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Author Bremaud, I.; Cabrolier, P.; Gril, J.; Clair, B.; Gerard, J.; Minato, K.; Thibaut, B.
Title Identification of anisotropic vibrational properties of Padauk wood with interlocked grain Type Journal Article
Year 2010 Publication Wood Science and Technology Abbreviated Journal Wood Sci. Technol.
Volume 44 Issue 3 Pages 355-367
Keywords
Abstract Grain deviations and high extractives content are common features of many tropical woods. This study aimed at clarifying their respective impact on vibrational properties, referring to African Padauk (Pterocarpus soyauxii Taub.), a species selected for its interlocked grain, high extractives content and uses in xylophones. Specimens were cut parallel to the trunk axis (L), and local variations in grain angle (GA), microfibril angle (MFA), specific Young's modulus (E' (L) /rho, where rho stands for the density) and damping coefficient (tan delta(L)) were measured. GA dependence was analysed by a mechanical model which allowed to identify the specific Young's modulus (E'(3)/rho) and shear modulus (G'/rho) along the grain (3) as well as their corresponding damping coefficients (tan delta(3), tan delta(G)). This analysis was done for native and then for extracted wood. Interlocked grain resulted in 0-25A degrees GA and in variations of a factor 2 in E'(L)/rho and tan delta(L). Along the grain, Padauk wood was characterized, when compared to typical hardwoods, by a somewhat lower E'(3)/rho and elastic anisotropy (E'/G'), due to a wide microfibril angle plus a small weight effect of extracts, and a very low tan delta(3) and moderate damping anisotropy (tan delta(G)/tan delta(3)). Extraction affected mechanical parameters in the order: tan delta(3) a parts per thousand tan delta(G) > G'/rho > > E'(3)/rho. That is, extractives' effects were nearly isotropic on damping but clearly anisotropic on storage moduli.
Address [Bremaud, Iris; Minato, Kazuya] Kyoto Prefectural Univ, Grad Sch Life & Environm Sci, Lab Forest Resource Circulating Circles, Kyoto 6068522, Japan, Email: iris_bremaud@hotmail.com
Corporate Author Thesis
Publisher SPRINGER Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0043-7719 ISBN Medium
Area Expedition Conference
Notes ISI:000280090400001 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 48
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Author Castro, H.; Fortunel, C.; Freitas, H.
Title Effects of land abandonment on plant litter decomposition in a Montado system: relation to litter chemistry and community functional parameters Type Journal Article
Year 2010 Publication Plant and Soil Abbreviated Journal Plant Soil
Volume 333 Issue 1-2 Pages 181-190
Keywords Ecosystem processes; Land use change; Leaf dry matter content; Life form; Litter quality; Mediterranean
Abstract Changes in land use and subsequent shifts in vegetation can influence decomposition through changes in litter quality (chemistry and structure) and alterations of soil temperature and moisture. Our aim was to study the effects of land abandonment on litter decomposition in a Mediterranean area of Montado, South Portugal. We tested the hypothesis that decomposition tends to slow down with abandonment, as woody species, richer in lignified structures, replace herbaceous species. We assessed the decomposition of community litter in situ using litterbag technique. To test the influence of local conditions, we simultaneously incubated a standard litter in situ. Our results showed that the shift from herbaceous to shrub-dominated communities lead to decreased decomposition rates. Changes in litter decomposition were primarily driven by changes in litter quality, even though the uneven pattern of litter mass loss over the experiment might reveal an effect from possible differences in microclimate. Shrub litter had higher nutrient content than herbaceous litter, which seemed to favour higher initial decomposition rates, but lower decomposition rate in the longer term. Shrubs also contribute to woody litter, richer in lignin, and secondary compounds that retard decomposition, and may play a role in increasing pools of slowly decomposing organic matter.
Address [Castro, Helena; Freitas, Helena] Univ Coimbra, Dept Life Sci, Ctr Funct Ecol, P-3001401 Coimbra, Portugal, Email: hecastro@ci.uc.pt
Corporate Author Thesis
Publisher SPRINGER Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0032-079X ISBN Medium
Area Expedition Conference
Notes ISI:000280089400015 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 49
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Author Phillips, O.L.; van der Heijden, G.; Lewis, S.L.; Lopez-Gonzalez, G.; Aragao, L.E.O.C.; Lloyd, J.; Malhi, Y.; Monteagudo, A.; Almeida, S.; Davila, E.A.; Amaral, I.; Andelman, S.; Andrade, A.; Arroyo, L.; Aymard, G.; Baker, T.R.; Blanc, L.; Bonal, D.; de Oliveira, A.C.A.; Chao, K.J.; Cardozo, N.D.; da Costa, L.; Feldpausch, T.R.; Fisher, J.B.; Fyllas, N.M.; Freitas, M.A.; Galbraith, D.; Gloor, E.; Higuchi, N.; Honorio, E.; Jimenez, E.; Keeling, H.; Killeen, T.J.; Lovett, J.C.; Meir, P.; Mendoza, C.; Morel, A.; Vargas, P.N.; Patino, S.; Peh, K.S.H.; Cruz, A.P.; Prieto, A.; Quesada, C.A.; Ramirez, F.; Ramirez, H.; Rudas, A.; Salamao, R.; Schwarz, M.; Silva, J.; Silveira, M.; Slik, J.W.F.; Sonke, B.; Thomas, A.S.; Stropp, J.; Taplin, J.R.D.; Vasquez, R.; Vilanova, E.
