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Author Levionnois, S.; Tysklind, N.; Nicolini, E.; Ferry, B.; Troispoux, V.; Le Moguedec, G.; Morel, H.; Stahl, C.; Coste, S.; Caron, H.; Heuret, P. pdf  url
doi  openurl
  Title Soil variation response is mediated by growth trajectories rather than functional traits in a widespread pioneer Neotropical tree Type Journal Article
  Year 2020 Publication bioRxiv, peer-reviewed by Peer Community in Ecology Abbreviated Journal  
  Volume (down) 351197 Issue v4 Pages  
  Keywords  
  Abstract Trait-environment relationships have been described at the community level across tree species. However, whether interspecific trait-environment relationships are consistent at the intraspecific level is yet unknown. Moreover, we do not know how consistent is the response between organ vs. whole-tree level.We examined phenotypic variability for 16 functional leaf (dimensions, nutrient, chlorophyll) and wood traits (density) across two soil types, Ferralitic Soil (FS) vs. White Sands (WS), on two sites for 70 adult trees of Cecropia obtusa Trécul (Urticaceae) in French Guiana. Cecropia is a widespread pioneer Neotropical genus that generally dominates early successional forest stages. To understand how soil types impact resource-use through the processes of growth and branching, we examined the architectural development with a retrospective analysis of growth trajectories. We expect soil types to affect both, functional traits in relation to resource acquisition strategy as already described at the interspecific level, and growth strategies due to resource limitations with reduced growth on poor soils.Functional traits were not involved in the soil response, as only two traits-leaf residual water content and K content-showed significant differences across soil types. Soil effects were stronger on growth trajectories, with WS trees having the slowest growth trajectories and less numerous branches across their lifespan.The analysis of growth trajectories based on architectural analysis improved our ability to characterise the response of trees with soil types. The intraspecific variability is higher for growth trajectories than functional traits for C. obtusa, revealing the complementarity of the architectural approach with the functional approach to gain insights on the way trees manage their resources over their lifetime. Soil-related responses of Cecropia functional traits are not the same as those at the interspecific level, suggesting that the effects of the acting ecological processes are different between the two levels. Apart from soil differences, much variation was found across sites, which calls for further investigation of the factors shaping growth trajectories in tropical forests.  
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  Call Number EcoFoG @ webmaster @ Serial 931  
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Author Céréghino, R.; Corbara, B.; Leroy, C.; Carrias, J.-F. doi  openurl
  Title Ecological determinants of community structure across the trophic levels of freshwater food webs: a test using bromeliad phytotelmata Type Journal Article
  Year 2020 Publication Hydrobiologia Abbreviated Journal Hydrobiologia  
  Volume (down) 847 Issue 2 Pages 391-402  
  Keywords Environmental filtering; Functional group; Neotropical; Niche; Trophic interactions; alga; assembly rule; bacterium; community structure; ecological modeling; environmental conditions; food web; freshwater ecosystem; functional group; Neotropic Ecozone; niche; protozoan; taxonomy; trophic interaction; trophic level; algae; Invertebrata; Protozoa  
  Abstract Understanding the relative importance of habitat and biotic drivers on community assembly across food web components is an important step towards predicting the consequences of environmental changes. Because documenting entire food webs is often impractical, this question has been only partially investigated. Here, we partitioned variation in species assemblages of the major components of tank bromeliad food webs (bacteria, algae, protozoans, detritivorous and predatory invertebrates) into habitat and biotic determinants and examined the influence of habitat variables and predator or prey abundance on all taxonomic assemblages. Ecological determinism of assemblage structure ranged from weak in bacteria (< 10% of the explained variance) to strong in predatory invertebrates (90%). Habitat features and canopy openness significantly influenced species assemblages; however, prey or predator density had far and away the most significant structuring effects. If biotic forces are at least as important as the abiotic forces while the importance of stochasticity declines towards upper trophic levels, then trophic levels could respond differently to natural or anthropogenic disturbance and to shifts in species distributions. The effects of such differential responses on food web reconfiguration, however, remain to be elucidated. © 2019, Springer Nature Switzerland AG.  
