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Author Molto, Q.; Rossi, V.; Blanc, L. url  openurl
  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 (up) 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 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 Rodrigues, A.M.S.; Theodoro, P.N.E.T.; Eparvier, V.; Basset, C.; Silva, M.R.R.; Beauchene, J.; Espindola, L.S.; Stien, D. openurl 
  Title Search for Antifungal Compounds from the Wood of Durable Tropical Trees Type Journal Article
  Year 2010 Publication Journal of Natural Products Abbreviated Journal J. Nat. Prod.  
  Volume 73 Issue 10 Pages 1706-1707  
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  Abstract (up) Research on antifungal compounds from the durable wood from French Guiana Amazonian forest trees highlights the correlation between the activity of their extracts against wood-rotting fungi and human pathogens. The fractionation of an ethyl acetate extract of Sextonia rubra wood led to the isolation of rubrenolide (1) and rubrynolide (2). The potential of compounds 1 and 2 is described through the evaluation of their activity against 16 pathogenic fungi and their cytotoxicity toward NIH-3T3 mammalian fibroblast cells.  
  Address [Rodrigues, Alice M. S.; Eparvier, Veronique; Basset, Charlie; Espindola, Laila S.; Stien, Didier] Univ Antilles Guyane, CNRS, UMR ECOFOG, F-97300 Cayenne, France, Email: darvenne@unb.br  
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  Publisher AMER CHEMICAL SOC Place of Publication Editor  
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  ISSN 0163-3864 ISBN Medium  
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  Notes ISI:000283288900015 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 25  
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Author Falkowski, M.; Jahn-Oyac, A.; Ferrero, E.; Issaly, J.; Eparvier, V.; Girod, R.; Rodrigues, A.M.S.; Stien, D.; Houel, E.; Dusfour, I. pdf  url
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  Title Assessment of A Simple Compound-Saving Method to Study Insecticidal Activity of Natural Extracts and Pure Compounds Against Mosquito Larvae Type Journal Article
  Year 2016 Publication Journal of the American Mosquito Control Association Abbreviated Journal Journal of the American Mosquito Control Association  
  Volume 32 Issue 4 Pages 337-340  
  Keywords Mosquitoes; natural insecticides; screening method  
  Abstract (up) Research on natural insecticides has intensified with the spread of resistance to chemicals among insects, particularly disease vectors. To evaluate compounds, the World Health Organization (WHO) has published standardized procedures. However, those may be excessively compound-consuming when it comes to assessing the activity of natural extracts and pure compounds isolated in limited amount. As part of our work on the discovery of new mosquito larvicides from Amazonian plants, we developed a compound-saving assay in 5-ml glass tubes instead of WHO larval 100-ml cups. Comparing activity of synthetic and natural chemicals validated the glass tube assay. Raw data, lethal doses that kill 50% (LD50) and 90% (LD90) at 24 and 48 h, were highly correlated (0.68 < R2 < 0.96, P < 0.001, Pearson test) between cups and tubes. It was also established that 10 tubes (N = 50 larvae) provided the same level of sensitivity as 20 tubes (N = 100). This method proved suitable for rapid screening of natural extracts and molecules, identifying active compounds using 10 times less material than in the WHO protocol. © 2016 by The American Mosquito Control Association, Inc.  
  Address Sorbonne Universites, UPMC, Universite Paris 06, CNRS, Laboratoire de Biodiversite et Biotechnologies Microbiennes (USR 3579, LBBM), Observatoire Oceanologique, avenue de Fontaul e, Banyuls/Mer-sur-mer, France  
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  Notes Export Date: 3 March 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 740  
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Author Urbina, Ifigenia ; Grau, Oriol ; Sardans, Jordi ; Margalef, Olga ; Peguero, Guillermo ; Asensio, Dolores ; Llusia, Joan ; Ogaya, Roma ; Gargallo-Garriga, Albert ; Van Langenhove, Leandro ; Verryckt, Lore T. ; Courtois, Elodie A. ; Stahl, Clement ; Soong, Jennifer L. ; Chave, Jérome ; Hérault, Bruno ; Janssens, Ivan A. ; Sayer, Emma ; Penuelas, Josep doi  openurl
  Title High foliar K and P resorption efficiencies in old-growth tropical forests growing on nutrient-poor soils Type Journal Article
  Year 2021 Publication Ecology and Evolution Abbreviated Journal  
  Volume 11 Issue 13 Pages 8969-8982  
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  Abstract (up) Resorption is the active withdrawal of nutrients before leaf abscission. This mechanism represents an important strategy to maintain efficient nutrient cycling; however, resorption is poorly characterized in old-growth tropical forests growing in nutrient-poor soils. We investigated nutrient resorption from leaves in 39 tree species in two tropical forests on the Guiana Shield, French Guiana, to investigate whether resorption efficiencies varied with soil nutrient, seasonality, and species traits. The stocks of P in leaves, litter, and soil were low at both sites, indicating potential P limitation of the forests. Accordingly, mean resorption efficiencies were higher for P (35.9%) and potassium (K; 44.6%) than for nitrogen (N; 10.3%). K resorption was higher in the wet (70.2%) than in the dry (41.7%) season. P resorption increased slightly with decreasing total soil P; and N and P resorptions were positively related to their foliar concentrations. We conclude that nutrient resorption is a key plant nutrition strategy in these old-growth tropical forests, that trees with high foliar nutrient concentration reabsorb more nutrient, and that nutrients resorption in leaves, except P, are quite decoupled from nutrients in the soil. Seasonality and biochemical limitation played a role in the resorption of nutrients in leaves, but species-specific requirements obscured general tendencies at stand and ecosystem level.  
