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Author Talaga, S.; Dejean, A.; Azémar, F.; Dumont, Y.; Leroy, C. doi  openurl
  Title Impacts of biotic and abiotic parameters on immature populations of Aedes aegypti Type Journal Article
  Year 2020 Publication Journal of Pest Science Abbreviated Journal J. Pest Sci.  
  Volume 93 Issue 3 Pages 941-952  
  Keywords Biocontrol agents; Competition; Ecosystem services; Mosquito control; Mosquito management; Predation; abiotic factor; biotic factor; competitive displacement; disease vector; maturation; mosquito; pest control; Aedes aegypti; Hexapoda; Zika virus  
  Abstract In recent centuries, the mosquito Aedes aegypti has spread into most urban areas throughout the tropics. This species is considered the main vector of the chikungunya, dengue, yellow fever and Zika viruses and causes major public health issues. The aim of this study is to investigate the relative influence of biotic and abiotic parameters on immature populations of Ae. aegypti. During a one-year-long field experiment, we monitored 108 macroinvertebrate aquatic communities inhabiting four types of water containers across three different urbanized sites in a Neotropical city. A multimodel inference approach revealed that, in addition to abiotic parameters, biotic interactions with aquatic organisms had an important influence on the abundance of Ae. aegypti and that the urbanized site considered influences the outcomes of the interactions. Controphic species other than mosquitoes aided Ae. aegypti development, suggesting a mechanism of facilitation through a chain of processes. However, the abundance of Ae. aegypti was lowered by competition with native mosquito species in the slightly urbanized area and by predation in more urbanized areas. Competitive displacement and reduction, as well as predation by native aquatic organisms, can be considered a form of ecosystem service. The conservation and/or augmentation of natural enemies should improve the short- and long-term success of incompatible and/or sterile insect techniques, thus opening up perspectives for the future of mosquito management. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.  
  Address University of Pretoria, Department of Mathematics and Applied Mathematics, Pretoria, South Africa  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 16124758 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 962  
Permanent link to this record
 

 
Author Verryckt, L.T.; Van Langenhove, L.; Ciais, P.; Courtois, E.A.; Vicca, S.; Peñuelas, J.; Stahl, C.; Coste, S.; Ellsworth, D.S.; Posada, J.M.; Obersteiner, M.; Chave, J.; Janssens, I.A. doi  openurl
  Title Coping with branch excision when measuring leaf net photosynthetic rates in a lowland tropical forest Type Journal Article
  Year 2020 Publication Biotropica Abbreviated Journal Biotropica  
  Volume 52 Issue 4 Pages 608-615  
  Keywords branch cutting; canopy physiology; French Guiana; gas exchange; photosynthesis; rainforest; stomatal conductance; ecological modeling; environmental conditions; forest canopy; leaf; measurement method; photosynthesis; tree; tropical forest; Gruidae  
  Abstract 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 branches. We selected branches positioned at three canopy positions, estimated relative to the top of the canopy: upper sunlit foliage, middle canopy foliage, and lower canopy foliage. We studied the variation of the effects of branch excision and transport among branches at these different heights in the canopy. After excision and transport, light-saturated leaf net photosynthetic rates were close to zero for most leaves due to stomatal closure. However, when the branch had acclimated to its new environmental conditions—which took on average 20 min—light-saturated leaf net photosynthetic rates did not significantly differ between the excised and intact branches. We therefore conclude that branch excision does not affect the measurement of light-saturated leaf net photosynthesis, provided that the branch is recut under water and is allowed sufficient time to acclimate to its new environmental conditions. © 2020 The Association for Tropical Biology and Conservation  
  Address UMR 5174 Laboratoire Evolution et Diversité Biologique, Université Paul Sabatier, CNRS, Toulouse, France  
  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 00063606 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 960  
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Author Donald, J.; Maxfield, P.; Leroy, C.; Ellwood, M.D.F. doi  openurl
  Title Epiphytic suspended soils from Borneo and Amazonia differ in their microbial community composition Type Journal Article
  Year 2020 Publication Acta Oecologica Abbreviated Journal Acta Oecol.  
