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| Author | Grau, O.; Peñuelas, J.; Ferry, B.; Freycon, V.; Blanc, L.; Desprez, M.; Baraloto, C.; Chave, J.; Descroix, L.; Dourdain, A.; Guitet, S.; Janssens, I.A.; Sardans, J.; Herault, B. | ||||
| Title | Nutrient-cycling mechanisms other than the direct absorption from soil may control forest structure and dynamics in poor Amazonian soils | Type | Journal Article | ||
| Year | 2017 | Publication | Scientific Reports | Abbreviated Journal | Sci. Rep. |
| Volume | 7 | Issue | Pages | 45017 | |
| Keywords | biomass; forest structure; French Guiana; mortality; nutrient availability; nutrient content; nutrient cycling; nutrient uptake; productivity; soil; storage; tropical rain forest | ||||
| Abstract | Tropical forests store large amounts of biomass despite they generally grow in nutrient-poor soils, suggesting that the role of soil characteristics in the structure and dynamics of tropical forests is complex. We used data for >34 000 trees from several permanent plots in French Guiana to investigate if soil characteristics could predict the structure (tree diameter, density and aboveground biomass), and dynamics (growth, mortality, aboveground wood productivity) of nutrient-poor tropical forests. Most variables did not covary with site-level changes in soil nutrient content, indicating that nutrient-cycling mechanisms other than the direct absorption from soil (e.g. the nutrient uptake from litter, the resorption, or the storage of nutrients in the biomass), may strongly control forest structure and dynamics. Ecosystem-level adaptations to low soil nutrient availability and long-term low levels of disturbance may help to account for the lower productivity and higher accumulation of biomass in nutrient-poor forests compared to nutrient-richer forests. | ||||
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| Notes | Export Date: 8 April 2017 | Approved | no | ||
Call Number  |
EcoFoG @ webmaster @ | Serial | 748 | ||
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| Author | Stahl, C.; Fontaine, S.; Klumpp, K.; Picon-Cochard, C.; Grise, M.M.; Dezecache, C.; Ponchant, L.; Freycon, V.; Blanc, L.; Bonal, D.; Burban, B.; Soussana, J.-F.; Blanfort, V. | ||||
| Title | Continuous soil carbon storage of old permanent pastures in Amazonia | Type | Journal Article | ||
| Year | 2017 | Publication | Global Change Biology | Abbreviated Journal | Glob Change Biol |
| Volume | 23 | Issue | 8 | Pages | 3382-3392 |
| Keywords | carbon storage; CN coupling; deep soil; mixed-grass pasture; native forest | ||||
| Abstract | Amazonian forests continuously accumulate carbon (C) in biomass and in soil, representing a carbon sink of 0.42–0.65 GtC yr−1. In recent decades, more than 15% of Amazonian forests have been converted into pastures, resulting in net C emissions (~200 tC ha−1) due to biomass burning and litter mineralization in the first years after deforestation. However, little is known about the capacity of tropical pastures to restore a C sink. Our study shows in French Amazonia that the C storage observed in native forest can be partly restored in old (≥24 year) tropical pastures managed with a low stocking rate (±1 LSU ha−1) and without the use of fire since their establishment. A unique combination of a large chronosequence study and eddy covariance measurements showed that pastures stored between −1.27 ± 0.37 and −5.31 ± 2.08 tC ha−1 yr−1 while the nearby native forest stored −3.31 ± 0.44 tC ha−1 yr−1. This carbon is mainly sequestered in the humus of deep soil layers (20–100 cm), whereas no C storage was observed in the 0- to 20-cm layer. C storage in C4 tropical pasture is associated with the installation and development of C3 species, which increase either the input of N to the ecosystem or the C:N ratio of soil organic matter. Efforts to curb deforestation remain an obvious priority to preserve forest C stocks and biodiversity. However, our results show that if sustainable management is applied in tropical pastures coming from deforestation (avoiding fires and overgrazing, using a grazing rotation plan and a mixture of C3 and C4 species), they can ensure a continuous C storage, thereby adding to the current C sink of Amazonian forests. | ||||
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| ISSN | 1365-2486 | ISBN | Medium | ||
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| Notes | Approved | no | |||
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EcoFoG @ webmaster @ | Serial | 783 | ||
