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Author Molto, Q.; Rossi, V.; Blanc, L.
Title Error propagation in biomass estimation in tropical forests Type Journal Article
Year 2013 Publication Methods in Ecology and Evolution Abbreviated Journal
Volume 4 Issue 2 Pages 175-183
Keywords Bayesian framework; Modelling; Redd; Uncertainty propagation
Abstract Reliable above-ground biomass (AGB) estimates are required for studies of carbon fluxes and stocks. However, there is a huge lack of knowledge concerning the precision of AGB estimates and the sources of this uncertainty. At the tree level, the tree height is predicted using the tree diameter at breast height (DBH) and a height sub-model. The wood-specific gravity (WSG) is predicted with taxonomic information and a WSG sub-model. The tree mass is predicted using the predicted height, the predicted WSG and the biomass sub-model. Our models were inferred with Bayesian methods and the uncertainty propagated with a Monte Carlo scheme. The uncertainties in the predictions of tree height, tree WSG and tree mass were neglected sequentially to quantify their contributions to the uncertainty in AGB. The study was conducted in French Guiana where long-term research on forest ecosystems provided an outstanding data collection on tree height, tree dynamics, tree mass and species WSG. We found that the uncertainty in the AGB estimates was found to derive primarily from the biomass sub-model. The models used to predict the tree heights and WSG contributed negligible uncertainty to the final estimate. Considering our results, a poor knowledge of WSG and the height-diameter relationship does not increase the uncertainty in AGB estimates. However, it could lead to bias. Therefore, models and databases should be used with care. This study provides a methodological framework that can be broadly used by foresters and plant ecologist. It provides the accurate confidence intervals associated with forest AGB estimates made from inventory data. When estimating region-scale AGB values (through spatial interpolation, spatial modelling or satellite signal treatment), the uncertainty of the forest AGB value in the reference forest plots has to be taken in account. We believe that in the light of the Reducing Emissions from Deforestation and Degradation debate, our method is a crucial step in monitoring carbon stocks and their spatio-temporal evolution. © 2012 The Authors. Methods in Ecology and Evolution © 2012 British Ecological Society.
Address (down) CIRAD, UMR 'Ecologie des Forêts de Guyane', Kourou Cedex, 97 379, France
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Notes Export Date: 21 February 2013; Source: Scopus Approved no
Call Number EcoFoG @ webmaster @ Serial 470
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Author Le Guen, V.; Rodier-Goud, M.; Troispoux, V.; Xiong, T.C.; Brottier, P.; Billot, C.; Seguin, M.
Title Characterization of polymorphic microsatellite markers for Microcyclus ulei, causal, agent of South American leaf blight of rubber trees Type Journal Article
Year 2004 Publication Molecular Ecology Notes Abbreviated Journal Mol. Ecol. Notes
Volume 4 Issue 1 Pages 122-124
Keywords Hevea brasiliensis; Microcyclus ulei; microsatellite markers; phytopathogenic fungi; South American leaf blight
Abstract South American leaf blight caused by the ascomycete Microcyclus Wei is the most harmful disease of the rubber tree in Latin America and a potential threat to Asiatic and African natural rubber production. Until now, the variability of this fungus was assessed through observation of pathogenicity of isolates on a range of rubber tree clones with known resistance reactions. The present study describes the process used to design 11 microsatellite markers and evaluates their usefulness in detecting genetic polymorphism. Nine of these markers were polymorphic among six isolates from Brazil (with two to three alleles per locus) and five markers were polymorphic among four isolates from French Guiana (with two to four alleles per locus).
Address (down) CIRAD, F-97387 Kourou, France, Email: vincent.le_guen@cirad.fr
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 1471-8278 ISBN Medium
Area Expedition Conference
Notes ISI:000189159500037 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 265
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Author Gourlet-Fleury, S.; Comu, G.; Jesel, S.; Dessard, H.; Jourget, J.G.; Blanc, L.; Picard, N.
Title Using models to predict recovery and assess tree species vulnerability in logged tropical forests: A case study from French Guiana Type Journal Article
Year 2005 Publication Forest Ecology and Management Abbreviated Journal For. Ecol. Manage.