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  Publisher Wiley Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 1011  
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Author Fanin, N.; Hättenschwiler, S.; Schimann, H.; Fromin, N. url  openurl
  Title Interactive effects of C, N and P fertilization on soil microbial community structure and function in an Amazonian rain forest Type Journal Article
  Year 2015 Publication Functional Ecology Abbreviated Journal Funct. Ecol.  
  Volume 29 Issue 1 Pages 140-150  
  Keywords Ecosystem functioning; Functional significance; Microbial community structure; Multiple resource limitation; Phospholipid fatty acids (PLFA); Phosphorus; Soil functioning; Tropical forest  
  Abstract (up) Resource control over abundance, structure and functional diversity of soil microbial communities is a key determinant of soil processes and related ecosystem functioning. Copiotrophic organisms tend to be found in environments which are rich in nutrients, particularly carbon, in contrast to oligotrophs, which survive in much lower carbon concentrations. We hypothesized that microbial biomass, activity and community structure in nutrient-poor soils of an Amazonian rain forest are limited by multiple elements in interaction. We tested this hypothesis with a fertilization experiment by adding C (as cellulose), N (as urea) and P (as phosphate) in all possible combinations to a total of 40 plots of an undisturbed tropical forest in French Guiana. After 2 years of fertilization, we measured a 47% higher biomass, a 21% increase in substrate-induced respiration rate and a 5-fold higher rate of decomposition of cellulose paper discs of soil microbial communities that grew in P-fertilized plots compared to plots without P fertilization. These responses were amplified with a simultaneous C fertilization suggesting P and C colimitation of soil micro-organisms at our study site. Moreover, P fertilization modified microbial community structure (PLFAs) to a more copiotrophic bacterial community indicated by a significant decrease in the Gram-positive : Gram-negative ratio. The Fungi : Bacteria ratio increased in N fertilized plots, suggesting that fungi are relatively more limited by N than bacteria. Changes in microbial community structure did not affect rates of general processes such as glucose mineralization and cellulose paper decomposition. In contrast, community level physiological profiles under P fertilization combined with either C or N fertilization or both differed strongly from all other treatments, indicating functionally different microbial communities. While P appears to be the most critical from the three major elements we manipulated, the strongest effects were observed in combination with either supplementary C or N addition in support of multiple element control on soil microbial functioning and community structure. We conclude that the soil microbial community in the studied tropical rain forest and the processes it drives is finely tuned by the relative availability in C, N and P. Any shifts in the relative abundance of these key elements may affect spatial and temporal heterogeneity in microbial community structure, their associated functions and the dynamics of C and nutrients in tropical ecosystems.  
  Address INRA, UMR 614 Fractionnement des AgroRessources et Environnement, 2 esplanade Roland GarrosReims, France  
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  Notes Export Date: 4 February 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 583  
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Author Marcon, E.; Traissac, S.; Lang, G. pdf  url
doi  openurl
  Title A Statistical Test for Ripley’s Function Rejection of Poisson Null Hypothesis Type Journal Article
  Year 2013 Publication ISRN Ecology Abbreviated Journal ISRN Ecology  
  Volume 2013 Issue Article ID 753475 Pages 9  
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  Abstract (up) Ripley’s K function is the classical tool to characterize the spatial structure of point patterns. It is widely used in vegetation studies. Testing its values against a null hypothesis usually relies on Monte-Carlo simulations since little is known about its distribution.