  Volume 106 Issue Pages  
  Keywords Asplenium; Bacteria; Borneo; Bromeliaceae; Canopy; French Guiana; Fungi; Plfa; Rainforest; bacterium; community composition; epiphyte; fungus; microbial community; niche; relative abundance; soil microorganism; species diversity; tropical forest; Amazonia; Borneo; Danum Valley; East Malaysia; French Guiana; Malaysia; Nouragues; Sabah; Asplenium; Asplenium nidus; Aves; Bacteria (microorganisms); Bromeliaceae; Fungi  
  Abstract Microbial organisms support the high species diversity associated with tropical forests, and likely drive functional processes, but microorganisms found in rainforest canopies are not well understood. We quantified the microbial diversity of suspended soils from two classical epiphytic model systems (bromeliads & bird's nest ferns) across two localities: the Nouragues Reserve in French Guiana and Danum Valley in Malaysian Borneo. Non-epiphytic suspended soils were also collected as controls at the Nouragues Reserve. Effects of epiphyte type and sample location on microbial community composition were determined using Phospholipid Fatty Acid (PLFA) analysis. Total microbial biomass remained constant across the suspended soil types, but PLFA peaks denoting the relative abundance of different microbes varied between bromeliads, bird's nest ferns and non-epiphytic control soils. Suspended soils associated with bird's nest ferns from Borneo contained a microbial community significantly different in composition from those of congeneric bird's nest ferns from Amazonia, due to shifts in the relative abundance of fungi and bacteria. Our findings reveal that epiphytes create convergent niches for microorganisms in tropical canopies, while highlighting the sensitive nature of suspended soil microbial communities. © 2020 Elsevier Masson SAS  
  Address 20 Baily Place, Cheswick, Bristol, BS16 1BG, United Kingdom  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1146609x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 959  
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Author Pastorello, G.; Trotta, C.; Canfora, E.; Chu, H.; Christianson, D.; Cheah, Y.-W.; Poindexter, C.; Chen, J.; Elbashandy, A.; Humphrey, M.; Isaac, P.; Polidori, D.; Ribeca, A.; van Ingen, C.; Zhang, L.; Amiro, B.; Ammann, C.; Arain, M.A.; Ardö, J.; Arkebauer, T.; Arndt, S.K.; Arriga, N.; Aubinet, M.; Aurela, M.; Baldocchi, D.; Barr, A.; Beamesderfer, E.; Marchesini, L.B.; Bergeron, O.; Beringer, J.; Bernhofer, C.; Berveiller, D.; Billesbach, D.; Black, T.A.; Blanken, P.D.; Bohrer, G.; Boike, J.; Bolstad, P.V.; Bonal, D.; Bonnefond, J.-M.; Bowling, D.R.; Bracho, R.; Brodeur, J.; Brümmer, C.; Buchmann, N.; Burban, B.; Burns, S.P.; Buysse, P.; Cale, P.; Cavagna, M.; Cellier, P.; Chen, S.; Chini, I.; Christensen, T.R.; Cleverly, J.; Collalti, A.; Consalvo, C.; Cook, B.D.; Cook, D.; Coursolle, C.; Cremonese, E.; Curtis, P.S.; D'Andrea, E.; da Rocha, H.; Dai, X.; Davis, K.J.; De Cinti, B.; de Grandcourt, A.; De Ligne, A.; De Oliveira, R.C.; Delpierre, N.; Desai, A.R.; Di Bella, C.M.; di