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Author Trzcinski, M.K.; Srivastava, D.S.; Corbara, B.; Dezerald, O.; Leroy, C.; Carrias, J.-F.; Dejean, A.; Céréghino, R.; Rudolf, V.
Title The effects of food web structure on ecosystem function exceeds those of precipitation Type Journal Article
Year 2016 Publication Journal of Animal Ecology Abbreviated Journal Journal of Animal Ecology
Volume 85 Issue 5 Pages 1147-1160
Keywords bromeliad; climate change; community interactions; drought; ecosystem function; French Guiana; invertebrates; micro-organisms; phytotelmata; precipitation
Abstract 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
Address 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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Call Number EcoFoG @ webmaster @ Serial 685
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Author 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.
Title BAAD: a Biomass And Allometry Database for woody plants Type Journal Article
Year 2015 Publication Ecology Abbreviated Journal Ecology
Volume 96 Issue 5 Pages 1445
Keywords Allometric equations; Biomass allocation; Biomass partitioning; Global carbon cycle; Plant allometry; Plant traits
Abstract 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.
Address Department of Disturbance Ecology, University of Bayreuth, Germany
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Call Number EcoFoG @ webmaster @ Serial 686
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Author 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.
Title Terrestrial support of aquatic food webs depends on light inputs: A geographically-replicated test using tank bromeliads Type Journal Article
Year 2016 Publication Ecology Abbreviated Journal Ecology
Volume 97 Issue 8 Pages 2147-2156
Keywords Allochthonous carbon; Allochthony; Aquatic food webs; Autochthonous carbon; Autochthony; Natural microcosms; Stable isotopic analysis; Tank bromeliads; Tropics
Abstract 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.
Address Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), PO Box 6109, Campinas-SP, Brazil
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Author Piponiot, C.; Cabon, A.; Descroix, L.; Dourdain, A.; Mazzei, L.; Ouliac, B.; Rutishauser, E.; Sist, P.; Herault, B.
Title A methodological framework to assess the carbon balance of tropical managed forests Type Journal Article
Year 2016 Publication Carbon Balance and Management Abbreviated Journal Carbon Balance and Management
Volume 11 Issue 1 Pages
Keywords Amazonia; Carbon cycle; Error propagation; Production forests; Selective logging
Abstract 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).
Address CNRS, UMR EcoFoG, AgroParisTech, Inra, Université de la Guyane, Université des Antilles, Cirad, Campus Agronomique, Kourou, French Guiana
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Author Dejean, A.; Azémar, F.; Céréghino, R.; Leponce, M.; Corbara, B.; Orivel, J.; Compin, A.
Title The dynamics of ant mosaics in tropical rainforests characterized using the Self-Organizing Map algorithm Type Journal Article
Year 2016 Publication Insect Science Abbreviated Journal Insect Science
Volume 23 Issue 4 Pages 630-637
Keywords ant plant relationships; dynamics of associations; myrmecophytes; tropical rainforests
Abstract 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
Address Clermont Université, Université Blaise Pascal, LMGE, BP 10448, Clermont-Ferrand, France
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Author 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.
Title Amazon forest response to repeated droughts Type Journal Article
Year 2016 Publication Global Biogeochemical Cycles Abbreviated Journal Global Biogeochemical Cycles
Volume 30 Issue 7 Pages 964-982
Keywords carbon; forest productivity; precipitation; tree mortality; vegetation dynamics; water deficit
Abstract 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.
Address Centro de Investigación y Promoción del Campesinado Norte Amazónico, Riberalta, Bolivia
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Author Salas-Lopez, A.; Talaga, S.; Lalague, H.