Volume 209 Issue 1-2 Pages 69-86
Keywords matrix model; individual-based spatially explicit model; regeneration; recruitment; long-term population dynamics
Abstract A major challenge for forest managers is to define the optimal cutting cycle to ensure that the resource is sustained in the long term. Matrix models of forest dynamics allow time-projection of diameter-class distributions and thus assessment of the time needed, after logging, to recover a given part of the exploitable stock. They are easy to build and they only require, as input variables, the diameter structure of the population(s) under scope. However, such models are based on a coarse description of tree population dynamics and must be used with caution. In particular, as trees are only described from a diameter threshold (usually 10 cm dbh), recruitment of a new tree cannot be linked with the preceding generation since too much time elapsed between seed dispersal and the installation of a 10-cm recruit. This causes predictions of matrix models to be highly questionable in the long term when ingrowth to larger dbh classes greatly depends on the way recruitment has been modelled. We used a case study from French Guiana to test whether or not a simple matrix model is reliable enough to help forest managers choose between management alternatives. We focused on the major timber species Dicorynia guianensis Amshoff (Caesalpiniaceae) harvested under a selective cutting regime. We compared predictions of D. guianensis stock recovery in the short and long term provided by two models: StoMat, a non-regulated matrix model, and SELVA, a single-tree distance dependent model explicitly simulating the entire species life cycle. Both models were independently calibrated on data from Paracou permanent sample plots. We showed that: (i) the short-term recovery of the exploitable stock predicted by StoMat is reliable for a large range of disturbance conditions; (ii) recruitment implementation in StoMat does not influence projections until the third felling cycle; (iii) for shared initial stand conditions SELVA and StoMat give consistent mid- and long-term predictions: the simple recruitment model used into StoMat could efficiently summarise the regeneration processes of the species under low felling intensity. Our results indicate that the current felling regime used in French Guiana may not be sustainable on a long-term basis. In any case, no more than 60% of the initial stock would be recovered after logging. We conclude that simple models can provide as reliable predictions as more complicated ones. They may be sufficient to assess the recovery of a species' exploitable stock even in the long term, or at least assess the (un)sustainability of particular harvesting regimes. (c) 2005 Elsevier B.V. All rights reserved.
Address (down) CIRAD, Dept Forets, F-34398 Montpellier 5, France, Email: sylvie.gourlet-fleury@cirad.fr
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Publisher ELSEVIER SCIENCE BV Place of Publication Editor
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0378-1127 ISBN Medium
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Notes ISI:000228504600007 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 257
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Author Anouhe, J.-B.S.; Adima, A.A.; Niamké, F.B.; Stien, D.; Amian, B.K.; Blandinieres, P.-A.; Virieux, D.; Pirat, J.-L.; Kati-Coulibaly, S.; Amusant, N.
Title Dicorynamine and harmalan-N-oxide, two new β-carboline alkaloids from Dicorynia guianensis Amsh heartwood Type Journal Article
Year 2015 Publication Phytochemistry Letters Abbreviated Journal Phytochemistry Letters
Volume 12 Issue Pages 158-163
Keywords ABTS antioxidant; Biogenesis; Dicorynia guianensis; Nitrone; Spiroindolone
Abstract Abstract The chemical investigations of Dicorynia guianensis heartwood led to the isolation of four new indole alkaloids for the first time in this plant. Compound (1) identified as spiroindolone 2′,3′,4′,9′-tetrahydrospiro [indoline-3,1′pyrido[3,4-b]-indol]-2-one, and compound (3) described as nitrone 1-methyl-4,9-dihydro-3H-pyrido [3,4-b] indole 2-oxide and were isolated for the first time as natural products. ABTS antioxidant activity guided their isolation. © 2015 Published by Elsevier B.V. on behalf of Phytochemical Society of Europe.
Address (down) CIRAD, Département Environnements et Sociétés, UMR Ecologie des Forêts de GuyaneKourou cedex, France
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Notes Export Date: 24 April 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 598
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Author Marcon, E.; Herault, B.