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| Author | Dejean, A.; Rodríguez-Pérez, H.; Carpenter, J.M.; Azémar, F.; Corbara, B. | ||||
| Title | The predatory behavior of the Neotropical social wasp Polybia rejecta | Type | Journal Article | ||
| Year | 2017 | Publication | Behavioural Processes | Abbreviated Journal | |
| Volume | 140 | Issue | Pages | 161-168 | |
| Keywords | Epiponine wasps; Polistinae; Predation; Prey selection; Recruitment; Vespidae | ||||
| Abstract | Abstract We experimentally studied the predatory behavior of Polybia rejecta (Vespidae, Polistinae, Epiponini) towards 2–88 mm-long insects attracted to a UV light trap. Foragers, which began to hunt at 6:30, selected 4–14 mm-long prey insects. Prey detection by sight by hovering wasps was confirmed using decoys. After the wasps landed and walked along a sinuous path, prey were detected by contact or from a distance (1–3 cm). This was followed by seizure, stinging (contrarily to most other known cases), prey manipulation and retrieval. Prey that flew off might be caught in flight. The prey load, representing 30.7% of a forager’s weight, was optimized by capturing up to six small prey or two medium-sized prey successively (both of which might be consumed in situ). The foragers cut off the wings of larger prey or cut them into two pieces and returned to gather the second piece. The handling time increased exponentially with the weight of the prey. Partial loading (i.e., retrieving a load much inferior to the maximum possible) was likely related to social facilitation, a form of nest-based recruitment that was demonstrated through the experimental elimination of local enhancement by removing foragers (both mechanisms favor the exploitation of favorable patches). | ||||
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| ISSN | 0376-6357 | ISBN | Medium | ||
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| Notes | Approved | no | |||
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EcoFoG @ webmaster @ | Serial | 751 | ||
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| Author | Fox Ramos, A.E.; Alcover, C.; Evanno, L.; Maciuk, A.; Litaudon, M.; Duplais, C.; Bernadat, G.; Gallard, J.-F.; Jullian, J.-C.; Mouray, E.; Grellier, P.; Loiseau, P.M.; Pomel, S.; Poupon, E.; Champy, P.; Beniddir, M.A. | ||||
| Title | Revisiting Previously Investigated Plants: A Molecular Networking-Based Study of Geissospermum laeve | Type | Journal Article | ||
| Year | 2017 | Publication | Journal of Natural Products | Abbreviated Journal | |
| Volume | 80 | Issue | 4 | Pages | 1007-1014 |
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| Abstract | Three new monoterpene indole alkaloids (1-3) have been isolated from the bark of Geissospermum laeve, together with the known alkaloids (−)-leuconolam (4), geissolosimine (5), and geissospermine (6). The structures of 1-3 were elucidated by analysis of their HRMS and NMR spectroscopic data. The absolute configuration of geissolaevine (1) was deduced from the comparison of experimental and theoretically calculated ECD spectra. The isolation workflow was guided by a molecular networking-based dereplication strategy using an in-house database of monoterpene indole alkaloids. In addition, five known compounds previously undescribed in the Geissospermum genus were dereplicated from the G. laeve alkaloid extract network and were assigned with various levels of identification confidence. The antiparasitic activities against Plasmodium falciparum and Leishmania donovani as well as the cytotoxic activity against the MRC-5 cell line were determined for compounds 1-5. © 2017 The American Chemical Society and American Society of Pharmacognosy. | ||||
| Address | Équipe Chimiothérapie Antiparasitaire BioCIS, Univ. Paris-Sud, CNRS, Université Paris-Saclay, 5 Rue J.-B. Clément, Châtenay-Malabry, France | ||||
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| Notes | Export Date: 18 May 2017 | Approved | no | ||
| Call Number |
EcoFoG @ webmaster @ | Serial | 752 | ||
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| Author | Pierrejean, I.; Mehinto, T.; Beauchene, J. | ||||
| Title | Comparative Analysis of Three Different Methods Used to Determine the Elastic Modulus for a Choice of Tropical Guianese Wood Species | Type | Journal Article | ||
| Year | 2017 | Publication | Pro Ligno | Abbreviated Journal | |
| Volume | 13 | Issue | 1 | Pages | 3-17 |
| Keywords | density; modulus of elasticity; static and dynamic tests; tropical woods | ||||
