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Author Morel, H.; Lehnebach, R.; Cigna, J.; Ruelle, J.; Nicolini, É.; Beauchene, J. pdf  url
doi  openurl
  Title Basic wood density variations of Parkia velutina Benoist, a long-lived heliophilic Neotropical rainforest tree Type Journal Article
  Year 2018 Publication Bois et Forets des Tropiques Abbreviated Journal (up)  
  Volume 335 Issue Pages 59-69  
  Keywords Curvilinear pattern; French Guiana; Intra-tree; Tropical species  
  Abstract Investigations of basic radial wood density (WD) in tropical trees revealed linear patterns and some curvilinear patterns. Studies usually disregard longitudinal variations, which are often considered to be similar to radial variations. This study aimed to show (1) a new radial curvilinear WD pattern, (2) differences in amplitude between radial and longitudinal gradients and (3) to partition WD variations according to different scales in Parkia velutina, an emergent tree found in Neotropical rain forests. We collected full discs from six felled trees and radial cores from 10 standing trees to check WD variability, plus one dominant axis per tree for analysis of height growth rates. This species showed very high growth rates indicative of heliophilic habits. WD varied from 0.194 to 0.642 g/cm3. Such amplitude is rarely observed within the same tree. Radial variation in WD was curvilinear, with an amplitude generally less than the longitudinal amplitude. Consequently, in mature trees, WD values in the crown were higher than those in the outer trunk. WD variations can be highly significant at different scales. The variance partitioning also revealed that the whole WD range of Parkia velutina is more accurately estimated intra-individually when both longitudinal and radial gradient are covered.  
  Address INRA, LERFoB, AgroParisTech, Nancy, France  
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  Notes Export Date: 20 April 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 799  
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Author Pétillon, J.; Leroy, B.; Djoudi, E.A.; Vedel, V. url  doi
openurl 
  Title Small and large spatial scale coexistence of ctenid spiders in a neotropical forest (French Guiana) Type Journal Article
  Year 2018 Publication Tropical Zoology Abbreviated Journal (up)  
  Volume 31 Issue 2 Pages 85-98  
  Keywords Araneae; flooding; Guianese shield; inselberg; juveniles  
  Abstract While spiders constitute the most abundant and diverse arthropods in many habitats, they remained under-studied, especially in tropical rainforests. The goal of this study is to assess the spatial distribution of the spider family Ctenidae by assessing associations of species diversity and population traits among different habitat conditions. Fieldwork was carried out during 2013 in habitats varying in flooding frequency (plateau vs. flooded forest) and elevation (inselberg vs. lowland) in the Nouragues National Natural Reserve, French Guiana. Assemblage composition, population structure, and trait measurements of one dominant species were assessed using hand collection in replicated quadrats. We found strong effects on ctenid assemblages attributable to both elevation and flooding, with changes in relative abundance of species among habitats, but few correlated densities between species. At the population level, main differences in species distribution between and within habitats were detected only when juveniles were taken into account. No effect of elevation was found on the measurements of traits of the dominant species, but legs were proportionally shorter in flooded habitats, suggesting reduced active dispersal in these habitats. Our study highlights the value of complementary of measures of diversity and traits at different biological scales in Ctenidae.  
  Address UMR CNRS 8175 Ecologie des Forêts de Guyane, Université Antilles-Guyane, Kourou Cedex, Guyane Française, France  
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  Notes Export Date: 23 April 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 800  
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Author Lehnebach, R.; Beyer, R.; Letort, V.; Heuret, P. pdf  doi
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  Title The pipe model theory half a century on: a review Type Journal Article
  Year 2018 Publication Annals of Botany Abbreviated Journal (up)  
  Volume 121 Issue 5 Pages 773-795  
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  Abstract BackgroundMore than a half century ago, Shinozaki et al. (Shinozaki K, Yoda K, Hozumi K, Kira T. 1964a. A quantitative analysis of plant form – the pipe model theory. I. Basic analyses. Japanese Journal of Ecology B: 97–105) proposed an elegant conceptual framework, the pipe model theory (PMT), to interpret the observed linear relationship between the amount of stem tissue and corresponding supported leaves. The PMT brought a satisfactory answer to two vividly debated problems that were unresolved at the moment of its publication: (1) What determines tree form and which rules drive biomass allocation to the foliar versus stem compartments in plants? (2) How can foliar area or mass in an individual plant, in a stand or at even larger scales be estimated? Since its initial formulation, the PMT has been reinterpreted and used in applications, and has undoubtedly become an important milestone in the mathematical interpretation of plant form and functioning.ScopeThis article aims to review the PMT by going back to its initial formulation, stating its explicit and implicit properties and discussing them in the light of current biological knowledge and experimental evidence in order to identify the validity and range of applicability of the theory. We also discuss the use of the theory in tree biomechanics and hydraulics as well as in functional–structural plant modelling.ConclusionsScrutinizing the PMT in the light of modern biological knowledge revealed that most of its properties are not valid as a general rule. The hydraulic framework derived from the PMT has attracted much more attention than its mechanical counterpart and implies that only the conductive portion of a stem cross-section should be proportional to the supported foliage amount rather than the whole of it. The facts that this conductive portion is experimentally difficult to measure and varies with environmental conditions and tree ontogeny might cause the commonly reported non-linear relationships between foliage and stem metrics. Nevertheless, the PMT can still be considered as a portfolio of properties providing a unified framework to integrate and analyse functional–structural relationships.  
