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Author Sist, P.; Blanc, L.; Mazzei, L.; Baraloto, C.; Aussenac, R.
Title Current knowledge on overall post-logging biomass dynamics in Northern Amazonian forests Type Journal Article
Year 2012 Publication Bois et Forets des Tropiques Abbreviated Journal Bois Forets Tropiques
Volume 66 Issue 314 Pages 41-49
Keywords Above ground-biomass; Amazonian rainforests; Logging impact; Silviculture
Abstract This article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Pará, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the aboveground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha ). In Cikel the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to improve the growth of residual trees, it is compulsory to apply adequate silvicultural treatments such as selective thinning or removal of vines. While the two forests are geographically close enough, their regenerative abilities differ and because of the significant difference in size of the trees, the forest could tolerate more intensive harvesting in French Guiana.
Address Université Antilles-Guyane Cayenne, Guyane, France
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ISSN (down) 0006579x (Issn) ISBN Medium
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Notes Export Date: 5 June 2013; Source: Scopus; Language of Original Document: English; Correspondence Address: Cirad UR B and SEF, Campus international de Baillarguet, 34398 Montpellier Cedex 5, France Approved no
Call Number EcoFoG @ webmaster @ Serial 489
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Author Vincent, G.; Caron, F.; Sabatier, D.; Blanc, L.
Title LiDAR shows that higher forests have more slender trees Type Journal Article
Year 2012 Publication Bois et Forets des Tropiques Abbreviated Journal Bois Forets Tropiques
Volume 66 Issue 314 Pages 51-56
Keywords Competition; Fertility; French Guiana; LiDAR; Tree allometry
Abstract High-density Airborne Laser Scanning was used to derive the Canopy Height Model (CHM) of an experimental forest site in the neotropics (Paracou, French Guiana). Individual tree heights were computed by manually segmenting tree crowns on the CHM and then extracting the local maximum canopy height. Three hundred and ninety-six (396) height estimates were matched from dominant or emergent trees with the corresponding ground records of stem diameters sampled in two plots with different mean canopy heights (28.1 m vs. 31.3 m). Tree slenderness was found to be positively and very significantly correlated with mean canopy height at the plot level. The same correlation was observed at the species population level for the three species adequately sampled. It can therefore be concluded that stratification by canopy height is to be recommended when deriving allometric relationships in order to avoid bias in Above Ground Biomass estimations.
Address CIRAD, UMR Ecofog, 97300 Kourou, France
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Publisher Place of Publication Editor
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ISSN (down) 0006579x (Issn) ISBN Medium
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Notes Export Date: 5 June 2013; Source: Scopus; Language of Original Document: English; Correspondence Address: IRD, UMR AMAP, 34000 Montpellier, France Approved no
Call Number EcoFoG @ webmaster @ Serial 490
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Author Baraloto, C.; Molto, Q.; Rabaud, S.; Herault, B.; Valencia, R.; Blanc, L.; Fine, P.V.A.; Thompson, J.
Title Rapid simultaneous estimation of aboveground biomass and tree diversity across neotropical forests: A comparison of field inventory methods Type Journal Article
Year 2013 Publication Biotropica Abbreviated Journal Biotropica
Volume 45 Issue 3 Pages 288-298
Keywords Biodiversity assessment; carbon stocks; Monitoring; Permanent plot; Survey; Tropical rain forest
Abstract A standardized rapid inventory method providing information on both tree species diversity and aboveground carbon stocks in tropical forests will be an important tool for evaluating efforts to conserve biodiversity and to estimate the carbon emissions that result from deforestation and degradation (REDD). Herein, we contrast five common plot methods differing in shape, size, and effort requirements to estimate tree diversity and aboveground tree biomass (AGB). We simulated the methods across six Neotropical forest sites that represent a broad gradient in forest structure, tree species richness, and floristic composition, and we assessed the relative performance of methods by evaluating the bias and precision of their estimates of AGB and tree diversity. For a given sample of forest area, a 'several small' (< 1 ha) sampling strategy led to a smaller coefficient of variation (CV) in the estimate of AGB than a 'few large' one. The effort (person-days) required to achieve an accurate AGB estimate (< 10% CV), however, was greater for the smallest plots (0.1 ha) than for a compromise approach using 0.5 ha modified Gentry plots, which proved to be the most efficient method to estimate AGB across all forest types. Gentry plots were also the most efficient at providing accurate estimates of tree diversity (< 10% CV of Hill number). We recommend the use of the 0.5 ha modified Gentry plot method in future rapid inventories, and we discuss a set of criteria that should inform any choice of inventory method. © 2012 The Author(s) Journal compilation © 2012 by The Association for Tropical Biology and Conservation.