| Abstract | This study compares variability in the longitudinal Modulus of Elasticity (MOE) values, measured by three different methods, for eight tropical wood species covering a wide range of densities, a property that has been little described in the literature for some of the species studied. The modulus of elasticity in wood species is one of the main mechanical properties measured to characterize wood materials. However, this property is seldom described for the tropical wood species studied here, and the method used is often variable. The aim is to answer the following questions. In the methods used, what are the main variability factors which influence modulus measurement? Is the modulus different with regard to the solicitation direction (radial or tangential)? Which relationship exists between modulus and density for these species?
The samples were subjected to the four-point bending test, then to the free vibration test and to the forced-vibration test (which allows tests on small samples).The samples were subjected to stress in radial and tangential directions. The modulus values obtained by the different methods were well correlated for most of the species. The relationship between modulus and density was very good at inter-specific level because sampling covered a wide range of densities. But this relationship was not so good for each of the species sampled. This kind of test was not appropriate for detecting differences in behavior between the two directions of solicitation for these species. The main features of the three methods were summarized, highlighting the advantages of each for the species studied. |
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| Notes | Approved | no | |||
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EcoFoG @ webmaster @ | Serial | 753 | ||
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| Author | Wagner, F.H.; Herault, B.; Rossi, V.; Hilker, T.; Maeda, E.E.; Sanchez, A.; Lyapustin, A.I.; Galvão, L.S.; Wang, Y.; Aragão, L.E.O.C. | ||||
| Title | Climate drivers of the Amazon forest greening | Type | Journal Article | ||
| Year | 2017 | Publication | PLoS ONE | Abbreviated Journal | |
| Volume | 12 | Issue | 7 | Pages | e0180932 |
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| Abstract | Our limited understanding of the climate controls on tropical forest seasonality is one of the biggest sources of uncertainty in modeling climate change impacts on terrestrial ecosystems. Combining leaf production, litterfall and climate observations from satellite and ground data in the Amazon forest, we show that seasonal variation in leaf production is largely triggered by climate signals, specifically, insolation increase (70.4% of the total area) and precipitation increase (29.6%). Increase of insolation drives leaf growth in the absence of water limitation. For these non-water-limited forests, the simultaneous leaf flush occurs in a sufficient proportion of the trees to be observed from space. While tropical cycles are generally defined in terms of dry or wet season, we show that for a large part of Amazonia the increase in insolation triggers the visible progress of leaf growth, just like during spring in temperate forests. The dependence of leaf growth initiation on climate seasonality may result in a higher sensitivity of these ecosystems to changes in climate than previously thought.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. | ||||
| Address | College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom | ||||
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| Notes | Export Date: 3 August 2017 | Approved | no | ||
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EcoFoG @ webmaster @ | Serial | 760 | ||
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| Author | Fukami, T.; Nakajima, M.; Fortunel, C.; Fine, P.V.A.; Baraloto, C.; Russo, S.E.; Peay, K.G. | ||||
| Title | Geographical variation in community divergence: insights from tropical forest monodominance by ectomycorrhizal trees | Type | Journal Article | ||
| Year | 2017 | Publication | American Naturalist | Abbreviated Journal | American Naturalist |
| Volume | 190 | Issue | Pages | S105-S122 | |
| Keywords | Community assembly; Mycorrhizae; Plant traits; Plant-soil feedback; Priority effects; Species pools | ||||