We introduce a statistical test against complete spatial randomness (CSR). The test returns the p-value to reject the null hypothesis of independence between point locations. It is more rigorous and faster than classical Monte-Carlo simulations. We show how to apply it to a tropical forest plot. The necessary R code is provided.
 
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  Call Number EcoFoG @ webmaster @ 852 Serial 479  
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Author Brosse, Sébastien ; Baglan, Antoine ; Covain, Raphael ; Lalague, Hadrien ; Le Bail, Pierre-Yve ; Vigouroux, Régis ; Quartarollo, Grégory doi  openurl
  Title Aquarium trade and fish farms as a source of non-native freshwater fish introductions in French Guiana Type Journal Article
  Year 2021 Publication Annales de Limnologie – International Journal of Limnology Abbreviated Journal  
  Volume 57 Issue 4 Pages  
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  Abstract (up) Rivers of French Guiana are still little invaded by non-native fish, but several fish introductions were recently recorded through the development of aquarium fish trade and fish farms. Here we report records of 11 non-native fish species. Among them, four (Cichla monoculus, Heros efasciatus, Mesonauta guyanae and Poecilia reticulata) are established and one of them (Heros efasciatus) is rapidly increasing its spatial range. Two species (Hyphessobrycon eques and Pterophyllum scalare) were not retrieved in recent records and are probably extinct from French Guiana. The establishment status of the five other species (Arapaima gigas, Colossoma macropomum, Cyprinus carpio, Oreochromis mossambicus and Osteoglossum bicirrhosum) is uncertain and only a few specimens were observed in the wild. Nevertheless, these species, intensively reared in nearby countries, belong to highly invasive species able to cause detrimental impacts on recipient ecosystems. Those first occurrences of invasive fish species in French Guiana should therefore act as an early warning for both researchers and environmental managers.  
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  Language Anglais Summary Language Original Title  
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  Call Number EcoFoG @ webmaster @ Serial 1007  
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Author Baraloto, C.; Alverga, P.; Quispe, S.B.; Barnes, G.; Chura, N.B.; da Silva, I.B.; Castro, W.; da Souza, H.; de Souza Moll, I.E.; Del Alcazar Chilo, J.; Linares, H.D.; Quispe, J.G.; Kenji, D.; Marsik, M.; Medeiros, H.; Murphy, S.; Rockwell, C.; Selaya, G.; Shenkin, A.; Silveira, M.; Southworth, J.; Vasquez Colomo, G.H.; Perz, S. url  openurl
  Title Effects of road infrastructure on forest value across a tri-national Amazonian frontier Type Journal Article
  Year 2015 Publication Biological Conservation Abbreviated Journal Biological Conservation  
  Volume 191 Issue Pages 674-681  
  Keywords Açai; Biodiversity; Brazil nut; Carbon stocks; Connectivity; Infrastructure; Livelihood; Ntfp; Redd; Road impact; Rubber; Timber; Tropical rainforest  
  Abstract (up) Road construction demonstrably accelerates deforestation rates in tropical forests, but its consequences for forest degradation remain less clear. We estimated a series of forest value metrics including components of biodiversity, carbon stocks, and timber and non-timber forest product resources, along the recently paved Inter-Oceanic Highway (IOH) integrating Brazil and Peru along the Bolivian border. We installed 69 vegetation plots in intact terra firme forests representative of local community holdings near and far from the IOH, and we characterized 15 components of forest value for each plot.We observed strong geographic gradients in forest value components across the region, with increases from west to east in aboveground biomass and in the abundance of timber and non-timber forest product trees and regeneration. Plots in communities in Pando, Bolivia, where the IOH remains in part unpaved, had the highest aboveground biomass, standing timber volumes and Brazil nut tree density. In contrast, communities in Madre de Dios, Peru, where settlements and unpaved portions of the IOH have existed for decades, and in Acre, Brazil, where paving of the IOH has been underway for more than a decade, were more degraded. Seven of the fifteen forest value components we measured increased with increasing distance from the IOH, although the magnitude of these effects was weak. Landscape scale remote sensing analyses showed much stronger effects of road proximity on deforestation. We suggest that remote sensing techniques including canopy spectral signatures might be calibrated to characterize multiple components of forest value, so that we can estimate landscape scale impacts of infrastructure developments on both deforestation and forest degradation in tropical regions. © 2015 Elsevier B.V.  
