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Author (up) Van Langenhove, L.; Janssens, I.A.; Verryckt, L.; Brechet, L.; Hartley, I.P.; Stahl, C.; Courtois, E.; Urbina, I.; Grau, O.; Sardans, J.; Peguero, G.; Gargallo-Garriga, A.; Peñuelas, J.; Vicca, S. url  doi
openurl 
  Title Rapid root assimilation of added phosphorus in a lowland tropical rainforest of French Guiana Type Journal Article
  Year 2020 Publication Soil Biology and Biochemistry Abbreviated Journal Soil Biol. Biochem.  
  Volume 140 Issue 107646 Pages  
  Keywords Fertilization; Nitrogen; Phosphorus; Plant root simulator probes; Root system; Tropical forest; Nitrogen; Nitrogen fertilizers; Phosphorus; Plants (botany); Soils; Tropics; Fertilization; Mycorrhizal fungus; N and P fertilizer; P availabilities; Plant root simulators; Root system; Tropical forest; Tropical rain forest; Forestry; Fungi  
  Abstract Tree growth on weathered soils in lowland tropical forests is limited by low phosphorous (P) availability. However, nutrient manupulation experiments do not always increase the P content in these trees, which raises the question whether trees are taking up added P. In French Guianese lowland rainforest, we measured changes in nitrogen (N) and P availability before and up to two months after N and P fertilizer addition, in soils with intact root systems and in soils where roots and mycorrhizal fungi were excluded by root exclusion cylinders. When the root system was excluded, P addition increased P availability to a much greater extent and for a longer time than in soils with an intact root system. Soil N dynamics were unaffected by root presence/absence. These results indicate rapid P uptake, but not N uptake, by tree roots, suggesting a very effective P acquisition process in these lowland rainforests.  
  Address Global Change Research Institute, Czech Academy of Sciences, Czech Republic  
  Corporate Author Thesis  
  Publisher Elsevier Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00380717 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 19 November 2019; Coden: Sbioa; Correspondence Address: Van Langenhove, L.; Centre of Excellence PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Wilrijk, Belgium; email: leandro.vanlangenhove@uantwerpen.be Approved no  
  Call Number EcoFoG @ webmaster @ Serial 897  
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Author (up) Van Langenhove, L.; Verryckt, L.T.; Bréchet, L.; Courtois, E.A.; Stahl, C.; Hofhansl, F.; Bauters, M.; Sardans, J.; Boeckx, P.; Fransen, E.; Peñuelas, J.; Janssens, I.A. doi  openurl
  Title Atmospheric deposition of elements and its relevance for nutrient budgets of tropical forests Type Journal Article
  Year 2020 Publication Biogeochemistry Abbreviated Journal Biogeochemistry  
  Volume 149 Issue 2 Pages 175-193  
  Keywords Litterfall; Nitrogen; Nutrient cycling; Phosphorus; Potassium; Throughfall; atmospheric deposition; canopy exchange; field method; forest floor; leaching; litterfall; nutrient cycling; phosphorus; potassium; precipitation (climatology); rainforest; tropical forest; French Guiana  
  Abstract 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 were an order of magnitude higher. In contrast to nitrogen, we found that atmospheric deposition of phosphorus (0.5 kg ha−1 year−1) supplied up to one third of the annual litterfall input to the forest floor. Most strikingly, combined annual inputs of potassium via atmospheric deposition (14 kg ha−1 year−1) and canopy leaching (22 kg ha−1 year−1) were three times larger than internal nutrient recycling via litterfall (11 kg ha−1 year−1). We conclude that atmospheric deposition of phosphorus and especially potassium may play an important role in sustaining the productivity of this old-growth tropical rainforest. © 2020, Springer Nature Switzerland AG.  
  Address StatUa Center for Statistics, University of Antwerp, Prinsstraat 13, Antwerp, 2000, Belgium  
  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 01682563 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 964  
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Author (up) Verryckt, L.T.; Ellsworth, D.S.; Vicca, S.; Van Langenhove, L.; Peñuelas, J.; Ciais, P.; Posada, J.M.; Stahl, C.; Coste, S.; Courtois, E.A.; Obersteiner, M.; Chave, J.; Janssens, I.A. doi  openurl
  Title Can light-saturated photosynthesis in lowland tropical forests be estimated by one light level? Type Journal Article
  Year 2020 Publication Biotropica Abbreviated Journal Biotropica  
  Volume 52 Issue 6 Pages 1183-1193  
  Keywords canopy architecture; interspecific variation; light intensity; lowland environment; parameter estimation; photon flux density; photosynthesis; saturation; tropical forest; French Guiana  
  Abstract Leaf-level net photosynthesis (An) estimates and associated photosynthetic parameters are crucial for accurately parameterizing photosynthesis models. For tropical forests, such data are poorly available and collected at variable light conditions. To avoid over- or underestimation of modeled photosynthesis, it is critical to know at which photosynthetic photon flux density (PPFD) photosynthesis becomes light-saturated. We studied the dependence of An on PPFD in two tropical forests in French Guiana. We estimated the light saturation range, including the lowest PPFD level at which Asat (An at light saturation) is reached, as well as the PPFD range at which Asat remained unaltered. The light saturation range was derived from photosynthetic light-response curves, and within-canopy and interspecific differences were studied. We observed wide light saturation ranges of An. Light saturation ranges differed among canopy heights, but a PPFD level of 1,000 µmol m−2 s−1 was common across all heights, except for pioneer trees species that did not reach light saturation below 2,000 µmol m−2 s−1. A light intensity of 1,000 µmol m−2 s−1 sufficed for measuring Asat of climax species at our study sites, independent of the species or the canopy height. Because of the wide light saturation ranges, results from studies measuring Asat at higher PPFD levels (for upper canopy leaves up to 1,600 µmol m−2 s−1) are comparable with studies measuring at 1,000 µmol m−2 s−1. © 2020 The Association for Tropical Biology and Conservation  
  Address UMR 5174, Laboratoire Evolution et Diversité Biologique, CNRS, Université Paul Sabatier, 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 948  
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Author (up) 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 960  
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Author (up) Vleminckx, J.; Bauman, D.; Demanet, M.; Hardy, O.J.; Doucet, J.-L.; Drouet, T. doi  openurl
  Title Past human disturbances and soil fertility both influence the distribution of light-demanding tree species in a Central African tropical forest Type Journal Article
  Year 2020 Publication Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.  
