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Piponiot, C.; Derroire, G.; Descroix, L.; Mazzei, L.; Rutishauser, E.; Sist, P.; Hérault, B. |
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Assessing timber volume recovery after disturbance in tropical forests – A new modelling framework |
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Journal Article |
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2018 |
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Ecological Modelling |
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384 |
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353-369 |
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Disturbance; Ecosystem modelling; Recovery; Sustainability; Tropical forest management |
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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. |
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INPHB (Institut National Polytechnique Félix Houphouet Boigny), Yamoussoukro, Cote d'Ivoire |
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Export Date: 1 September 2018 |
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EcoFoG @ webmaster @ |
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813 |
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Medjigbodo, G.; Rozière, E.; Charrier, K.; Izoret, L.; Loukili, A. |
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Hydration, shrinkage, and durability of ternary binders containing Portland cement, limestone filler and metakaolin |
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2018 |
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Construction and Building Materials |
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183 |
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114-126 |
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Durability; Limestone filler; Metakaolin; Shrinkage; Strength; Ternary binders |
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A partial replacement of the clinker by latent hydraulic or pozzolanic materials is encouraged due to environmental and specific technical requirements. Such substitution remains limited to a relatively low level (less than 30% by mass of cementitious materials). An experimental research work was carried out on mortars made with binary and ternary binders (Portland cement; metakaolin; limestone filler) to reach 45% total replacement. In order to investigate the activating effect of reduced water-to-cement ratio, two series of mixtures were designed with W/C0 of 0.42 and 0.5. Their heat of hydration, portlandite content, shrinkage, porosity, and carbonation were monitored. The tests were performed to understand the evolution of their relative strength (activity index) and durability parameters. The strength development of mortars with ternary binders was found to depend on metakaolin properties, including manufacturing process and particle size distribution. Reducing W/C0 ratio accelerated pozzolanic reaction and allowed improving early-age strength and durability parameters. © 2018 Elsevier Ltd |
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Association Technique de l'Industrie des Liants Hydrauliques (ATILH), 7 place de la Défense, Paris La Défense, 92974, France |
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EcoFoG @ webmaster @ |
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814 |
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Dejean, A.; Azémar, F.; Petitclerc, F.; Delabie, J.H.C.; Corbara, B.; Leroy, C.; Céréghino, R.; Compin, A. |
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Highly modular pattern in ant-plant interactions involving specialized and non-specialized myrmecophytes |
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2018 |
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Science of Nature |
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105 |
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43 |
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Ant-plant mutualism; Ecological network; Modularity; Myrmecophytes; Nestedness; Sympatric species |
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Because Tachia guianensis (Gentianaceae) is a “non-specialized myrmecophyte” associated with 37 ant species, we aimed to determine if its presence alters the ant guild associated with sympatric “specialized myrmecophytes” (i.e., plants sheltering a few ant species in hollow structures). The study was conducted in a hilly zone of a neotropical rainforest where two specialized myrmecophytes grow at the bottom of the slopes, another at mid-slope, and a fourth on the hilltops. Tachia guianensis, which occurred everywhere, had its own guild of associated ant species. A network analysis showed that its connections with the four other myrmecophytes were rare and weak, the whole resulting in a highly modular pattern of interactions with one module (i.e., subnetwork) per myrmecophyte. Three ant species parasitized three out of the four specialized myrmecophytes (low nestedness noted), but were not or barely associated with T. guianensis that therefore did not influence the parasitism of specialized myrmecophytes. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. |
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AMAP, IRD, CIRAD, CNRS, INRA, Université de Montpellier, Montpellier, France |
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EcoFoG @ webmaster @ |
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815 |
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Chaves, C.L.; Degen, B.; Pakull, B.; Mader, M.; Honorio, E.; Ruas, P.; Tysklind, N.; Sebbenn, A.M. |
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Assessing the Ability of Chloroplast and Nuclear DNA Gene Markers to Verify the Geographic Origin of Jatoba (Hymenaea courbaril L.) Timber |
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2018 |