  Address UMR EcoFoG (AgroParisTech, CIRAD, CNRS, INRA, Université de Guyane, Université des Antilles), Kourou, 97310, France  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 00188158 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 996  
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Author Mirabel, A.; Hérault, B.; Marcon, E. url  doi
openurl 
  Title Diverging taxonomic and functional trajectories following disturbance in a Neotropical forest Type Journal Article
  Year 2020 Publication Science of The Total Environment Abbreviated Journal  
  Volume (down) 720 Issue Pages 137397  
  Keywords Community ecology; Disturbance trajectories; Intermediate disturbance hypothesis; Mid-term resilience; Neotropical forests; Taxonomic and functional biodiversity  
  Abstract In the current global change context, it is urgent to anticipate the fate of tropical forests. This means understanding tree community response to disturbance and the underlying processes. In that respect, we aim here to clarify taxonomic and functional post-disturbance trajectories, and determine the scope of the Intermediate Disturbance Hypothesis (IDH) that remains debated in tropical forests. We analyzed community trajectories following a disturbance gradient from 10 to 60% of above-ground biomass loss in a Neotropical forest over 30 years. We considered trajectories along time of community taxonomic and functional trajectories in terms of richness, evenness, composition, and redundancy. We based on the annual botanical inventories of 75 ha of a Neotropical forest and on large trait datasets comprising seven leaf, stem, and life-history traits. We identified a decoupling between taxonomic composition, differing among communities, and functional composition, similar among communities and convergent in the functional space. The taxonomic diversity followed humped-shaped trajectories along time after disturbance depending on the initial disturbance intensity, which validated the IDH (Intermediate Disturbance Hypothesis). The functional diversity trajectories, however, were homogeneous among plots and dismissed the IDH. We explained this decoupling by the variations in community functional redundancy that mitigated the functional impact of disturbance. Although consistent, the recovery of community composition, diversity, and redundancy remained divergent from the initial state after 30 years. These results acknowledged the need of decades-long cycles without disturbance to ensure community complete recovery.  
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  Call Number EcoFoG @ webmaster @ Serial 920  
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Author Dessert, C.; Clergue, C.; Rousteau, A.; Crispi, O.; Benedetti, M.F. url  doi
openurl 
  Title Atmospheric contribution to cations cycling in highly weathered catchment, Guadeloupe (Lesser Antilles) Type Journal Article
  Year 2020 Publication Chemical Geology Abbreviated Journal Chem. Geol.  
  Volume (down) 531 Issue 119354 Pages  
  Keywords Atmospheric deposit; Cation-nutrient recycling; Critical Zone; Saharan dust; Sr and Nd isotopes; Atmospheric chemistry; Biogeochemistry; Catchments; Deposits; Dust; Ecosystems; Forestry; Isotopes; Lakes; Positive ions; Rain; Recycling; Runoff; Soil moisture; Soil surveys; Tropics; Vegetation; Volcanoes; Weathering; Atmospheric deposits; Critical zones; Nutrient recycling; Saharan dust; Sr and Nd isotopes; Nutrients; catchment; cation; dust; isotopic composition; neodymium isotope; regolith; strontium isotope; trace element; water chemistry; water quality; Guadeloupe; Leeward Islands [Lesser Antilles]; Sahara  
  Abstract The important fertilizing role of atmospheric dust, and particularly African dust, in tropical rainforests is increasingly recognized but still poorly quantified. To better evaluate dust input into the Caribbean basin, we sampled critical zone compartments of a small forested volcanic catchment in Guadeloupe (soils, parent rock, atmospheric dust, plants, soil solutions, stream and rain waters). The aims of this study are to track sources of cation nutrients (Ca, Mg, K, Sr) developed on highly weathered soil in the rainforest of Guadeloupe, to quantify plant recycling of these nutrients, and to identify constraints on regolith development and its associated nutrient pool. In the Quiock Creek catchment, a large isotopic range of 87Sr/86Sr and eNd values was observed despite the small scale of observation. Sr isotopic composition of the dissolved load varied from 0.7084 in rainfall to 0.7110 in soil solution, whereas it ranges between 0.7068 and 0.7153 for soil samples and between 0.7096 and 0.7102 for plants. The Nd isotopic composition varied between -8.39 in near-surface soil samples to 2.71 in deeper soil. All samples had an intermediate signature between that of