Tommasi, P.; Dolman, H.; Domingo, F.; Dong, G.; Dore, S.; Duce, P.; Dufrêne, E.; Dunn, A.; Dušek, J.; Eamus, D.; Eichelmann, U.; ElKhidir, H.A.M.; Eugster, W.; Ewenz, C.M.; Ewers, B.; Famulari, D.; Fares, S.; Feigenwinter, I.; Feitz, A.; Fensholt, R.; Filippa, G.; Fischer, M.; Frank, J.; Galvagno, M.; Gharun, M.; Gianelle, D.; Gielen, B.; Gioli, B.; Gitelson, A.; Goded, I.; Goeckede, M.; Goldstein, A.H.; Gough, C.M.; Goulden, M.L.; Graf, A.; Griebel, A.; Gruening, C.; Grünwald, T.; Hammerle, A.; Han, S.; Han, X.; Hansen, B.U.; Hanson, C.; Hatakka, J.; He, Y.; Hehn, M.; Heinesch, B.; Hinko-Najera, N.; Hörtnagl, L.; Hutley, L.; Ibrom, A.; Ikawa, H.; Jackowicz-Korczynski, M.; Janouš, D.; Jans, W.; Jassal, R.; Jiang, S.; Kato, T.; Khomik, M.; Klatt, J.; Knohl, A.; Knox, S.; Kobayashi, H.; Koerber, G.; Kolle, O.; Kosugi, Y.; Kotani, A.; Kowalski, A.; Kruijt, B.; Kurbatova, J.; Kutsch, W.L.; Kwon, H.; Launiainen, S.; Laurila, T.; Law, B.; Leuning, R.; Li, Y.; Liddell, M.; Limousin, J.-M.; Lion, M.; Liska, A.J.; Lohila, A.; López-Ballesteros, A.; López-Blanco, E.; Loubet, B.; Loustau, D.; Lucas-Moffat, A.; Lüers, J.; Ma, S.; Macfarlane, C.; Magliulo, V.; Maier, R.; Mammarella, I.; Manca, G.; Marcolla, B.; Margolis, H.A.; Marras, S.; Massman, W.; Mastepanov, M.; Matamala, R.; Matthes, J.H.; Mazzenga, F.; McCaughey, H.; McHugh, I.; McMillan, A.M.S.; Merbold, L.; Meyer, W.; Meyers, T.; Miller, S.D.; Minerbi, S.; Moderow, U.; Monson, R.K.; Montagnani, L.; Moore, C.E.; Moors, E.; Moreaux, V.; Moureaux, C.; Munger, J.W.; Nakai, T.; Neirynck, J.; Nesic, Z.; Nicolini, G.; Noormets, A.; Northwood, M.; Nosetto, M.; Nouvellon, Y.; Novick, K.; Oechel, W.; Olesen, J.E.; Ourcival, J.-M.; Papuga, S.A.; Parmentier, F.-J.; Paul-Limoges, E.; Pavelka, M.; Peichl, M.; Pendall, E.; Phillips, R.P.; Pilegaard, K.; Pirk, N.; Posse, G.; Powell, T.; Prasse, H.; Prober, S.M.; Rambal, S.; Rannik, Ü.; Raz-Yaseef, N.; Reed, D.; de Dios, V.R.; Restrepo-Coupe, N.; Reverter, B.R.; Roland, M.; Sabbatini, S.; Sachs, T.; Saleska, S.R.; Sánchez-Cañete, E.P.; Sanchez-Mejia, Z.M.; Schmid, H.P.; Schmidt, M.; Schneider, K.; Schrader, F.; Schroder, I.; Scott, R.L.; Sedlák, P.; Serrano-Ortíz, P.; Shao, C.; Shi, P.; Shironya, I.; Siebicke, L.; Šigut, L.; Silberstein, R.; Sirca, C.; Spano, D.; Steinbrecher, R.; Stevens, R.M.; Sturtevant, C.; Suyker, A.; Tagesson, T.; Takanashi, S.; Tang, Y.; Tapper, N.; Thom, J.; Tiedemann, F.; Tomassucci, M.; Tuovinen, J.-P.; Urbanski, S.; Valentini, R.; van der Molen, M.; van Gorsel, E.; van Huissteden, K.; Varlagin, A.; Verfaillie, J.; Vesala, T.; Vincke, C.; Vitale, D.; Vygodskaya, N.; Walker, J.P.; Walter-Shea, E.; Wang, H.; Weber, R.; Westermann, S.; Wille, C.; Wofsy, S.; Wohlfahrt, G.; Wolf, S.; Woodgate, W.; Li, Y.; Zampedri, R.; Zhang, J.; Zhou, G.; Zona, D.; Agarwal, D.; Biraud, S.; Torn, M.; Papale, D. doi  openurl
  Title The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data Type Journal Article
  Year 2020 Publication Scientific data Abbreviated Journal Sci Data  
  Volume 7 Issue 1 Pages 225  
  Keywords article; breathing; ecophysiology; ecosystem; Eddy covariance; licence; metadata; photosynthesis; pipeline; remote sensing; time series analysis; uncertainty  
  Abstract The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.  
  Address Euro-Mediterranean Centre on Climate Change Foundation (CMCC), Lecce, 73100, Italy  
  Corporate Author Thesis  
  Publisher NLM (Medline) Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 20524463 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 958  
Permanent link to this record
 

 
Author 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. doi  openurl
  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  
  Keywords 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  
  Abstract 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.  