Address Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, United Kingdom
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ISSN (down) 00063606 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 16 May 2013; Source: Scopus; Coden: Btroa; :doi 10.1111/btp.12006; Language of Original Document: English; Correspondence Address: Baraloto, C.; INRA, UMR 'Ecologie des Forêts de Guyane', 97387, Kourou Cedex, French Guiana; email: chris.baraloto@ecofog.gf Approved no
Call Number EcoFoG @ webmaster @ Serial 485
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Author Verryckt, L.T.; Ellsworth, D.S.; Vicca, S.; Van Langenhove, L.; Peñuelas, J.; Ciais, P.; Posada, J.M.; Stahl, C.; Coste, S.; Courtois, E.A.; Obersteiner, M.; Chave, J.; Janssens, I.A.
Title Can light-saturated photosynthesis in lowland tropical forests be estimated by one light level? Type Journal Article
Year 2020 Publication Biotropica Abbreviated Journal Biotropica
Volume 52 Issue 6 Pages 1183-1193
Keywords canopy architecture; interspecific variation; light intensity; lowland environment; parameter estimation; photon flux density; photosynthesis; saturation; tropical forest; French Guiana
Abstract Leaf-level net photosynthesis (An) estimates and associated photosynthetic parameters are crucial for accurately parameterizing photosynthesis models. For tropical forests, such data are poorly available and collected at variable light conditions. To avoid over- or underestimation of modeled photosynthesis, it is critical to know at which photosynthetic photon flux density (PPFD) photosynthesis becomes light-saturated. We studied the dependence of An on PPFD in two tropical forests in French Guiana. We estimated the light saturation range, including the lowest PPFD level at which Asat (An at light saturation) is reached, as well as the PPFD range at which Asat remained unaltered. The light saturation range was derived from photosynthetic light-response curves, and within-canopy and interspecific differences were studied. We observed wide light saturation ranges of An. Light saturation ranges differed among canopy heights, but a PPFD level of 1,000 µmol m−2 s−1 was common across all heights, except for pioneer trees species that did not reach light saturation below 2,000 µmol m−2 s−1. A light intensity of 1,000 µmol m−2 s−1 sufficed for measuring Asat of climax species at our study sites, independent of the species or the canopy height. Because of the wide light saturation ranges, results from studies measuring Asat at higher PPFD levels (for upper canopy leaves up to 1,600 µmol m−2 s−1) are comparable with studies measuring at 1,000 µmol m−2 s−1. © 2020 The Association for Tropical Biology and Conservation
Address UMR 5174, Laboratoire Evolution et Diversité Biologique, CNRS, Université Paul Sabatier, Toulouse, France
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 (down) 00063606 (Issn) ISBN Medium
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Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 948
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Author Verryckt, L.T.; Van Langenhove, L.; Ciais, P.; Courtois, E.A.; Vicca, S.; Peñuelas, J.; Stahl, C.; Coste, S.; Ellsworth, D.S.; Posada, J.M.; Obersteiner, M.; Chave, J.; Janssens, I.A.
Title Coping with branch excision when measuring leaf net photosynthetic rates in a lowland tropical forest Type Journal Article
Year 2020 Publication Biotropica Abbreviated Journal Biotropica
Volume 52 Issue 4 Pages 608-615
Keywords branch cutting; canopy physiology; French Guiana; gas exchange; photosynthesis; rainforest; stomatal conductance; ecological modeling; environmental conditions; forest canopy; leaf; measurement method; photosynthesis; tree; tropical forest; Gruidae
Abstract Measuring leaf gas exchange from canopy leaves is fundamental for our understanding of photosynthesis and for a realistic representation of carbon uptake in vegetation models. Since canopy leaves are often difficult to reach, especially in tropical forests with emergent trees up to 60 m at remote places, canopy access techniques such as canopy cranes or towers have facilitated photosynthetic measurements. These structures are expensive and therefore not very common. As an alternative, branches are often cut to enable leaf gas exchange measurements. The effect of branch excision on leaf gas exchange rates should be minimized and quantified to evaluate possible bias. We compared light-saturated leaf net photosynthetic rates measured on excised and intact branches. We selected branches positioned at three canopy positions, estimated relative to the top of the canopy: upper sunlit foliage, middle canopy foliage, and lower canopy foliage. We studied the variation of the effects of branch excision and transport among branches at these different heights in the canopy. After excision and transport, light-saturated leaf net photosynthetic rates were close to zero for most leaves due to stomatal closure. However, when the branch had acclimated to its new environmental conditions—which took on average 20 min—light-saturated leaf net photosynthetic rates did not significantly differ between the excised and intact branches. We therefore conclude that branch excision does not affect the measurement of light-saturated leaf net photosynthesis, provided that the branch is recut under water and is allowed sufficient time to acclimate to its new environmental conditions. © 2020 The Association for Tropical Biology and Conservation
Address UMR 5174 Laboratoire Evolution et Diversité Biologique, Université Paul Sabatier, CNRS, Toulouse, France
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 (down) 00063606 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 960
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Author Schimann, H.; Vleminckx, J.; Baraloto, C.; Engel, J.; Jaouen, G.; Louisanna, E.; Manzi, S.; Sagne, A.; Roy, M.
