courtois, Elodie A.; Saint-germain, Thomas; Janssens, Ivan A.; Asensio, Dolores; Ramirez-rojas, Irene; Soong, Jennifer L.; Van Langenhove, Leandro; Verbruggen, Erik; Stahl, Clément. |
| Tropical soils are a major contributor to the balance of greenhouse gas (GHG) fluxes in the atmosphere. Models of tropical GHG fluxes predict that both the frequency of drought events and changes in atmospheric deposition of nitrogen (N) will significantly affect dynamics of soil carbon dioxide (CO2) and methane (CH4) production and consumption. In this study, we examined the combined effect of a reduction in precipitation and an increase in nutrient availability on soil CO2 and CH4 fluxes in a primary French Guiana tropical forest. Drought conditions were simulated by intercepting precipitation falling through the forest canopy with tarpaulin roofs. Nutrient availability was manipulated through application of granular N and/or phosphorus (P) fertilizer to... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Drought; Fertilization; Methane; Nitrogen; Phosphorus; Soil GHG fluxes; Tropical forest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70694/68903.pdf |
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| Ulloa, Juan Sebastian; Aubin, Thierry; Llusia, Diego; Courtois, Elodie A.; Fouquet, Antoine; Gaucher, Philippe; Pavoine, Sandrine; Sueur, Jerome. |
| Background: Anurans largely rely on acoustic communication for sexual selection and reproduction. While multiple studies have focused on the calling activity patterns of prolonged breeding assemblages, species that concentrate their reproduction in short-time windows, explosive breeders, are still largely unknown, probably because of their ephemeral nature. In tropical regions, multiple species of explosive breeders may simultaneously aggregate leading to massive, mixed and dynamic choruses. To understand the environmental triggers, the phenology and composition of these choruses, we collected acoustic and environmental data at five ponds in French Guiana during a rainy season, assessing acoustic communities before and during explosive breeding events.... |
| Tipo: Text |
Palavras-chave: Acoustic diversity; Anuran community; Ecoacoustics; Biodiversity monitoring. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62021/66144.pdf |
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| Courtois, Elodie A.; Loyau, Adeline; Bourgoin, Megane; Schmeller, Dirk S.. |
| Understanding transmission is a critical prerequisite for predicting disease dynamics and impacts on host populations. It is well established that Batrachochytrium dendrobatidis (Bd), the amphibian fungal pathogen responsible for chytridiomycosis, can be transmitted directly, through physical contact with an infected host. However, indirect pathways of transmission remain poorly investigated. We conducted a five-week long field infection experiment at a high altitude mountain lake in the French Pyrenees to investigate Bd transmission pathways in larval midwife toads Alytes obstetricans. Uninfected naive tadpoles were co-housed either with infected tadpoles (direct and indirect transmission) or with uninfected ones (indirect transmission only). We found... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00389/49998/79397.pdf |
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| Peguero, Guille; Sardans, Jordi; Asensio, Dolores; Fernández-martínez, Marcos; Gargallo-garriga, Albert; Grau, Oriol; Llusià, Joan; Margalef, Olga; Márquez, Laura; Ogaya, Romà; Urbina, Ifigenia; Courtois, Elodie A.; Stahl, Clément; Van Langenhove, Leandro; Verryckt, Lore T.; Richter, Andreas; Janssens, Ivan A.; Peñuelas, Josep. |
| Soil fauna is a key control of the decomposition rate of leaf litter, yet its interactions with litter quality and the soil environment remain elusive. We conducted a litter decomposition experiment across different topographic levels within the landscape replicated in two rainforest sites providing natural gradients in soil fertility to test the hypothesis that low nutrient availability in litter and soil increases the strength of fauna control over litter decomposition. We crossed these data with a large dataset of 44 variables characterizing the biotic and abiotic microenvironment of each sampling point and found that microbe-driven carbon (C) and nitrogen (N) losses from leaf litter were 10.1 and 17.9% lower, respectively, in the nutrient-poorest site,... |
| Tipo: Text |
Palavras-chave: Biogeochemistry; Extracellular enzyme activity; Litter decomposition; Nutrients; Soil fauna. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62424/69469.pdf |
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