  Address International Center for Tropical Botany, Department of Earth and Environment, Florida International University, Miami, FL, United States  
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  Notes Export Date: 8 September 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 619  
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Author Christensen-Dalsgaard, K.K.; Ennos, A.R.; Fournier, M. url  openurl
  Title Changes in hydraulic conductivity, mechanical properties, and density reflecting the fall in strain along the lateral roots of two species of tropical trees Type Journal Article
  Year 2007 Publication Journal of Experimental Botany Abbreviated Journal J. Exp. Bot.  
  Volume 58 Issue 15-16 Pages 4095-4105  
  Keywords Buttress roots; Density; Hydraulic conductivity; Hydraulic-mechanical trade-offs; Modulus of elasticity; Tropical trees; Wood; Elastic moduli; Hydraulic conductivity; Wood; Buttress roots; Hydraulic-mechanical trade-offs; Tropical trees; Forestry; water; article; biomechanics; histology; legume; physiology; plant root; plant stem; tree; wood; Xylopia; Biomechanics; Fabaceae; Plant Roots; Plant Stems; Trees; Water; Wood; Xylopia; Conductivity; Elastic Strength; Forestry; Wood  
  Abstract (up) Roots have been described as having larger vessels and so greater hydraulic efficiency than the stem. Differences in the strength and stiffness of the tissue within the root system itself are thought to be an adaptation to the loading conditions experienced by the roots and to be related to differences in density. It is not known how potential mechanical adaptations may affect the hydraulic properties of the roots. The change in strength, stiffness, conductivity, density, sapwood area, and second moment of area distally along the lateral roots of two tropical tree species in which the strain is known to decrease rapidly was studied and the values were compared with those of the trunk. It was found that as the strain fell distally along the roots, so did the strength and stiffness of the tissue, whereas the conductivity increased exponentially. These changes appeared to be related to differences in density. In contrast to the distal-most roots, the tissue of the proximal roots had a lower conductivity and higher strength than that of the trunk. This suggests that mechanical requirements on the structure rather than the water potential gradient from roots to branches are responsible for the general pattern that roots have larger vessels than the stem. In spite of their increased transectional area, the buttressed proximal roots were subjected to higher levels of stress and had a lower total conductivity than the rest of the root system. © 2007 The Author(s).  
  Address AgroParisTech, LERFOB, Ecole Nationale du Genie Rural, des Eaux et Forêts, 14 Avenue Girardet-CS 4216, 54000 Nancy Cedex, France  
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  Notes Cited By (since 1996): 6; Export Date: 22 October 2011; Source: Scopus; Coden: Jeboa; doi: 10.1093/jxb/erm268; PubMed ID: 18039738; Language of Original Document: English; Correspondence Address: Christensen-Dalsgaard, K.K.; University of Manchester, Faculty of Life Sciences, Jackson's Mill, Manchester M60 1QD, United Kingdom; email: karen@cd-mail.dk; Chemicals/CAS: water, 7732-18-5; Water, 7732-18-5 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 353  
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Author Amusant, N.; Beauchene, J.; Digeon, A.; Chaix, G. url  doi
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  Title Essential oil yield in rosewood (Aniba rosaeodora Ducke): Initial application of rapid prediction by near infrared spectroscopy based on wood spectra Type Journal Article
  Year 2016 Publication Journal of Near Infrared Spectroscopy Abbreviated Journal Journal of Near Infrared Spectroscopy  
  Volume 24 Issue 6 Pages 507-515  
  Keywords Aniba rosaeodora; Calibration; Essential oil yield; Nir; Pls; Rosewood  
  Abstract (up) Rosewood (Aniba rosaeodora) essential oil is a valuable ingredient that has long been used in the perfume and cosmetic industries. The main rosewood timber quality parameters are its essential oil yield and quality. A hydrodistillation method has been developed for yield determination, but it is time consuming. Here we tested the applicability of near infrared (NIR) spectroscopy for determining essential oil yield directly from wood powder. Essential oil from 139 wood powders was extracted via hydrodistillation. The measurements were based on the ratio between the extracted essential oil mass and the oven-dried wood mass and were correlated with the wood powder NIR spectra. The calibration model statistical findings demonstrated that NIR could be a fast and feasible alternative method for selecting trees with a high essential oil yield potential. NIR-based predictions obtained in an independent validation set indicated a high correlation (r2e = 0.92) with laboratory essential oil yield measurements. This NIR model could help wood managers in selecting trees with a high essential oil yield potential and in developing sustainable rosewood management strategies. © IM Publications LLP 2016. All rights reserved.  
  Address ESALQ-USP, Piracicaba, Brazil  
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  Notes Cited By :1; Export Date: 17 January 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 707  
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