Title Drought-mortality relationships for tropical forests Type Journal Article
Year 2010 Publication New Phytologist Abbreviated Journal New Phytol.
Volume 187 Issue 3 Pages 631-646
Keywords Amazon; Borneo; drought; lags mortality; RAINFOR; trees; tropics
Abstract The rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119 monitoring plots in 10 countries concentrated in Amazonia and Borneo. In most sites, larger trees are disproportionately at risk. At least within Amazonia, low wood density trees are also at greater risk of drought-associated mortality, independent of size. For comparable drought intensities, trees in Borneo are more vulnerable than trees in the Amazon. There is some evidence for lagged impacts of drought, with mortality rates remaining elevated 2 yr after the meteorological event is over. These findings indicate that repeated droughts would shift the functional composition of tropical forests toward smaller, denser-wooded trees. At very high drought intensities, the linear relationship between tree mortality and moisture stress apparently breaks down, suggesting the existence of moisture stress thresholds beyond which some tropical forests would suffer catastrophic tree mortality.
Address [Phillips, Oliver L.; van der Heijden, Geertje; Lewis, Simon L.; Lopez-Gonzalez, Gabriela; Lloyd, Jon; Baker, Tim R.; Chao, Kuo-Jung; Feldpausch, Ted R.; Fyllas, Nikolaos M.; Gloor, Emanuel; Honorio, Euridice; Keeling, Helen; Quesada, Carlos A.; Schwarz, Michael] Univ Leeds, Sch Geog, Leeds LS2 9JT, W Yorkshire, England, Email: o.phillips@leeds.ac.uk
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 (down) Series Issue Edition
ISSN 0028-646X ISBN Medium
Area Expedition Conference
Notes ISI:000280122500028 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 50
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Author Quilichini, A.; Macquart, D.; Barabe, D.; Albre, J.; Gibernau, M.
Title Reproduction of the West Mediterranean endemic Arum pictum (Araceae) on Corsica Type Journal Article
Year 2010 Publication Plant Systematics and Evolution Abbreviated Journal Plant Syst. Evol.
Volume 287 Issue 3-4 Pages 179-187
Keywords Floral volatiles; Ocimene; Insect pollination; Reproductive success; Sphaeroceridae; Thermogenesis
Abstract Pollination in the genus Arum appears to be in general a complex deceptive pollination process. The genus Arum is composed of 28 species, all belonging to the subgenus Arum, except A. pictum, the only species of the subgenus Gymnomesium, which is basal and sister to all other Arum species. The aim of this paper is to document the pollination ecology of the insular Arum pictum, the only Arum species to flower in autumn, on the island of Corsica (France). The anthesis cycle of A. pictum occurs during the day, attracting sphaerocerid flies and staphylinid beetles early in the morning and late in the afternoon of the first day. The pollen is released from the anthers early in the morning of the second day before the departure of the insects. Its thermogenic cycle matches the anthesis cycle with an original and unique, bimodal temperature pattern of the appendix (morning and afternoon), contrary to the unimodal pattern found in all other studied Arum species. Data from reproductive success and seed sets suggest that sexual reproduction in this species is limited by pollen (e.g. attracting lured insects) rather than by resources. The biology of this Western Mediterranean species appears to be different from other Western European Arum and close to some Eastern Mediterranean species. Further studies are needed to establish whether Arum pictum represents some ancestral stage or whether its peculiar biological traits are adapted to its insular distribution.
Address [Quilichini, Angelique; Gibernau, Marc] CNRS, UMR 8172, Ecole Forets Guyane, F-97387 Kourou, France, Email: marc.gibernau@ecofog.gf
Corporate Author Thesis
Publisher SPRINGER WIEN Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0378-2697 ISBN Medium
Area Expedition Conference
Notes ISI:000279479800008 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 51
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Author Rutishauser, E.; Wagner, F.; Herault, B.; Nicolini, E.A.; Blanc, L.