  Address AMAP, Univ Montpellier, IRD, CIRAD, CNRS, INRAE, Montpellier, France  
  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 21698953 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 957  
Permanent link to this record
 

 
Author Dejean, A.; Petitclerc, F.; Azémar, F. doi  openurl
  Title Seasonality influences ant-mediated nutrient acquisition (myrmecotrophy) by a Neotropical myrmecophyte Type Journal Article
  Year 2020 Publication Evolutionary Ecology Abbreviated Journal Evol. Ecol.  
  Volume 34 Issue 4 Pages 645-657  
  Keywords Ant-plant relationships; Mutualism; Myrmecophyte; Myrmecotrophy; Phenology; Stable isotopes; ant; herb; host plant; life cycle; myrmecochory; myrmecophyte; Neotropical Region; phenology; seasonality; stable isotope; understory; Gentianaceae; Tachia; Tachia guianensis  
  Abstract Tachia guianensis (Gentianaceae), a Neotropical understory myrmecophyte, shelters ant colonies in its hollow trunks and branches (domatia). In turn, it is protected from defoliators and obtains nutrients from ant-produced wastes (myrmecotrophy). Aiming to verify if seasonality influences nitrogen assimilation via ant wastes using the stable isotope nitrogen-15, we first studied Tachia’s phenology and its seasonal leaf production, and then the life cycle of its two more frequent guest ant species. We found that leaf production was much higher during the rainy than the dry season. Mature guest ant colonies produced sexuals regardless of the season and the net weight of the waste piles inside the domatia did not vary between seasons, so that the availability of nutrients to their host plant is steady year-long. By providing the two most frequent mutualistic guest ant species with food enriched with nitrogen-15, we showed that Tachia individuals assimilate more nitrogen from ant wastes during the rainy season, when the plant is physiologically active, compared to the dry season. Thus, one can deduce that the increase in nitrogen assimilation during the rainy season is determined by the increase in Tachia’s physiological activity during that season. Information gathered through a bibliographic compilation confirms that none of the 15 ant species known to be associated with myrmecophytes for which the life cycle was studied is characterized by seasonal reproduction (which would result in fluctuating waste production). The same is true for 49.7% of 167 tropical ant species (seasonal production for the remaining species). We concluded that, in contrast to the non-seasonal ant colony reproductive cycle, Tachia’s phenology determines the myrmecotrophic assimilation rate. © 2020, Springer Nature Switzerland AG.  
  Address CNRS, UMR EcoFoG, AgroParisTech, CIRAD, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 02697653 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 956  
Permanent link to this record
 

 
Author Perrot, T.; Guillaume, S.; Nadine, A.; Jacques, B.; Philippe, G.; Stéphane, D.; Rodnay, S.; Mélanie, M.-R.; Eric, G. doi  openurl
  Title A reverse chemical ecology approach to explore wood natural durability Type Journal Article
  Year 2020 Publication Microbial Biotechnology Abbreviated Journal Microb. Biotechnol.  
  Volume 13 Issue 5 Pages 1673-1677  
  Keywords glutathione transferase; Article; biodegradation; data base; detoxification; ecology; enzyme activity; enzyme metabolism; forest; molecular dynamics; physical parameters; species identification; thermal analysis; Trametes versicolor; wood; wood durability  
  Abstract The natural durability of wood species, defined as their inherent resistance to wood-destroying agents, is a complex phenomenon depending on many biotic and abiotic factors. Besides the presence of recalcitrant polymers, the presence of compounds with antimicrobial properties is known to be important to explain wood durability. Based on the advancement in our understanding of fungal detoxification systems, a reverse chemical ecology approach was proposed to explore wood natural durability using fungal glutathione transferases. A set of six glutathione transferases from the white-rot Trametes versicolor were used as targets to test wood extracts from seventeen French Guiana neotropical species. Fluorescent thermal shift assays quantified interactions between fungal glutathione transferases and these extracts. From these data, a model combining this approach and wood density significantly predicts the wood natural durability of the species tested previously using long-term soil bed tests. Overall, our findings confirm that detoxification systems could be used to explore the chemical environment encountered by wood-decaying fungi and also wood natural durability. © 2020 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.  
  Address Université de Lorraine, INRAE, LERMAB, Nancy, France  
  Corporate Author Thesis  
  Publisher John Wiley and Sons Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 17517907 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 955  
Permanent link to this record
 

 
Author Sardans, J.; Urbina, I.; Grau, O.; Asensio, D.; Ogaya, R.; Peñuelas, J. doi  openurl
  Title Long-term drought decreases ecosystem C and nutrient storage in a Mediterranean holm oak forest Type Journal Article
  Year 2020 Publication Environmental and Experimental Botany Abbreviated Journal Environ. Exp. Bot.  