Title entropart: An R package to measure and partition diversity Type Journal Article
Year 2015 Publication Journal of Statistical Software Abbreviated Journal Journal of Statistical Software
Volume 67 Issue 8 Pages 1-26
Keywords Biodiversity; Entropy; Partitioning
Abstract entropart is a package for R designed to estimate diversity based on HCDT entropy or similarity-based entropy. It allows calculating species-neutral, phylogenetic and functional entropy and diversity, partitioning them and correcting them for estimation bias. © 2015, American Statistical Association. All rights reserved.
Address (down) Cirad, Campus agronomique, BP 316, Kourou, French Guiana
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Notes Export Date: 22 October 2015 Approved no
Call Number EcoFoG @ webmaster @ Serial 633
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Author Gourlet-Fleury, S.; Rossi, V.; Rejou-Mechain, M.; Freycon, V.; Fayolle, A.; Saint-André, L.; Cornu, G.; Gérard, J.; Sarrailh, J.-M.; Flores, O.; Baya, F.; Billand, A.; Fauvet, N.; Gally, M.; Henry, M.; Hubert, D.; Pasquier, A.; Picard, N.
Title Environmental filtering of dense-wooded species controls above-ground biomass stored in African moist forests Type Journal Article
Year 2011 Publication Journal of Ecology Abbreviated Journal J. Ecol.
Volume 99 Issue 4 Pages 981-990
Keywords Basal area; Central African Republic; Determinants of plant community diversity and structure; Life-history strategy; Soil fertility; Species sorting; Vital rates; Water reserve; Wood density; aboveground biomass; basal area; climate change; data set; database; diameter; forest ecosystem; forest inventory; life history trait; nutrient availability; physical property; plant community; resource availability; soil fertility; soil nutrient; soil texture; soil type; stem; tropical forest; wood; Central African Republic
Abstract 1.Regional above-ground biomass estimates for tropical moist forests remain highly inaccurate mostly because they are based on extrapolations from a few plots scattered across a limited range of soils and other environmental conditions. When such conditions impact biomass, the estimation is biased. The effect of soil types on biomass has especially yielded controversial results. 2.We investigated the relationship between above-ground biomass and soil type in undisturbed moist forests in the Central African Republic. We tested the effects of soil texture, as a surrogate for soil resources availability and physical constraints (soil depth and hydromorphy) on biomass. Forest inventory data were collected for trees ≥20cm stem diameter in 2754 0.5ha plots scattered over 4888km2. The plots contained 224 taxons, of which 209 were identified to species. Soil types were characterized from a 1:1000000 scale soil map. Species-specific values for wood density were extracted from the CIRAD's data base of wood technological properties. 3.We found that basal area and biomass differ in their responses to soil type, ranging from 17.8m2ha-1 (217.5tha-1) to 22.3m2ha-1 (273.3tha-1). While shallow and hydromorphic soils support forests with both low stem basal area and low biomass, forests on deep resource-poor soils are typically low in basal area but as high in biomass as forests on deep resource-rich soils. We demonstrated that the environmental filtering of slow growing dense-wooded species on resource-poor soils compensates for the low basal area, and we discuss whether this filtering effect is due to low fertility or to low water reserve. 4.Synthesis. We showed that soil physical conditions constrained the amount of biomass stored in tropical moist forests. Contrary to previous reports, our results suggest that biomass is similar on resource-poor and resource-rich soils. This finding highlights both the importance of taking into account soil characteristics and species wood density when trying to predict regional patterns of biomass. Our findings have implications for the evaluation of biomass stocks in tropical forests, in the context of the international negotiations on climate change. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society.
Address (down) CIRAD, BP 4035, Libreville, Gabon
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ISSN 00220477 (Issn) ISBN Medium
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Notes Cited By (since 1996): 1; Export Date: 23 October 2011; Source: Scopus; Coden: Jecoa; doi: 10.1111/j.1365-2745.2011.01829.x; Language of Original Document: English; Correspondence Address: Gourlet-Fleury, S.; Cirad, UR BandSEF, Biens et Services des Ecosystèmes Forestiers tropicaux, Campus International de Baillarguet, TA C-105/D, F-34398, Montpellier, France; email: sylvie.gourlet-fleury@cirad.fr Approved no
Call Number EcoFoG @ webmaster @ Serial 361
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Author Zaremski, A.; Gastonguay, L.; Zaremski, C.; Chaffanel, F.; Le Floch, G.; Beauchene, J.