the bedrock endmember (87Sr/86Sr = 0.7038; eNd = 4.8) and the atmospheric endmember (sea salt: 87Sr/86Sr = 0.7092 and Saharan dust: 87Sr/86Sr = 0.7187, eNd=-11.5). The regolith was built on pyroclastic deposits, but, because of extreme leaching, the regolith has lost its original bedrock signature and inherited an exogenous atmospheric signature. Our results show that only the chemical weathering of the fresh near-surface minerals can provide nutrients to the ecosystem (first 30 cm). However, this dust weathering is too low to sustain the tropical forest ecosystem on its own. The cationic mass balance at the catchment scale, as well as the Sr isotopic signature, show that cation and Sr fluxes are of atmospheric origin only and that original bedrock no longer participates in nutrient cycles. The vegetation reflects the 87Sr/86Sr of the dissolved pool of atmospheric Sr. At the soil-plant scale, the cation-nutrient fluxes provided by vegetation (litter fall + leaf excretion) are major compared to input and output fluxes. The annual Ca, K, Sr and Mg fluxes within the vegetation are, respectively, 31, 28, 20 and 3 times greater than the exported fluxes at the outlet of the basin. The residence time of nutrients in the vegetation is 16 years for K and close to 45 years for Sr, Ca and Mg. These results emphasize the highly efficient vegetative turnover that dominates the nutrient cycle in the Quiock Creek catchment. This first characterization of biogeochemical cycles in the Guadeloupean rainforest suggests that the forest community of Quiock Creek is sustained by a small near-surface nutrient pool disconnected from the deep volcanic bedrock. We also demonstrated that, even with efficient nutrient recycling, Saharan dust plays a significant role in maintaining ecosystem productivity in Guadeloupe over long-time scales.  
  Address Laboratoire de biologie et de physiologie végétales, UMR EcoFoG, CNRS, Cirad, INRA, Université des Antilles, Université de Guyane, Pointe-à-Pitre, 97159, France  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 00092541 (Issn) ISBN Medium  
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  Notes Export Date: 18 November 2019; Correspondence Address: Dessert, C.; Université de Paris, Institut de physique du globe de Paris, CNRSFrance; email: dessert@ipgp.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 895  
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Author Van Langenhove, L.; Depaepe, T.; Vicca, S.; van den Berge, J.; Stahl, C.; Courtois, E.; Weedon, J.; Urbina, I.; Grau, O.; Asensio, D.; Peñuelas, J.; Boeckx, P.; Richter, A.; Van Der Straeten, D.; Janssens, I.A. doi  openurl
  Title Regulation of nitrogen fixation from free-living organisms in soil and leaf litter of two tropical forests of the Guiana shield Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume (down) 450 Issue 1-2 Pages 93-110  
  Keywords Free-living nitrogen fixation; French Guiana; Molybdenum; Nutrients; Phosphorus; Tropical forest; acetylene; leaf litter; molybdenum; nitrogen fixation; nutrient cycling; phosphorus; rainforest; reduction; soil biota; soil carbon; soil nitrogen; soil water; topographic effect; tropical forest; French Guiana  
  Abstract Background and aims: Biological fixation of atmospheric nitrogen (N2) is the main pathway for introducing N into unmanaged ecosystems. While recent estimates suggest that free-living N fixation (FLNF) accounts for the majority of N fixed in mature tropical forests, the controls governing this process are not completely understood. The aim of this study was to quantify FLNF rates and determine its drivers in two tropical pristine forests of French Guiana. Methods: We used the acetylene reduction assay to measure FLNF rates at two sites, in two seasons and along three topographical positions, and used regression analyses to identify which edaphic explanatory variables, including carbon (C), nitrogen (N), phosphorus (P) and molybdenum (Mo) content, pH, water and available N and P, explained most of the variation in FLNF rates. Results: Overall, FLNF rates were lower than measured in tropical systems elsewhere. In soils seasonal variability was small and FLNF rates differed among topographies at only one site. Water, P and pH explained 24% of the variation. In leaf litter, FLNF rates differed seasonally, without site or topographical differences. Water, C, N and P explained 46% of the observed variation. We found no regulatory role of Mo at our sites. Conclusions: Rates of FLNF were low in primary rainforest on poor soils on the Guiana shield. Water was the most important rate-regulating factor and FLNF increased with increasing P, but decreased with increasing N. Our results support the general assumption that N fixation in tropical lowland forests is limited by P availability. © 2019, The Author(s).  