Title Tree communities and soil properties influence fungal community assembly in neotropical forests Type Journal Article
Year 2020 Publication Biotropica Abbreviated Journal Biotropica
Volume 52 Issue 3 Pages 444-456
Keywords communities; composition; diversity; habitat; lowland neotropical rain forest; macrofungi; soil properties; trees; ectomycorrhiza; fungus; heterogeneity; Neotropical Region; physicochemical property; rainforest; species inventory; species richness; tree; tropical forest; French Guiana; Agaricales; Aphyllophorales; Basidiomycota
Abstract The influence exerted by tree communities, topography, and soil chemistry on the assembly of macrofungal communities remains poorly understood, especially in highly diverse tropical forests. Here, we used a large dataset that combines inventories of macrofungal Basidiomycetes fruiting bodies, tree species composition, and measurements for 16 soil physicochemical parameters, collected in 34 plots located in four sites of lowland rain forests in French Guiana. Plots were established on three different topographical conditions: hilltop, slope, and seasonally flooded soils. We found hyperdiverse Basidiomycetes communities, mainly comprising members of Agaricales and Polyporales. Phosphorus, clay contents, and base saturation in soils strongly varied across plots and shaped the richness and composition of tree communities. The latter composition explained 23% of the variation in the composition of macrofungal communities, probably through high heterogeneity of the litter chemistry and selective effects of biotic interactions. The high local heterogeneity of habitats influenced the distribution of both macrofungi and trees, as a result of diversed local soil hydromorphic conditions associated with contrasting soil chemistry. This first regional study across habitats of French Guiana forests revealed new niches for macrofungi, such as ectomycorrhizal ones, and illustrates how macrofungi inventories are still paramount to can be to understand the processes at work in the tropics. Abstract in Spanish is available with online material. © 2020 The Association for Tropical Biology and Conservation
Address Laboratoire Évolution et Diversité Biologique, CNRS, UMR 5174 UPS CNRS ENFA IRD, Université Toulouse 3 Paul Sabatier, Toulouse, France
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 (down) 00063606 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 968
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Author Guitet, S.; Blanc, L.; Trombe, P.J.; Lehallier, B.
Title Silvicultural Treatments in the Tropical Forests of Guiana: A Review of Ten Years of Trials Type Journal Article
Year 2009 Publication Bois et Forets des Tropiques Abbreviated Journal Bois For. Trop.
Volume 63 Issue 301 Pages 7-19
Keywords cutting cycle; thinning; stand dynamics; logging; French Guiana
Abstract This article reviews an experimental system set up in French Guiana to test different selective thinning methods that started ten to fifteen years after logging in order to reconstitute commercially viable stands within the shortest time. The thinning methods tested involve a combination of selective intervention within a radius of 10 metres around crop trees and systematic intervention applied uniformly to the entire forest parcel. The resulting thinning intensity produces an 8% to 45% reduction in basal area. While the growth of the residual stand is strongly boosted in all species and for all diameters, there is little change in basal area because of high mortality and lower recruitment of commercial species. Standing commercial capital, however, is strongly affected by the thinning operations as defined. In effect, these thinning methods that benefit crop stems do not meet the objective of shorter rotations in Guiana's tropical logging forests. On the other hand, the measurements made in under-treatment stands agree with those obtained at the Paracou experimental station and confirm the need to adopt long cutting cycles of more than fifty years to ensure that the extraction of valuable species is sustainable in the current logging context in French Guiana.
Address [Guitet, Stephane; Trombe, Pierre-Julien; Lehallier, Benoit] Direct Reg Guyane, Off Natl Forets, F-97307 Cayenne, France
Corporate Author Thesis
Publisher CIRAD-CENTRE COOPERATION INT RECHERCHE AGRONOMIQUE POUR Place of Publication Editor
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ISSN (down) 0006-579X ISBN Medium
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Notes ISI:000272488700002 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 91
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Author Gond, V.; Guitet, S.
Title Remote Sensing in Post-Logging Diagnoses for Forest Management in French Guiana Type Journal Article
Year 2009 Publication Bois et Forets des Tropiques Abbreviated Journal Bois For. Trop.