| Abstract | Convergence occurs in both species traits and community structure, but how convergence at the two scales influences each other remains unclear. To address this question, we focus on tropical forest monodominance, in which a single, often ectomycorrhizal (EM) tree species occasionally dominates forest stands within a landscape otherwise characterized by diverse communities of arbuscular mycorrhizal (AM) trees. Such monodominance is a striking potential example of community divergence resulting in alternative stable states. However, it is observed only in some tropical regions. A diverse suite of AM and EM trees locally codominate forest stands elsewhere. We develop a hypothesis to explain this geographical difference using a simulation model of plant community assembly. Simulation results suggest that in a region with a few EM species (e.g., South America), EM trees experience strong selection for convergent traits that match the abiotic conditions of the environment. Consequently, EM species successfully compete against other species to form monodominant stands via positive plant-soil feedbacks. By contrast, in a region with many EM species (e.g., Southeast Asia), species maintain divergent traits because of complex plant-soil feedbacks, with no species having traits that enablemonodominance. An analysis of plant trait data from Borneo and Peruvian Amazon was inconclusive. Overall, this work highlights the utility of geographical comparison in understanding the relationship between trait convergence and community convergence. © 2017 by The University of Chicago. | ||||
| Address | School of Biological Sciences, University of Nebraska, Lincoln, NE, United States | ||||
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| Notes | Approved | no | |||
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EcoFoG @ webmaster @ | Serial | 761 | ||
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| Author | Jona Lasinio, G.; Pollice, A.; Marcon, E.; Fano, E.A. | ||||
| Title | Assessing the role of the spatial scale in the analysis of lagoon biodiversity. A case-study on the macrobenthic fauna of the Po River Delta | Type | Journal Article | ||
| Year | 2017 | Publication | Ecological Indicators | Abbreviated Journal | Ecological Indicators |
| Volume | 80 | Issue | Pages | 303-315 | |
| Keywords | Biodiversity partitioning; Lagoon biodiversity; Macrobenthic fauna; Mixed effects models; Tsallis entropy | ||||
| Abstract | The analysis of benthic assemblages is a valuable tool to describe the ecological status of transitional water ecosystems, but species are extremely sensitive and respond to both microhabitat and seasonal differences. The identification of changes in the composition of the macrobenthic community in specific microhabitats can then be used as an “early warning” for environmental changes which may affect the economic and ecological importance of lagoons, through their provision of Ecosystem Services. From a conservational point of view, the appropriate definition of the spatial aggregation level of microhabitats or local communities is of crucial importance. The main objective of this work is to assess the role of the spatial scale in the analysis of lagoon biodiversity. First, we analyze the variation in the sample coverage for alternative aggregations of the monitoring stations in three lagoons of the Po River Delta. Then, we analyze the variation of a class of entropy indices by mixed effects models, properly accounting for the fixed effects of biotic and abiotic factors and random effects ruled by nested sources of variability corresponding to alternative definitions of local communities. Finally, we address biodiversity partitioning by a generalized diversity measure, namely the Tsallis entropy, and for alternative definitions of the local communities. The main results obtained by the proposed statistical protocol are presented, discussed and framed in the ecological context. © 2017 Elsevier Ltd | ||||
| Address | Dipartimento di Scienze della Vita e Biotecnologie, Università degli Studi di Ferrara, Ferrara, Italy | ||||
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| Notes | Export Date: 12 June 2017 | Approved | no | ||
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EcoFoG @ webmaster @ | Serial | 755 | ||
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| Author | Groc, S.; Delabie, J.H.C.; Fernandez, F.; Petitclerc, F.; Corbara, B.; Leponce, M.; Céréghino, R.; Dejean, A. | ||||
| Title | Litter-dwelling ants as bioindicators to gauge the sustainability of small arboreal monocultures embedded in the Amazonian rainforest | Type | Journal Article | ||
| Year | 2017 | Publication | Ecological Indicators | Abbreviated Journal | |
| Volume | 82 | Issue | Pages | 43-49 | |
| Keywords | Ant diversity; Community alteration; Forest species; Functional traits; Human disturbance; Tree monocultures | ||||