  Address Department of Microbiology and Ecosystem Science, University of Vienna, Althanstr. 14, Vienna, 1090, Austria  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN 0032079x (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 971  
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Author Urbina, I.; Grau, O.; Sardans, J.; Ninot, J.M.; Peñuelas, J. doi  openurl
  Title Encroachment of shrubs into subalpine grasslands in the Pyrenees changes the plant-soil stoichiometry spectrum Type Journal Article
  Year 2020 Publication Plant and Soil Abbreviated Journal Plant Soil  
  Volume (down) 448 Issue 1-2 Pages 37-53  
  Keywords Nutrient stocks; Plant strategy; Plant-soil stoichiometry; Shrub encroachment; Subalpine grassland succession; aboveground biomass; biogeochemical cycle; carbon sequestration; ectomycorrhiza; fungus; grass; nitrogen; nutrient uptake; shrub; soil-vegetation interaction; stoichiometry; subalpine environment; succession; Europe; Pyrenees; Fungi  
  Abstract Aims: Shrub encroachment has been reported over a large proportion of the subalpine grasslands across Europe and is expected to have an important impact on the biogeochemical cycle of these ecosystems. We investigated the stoichiometric changes in the plant-soil system along the succession (e.g. increase in encroachment from unencroached grassland to mature shrubland) at two contrasting sites in the Pyrenees. Methods: We analyzed the chemical composition (C, N,15N, P, K, Ca, Mg and Fe) in the soil and in the aboveground plant compartments (leaves, leaf-litter and stems) of the main herbaceous species and shrubs at three contrasting stages of the succession: unencroached grassland, young shrubland and mature shrubland. Results: The plant-soil stoichiometry spectrum differed between the successional stages. Shrub encroachment generally increased the concentration of C and Ca and the C:N ratio and often reduced to concentrations of N, P and K in the leaves and leaf-litter, while several soil nutrient concentrations (N, P, K Ca and Mg) decreased. The stocks of C, N, P, Ca, and Mg in the total aboveground biomass increased with encroachment. Conclusions: Shrub encroachment favored the dominance of long-lived species with low concentrations of N and P in the plant-soil compartments, high C:nutrient ratios in the aboveground biomass and increase the uptake of N through ericoid or ectomycorrhizal fungi. We highlight the role of shrubs in the sequestration of C and nutrients through the allocation to the aboveground biomass. The changes in plant-soil elemental composition and stocks suggest a slowdown of the biogeochemical cycles in the subalpine mountain areas where shrub encroachment occurred. © 2020, Springer Nature Switzerland AG.  
  Address Biodiversity Research Institute (IRBio) and Department of Evolutionary Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Catalonia, Spain  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0032079x (Issn) ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 983  
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Author Sullivan, M.J.P.; Lewis, S.L.; Affum-Baffoe, K.; Castilho, C.; Costa, F.; Sanchez, A.C.; Ewango, C.E.N.; Hubau, W.; Marimon, B.; Monteagudo-Mendoza, A.; Qie, L.; Sonké, B.; Martinez, R.V.; Baker, T.R.; Brienen, R.J.W.; Feldpausch, T.R.; Galbraith, D.; Gloor, M.; Malhi, Y.; Aiba, S.-I.; Alexiades, M.N.; Almeida, E.C.; de Oliveira, E.A.; Dávila, E.Á.; Loayza, P.A.; Andrade, A.; Vieira, S.A.; Aragão, L.E.O.C.; Araujo-Murakami, A.; Arets, E.J.M.M.; Arroyo, L.; Ashton, P.; Aymard C., G.; Baccaro, F.B.; Banin, L.F.; Baraloto, C.; Camargo, P.B.; Barlow, J.; Barroso, J.; Bastin, J.