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Journal of Heredity |
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109 |
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5 |
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543-552 |
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forensics; illegal logging; nSSRs; SNPs; timber tracking; tropical trees |
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Deforestation-reinforced by illegal logging-is a serious problem in many tropical regions and causes pervasive environmental and economic damage. Existing laws that intend to reduce illegal logging need efficient, fraud resistant control methods. We developed a genetic reference database for Jatoba (Hymenaea courbaril), an important, high value timber species from the Neotropics. The data set can be used for controls on declarations of wood origin. Samples from 308 Hymenaea trees from 12 locations in Brazil, Bolivia, Peru, and French Guiana have been collected and genotyped on 10 nuclear microsatellites (nSSRs), 13 chloroplast SNPs (cpSNP), and 1 chloroplast indel marker. The chloroplast gene markers have been developed using Illumina DNA sequencing. Bayesian cluster analysis divided the individuals based on the nSSRs into 8 genetic groups. Using self-assignment tests, the power of the genetic reference database to judge on declarations on the location has been tested for 3 different assignment methods. We observed a strong genetic differentiation among locations leading to high and reliable self-assignment rates for the locations between 50% to 100% (average of 88%). Although all 3 assignment methods came up with similar mean self-assignment rates, there were differences for some locations linked to the level of genetic diversity, differentiation, and heterozygosity. Our results show that the nuclear and chloroplast gene markers are effective to be used for a genetic certification system and can provide national and international authorities with a robust tool to confirm legality of timber. © 2018 The American Genetic Association. All rights reserved. |
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Instituto Florestal de São Paulo, São Paulo, SP, Brazil |
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EcoFoG @ webmaster @ |
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817 |
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Trzcinski, M.K.; Srivastava, D.S.; Corbara, B.; Dezerald, O.; Leroy, C.; Carrias, J.-F.; Dejean, A.; Céréghino, R.; Rudolf, V. |
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The effects of food web structure on ecosystem function exceeds those of precipitation |
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2016 |
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Journal of Animal Ecology |
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Journal of Animal Ecology |
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85 |
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5 |
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1147-1160 |
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bromeliad; climate change; community interactions; drought; ecosystem function; French Guiana; invertebrates; micro-organisms; phytotelmata; precipitation |
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Ecosystems are being stressed by climate change, but few studies have tested food web responses to changes in precipitation patterns and the consequences to ecosystem function. Fewer still have considered whether results from one geographic region can be applied to other regions, given the degree of community change over large biogeographic gradients. We assembled, in one field site, three types of macroinvertebrate communities within water-filled bromeliads. Two represented food webs containing both a fast filter feeder–microbial and slow detritivore energy channels found in Costa Rica and Puerto Rico, and one represented the structurally simpler food webs in French Guiana, which only contained the fast filter feeder–microbial channel. We manipulated the amount and distribution of rain entering bromeliads and examined how food web structure mediated ecosystem responses to changes in the quantity and temporal distribution of precipitation. Food web structure affected the survival of functional groups in general and ecosystem functions such as decomposition and the production of fine particulate organic matter. Ecosystem processes were more affected by decreased precipitation than were the abundance of micro-organisms and metazoans. In our experiments, the sensitivity of the ecosystem to precipitation change was primarily revealed in the food web dominated by the single filter feeder–microbial channel because other top-down and bottom-up processes were weak or absent. Our results show stronger effects of food web structure than precipitation change per se on the functioning of bromeliad ecosystems. Consequently, we predict that ecosystem function in bromeliads throughout the Americas will be more sensitive to changes in the distribution of species, rather than to the direct effects caused by changes in precipitation. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society |
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Boulevard de la Lironde, IRD, botAnique et bioinforMatique de l'Architecture des Plantes (UMR-IRD 123), TA A-51/PS2, Montpellier Cedex 5, France |
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Export Date: 1 September 2016 |
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EcoFoG @ webmaster @ |
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685 |