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  ISSN 0305-7364 ISBN Medium  
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  Notes 10.1093/aob/mcx194 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 801  
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Author Soong, J.L.; Marañon-Jimenez, S.; Cotrufo, M.F.; Boeckx, P.; Bodé, S.; Guenet, B.; Peñuelas, J.; Richter, A.; Stahl, C.; Verbruggen, E.; Janssens, I.A. doi  openurl
  Title Soil microbial CNP and respiration responses to organic matter and nutrient additions: Evidence from a tropical soil incubation Type Journal Article
  Year 2018 Publication Soil Biology and Biochemistry Abbreviated Journal (up)  
  Volume 122 Issue Pages 141-149  
  Keywords 13c; Cnp; Microbial stoichiometry; Priming; Soil respiration; Tropics  
  Abstract Soil nutrient availability has a strong influence on the fate of soil carbon (C) during microbial decomposition, contributing to Earth's C balance. While nutrient availability itself can impact microbial physiology and C partitioning between biomass and respiration during soil organic matter decomposition, the availability of labile C inputs may mediate the response of microorganisms to nutrient additions. As soil organic matter is decomposed, microorganisms retain or release C, nitrogen (N) or phosphorus (P) to maintain a stoichiometric balance. Although the concept of a microbial stoichiometric homeostasis has previously been proposed, microbial biomass CNP ratios are not static, and this may have very relevant implications for microbial physiological activities. Here, we tested the hypothesis that N, P and potassium (K) nutrient additions impact C cycling in a tropical soil due to microbial stoichiometric constraints to growth and respiration, and that the availability of energy-rich labile organic matter in the soil (i.e. leaf litter) mediates the response to nutrient addition. We incubated tropical soil from French Guiana with a 13C labeled leaf litter addition and with mineral nutrient additions of +K, +N, +NK, +PK and +NPK for 30 days. We found that litter additions led to a ten-fold increase in microbial respiration and a doubling of microbial biomass C, along with greater microbial N and P content. We found some evidence that P additions increased soil CO2 fluxes. Additionally, we found microbial biomass CP and NP ratios varied more widely than CN in response to nutrient and organic matter additions, with important implications for the role of microorganisms in C cycling. The addition of litter did not prime soil organic matter decomposition, except in combination with +NK fertilization, indicating possible P-mining of soil organic matter in this P-poor tropical soil. Together, these results point toward an ultimate labile organic substrate limitation of soil microorganisms in this tropical soil, but also indicate a complex interaction between C, N, P and K availability. This highlights the difference between microbial C cycling responses to N, P, or K additions in the tropics and explains why coupled C, N and P cycle modeling efforts cannot rely on strict microbial stoichiometric homeostasis as an underlying assumption.  
  Address INRA, UMR Ecology of Guiana Forests (Ecofog), AgroParisTech, Cirad, CNRS, Université de Guyane, Université des Antilles, Kourou, France  
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  Notes Export Date: 16 May 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 804  
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Author Clair, B.; Déjardin, A.; Pilate, G.; Alméras, T. pdf  url
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  Title Is the G-layer a tertiary cell wall? Type Journal Article
  Year 2018 Publication Frontiers in Plant Science Abbreviated Journal (up)  
  Volume 9 Issue Pages 623  
  Keywords Flax; G-layer; Gelatinous layer; Maturation stress; Secondary cell wall; Tension wood; Tertiary cell wall  
  Abstract  
  Address LMGC, CNRS, Université de Montpellier, Montpellier, France  
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  Notes Export Date: 31 May 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 805  
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Author Barraza, F.; Schreck, E.; Lévêque, T.; Uzu, G.; Lopez, F.; Ruales, J.; Prunier, J.; Marquet, A.; Maurice, L. url  doi
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  Title Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador Type Journal Article
  Year 2017 Publication Environmental Pollution Abbreviated Journal (up)  
  Volume 229 Issue Pages 950-963  
  Keywords Cacao; Cadmium; Ecuador; Health risk assessment; Uptake and bioaccumulation  
  Abstract Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg−1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0–20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg−1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate.  