-F.; Batterman, S.A.; Beeckman, H.; Begne, S.K.; Bennett, A.C.; Berenguer, E.; Berry, N.; Blanc, L.; Boeckx, P.; Bogaert, J.; Bonal, D.; Bongers, F.; Bradford, M.; Brearley, F.Q.; Brncic, T.; Brown, F.; Burban, B.; Camargo, J.L.; Castro, W.; Céron, C.; Ribeiro, S.C.; Moscoso, V.C.; Chave, J.; Chezeaux, E.; Clark, C.J.; de Souza, F.C.; Collins, M.; Comiskey, J.A.; Valverde, F.C.; Medina, M.C.; da Costa, L.; Dančák, M.; Dargie, G.C.; Davies, S.; Cardozo, N.D.; de Haulleville, T.; de Medeiros, M.B.; del Aguila Pasquel, J.; Derroire, G.; Di Fiore, A.; Doucet, J.-L.; Dourdain, A.; Droissant, V.; Duque, L.F.; Ekoungoulou, R.; Elias, F.; Erwin, T.; Esquivel-Muelbert, A.; Fauset, S.; Ferreira, J.; Llampazo, G.F.; Foli, E.; Ford, A.; Gilpin, M.; Hall, J.S.; Hamer, K.C.; Hamilton, A.C.; Harris, D.J.; Hart, T.B.; Hédl, R.; Herault, B.; Herrera, R.; Higuchi, N.; Hladik, A.; Coronado, E.H.; Huamantupa-Chuquimaco, I.; Huasco, W.H.; Jeffery, K.J.; Jimenez-Rojas, E.; Kalamandeen, M.; Djuikouo, M.N.K.; Kearsley, E.; Umetsu, R.K.; Kho, L.K.; Killeen, T.; Kitayama, K.; Klitgaard, B.; Koch, A.; Labrière, N.; Laurance, W.; Laurance, S.; Leal, M.E.; Levesley, A.; Lima, A.J.N.; Lisingo, J.; Lopes, A.P.; Lopez-Gonzalez, G.; Lovejoy, T.; Lovett, J.C.; Lowe, R.; Magnusson, W.E.; Malumbres-Olarte, J.; Manzatto, Â.G.; Marimon, B.H.; Marshall, A.R.; Marthews, T.; de Almeida Reis, S.M.; Maycock, C.; Melgaço, K.; Mendoza, C.; Metali, F.; Mihindou, V.; Milliken, W.; Mitchard, E.T.A.; Morandi, P.S.; Mossman, H.L.; Nagy, L.; Nascimento, H.; Neill, D.; Nilus, R.; Vargas, P.N.; Palacios, W.; Camacho, N.P.; Peacock, J.; Pendry, C.; Peñuela Mora, M.C.; Pickavance, G.C.; Pipoly, J.; Pitman, N.; Playfair, M.; Poorter, L.; Poulsen, J.R.; Poulsen, A.D.; Preziosi, R.; Prieto, A.; Primack, R.B.; Ramírez-Angulo, H.; Reitsma, J.; Réjou-Méchain, M.; Correa, Z.R.; de Sousa, T.R.; Bayona, L.R.; Roopsind, A.; Rudas, A.; Rutishauser, E.; Abu Salim, K.; Salomão, R.P.; Schietti, J.; Sheil, D.; Silva, R.C.; Espejo, J.S.; Valeria, C.S.; Silveira, M.; Simo-Droissart, M.; Simon, M.F.; Singh, J.; Soto Shareva, Y.C.; Stahl, C.; Stropp, J.; Sukri, R.; Sunderland, T.; Svátek, M.; Swaine, M.D.; Swamy, V.; Taedoumg, H.; Talbot, J.; Taplin, J.; Taylor, D.; ter Steege, H.; Terborgh, J.; Thomas, R.; Thomas, S.C.; Torres-Lezama, A.; Umunay, P.; Gamarra, L.V.; van der Heijden, G.; van der Hout, P.; van der Meer, P.; van Nieuwstadt, M.; Verbeeck, H.; Vernimmen, R.; Vicentini, A.; Vieira, I.C.G.; Torre, E.V.; Vleminckx, J.; Vos, V.; Wang, O.; White, L.J.T.; Willcock, S.; Woods, J.T.; Wortel, V.; Young, K.; Zagt, R.; Zemagho, L.; Zuidema, P.A.; Zwerts, J.A.; Phillips, O.L. url  doi
openurl 
  Title Long-term thermal sensitivity of Earth’s tropical forests Type Journal Article
  Year 2020 Publication Science Abbreviated Journal  
  Volume (down) 368 Issue 6493 Pages 869-874  
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  Abstract A key uncertainty in climate change models is the thermal sensitivity of tropical forests and how this value might influence carbon fluxes. Sullivan et al. measured carbon stocks and fluxes in permanent forest plots distributed globally. This synthesis of plot networks across climatic and biogeographic gradients shows that forest thermal sensitivity is dominated by high daytime temperatures. This extreme condition depresses growth rates and shortens the time that carbon resides in the ecosystem by killing trees under hot, dry conditions. The effect of temperature is worse above 32°C, and a greater magnitude of climate change thus risks greater loss of tropical forest carbon stocks. Nevertheless, forest carbon stocks are likely to remain higher under moderate climate change if they are protected from direct impacts such as clearance, logging, or fires.Science, this issue p. 869The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate.  