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Falster, D.S.; Duursma, R.A.; Ishihara, M.I.; Barneche, D.R.; FitzJohn, R.G.; Vårhammar, A.; Aiba, M.; Ando, M.; Anten, N.; Aspinwall, M.J.; Baltzer, J.L.; Baraloto, C.; Battaglia, M.; Battles, J.J.; Lamberty, B.B.; Van Breugel, M.; Camac, J.; Claveau, Y.; Coll, L.; Dannoura, M.; Delagrange, S.; Domec, J.C.; Fatemi, F.; Feng, W.; Gargaglione, V.; Goto, Y.; Hagihara, A.; Hall, J.S.; Hamilton, S.; Harja, D.; Hiura, T.; Holdaway, R.; Hutley, L.B.; Ichie, T.; Jokela, E.J.; Kantola, A.; Kelly, J.W.G.; Kenzo, T.; King, D.; Kloeppel, B.D.; Kohyama, T.; Komiyama, A.; Laclau, J.P.; Lusk, C.H.; Maguire, D.A.; Le Maire, G.; Mäkelä, A.; Markesteijn, L.; Marshall, J.; McCulloh, K.; Miyata, I.; Mokany, K.; Mori, S.; Myster, R.W.; Nagano, M.; Naidu, S.L.; Nouvellon, Y.; O'Grady, A.P.; O'Hara, K.L.; Ohtsuka, T.; Osada, N.; Osunkoya, O.O.; Peri, P.L.; Petritan, A.M.; Poorter, L.; Portsmuth, A.; Potvin, C.; Ransijn, J.; Reid, D.; Ribeiro, S.C.; Roberts, S.D.; Rodríguez, R.; Acosta, A.S.; Santa-Regina, I.; Sasa, K.; Selaya, N.G.; Sillett, S.C.; Sterck, F.; Takagi, K.; Tange, T.; Tanouchi, H.; Tissue, D.; Umehara, T.; Utsugi, H.; Vadeboncoeur, M.A.; Valladares, F.; Vanninen, P.; Wang, J.R.; Wenk, E.; Williams, R.; De Aquino Ximenes, F.; Yamaba, A.; Yamada, T.; Yamakura, T.; Yanai, R.D.; York, R.A. |
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Title |
BAAD: a Biomass And Allometry Database for woody plants |
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Journal Article |
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2015 |
Publication |
Ecology |
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Ecology |
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96 |
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5 |
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1445 |
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Allometric equations; Biomass allocation; Biomass partitioning; Global carbon cycle; Plant allometry; Plant traits |
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Understanding how plants are constructed; i.e., how key size dimensions and the amount of mass invested in different tissues varies among individuals; is essential for modeling plant growth, estimating carbon stocks, and mapping energy fluxes in the terrestrial biosphere. Allocation patterns can differ through ontogeny, but also among coexisting species and among species adapted to different environments. While a variety of models dealing with biomass allocation exist, we lack a synthetic understanding of the underlying processes. This is partly due to the lack of suitable data sets for validating and parameterizing models. To that end, we present the Biomass and allometry database (BAAD) for woody plants. The BAAD contains 259 634 measurements collected in 176 different studies, from 21 084 individuals across 678 species. Most of these data come from existing publications. However, raw data were rarely made public at time of publication. Thus the BAAD contains individual level data from different studies, transformed into standard units and variable names. The transformations were achieved using a common workflow for all raw data files. Other features that distinguish the BAAD are: (i) measurements were for individual plants rather than stand averages; (ii) individuals spanning a range of sizes were measured; (iii) inclusion of plants from 0.01-100 m in height; and (iii) biomass was estimated directly, i.e., not indirectly via allometric equations (except in very large trees where biomass was estimated from detailed subsampling). We included both wild and artificially grown plants. The data set contains the following size metrics: total leaf area; area of stem crosssection including sapwood, heartwood, and bark; height of plant and crown base, crown area, and surface area; and the dry mass of leaf, stem, branches, sapwood, heartwood, bark, coarse roots, and fine root tissues. We also report other properties of individuals (age, leaf size, leaf mass per area, wood density, nitrogen content of leaves and wood), as well as information about the growing environment (location, light, experimental treatment, vegetation type) where available. It is our hope that making these data available will improve our ability to understand plant growth, ecosystem dynamics, and carbon cycling in the world's vegetation. |
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Department of Disturbance Ecology, University of Bayreuth, Germany |
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Export Date: 1 September 2016 |
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EcoFoG @ webmaster @ |
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686 |
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Farjalla, V.F.; González, A.L.; Céréghino, R.; Dezerald, O.; Marino, N.A.C.; Piccoli, G.C.O.; Richardson, B.A.; Richardson, M.J.; Romero, G.Q.; Srivastava, D.S. |
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Terrestrial support of aquatic food webs depends on light inputs: A geographically-replicated test using tank bromeliads |
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2016 |
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Ecology |
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Ecology |
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97 |
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8 |
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2147-2156 |
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Allochthonous carbon; Allochthony; Aquatic food webs; Autochthonous carbon; Autochthony; Natural microcosms; Stable isotopic analysis; Tank bromeliads; Tropics |