Title Capacity of tropical forest soils of french guiana and réunion for depolluting the woods impregnated with biocides Type Journal Article
Year 2013 Publication Bois et Forets des Tropiques Abbreviated Journal Bois Forets Tropiques
Volume 67 Issue 318 Pages 51-58
Keywords Bioremediation; Copper chromium arsenic(CCA) wood-destroying fungi; Depollution; Loss of mass; Pentachlorophenol(PCP); Treated timber; Tropical soil
Abstract Wood material for a long time was treated with fungicides or insecticides whose impact on the soil after leaching constitutes a real environmental problem. Nowadays, most of the studies on degradation of these toxic products was carried out with microorganisms which have been isolated in the laboratory. The present study sought to refine the knowledge vis-à-vis these microorganisms, especially wood-destroying fungi degrading pollutants in situ, from which few data are actually available. To decontaminate treated wood, the capacity of wooddestroying microorganisms from tropical forest soils of French Guiana and Reunion was evaluated to degrade toxic biocides. These are pentachlorophenol (PCP) and copper- chromium arsenic based compounds (CCA). Monitoring the degradation of samples of red pine, Pinus resinosa, shows that soils of French Guiana are more efficient than those of Reunion Island in terms of microbial activity vis-àvis these two biocides. A significant difference in loss of mass in specimens of red pine treated with CCA and PCP can range from single to double (respectively 18% and 30%). These findings confirm that CCA is less leacher and less degradable than the PCP by microorganisms in the soil. According to the scale of mass loss in laboratory tests, the wood so treated would be classified very not durable after three years of contact with soil, while the treatment is expected to be very durable.
Address (down) Cirad Umr Ecofog, BP 701, 97387 Kourou cedex, France
Corporate Author Thesis
Publisher Lavoisier Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 17775760 (Issn) ISBN Medium
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Notes Export Date: 12 May 2014; Source: Scopus; Language of Original Document: French Approved no
Call Number EcoFoG @ webmaster @ Serial 540
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Author Tahiri, A.; Amissa Adima, A.; Adjé, F.A.; Amusant, N.
Title Pesticide effects and screening of extracts of Azadirachta Indica (A.) Juss. on the Macrotermes bellicosus rambur termite Type Journal Article
Year 2011 Publication Bois et Forets des Tropiques Abbreviated Journal Effet pesticide et screening des extraits de Azadirachta indica (A.) Juss. sur le termite Macroterme
Volume 65 Issue 310 Pages 79-88
Keywords Azadirachta indica; Pesticide properties; Phytochemical screening; Termite
Abstract To recommend applications in the field of a naturally insecticide plant substance as an alternative to chemical control against termite attacks, several important prerequisites need to be satisfied to ensure its effectiveness. The toxicity, lethal dose, mode of action, persistence of insecticide effect and chemical composition of total aqueous, alcohol and hexane extracts of the leaves and seeds of the neem tree, Azadirachta indica, were tested with the Macrotermes bellicosus termite. The extracts were found to be highly toxic to termites on contact, killing the entire population tested. The insecticide effect of the extracts persisted from 2.4 to 4.2 days. The aqueous and hexane extracts were the most toxic (LD50 0.422±0.018 to 4,466±0,162 mg/l). Contact and inhalation were both essential to their effectiveness. The aqueous extract of seeds, which is the most active, is also capable of being transferred through the colony during social tasks. However, it seems to have an anti-appetent effect on termites and does not act by ingestion. It contains phenol compounds (tannins and flavonoids) and saponins. The hexane extract of seeds is oily and contains 11 fatty acids as well as terpenoids, flavonoids and saponins.