  Address Laboratoire des Sciences du Bois, UMR EcoFoG, ZI Pariacabo, Kourou, French Guiana  
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  Notes Cited By :1; Export Date: 4 June 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 806  
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Author Dejean, A.; Compin, A.; Leponce, M.; Azémar, F.; Bonhomme, C.; Talaga, S.; Pelozuelo, L.; Hénaut, Y.; Corbara, B. url  doi
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  Title Ants impact the composition of the aquatic macroinvertebrate communities of a myrmecophytic tank bromeliad Type Journal Article
  Year 2018 Publication Comptes Rendus Biologies Abbreviated Journal (up)  
  Volume 341 Issue 3 Pages 200-207  
  Keywords Aquatic macroinvertebrates; Ant-plant relationships; Diversity; Food webs; Tank bromeliads; Macro-invertébrés aquatiques; Relations plantes-fourmis; Diversité; Réseaux trophiques; Broméliacées à réservoirs  
  Abstract In an inundated Mexican forest, 89 out of 92 myrmecophytic tank bromeliads (Aechmea bracteata) housed an associated ant colony: 13 sheltered Azteca serica, 43 Dolichoderus bispinosus, and 33 Neoponera villosa. Ant presence has a positive impact on the diversity of the aquatic macroinvertebrate communities (n=30 bromeliads studied). A Principal Component Analysis (PCA) showed that the presence and the species of ant are not correlated to bromeliad size, quantity of water, number of wells, filtered organic matter or incident radiation. The PCA and a generalized linear model showed that the presence of Azteca serica differed from the presence of the other two ant species or no ants in its effects on the aquatic invertebrate community (more predators). Therefore, both ant presence and species of ant affect the composition of the aquatic macroinvertebrate communities in the tanks of A. bracteata, likely due to ant deposition of feces and other waste in these tanks. Résumé Dans une forêt inondable du Mexique, sur 92 individus de la broméliacée myrmécophyte Aechmea bracteata, seuls trois étaient dépourvus d’une colonie de fourmis, 13 abritaient Azteca serica, 43 Dolichoderus bispinosus et 33 Neoponera villosa. La présence des fourmis favorise la diversité au sein des communautés aquatiques de macro-invertébrés (30 broméliacées étudiées, index de Shannon, profils de diversité). Une analyse en composantes principales (ACP) montre que la présence de fourmis n’est pas corrélée avec la taille de la plante, la quantité d’eau, le nombre de puits, la quantité de matière organique et la radiation incidente. L’ACP et un modèle mixte généralisé montrent un impact d’Azteca serica (comparé aux autres cas) attribuable à une plus grande quantité de prédateurs (effet top–down). La présence et l’identité des fourmis jouent un rôle sur la composition des communautés de macro-invertébrés aquatiques à travers des interactions directes, les ouvrières évacuant fèces et déchets dans les réservoirs.  
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  ISSN 1631-0691 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 821  
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Author Imbert, D. pdf  url
doi  openurl
  Title Hurricane disturbance and forest dynamics in east Caribbean mangroves Type Journal Article
  Year 2018 Publication Ecosphere Abbreviated Journal (up)  
  Volume 9 Issue 7 Pages e02231  
  Keywords Caribbean; forest recovery; high-energy storms; mangrove; resilience; resistance; Special Feature: High-Energy Storms  
  Abstract Despite low plant diversity and structural simplicity, mangroves offer various ecosystem services to local human communities, including sheltering coastal social-ecological systems from high-energy storm damage. The expected increasing intensity of hurricanes due to climate change raises questions concerning the capacity of mangroves to resist and recover from such disturbances. Herein, this study contributes to a better understanding of (1) the relation between storm intensity and damage to mangrove vegetation, (2) the contributions of species-specific as well as stand-specific components of mangrove vegetation to ecosystem resistance, and (3) the recovery of pre-hurricane forest structure through time. The first two issues have been addressed using a stand-level approach implemented at two east Caribbean mangrove sites in response to three storm events. The third was addressed through a 23-yr survey of forest recovery following the passage of a high-energy storm across one of the two study sites. Generally, hurricane damage was primarily controlled by wind velocity, followed by the hydro-geomorphic context of mangrove forests and species-specific composition, respectively. The relationship between damage to trees and wind velocity evidenced a sigmoidal trend, with a maximum slope at a wind velocity averaging 130 and 180 km/h for higher vs. lower canopy stands, respectively. The red mangrove, Rhizophora mangle, was significantly less resistant to hurricane damage than was the black mangrove, Avicennia germinans. Unlike the fringe and scrub stands, inner, tall-canopy stands fully recovered by the end of the study (23 yr). These stands were more resilient because of their growth performances. Finally, the time for east Caribbean mangroves to recover from high-energy storms seems to fall within the range of the average return time of such disturbances. This may prevent such ecosystems from ever reaching a steady state.  