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Food webs of freshwater ecosystems can be subsidized by allochthonous resources. However, it is still unknown which environmental factors regulate the relative consumption of allochthonous resources in relation to autochthonous resources. Here, we evaluated the importance of allochthonous resources (litterfall) for the aquatic food webs in Neotropical tank bromeliads, a naturally replicated aquatic microcosm. Aquatic invertebrates were sampled in more than 100 bromeliads within either open or shaded habitats and within five geographically distinct sites located in four different countries. Using stable isotope analyses, we determined that allochthonous sources comprised 74% (±17%) of the food resources of aquatic invertebrates. However, the allochthonous contribution to aquatic invertebrates strongly decreased from shaded to open habitats, as light incidence increased in the tanks. The density of detritus in the tanks had no impact on the importance of allochthonous sources to aquatic invertebrates. This overall pattern held for all invertebrates, irrespective of the taxonomic or functional group to which they belonged. We concluded that, over a broad geographic range, aquatic food webs of tank bromeliads are mostly allochthonous-based, but the relative importance of allochthonous subsidies decreases when light incidence favors autochthonous primary production. These results suggest that, for other freshwater systems, some of the between-study variation in the importance of allochthonous subsidies may similarly be driven by the relative availability of autochthonous resources. © 2016 by the Ecological Society of America. |
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Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), PO Box 6109, Campinas-SP, Brazil |
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EcoFoG @ webmaster @ |
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687 |
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Piponiot, C.; Cabon, A.; Descroix, L.; Dourdain, A.; Mazzei, L.; Ouliac, B.; Rutishauser, E.; Sist, P.; Herault, B. |
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A methodological framework to assess the carbon balance of tropical managed forests |
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2016 |
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Carbon Balance and Management |
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Carbon Balance and Management |
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11 |
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1 |
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Amazonia; Carbon cycle; Error propagation; Production forests; Selective logging |
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Background: Managed forests are a major component of tropical landscapes. Production forests as designated by national forest services cover up to 400 million ha, i.e. half of the forested area in the humid tropics. Forest management thus plays a major role in the global carbon budget, but with a lack of unified method to estimate carbon fluxes from tropical managed forests. In this study we propose a new time- and spatially-explicit methodology to estimate the above-ground carbon budget of selective logging at regional scale. Results: The yearly balance of a logging unit, i.e. the elementary management unit of a forest estate, is modelled by aggregating three sub-models encompassing (i) emissions from extracted wood, (ii) emissions from logging damage and deforested areas and (iii) carbon storage from post-logging recovery. Models are parametrised and uncertainties are propagated through a MCMC algorithm. As a case study, we used 38 years of National Forest Inventories in French Guiana, northeastern Amazonia, to estimate the above-ground carbon balance (i.e. the net carbon exchange with the atmosphere) of selectively logged forests. Over this period, the net carbon balance of selective logging in the French Guianan Permanent Forest Estate is estimated to be comprised between 0.12 and 1.33 Tg C, with a median value of 0.64 Tg C. Uncertainties over the model could be diminished by improving the accuracy of both logging damage and large woody necromass decay submodels. Conclusions: We propose an innovating carbon accounting framework relying upon basic logging statistics. This flexible tool allows carbon budget of tropical managed forests to be estimated in a wide range of tropical regions. © 2016 The Author(s). |
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CNRS, UMR EcoFoG, AgroParisTech, Inra, Université de la Guyane, Université des Antilles, Cirad, Campus Agronomique, Kourou, French Guiana |
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Export Date: 1 September 2016 |
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EcoFoG @ webmaster @ |
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688 |
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Dejean, A.; Azémar, F.; Céréghino, R.; Leponce, M.; Corbara, B.; Orivel, J.; Compin, A. |
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The dynamics of ant mosaics in tropical rainforests characterized using the Self-Organizing Map algorithm |
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2016 |
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Insect Science |
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Insect Science |
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23 |
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4 |
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630-637 |
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ant plant relationships; dynamics of associations; myrmecophytes; tropical rainforests |