Volume 63 Issue 299 Pages 5-13
Keywords selective logging; logging impact inspections; French Guiana; remote sensing; forest management
Abstract This study is part of the activities carried out to monitor tow-impact logging operations in humid tropical forests. The sustainability of these activities is highly dependent on the scale of logging damage, and managers therefore need to carry out effective checks on the quality of forestry work. In this study, remote sensing was used to track the extension of logging operations and to assess damage, through images acquired during and after logging in each parcel. Analysis of the high-resolution images (10 m) clearly identifies logged-over clearings and some skidding tracks, allowing assessments of gaps opening up in the canopy. Several parcels were monitored in this French Guiana study. A simple diagnostic procedure was established for each parcel to assess logging intensity and identify new logging tracks and timber losses. The remote sensing toot thus helps to make more accurate assessments of logging quality and to draw relevant conclusions for the logging company. The study has demonstrated the usefulness of remote sensing to identify damage after logging. The quality of restitution of the damage was validated by means of a database on the logging terrain and through field missions. This post-logging inspection tool can now be automated for fully operational use by forest managers.
Address [Gond, Valery] Univ Laval, Fac Foresterie, Umr Ecofog Guyane francaise, Cirad,UR 36, Quebec City, PQ G1V OA6, Canada
Corporate Author Thesis
Publisher CIRAD-CENTRE COOPERATION INT RECHERCHE AGRONOMIQUE POUR Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (down) 0006-579X ISBN Medium
Area Expedition Conference
Notes ISI:000266156700001 Approved no
Call Number EcoFoG @ webmaster @ Serial 280
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Author Wagner, F.; Rutishauser, E.; Blanc, L.; Herault, B.
Title Effects of Plot Size and Census Interval on Descriptors of Forest Structure and Dynamics Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume 42 Issue 6 Pages 664-671
Keywords Amazonia; biomass fluxes; coefficient of variation; forest permanent plots; turnover rates; WinBUGS
Abstract This study was designed to explicitly formulate the effect of census interval and plot size on the variability of descriptors of tropical forest structure (stand density, basal area, aboveground biomass [AGB]) and dynamic (tree growth, mortality and recruitment rates, biomass fluxes). A unique dataset from a broad plot network (37.5 ha) surveyed every 2 yr over a 16-yr period was used to develop and parameterize a new statistical model predicting the coefficients of variation for each forest descriptor. More than 90 percent of the inherent variability of these coefficients was predicted using a simple model including plot size and census interval in a Bayesian modeling framework. All descriptors of forest structure varied by <10 percent for plot sizes 42 ha. Among the descriptors of forest dynamics, AGB loss was the most variable. The number of 6.25 ha plots required to estimate its mean, over a 16-yr period, within a 20 percent error of the mean remains above four. This contrasts with a relative constant flux of biomass entering the plot through tree growth and tree recruitment. Tree growth was remarkably well estimated with <15 percent variability for a 2-yr census in a plot of 2 ha. This study provides an easy method to assess dataset limitations in efforts to estimate descriptors of forest structure and dynamic, which is of primary importance to decipher any clear consequences of global change in tropical forests.
Address [Wagner, Fabien; Herault, Bruno] Univ Antilles Guyane, UMR Ecol Forets Guyane, Kourou 97379, French Guiana, Email: bruno.herault@ecofog.gf
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000283949700006 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 16
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Author Vantaux, A.; Roux, O.; Magro, A.; Ghomsi, N.T.; Gordon, R.D.; Dejean, A.; Orivel, J.
Title Host-Specific Myrmecophily and Myrmecophagy in the Tropical Coccinellid Diomus thoracicus in French Guiana Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume 42 Issue 5 Pages 622-629
Keywords ants; ladybird; mimicry; parasite; Wasmannia auropunctata
Abstract A variety of arthropods, particularly insects, have developed myrmecophilous interactions with ants to gain access to resources and/or for protection. Among these myrmecophiles, only a few examples have been documented in the Coccinellidae, most of them involving species able to feed on ant-tended Hemiptera. We report here a new case of obligate myrmecophily in the coccinellid Diomus thoracicus. Larvae are invariably and exclusively found in the nests of the ant Wasmannia auropunctata and seem to rely on ant brood as their only food source. Not only do ant workers show no aggressiveness toward the D. thoracicus larvae in their behavioral interactions at the colonial level, but also at the species level; while coccinellid adults are always attacked. The integration of the larvae inside of the ant nests is based on their chemical mimicry of the host's cuticular cues. Therefore, given the presence of the D. thoracicus larvae inside of the ant's nest, their predation on Wasmannia brood and their chemical mimicry, this species can be considered a specific parasite of W. auropunctata. Overall, this new case of myrmecophily not only specifically involves a highly invasive ant species, but also provides insights into the evolution of myrmecophily and myrmecophagy in coccinellids.
Address [Vantaux, Amelie; Magro, Alexandra; Orivel, Jerome] Univ Toulouse, UPS, EDB Lab Evolut & Diversite Biol, F-31062 Toulouse, France, Email: orivel@cict.fr
Corporate Author Thesis
Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (down) 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000281707700025 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 27
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