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Author Croft, H.; Chen, J.M.; Wang, R.; Mo, G.; Luo, S.; Luo, X.; He, L.; Gonsamo, A.; Arabian, J.; Zhang, Y.; Simic-Milas, A.; Noland, T.L.; He, Y.; Homolová, L.; Malenovský, Z.; Yi, Q.; Beringer, J.; Amiri, R.; Hutley, L.; Arellano, P.; Stahl, C.; Bonal, D. url  doi
openurl 
  Title The global distribution of leaf chlorophyll content Type Journal Article
  Year 2020 Publication Remote Sensing of Environment Abbreviated Journal Remote Sens. Environ.  
  Volume (down) 236 Issue 111479 Pages  
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  Abstract Leaf chlorophyll is central to the exchange of carbon, water and energy between the biosphere and the atmosphere, and to the functioning of terrestrial ecosystems. This paper presents the first spatially-continuous view of terrestrial leaf chlorophyll content (ChlLeaf) at the global scale. Weekly maps of ChlLeaf were produced from ENVISAT MERIS full resolution (300 m) satellite data using a two-stage physically-based radiative transfer modelling approach. Firstly, leaf-level reflectance was derived from top-of-canopy satellite reflectance observations using 4-Scale and SAIL canopy radiative transfer models for woody and non-woody vegetation, respectively. Secondly, the modelled leaf-level reflectance was input into the PROSPECT leaf-level radiative transfer model to derive ChlLeaf. The ChlLeaf retrieval algorithm was validated using measured ChlLeaf data from 248 sample measurements at 28 field locations, and covering six plant functional types (PFTs). Modelled results show strong relationships with field measurements, particularly for deciduous broadleaf forests (R2 = 0.67; RMSE = 9.25 microg cm-2; p < 0.001), croplands (R2 = 0.41; RMSE = 13.18 microg cm-2; p < 0.001) and evergreen needleleaf forests (R2 = 0.47; RMSE = 10.63 microg cm-2; p < 0.001). When the modelled results from all PFTs were considered together, the overall relationship with measured ChlLeaf remained good (R2 = 0.47, RMSE = 10.79 microg cm-2; p < 0.001). This result is an improvement on the relationship between measured ChlLeaf and a commonly used chlorophyll-sensitive spectral vegetation index; the MERIS Terrestrial Chlorophyll Index (MTCI; R2 = 0.27, p < 0.001). The global maps show large temporal and spatial variability in ChlLeaf, with evergreen broadleaf forests presenting the highest leaf chlorophyll values, with global annual median values of 54.4 microg cm-2. Distinct seasonal ChlLeaf phenologies are also visible, particularly in deciduous plant forms, associated with budburst and crop growth, and leaf senescence. It is anticipated that this global ChlLeaf product will make an important step towards the explicit consideration of leaf-level biochemistry in terrestrial water, energy and carbon cycle modelling.  
  Address UMR EEF, INRA Université de Lorraine, Champenoux54280, France  
  Corporate Author Thesis  
  Publisher Elsevier Inc. Place of Publication Editor  
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  Series Volume Series Issue Edition  
  ISSN 00344257 (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 898  
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Author Levionnois, S.; Ziegler, C.; Jansen, S.; Calvet, E.; Coste, S.; Stahl, C.; Salmon, C.; Delzon, S.; Guichard, C.; Heuret, P. doi  openurl
  Title Vulnerability and hydraulic segmentations at the stem–leaf transition: coordination across Neotropical trees Type Journal Article
  Year 2020 Publication New Phytologist Abbreviated Journal New Phytol.  