Address (down) Cirad Laboratoire de Chimie du Bois, 34398 Montpellier Cedex 5, France
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Notes Export Date: 20 November 2012; Source: Scopus Approved no
Call Number EcoFoG @ webmaster @ Serial 447
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Author Dutech, C.; Maggia, L.; Tardy, C.; Joly, H.I.; Jarne, P.
Title Tracking a genetic signal of extinction-recolonization events in a neotropical tree species: Vouacapoua americana aublet in french guiana Type Journal Article
Year 2003 Publication Evolution Abbreviated Journal Evolution
Volume 57 Issue 12 Pages 2753-2764
Keywords allelic richness; caesalpinioideae; chloroplast DNA; climatic changes; cytonuclear disequilibrium; legummosae; microsatellite loci; tropical rainforest
Abstract Drier periods from the late Pleistocene and early Holocene have been hypothesized to have caused the disappearance of various rainforest species over large geographical areas in South America and restricted the extant populations to mesic sites. Subsequent improvement in climatic conditions has been associated with recolonization. Changes in population size associated with these extinction-recolonization events should have affected genetic diversity within species. However, these historical hypotheses and their genetic consequences have rarely been tested in South America. Here, we examine the diversity of the chloroplast and nuclear genomes in a Neotropical rainforest tree species, Vouacapoua americana (Leguminosae, Caesalpinioideae) in French Guiana. The chloroplast diversity was analyzed using a polymerase chain reaction-restriction fragment length polymorphism method (six pairs of primers) in 29 populations distributed over most of French Guiana, and a subset of 17 populations was also analyzed at nine polymorphic microsatellite loci. To determine whether this species has experienced extinction-recolonization, we sampled populations in areas supposedly not or only slightly affected by climatic changes, where the populations would not have experienced frequent extinction, and in areas that appear to have been recently recolonized. In the putatively recolonized areas, we found patches of several thousands of hectares homogeneous for chloroplast variation that can be interpreted as the effect of recolonization processes from several geographical origins. In addition, we observed that, for both chloroplast and nuclear genomes, the populations in newly recolonized areas exhibited a significantly smaller allelic richness than others. Controlling for geographic distance, we also detected a significant correlation between chloroplast and nuclear population differentiation. This result indicates a cytonuclear disequilibrium that can be interpreted as a historical signal of a genetic divergence between fragmented populations. In conclusion, the spatial genetic structure of contemporary V. americana populations shows evidence that this species has experienced large extinction-recolonization events, which were possibly caused by past climatic change.
Address (down) CIRAD Foret, Silvolab, Ecol Mol, F-97387 Kourou, France, Email: laruent.maggia@cirad.fr
Corporate Author Thesis
Publisher SOC STUDY EVOLUTION Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0014-3820 ISBN Medium
Area Expedition Conference
Notes ISI:000188061800007 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 241
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Author Picard, N.; Gourlet-Fleury, S.; Sist, P.
Title Using process-dependent groups of species to model the dynamics of a tropical rainforest Type Journal Article
Year 2003 Publication Modelling Forest Systems Abbreviated Journal
Volume Issue Pages 237-248
Keywords
Abstract The high tree species diversity in tropical forests is difficult to take into account in models. The usual solution consists of defining groups of species and then adjusting a set of parameters for each group. In this study, we address this issue by allowing a species to move from one species group to another, depending on the biological process that is concerned. We developed this approach with a matrix model of forest dynamics, for a tropical rainforest in French Guiana, at Paracou, focusing on the methodological aspects. The forest dynamics is split into three components: recruitment, growth and mortality. We then built five recruitment groups, five growth groups and five mortality groups. One species is characterized by a combination of the three groups, thus yielding in total 5 X 5 X 5 = 125 possibilities, out of which 43 are actually observed. The resulting matrix model provides a better view of the floristic composition of the forest, and does not have more parameters than it would have with five global species groups. However, its predictions are no more precise than those of the matrix model based on five global groups.
Address (down) Cirad Foret, Montpellier, France
Corporate Author Thesis
Publisher CABI PUBLISHING Place of Publication Editor
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Notes ISI:000231866400021 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 249
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