Title Contrasting above-ground biomass balance in a Neotropical rain forest Type Journal Article
Year 2010 Publication Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.
Volume 21 Issue 4 Pages 672-682
Keywords Biomass balance; Biomass fluxes; Forest dynamics; Permanent plots; Tropical forests
Abstract Question What are the relative roles of tree growth, mortality and recruitment in variations of above-ground biomass in tropical forests? Location Paracou, French Guiana. Methods We quantified the contribution of growth, recruitment and mortality to total biomass of stands (trees DBH >= 10 cm) in six 6.25-ha permanent plots over 16 yr. Live biomass stocks and fluxes were computed for four separate size classes. Results All plots showed increasing biomass stocks over the study period, with an average value of +0.9 Mg ha-1 yr-1. Plots aggrading biomass were characterized by either minor biomass losses due to mortality or substantial increases in the biomass of large trees (DBH >= 60 cm). Conclusions Within the study period, the rarity of mortality events could not counter-balance the slow permanent increase in biomass, resulting in an apparent increase in biomass. Accounting for such rare events results in no net change in biomass balance.
Address [Rutishauser, Ervan; Nicolini, Eric-Andre] Cirad, UMR AMAP, Kourou 97379, French Guiana, Email: ervan.rutishauser@cirad.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 (down) Series Issue Edition
ISSN 1100-9233 ISBN Medium
Area Expedition Conference
Notes ISI:000279450200005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 52
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Author Herault, B.; Ouallet, J.; Blanc, L.; Wagner, F.; Baraloto, C.
Title Growth responses of neotropical trees to logging gaps Type Journal Article
Year 2010 Publication Journal of Applied Ecology Abbreviated Journal J. Appl. Ecol.
Volume 47 Issue 4 Pages 821-831
Keywords canopy openings; functional traits; incidence function model; light partitioning; selective logging; tree growth rates; tropical rain forest
Abstract P>1. Modelling growth strategies among tropical trees is an important objective in predicting the response of tree dynamics to selective logging and in gaining insights into the ecological processes that structure tree communities in managed tropical forests. 2. We developed a disturbance index to model the effects of distance to and area of logging gaps on stem radial growth rates. This index was tested using census data of 43 neotropical tree species, representing a variety of life-history strategies and developmental stages, from a selectively logged forest at Paracou, French Guiana. Growth strategies were analyzed in light of two indicators: the inherent species growth rate (when disturbance index is null) and the species reaction (change in growth rate) to logging gaps. 3. Across species, the predicted inherent growth rates in unlogged forest ranged from 0 center dot 25 to 6 center dot 47 mm year-1, with an average growth of 2 center dot 29 mm year-1. Ontogenetic shifts in inherent growth rate were found in 26 of the 43 species. 4. Species growth response to logging gaps varied widely among species but was significantly positive for 27 species. The effect of ontogeny on growth response to logging was retained for 14 species, and species with inherent fast growth rate (5 mm year-1) responded less to logging gap disturbances than did species with slow inherent growth (1 mm year-1). 5. Functional traits explained 19-42% of the variation in the inherent growth rate and in species' response across all developmental stages. Whereas maximum diameters and seed mass were strong predictors of inherent growth rate, maximum height, wood density, mode of germination and stem architecture were additionally involved in tree growth response. 6. Synthesis and applications: This study provides a necessary framework for developing predictive post-logging growth models for the thousands of species comprising tropical forests and is sufficiently general to apply to a broad range of managed tropical forests.
Address [Herault, Bruno] Univ Antilles Guyane, UMR Ecol Forets Guyane, F-97387 Kourou, France, 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 (down) Series Issue Edition
ISSN 0021-8901 ISBN Medium
Area Expedition Conference
Notes ISI:000279405100012 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 53
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Author Ruiz-Gonzalez, M.X.; Corbara, B.; Leroy, C.; Dejean, A.; Orivel, J.
Title The Weaver Wasp: Spinning Fungus into a Nest Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume 42 Issue 4 Pages 402-404
Keywords Allomerus decemarticulatus; French Guiana; Hirtella physophora; nest architecture; Nitela constructor; wasp biology
Abstract Wasp nests range from simple to complex structures made of paper or mud. Here, we show that a Neotropical wasp of the genus Nitela builds its nest entirely by weaving endophytic fungal hyphae and spider silk harvested from the leaves growing in the understory of the rain forest in French Guiana.
Address [Ruiz-Gonzalez, Mario X.; Orivel, Jerome] Univ Toulouse, UPS, EDB, Lab Evolut & Divers 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 (down) Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000279438900002 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 54
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Author Baraloto, C.; Couteron, P.