  Volume 177 Issue 104135 Pages  
  Keywords Aridity; Carbon stocks; Climate change; Nitrogen; Phosphorus; Potassium; Stoichiometry; carbon sequestration; deciduous forest; drought; experimental study; forest soil; long-term change; Mediterranean environment; net ecosystem exchange; nutrient cycling; shrub; stoichiometry; Mediterranean Sea; Phillyrea latifolia  
  Abstract Aridity has increased in recent decades in the Mediterranean Basin and is projected to continue to increase in the coming decades. We studied the consequences of drought on the concentrations, stoichiometries and stocks of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in leaves, foliar litter of a three dominant woody species and soil of a Mediterranean montane holm oak forest where soil-water content was experimentally reduced (15 % lower than the control plots) for 15 years. Nitrogen stocks were lower in the drought plots than in the control plots (8.81 ± 1.01 kg ha−1 in the forest canopy and 856 ± 120 kg ha−1 in the 0−15 cm soil layer), thus representing 7 and 18 % lower N stocks in the canopy and soil respectively. δ15N was consistently higher under drought conditions in all samples, indicating a general loss of N. Foliar C and K stocks were also lower but to a lesser extent than N. Decreases in biomass and C and N stocks due to drought were smallest for the most dominant tall shrub, Phillyrea latifolia, so our results suggest a lower capacity of this forest to store C and nutrients but also substantial resulting changes in forest structure with increasing drought. © 2020 Elsevier B.V.  
  Address Cirad, UMR EcoFoG (AgroParisTech, CNRS, Inra, Univ Antilles, Univ Guyane), Campus Agronomique, Kourou, 97310, French Guiana  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00988472 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 954  
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Author Ziegler, C.; Dusenge, M.E.; Nyirambangutse, B.; Zibera, E.; Wallin, G.; Uddling, J. doi  openurl
  Title Contrasting Dependencies of Photosynthetic Capacity on Leaf Nitrogen in Early- and Late-Successional Tropical Montane Tree Species Type Journal Article
  Year 2020 Publication Frontiers in Plant Science Abbreviated Journal Front. Plant Sci.  
  Volume 11 Issue Pages 500479  
  Keywords allocation; early successional; late successional; nitrogen; photosynthesis; tropical montane forests  
  Abstract Differences in photosynthetic capacity among tree species and tree functional types are currently assumed to be largely driven by variation in leaf nutrient content, particularly nitrogen (N). However, recent studies indicate that leaf N content is often a poor predictor of variation in photosynthetic capacity in tropical trees. In this study, we explored the relative importance of area-based total leaf N content (Ntot) and within-leaf N allocation to photosynthetic capacity versus light-harvesting in controlling the variation in photosynthetic capacity (i.e. Vcmax, Jmax) among mature trees of 12 species belonging to either early (ES) or late successional (LS) groups growing in a tropical montane rainforest in Rwanda, Central Africa. Photosynthetic capacity at a common leaf temperature of 25˚C (i.e. maximum rates of Rubisco carboxylation, Vcmax25 and of electron transport, Jmax25) was higher in ES than in LS species (+ 58% and 68% for Vcmax25 and Jmax25, respectively). While Ntot did not significantly differ between successional groups, the photosynthetic dependency on Ntot was markedly different. In ES species, Vcmax25 was strongly and positively related to Ntot but this was not the case in LS species. However, there was no significant trade-off between relative leaf N investments in compounds maximizing photosynthetic capacity versus compounds maximizing light harvesting. Both leaf dark respiration at 25˚C (+ 33%) and, more surprisingly, apparent photosynthetic quantum yield (+ 35%) was higher in ES than in LS species. Moreover, Rd25 was positively related to Ntot for both ES and LS species. Our results imply that efforts to quantify carbon fluxes of tropical montane rainforests would be improved if they considered contrasting within-leaf N allocation and photosynthetic Ntot dependencies between species with different successional strategies. © Copyright © 2020 Ziegler, Dusenge, Nyirambangutse, Zibera, Wallin and Uddling.  
  Address Department of Biology, The University of Western Ontario, London, ON, Canada  
  Corporate Author Thesis  
  Publisher Frontiers Media S.A. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1664462x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial (down) 953  
Permanent link to this record
 

 
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 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  
  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 (down) 952  
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