  Volume (down) 228 Issue 2 Pages 512-524  
  Keywords drought-induced embolism resistance; hydraulic segmentation; leaf-specific conductivity; stem–leaf transition; tropical trees; vulnerability segmentation; air bubble; hydraulic conductivity; leaf; Neotropical Region; rainforest; tropical forest; vulnerability; xylem  
  Abstract Hydraulic segmentation at the stem–leaf transition predicts higher hydraulic resistance in leaves than in stems. Vulnerability segmentation, however, predicts lower embolism resistance in leaves. Both mechanisms should theoretically favour runaway embolism in leaves to preserve expensive organs such as stems, and should be tested for any potential coordination. We investigated the theoretical leaf-specific conductivity based on an anatomical approach to quantify the degree of hydraulic segmentation across 21 tropical rainforest tree species. Xylem resistance to embolism in stems (flow-centrifugation technique) and leaves (optical visualization method) was quantified to assess vulnerability segmentation. We found a pervasive hydraulic segmentation across species, but with a strong variability in the degree of segmentation. Despite a clear continuum in the degree of vulnerability segmentation, eight species showed a positive vulnerability segmentation (leaves less resistant to embolism than stems), whereas the remaining species studied exhibited a negative or no vulnerability segmentation. The degree of vulnerability segmentation was positively related to the degree of hydraulic segmentation, such that segmented species promote both mechanisms to hydraulically decouple leaf xylem from stem xylem. To what extent hydraulic and vulnerability segmentation determine drought resistance requires further integration of the leaf–stem transition at the whole-plant level, including both xylem and outer xylem tissue. © 2020 The Authors. New Phytologist © 2020 New Phytologist Trust  
  Address Univ. Bordeaux, INRAE, BIOGECO, Pessac, F-33615, France  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
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  Series Volume Series Issue Edition  
  ISSN 0028646x (Issn) ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 952  
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Author Fortunel, C.; Stahl, C.; Heuret, P.; Nicolini, E.; Baraloto, C. doi  openurl
  Title Disentangling the effects of environment and ontogeny on tree functional dimensions for congeneric species in tropical forests Type Journal Article
  Year 2020 Publication New Phytologist Abbreviated Journal New Phytol.  
  Volume (down) 226 Issue 2 Pages 385-395  
  Keywords chemistry; developmental stage; habitats; Micropholis; morphology; physiology; plant traits; seasons; developmental stage; ecosystem function; forest ecosystem; habitat selection; habitat structure; nutrient availability; ontogeny; physiological response; soil water; taxonomy; tropical forest; Amazonia  
  Abstract Soil water and nutrient availability are key drivers of tree species distribution and forest ecosystem functioning, with strong species differences in water and nutrient use. Despite growing evidence for intraspecific trait differences, it remains unclear under which circumstances the effects of environmental gradients trump those of ontogeny and taxonomy on important functional dimensions related to resource use, particularly in tropical forests. Here, we explore how physiological, chemical, and morphological traits related to resource use vary between life stages in four species within the genus Micropholis that is widespread in lowland Amazonia. Specifically, we evaluate how environment, developmental stage, and taxonomy contribute to single-trait variation and multidimensional functional strategies. We find that environment, developmental stage, and taxonomy differentially contribute to functional dimensions. Habitats and seasons shape physiological and chemical traits related to water and nutrient use, whereas developmental stage and taxonomic identity impact morphological traits –especially those related to the leaf economics spectrum. Our findings suggest that combining environment, ontogeny, and taxonomy allows for a better understanding of important functional dimensions in tropical trees and highlights the need for integrating tree physiological and chemical traits with classically used morphological traits to improve predictions of tropical forests’ responses to environmental change. © 2019 The Authors New Phytologist © 2019 New Phytologist Trust  
  Address Department of Biological Sciences, Florida International University, Miami, FL 33133, United States  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0028646x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 977  
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