  Address Laboratoire de Biologie Végétale, UMR EcoFoG, BP 592, Université des Antilles, Pointe-à-Pitre Cedex, 97159, France  
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  Notes Export Date: 17 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 819  
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Author Alméras, T.; Ghislain, B.; Clair, B.; Secerovic, A.; Pilate, G.; Fournier, M. url  doi
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  Title Quantifying the motor power of trees Type Journal Article
  Year 2018 Publication Trees Abbreviated Journal (up)  
  Volume 32 Issue 3 Pages 689-702  
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  Abstract Wood maturation strains can be estimated from the change in curvature that occurs when a stem grown staked in tilted position is released from the stake.
Trees have a motor system to enable upright growth in the field of gravity. This motor function is taken on by reaction wood, a special kind of wood that typically develops in leaning axes and generates mechanical force during its formation, curving up the stem and counteracting the effect of gravity or other mechanical disturbances. Quantifying the mechanical stress induced in wood during maturation is essential to many areas of research ranging from tree architecture to functional genomics. Here, we present a new method for quantifying wood maturation stress. It consists of tilting a tree, tying it to a stake, letting it grow in tilted position, and recording the change in stem curvature that occurs when the stem is released from the stake. A mechanical model is developed to make explicit the link between the change in curvature, maturation strain and morphological traits of the stem section. A parametric study is conducted to analyse how different parameters influence the change in curvature. This method is applied to the estimation of maturation strain in two different datasets. Results show that the method is able to detect genotypic variations in motor power expression. As predicted by the model, we observe that the change in stem curvature is correlated to stem diameter and diameter growth. In contrast, wood maturation strain is independent from these dimensional effects, and is suitable as an intrinsic parameter characterising the magnitude of the plant’s gravitropic reaction.
 
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  Call Number EcoFoG @ webmaster @ Alméras2018 Serial 835  
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Author Piponiot, C.; Derroire, G.; Descroix, L.; Mazzei, L.; Rutishauser, E.; Sist, P.; Hérault, B. doi  openurl
  Title Assessing timber volume recovery after disturbance in tropical forests – A new modelling framework Type Journal Article
  Year 2018 Publication Ecological Modelling Abbreviated Journal (up)  
  Volume 384 Issue Pages 353-369  
  Keywords Disturbance; Ecosystem modelling; Recovery; Sustainability; Tropical forest management  
  Abstract One third of contemporary tropical forests is designated by national forest services for timber production. Tropical forests are also increasingly affected by anthropogenic disturbances. However, there is still much uncertainty around the capacity of tropical forests to recover their timber volume after logging as well as other disturbances such as fires, large blow-downs and extreme droughts, and thus on the long-term sustainability of logging. We developed an original Bayesian hierarchical model of Volume Dynamics with Differential Equations (VDDE) to infer the dynamic of timber volumes as the result of two ecosystem processes: volume gains from tree growth and volume losses from tree mortality. Both processes are expressed as explicit functions of the forest maturity, i.e. the overall successional stage of the forest that primarily depends on the frequency and severity of the disturbances that the forest has undergone. As a case study, the VDDE model was calibrated with data from Paracou, a long-term disturbance experiment in a neotropical forest where over 56 ha of permanent forest plots were logged with different intensities and censused for 31 years. With this model, we could predict timber recovery at Paracou at the end of a cutting cycle depending on the logging intensity, the rotation cycle length, and the proportion of commercial volume. The VDDE modelling framework developed presents three main advantages: (i) it can be calibrated with large tree inventories which are widely available from national forest inventories or logging concession management plans and are easy to measure, both on the field and with remote sensing; (ii) it depends on only a few input parameters, which can be an advantage in tropical regions where data availability is scarce; (iii) the modelling framework is flexible enough to explicitly include the effect of other types of disturbances (both natural and anthropogenic: e.g. blow-downs, fires and climate change) on the forest maturity, and thus to predict future timber provision in the tropics in a context of global changes. © 2018 Elsevier B.V.  
  Address INPHB (Institut National Polytechnique Félix Houphouet Boigny), Yamoussoukro, Cote d'Ivoire  
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  Notes Export Date: 1 September 2018 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 813  
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