  Volume 31 Issue 3 Pages 440-453  
  Keywords light-demanding species; moist tropical forests; past human disturbances; shade-bearer species; soil charcoal abundance; soil properties; tree community assemblages; wood-specific gravity; anthropogenic effect; forest canopy; forest ecosystem; shifting cultivation; soil fertility; soil property; tree; tropical forest; Cameroon  
  Abstract Questions: In vast areas of Central African forests, the upper canopy is presently dominated by light-demanding tree species. Here, we confront three hypotheses to explain this dominance: (a) these species have expanded their distribution because of widespread past slash-and-burn activities, as suggested by important charcoal amounts recorded in the soils of the region; (b) their abundance is rather explained by soil properties, as this guild establishes preferentially on favourable physico-chemical conditions for rapid growth; (c) soil properties have been substantially influenced by past human disturbances and those two effects cannot be disentangled. Location: Pallisco-CIFM logging concession, southeastern Cameroon (300,000 ha). Methods: We quantified soil charcoal abundance and measured ten soil variables at the basis of 60 target trees that belonged to a list of three long-living pioneer light-demanding (LLP) and four shade-bearer (SB) species. We identified all stems with a diameter at breast height (DBH) ≥ 20 cm within a distance of 15 m around each target tree. Species were characterised by their wood-specific gravity (WSG), which reflected their light requirement. Multiple regression models were used to quantify and test the relative effects of charcoal abundance and soil variables on the mean WSG of the 60 tree communities, as well as the abundance of three guilds: LLP, SB, and non-pioneer light demanders (NPLD). Results: The mean WSG was the only response variable significantly explained by soil variables and charcoal abundance combined. It was significantly negatively associated with soil calcium and Mg content and with charcoal abundance, with soil and charcoal influencing the mean WSG independently. Conclusion: Our study provides evidence that past human disturbances and soil fertility have independently promoted the establishment of light-demanding species in western Central African forests, thereby shedding light on tree community assembly rules in these ecosystems which remain considerably understudied compared to the tropical forests of other continents. © 2020 International Association for Vegetation Science  
  Address Forest is life, TERRA Teaching and Research Centre, Université de Liège – Gembloux Agro-Bio Tech, Gembloux, Belgium  
  Corporate Author Thesis  
  Publisher Wiley-Blackwell Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 11009233 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 970  
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Author (up) 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 953  
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Author (up) Zinger, L.; Donald, J.; Brosse, S.; Gonzalez, M.A.; Iribar, A.; Leroy, C.; Murienne, J.; Orivel, J.; Schimann, H.; Taberlet, P.; Lopes, C.M. doi  openurl
  Title Advances and prospects of environmental DNA in neotropical rainforests Type Journal Article
  Year 2020 Publication Advances in Ecological Research Abbreviated Journal Adv. Ecol. Res.  
  Volume 62 Issue Pages 331-373  
  Keywords Biomonitoring; Conservation biology; DNA metabarcoding; eDNA; Environmental genomics; Neotropics; Rainforests  
  Abstract The rainforests of the Neotropics shelter a vast diversity of plant, animal and microscopic species that provide critical ecosystem goods and services for both local and worldwide populations. These environments face a major crisis due to increased deforestation, pollution, and climate change, emphasizing the need for more effective conservation efforts. The adequate monitoring of these ecosystems has proven a complex and time consuming endeavour, which depends on ever dwindling taxonomic expertise. To date, many species remain undiscovered, let alone described, with otherwise limited information regarding known species population distributions and densities. Overcoming these knowledge shortfalls and practical limitations is becoming increasingly possible through techniques based on environmental DNA (eDNA), i.e., DNA that can be obtained from environmental samples (e.g. tissues, soil, sediment, water, etc.). When coupled with high-throughput sequencing, these techniques now enable realistic, cost-effective, and standardisable biodiversity assessments. This opens up enormous opportunities for advancing our understanding of complex and species-rich tropical communities, but also in facilitating large-scale biomonitoring programs in the neotropics. In this review, we provide a brief introduction to eDNA methods, and an overview of their current and potential uses in both terrestrial and aquatic ecosystems of neotropical rainforests. We also discuss the limits and challenges of these methods for our understanding and monitoring of biodiversity, as well as future research and applied perspectives of these techniques in neotropical rainforests, and beyond. © 2020 Elsevier Ltd  
  Address Departamento de Zoologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rio Claro, SP, Brazil  
  Corporate Author Thesis  
  Publisher Academic Press Inc. Place of Publication Editor Dumbrell A.J.; Turner E.C.; Fayle T.M.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title Advances in Ecological Research  
  Series Volume 62 Series Issue Edition  
  ISSN 00652504 (Issn); 9780128211342 (Isbn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 995  
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