Title The discovery of devil's gardens: An ant-plant mutualism in the cloud forests of the Eastern Amazon Type Journal Article
Year 2016 Publication Journal of Tropical Ecology Abbreviated Journal Journal of Tropical Ecology
Volume 32 Issue 3 Pages 264-268
Keywords ant-plant interactions; biogeography; cloud forest; Cordia nodosa; mutualism, Myrmelachista; refuge hypothesis
Abstract Devil's gardens are one of the most remarkable mutualistic associations between ants and plants. Myrmelachista ants eliminate all vegetation from around their host plants, resulting in wide forest clearings which have intrigued scientists from the start. Despite their noticeability, here we report the discovery of devil's gardens in remote highland cloud forests of the Eastern Amazon, more than 2000 km away from their nearest known analogues in Western Amazonia. We describe the ecological characteristics of these gardens and consider what factors could have produced the geographic isolation of Eastern Amazonian devil's gardens. Three hypotheses are investigated: (1) the host plant distribution restricts the distribution of the mutualism, (2) the ecological tolerances of Myrmelachista explain the isolation, and (3) the devil's gardens of the Eastern Amazon constitute relicts from ancient forest refugia. The distribution of the possible associated myrmecophytes and previously described ecological ranges of devil's gardens cannot explain their ecological restriction to cloud forests in Eastern Amazonia, but our discovery is consistent with the biogeographic refuge hypothesis (i.e. highlands along the Amazon Basin constitute refugia for humid forests that spread during the Cenozoic). Our finding opens exciting perspectives for comparative studies of the origin, ecology and evolutionary history of this ant-plant mutualism. Copyright © Cambridge University Press 2016.
Address INRA, UMR, EcoFoG, Campus Agronomique, BP 316, Kourou Cedex, France
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Call Number EcoFoG @ webmaster @ Serial 691
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Author Remy, C.C.; Fleury, M.; Beauchene, J.; Rivier, M.; Goli, T.
Title Analysis of PAH Residues and Amounts of Phenols in Fish Smoked with Woods Traditionally Used in French Guiana Type Journal Article
Year 2016 Publication Journal of Ethnobiology Abbreviated Journal Journal of Ethnobiology
Volume 36 Issue 2 Pages 312-325
Keywords French Guiana; phenols; polycyclic aromatic hydrocarbons; smoked fish; traditional knowledge
Abstract Fish smoking with local wood species is a traditional practice in French Guiana. We evaluated the carcinogenic risk and the smoky taste in acoupa weakfish (Cynoscion acoupa) smoked by a small Guianese company specializing in fish smoking using local wood species. The goal of this study is to promote regional economic development by encouraging the establishment of small companies offering fish smoked with local wood species in agreement with the European health norms in terms of polycyclic aromatic hydrocarbon (PAH) content in smoked fish. The fish smoked with three species of wood traditionally used in French Guiana, Parinari campestris, Caesaria grandiflora, and Laetia procera, conformed to European standards for PAH content. Their phenol contents (correlated with the smoky taste) were close to smoked salmon, the reference in Europe. Given the low rate of extractable compounds in these woods, other flavors had little chance of predominating on the smoky taste. These three tropical wood species might be used for the production of cold smoked fish in compliance with European standards for PAH residues. The flavor and consumer's acceptance of the smoked fish should now be investigated to characterize the added typicity of local woods in comparison to the commonly used European woods. © 2016 Society of Ethnobiology.
Address 4UMR Qualisud, CIRAD Persyst Bât, France
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Author Fortunel, C.; Paine, C.E.T.; Fine, P.V.A.; Mesones, I.; Goret, J.; Burban, B.; Cazal, J.; Baraloto, C.; Comita, L.