Title Fine-scale Microhabitat Heterogeneity in a French Guianan Forest Type Journal Article
Year 2010 Publication Biotropica Abbreviated Journal Biotropica
Volume 42 Issue 4 Pages 420-428
Keywords canopy gap; geostatistics; light availability; microclimate; soil moisture; soil nutrients; topography
Abstract We examined fine-scale heterogeneity of environmental conditions in a primary rain forest in French Guiana to describe variation in microhabitats that plants may experience during establishment. We characterized both the range as well as the spatial structuring of 11 environmental factors important for seedling establishment in six hexagonal sampling grids, one each in gap and understory sites at three points representing the predominant geomorphic units in this primary forest. Each grid contained 37 sampling points separated by 31 cm-20 m. Monte-Carlo tests of semivariograms against complete spatial randomness indicated that for many variables in all six sampling grids, spatial dependence did not exceed 1 m. A principal component analysis of all sampling points revealed a lack of spatial microhabitat structure, rather than homogeneous patches associated with canopy structure or geomorphology. Our results suggest that ample fine-scale spatial heterogeneity exists to support the coexistence of plant species with differential abiotic requirements for regeneration.
Address [Baraloto, Christopher] INRA, UMR Ecol Forets Guyane, F-97387 Kourou, France, Email: chris.baraloto@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 (down) Series Issue Edition
ISSN 0006-3606 ISBN Medium
Area Expedition Conference
Notes ISI:000279438900005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 55
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Author Dejean, A.; Leroy, C.; Corbara, B.; Roux, O.; Cereghino, R.; Orivel, J.; Boulay, R.
Title Arboreal Ants Use the "Velcro (R) Principle'' to Capture Very Large Prey Type Journal Article
Year 2010 Publication PLoS One Abbreviated Journal PLoS One
Volume 5 Issue 6 Pages e11331
Keywords
Abstract Plant-ants live in a mutualistic association with host plants known as "myrmecophytes'' that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro (R) that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker.
Address [Dejean, Alain; Leroy, Celine; Roux, Olivier; Orivel, Jerome] CNRS, Ecol Forets Guyane UMR CNRS 8172, Kourou, France, Email: alain.dejean@wanadoo.fr
Corporate Author Thesis
Publisher PUBLIC LIBRARY SCIENCE Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 1932-6203 ISBN Medium
Area Expedition Conference
Notes ISI:000279140800028 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 56
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Author Stahl, C.; Burban, B.; Bompy, F.; Jolin, Z.B.; Sermage, J.; Bonal, D.
Title Seasonal variation in atmospheric relative humidity contributes to explaining seasonal variation in trunk circumference of tropical rain-forest trees in French Guiana Type Journal Article
Year 2010 Publication Journal of Tropical Ecology Abbreviated Journal J. Trop. Ecol.
Volume 26 Issue Pages 393-405
Keywords bark; drought; secondary growth; seasonality; tropical rain forest; water
Abstract Large seasonal variation in the rate of change in girth of tropical rain-forest tree species has been described, but its origin is still under debate. We tested whether this variation might be related to variation in atmospheric relative humidity through its influence on bark water content and thickness. Variation in trunk circumference of 182 adult trees was measured about twice a month in an undisturbed tropical rain forest over 18 mo using dendrometers. Furthermore, a laboratory experiment was conducted to test the direct influence of relative air humidity on bark water content and thickness. in the field, most trees displayed highly positive rates of change in girth at the onset of the wet season, while a quarter of the trees displayed negative changes during long dry seasons, whatever their total annual growth. This variation was correlated with environmental conditions, particularly with atmospheric relative humidity. Trees with high bark water content and thickness displayed a stronger decrease in girth during the dry season. in the chamber experiment, desiccation induced a decrease in the diameter of the trunk sections in tandem with a decrease in bark water content. As a result, seasonal variation in the rate of change in girth of tropical rain-forest trees reflects variation in trunk biophysical properties, through the influence of relative humidity on bark properties. but not directly variation in secondary growth.
Address [Stahl, Clement; Burban, Benoit; Bompy, Felix; Jolin, Zachari B.; Sermage, Juliette; Bonal, Damien] INRA, UMR Ecol Forets Guyane 745, Kourou 97387, French Guiana, Email: bonal@nancy.inra.fr
Corporate Author Thesis
Publisher CAMBRIDGE UNIV PRESS Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume (down) Series Issue Edition
ISSN 0266-4674 ISBN Medium
Area Expedition Conference
Notes ISI:000279100600005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 57
Permanent link to this record