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Ants, the most abundant taxa among canopy-dwelling animals in tropical rainforests, are mostly represented by territorially dominant arboreal ants (TDAs) whose territories are distributed in a mosaic pattern (arboreal ant mosaics). Large TDA colonies regulate insect herbivores, with implications for forestry and agronomy. What generates these mosaics in vegetal formations, which are dynamic, still needs to be better understood. So, from empirical research based on 3 Cameroonian tree species (Lophira alata, Ochnaceae; Anthocleista vogelii, Gentianaceae; and Barteria fistulosa, Passifloraceae), we used the Self-Organizing Map (SOM, neural network) to illustrate the succession of TDAs as their host trees grow and age. The SOM separated the trees by species and by size for L. alata, which can reach 60 m in height and live several centuries. An ontogenic succession of TDAs from sapling to mature trees is shown, and some ecological traits are highlighted for certain TDAs. Also, because the SOM permits the analysis of data with many zeroes with no effect of outliers on the overall scatterplot distributions, we obtained ecological information on rare species. Finally, the SOM permitted us to show that functional groups cannot be selected at the genus level as congeneric species can have very different ecological niches, something particularly true for Crematogaster spp., which include a species specifically associated with B. fistulosa, nondominant species and TDAs. Therefore, the SOM permitted the complex relationships between TDAs and their growing host trees to be analyzed, while also providing new information on the ecological traits of the ant species involved. © 2015 Institute of Zoology, Chinese Academy of Sciences |
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Clermont Université, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand, France |
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Export Date: 1 September 2016 |
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EcoFoG @ webmaster @ |
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689 |
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Feldpausch, T.R.; Phillips, O.L.; Brienen, R.J.W.; Gloor, E.; Lloyd, J.; Lopez-Gonzalez, G.; Monteagudo-Mendoza, A.; Malhi, Y.; Alarcón, A.; Álvarez Dávila, E.; Alvarez-Loayza, P.; Andrade, A.; Aragao, L.E.O.C.; Arroyo, L.; Aymard C., G.A.; Baker, T.R.; Baraloto, C.; Barroso, J.; Bonal, D.; Castro, W.; Chama, V.; Chave, J.; Domingues, T.F.; Fauset, S.; Groot, N.; Honorio Coronado, E.; Laurance, S.; Laurance, W.F.; Lewis, S.L.; Licona, J.C.; Marimon, B.S.; Marimon-Junior, B.H.; Mendoza Bautista, C.; Neill, D.A.; Oliveira, E.A.; Oliveira dos Santos, C.; Pallqui Camacho, N.C.; Pardo-Molina, G.; Prieto, A.; Quesada, C.A.; Ramírez, F.; Ramírez-Angulo, H.; Réjou-Méchain, M.; Rudas, A.; Saiz, G.; Salomão, R.P.; Silva-Espejo, J.E.; Silveira, M.; ter Steege, H.; Stropp, J.; Terborgh, J.; Thomas-Caesar, R.; van der Heijden, G.M.F.; Vásquez Martinez, R.; Vilanova, E.; Vos, V.A. |
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Amazon forest response to repeated droughts |
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2016 |
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Global Biogeochemical Cycles |
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Global Biogeochemical Cycles |
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30 |
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7 |
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964-982 |
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carbon; forest productivity; precipitation; tree mortality; vegetation dynamics; water deficit |
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The Amazon Basin has experienced more variable climate over the last decade, with a severe and widespread drought in 2005 causing large basin-wide losses of biomass. A drought of similar climatological magnitude occurred again in 2010; however, there has been no basin-wide ground-based evaluation of effects on vegetation. We examine to what extent the 2010 drought affected forest dynamics using ground-based observations of mortality and growth from an extensive forest plot network. We find that during the 2010 drought interval, forests did not gain biomass (net change: −0.43 Mg ha−1, confidence interval (CI): −1.11, 0.19, n = 97), regardless of whether forests experienced precipitation deficit anomalies. This contrasted with a long-term biomass sink during the baseline pre-2010 drought period (1998 to pre-2010) of 1.33 Mg ha−1 yr−1 (CI: 0.90, 1.74, p < 0.01). The resulting net impact of the 2010 drought (i.e., reversal of the baseline net sink) was −1.95 Mg ha−1 yr−1 (CI:−2.77, −1.18; p < 0.001). This net biomass impact was driven by an increase in biomass mortality (1.45 Mg ha−1 yr−1 CI: 0.66, 2.25, p < 0.001) and a decline in biomass productivity (−0.50 Mg ha−1 yr−1, CI:−0.78, −0.31; p < 0.001). Surprisingly, the magnitude of the losses through tree mortality was unrelated to estimated local precipitation anomalies and was independent of estimated local pre-2010 drought history. Thus, there was no evidence that pre-2010 droughts compounded the effects of the 2010 drought. We detected a systematic basin-wide impact of the 2010 drought on tree growth rates across Amazonia, which was related to the strength of the moisture deficit. This impact differed from the drought event in 2005 which did not affect productivity. Based on these ground data, live biomass in trees and corresponding estimates of live biomass in lianas and roots, we estimate that intact forests in Amazonia were carbon neutral in 2010 (−0.07 Pg C yr−1 CI:−0.42, 0.23), consistent with results from an independent analysis of airborne estimates of land-atmospheric fluxes during 2010. Relative to the long-term mean, the 2010 drought resulted in a reduction in biomass carbon uptake of 1.1 Pg C, compared to 1.6 Pg C for the 2005 event. ©2016. American Geophysical Union. All Rights Reserved. |
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Centro de Investigación y Promoción del Campesinado Norte Amazónico, Riberalta, Bolivia |
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Export Date: 1 September 2016 |
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EcoFoG @ webmaster @ |
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690 |
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