| Abstract | One of the greatest threats to biodiversity and the sustainable functioning of ecosystems is the clearing of forests for agriculture. Because litter-dwelling ants are very good bioindicators of man-made disturbance, we used them to compare monospecific plantations of acacia trees, cocoa trees, rubber trees and pine trees with the surrounding Neotropical rainforest (in contrast to previous studies on forest fragments embedded in industrial monocultures). Although the global level of species turnover was weak, species richness decreased along a gradient from the forest (including a treefall gap) to the tree plantations among which the highest number of species was noted for the cocoa trees, which are known to be a good compromise between agriculture and conservation. Species composition was significantly different between natural habitats and the plantations that, in turn, were different from each other. Compared to the forest, alterations in the ant communities were (1) highest for the acacia and rubber trees, (2) intermediate for the cocoa trees, and, (3) surprisingly, far lower for the pine trees, likely due to very abundant litter. Functional traits only separated the rubber tree plantation from the other habitats due to the higher presence of exotic and leaf-cutting ants. This study shows that small monospecific stands are likely sustainable when embedded in the rainforest and that environmentally-friendly strategies can be planned accordingly. © 2017 Elsevier Ltd | ||||
| Address | Ecolab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France | ||||
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| Notes | Export Date: 9 July 2017 | Approved | no | ||
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EcoFoG @ webmaster @ | Serial | 758 | ||
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| Author | Torroba-Balmori, P.; Budde, K.B.; Heer, K.; González-Martínez, S.C.; Olsson, S.; Scotti-Saintagne, C.; Casalis, M.; Sonké, B.; Dick, C.W.; Heuertz, M. | ||||
| Title | Altitudinal gradients, biogeographic history and microhabitat adaptation affect fine-scale spatial genetic structure in African and Neotropical populations of an ancient tropical tree species | Type | Journal Article | ||
| Year | 2017 | Publication | PLoS ONE | Abbreviated Journal | PLoS ONE |
| Volume | 12 | Issue | 8 | Pages | e0182515 |
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| Abstract | The analysis of fine-scale spatial genetic structure (FSGS) within populations can provide insights into eco-evolutionary processes. Restricted dispersal and locally occurring genetic drift are the primary causes for FSGS at equilibrium, as described in the isolation by distance (IBD) model. Beyond IBD expectations, spatial, environmental or historical factors can affect FSGS. We examined FSGS in seven African and Neotropical populations of the late-successional rain forest tree Symphonia globulifera L. f. (Clusiaceae) to discriminate the influence of drift-dispersal vs. landscape/ecological features and historical processes on FSGS. We used spatial principal component analysis and Bayesian clustering to assess spatial genetic heterogeneity at SSRs and examined its association with plastid DNA and habitat features. African populations (from Cameroon and São Tomé) displayed a stronger FSGS than Neotropical populations at both marker types (mean Sp = 0.025 vs. Sp = 0.008 at SSRs) and had a stronger spatial genetic heterogeneity. All three African populations occurred in pronounced altitudinal gradients, possibly restricting animal-mediated seed dispersal. Cyto-nuclear disequilibria in Cameroonian populations also suggested a legacy of biogeographic history to explain these genetic patterns. Conversely, Neotropical populations exhibited a weaker FSGS, which may reflect more efficient wide-ranging seed dispersal by Neotropical bats and other dispersers. The population from French Guiana displayed an association of plastid haplotypes with two morphotypes characterized by differential habitat preferences. Our results highlight the importance of the microenvironment for eco-evolutionary processes within persistent tropical tree populations. © 2017 Torroba-Balmori et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. | ||||
| Address | Smithsonian Tropical Research Institute, Panama | ||||
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| Notes | Export Date: 2 September 2017 | Approved | no | ||
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EcoFoG @ webmaster @ | Serial | 762 | ||
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