Title There's no place like home: seedling mortality contributes to the habitat specialisation of tree species across Amazonia Type Journal Article
Year 2016 Publication Ecology Letters Abbreviated Journal Ecology Letters
Volume 19 Issue 10 Pages 1256-1266
Keywords Amazon basin; forests habitats; habitat association; herbivory; light availability; plant lineages; rainfall temporal variation; seedling performance; soil fertility; tropical trees
Abstract Understanding the mechanisms generating species distributions remains a challenge, especially in hyperdiverse tropical forests. We evaluated the role of rainfall variation, soil gradients and herbivory on seedling mortality, and how variation in seedling performance along these gradients contributes to habitat specialisation. In a 4-year experiment, replicated at the two extremes of the Amazon basin, we reciprocally transplanted 4638 tree seedlings of 41 habitat-specialist species from seven phylogenetic lineages among the three most important forest habitats of lowland Amazonia. Rainfall variation, flooding and soil gradients strongly influenced seedling mortality, whereas herbivory had negligible impact. Seedling mortality varied strongly among habitats, consistent with predictions for habitat specialists in most lineages. This suggests that seedling performance is a primary determinant of the habitat associations of adult trees across Amazonia. It further suggests that tree diversity, currently mostly harboured in terra firme forests, may be strongly impacted by the predicted climate changes in Amazonia. © 2016 John Wiley & Sons Ltd/CNRS
Address Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, United States
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Notes Export Date: 27 October 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 698
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Author Fayad, I.; Baghdadi, N.; Guitet, S.; Bailly, J.-S.; Herault, B.; Gond, V.; El Hajj, M.; Tong Minh, D.H.
Title Aboveground biomass mapping in French Guiana by combining remote sensing, forest inventories and environmental data Type Journal Article
Year 2016 Publication International Journal of Applied Earth Observation and Geoinformation Abbreviated Journal International Journal of Applied Earth Observation and Geoinformation
Volume 52 Issue Pages 502-514
Keywords Aboveground biomass mapping; Forests; French Guiana; ICESat GLAS; LiDAR
Abstract Mapping forest aboveground biomass (AGB) has become an important task, particularly for the reporting of carbon stocks and changes. AGB can be mapped using synthetic aperture radar data (SAR) or passive optical data. However, these data are insensitive to high AGB levels (>150 Mg/ha, and >300 Mg/ha for P-band), which are commonly found in tropical forests. Studies have mapped the rough variations in AGB by combining optical and environmental data at regional and global scales. Nevertheless, these maps cannot represent local variations in AGB in tropical forests. In this paper, we hypothesize that the problem of misrepresenting local variations in AGB and AGB estimation with good precision occurs because of both methodological limits (signal saturation or dilution bias) and a lack of adequate calibration data in this range of AGB values. We test this hypothesis by developing a calibrated regression model to predict variations in high AGB values (mean >300 Mg/ha) in French Guiana by a methodological approach for spatial extrapolation with data from the optical geoscience laser altimeter system (GLAS), forest inventories, radar, optics, and environmental variables for spatial inter- and extrapolation. Given their higher point count, GLAS data allow a wider coverage of AGB values. We find that the metrics from GLAS footprints are correlated with field AGB estimations (R2 = 0.54, RMSE = 48.3 Mg/ha) with no bias for high values. First, predictive models, including remote-sensing, environmental variables and spatial correlation functions, allow us to obtain “wall-to-wall” AGB maps over French Guiana with an RMSE for the in situ AGB estimates of ∼50 Mg/ha and R2 = 0.66 at a 1-km grid size. We conclude that a calibrated regression model based on GLAS with dependent environmental data can produce good AGB predictions even for high AGB values if the calibration data fit the AGB range. We also demonstrate that small temporal and spatial mismatches between field data and GLAS footprints are not a problem for regional and global calibrated regression models because field data aim to predict large and deep tendencies in AGB variations from environmental gradients and do not aim to represent high but stochastic and temporally limited variations from forest dynamics. Thus, we advocate including a greater variety of data, even if less precise and shifted, to better represent high AGB values in global models and to improve the fitting of these models for high values. © 2016 Elsevier B.V.
Address NOVELTIS, 153 rue du Lac, Labège, France
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Notes Export Date: 9 December 2016 Approved no
Call Number EcoFoG @ webmaster @ Serial 699
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