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Author Gibson, J.C.; Larabee, F.J.; Touchard, A.; Orivel, J.; Suarez, A.V.
Title Mandible strike kinematics of the trap-jaw ant genus Anochetus Mayr (Hymenoptera: Formicidae) Type Journal Article
Year 2018 Publication (down) Journal of Zoology Abbreviated Journal
Volume 306 Issue 2 Pages 119-128
Keywords catapult mechanism; comparative biomechanics; Formicidae; functional morphology; kinematics; mandible strike; power amplification
Abstract High-speed power-amplification mechanisms are common throughout the animal kingdom. In ants, power-amplified trap-jaw mandibles have evolved independently at least four times, including once in the subfamily Ponerinae which contains the sister genera Odontomachus and Anochetus. In Odontomachus, mandible strikes have been relatively well described and can occur in <0.15 ms and reach speeds of over 60 m s−1. In contrast, the kinematics of mandible strikes have not been examined in Anochetus, whose species are smaller and morphologically distinct from Odontomachus. In this study, we describe the mandible strike kinematics of four species of Anochetus representative of the morphological, phylogenetic, and size diversity present within the genus. We also compare their strikes to two representative species of Odontomachus. We found that two species, Anochetus targionii and Anochetus paripungens, have mandible strikes that overall closely resemble those found in Odontomachus, reaching a mean maximum rotational velocity and acceleration of around 3.7 × 104 rad s−1 and 8.5 × 108 rad s−2, respectively. This performance is consistent with predictions based on body size scaling relationships described for Odontomachus. In contrast, Anochetus horridus and Anochetus emarginatus have slower strikes relative to the other species of Anochetus and Odontomachus, reaching mean maximum rotational velocity and acceleration of around 1.3 × 104 rad s−1 and 2 × 108 rad s−2, respectively. This variation in strike performance among species of Anochetus likely reflects differences in evolutionary history, physiology, and natural history among species. © 2018 The Zoological Society of London
Address Department of Animal Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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Notes Export Date: 15 October 2018 Approved no
Call Number EcoFoG @ webmaster @ Serial 826
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Author Yamamoto, H.; Almeras, T.
Title A mathematical verification of the reinforced-matrix hypothesis using the Mori-Tanaka theory Type Journal Article
Year 2007 Publication (down) Journal of Wood Science Abbreviated Journal J. Wood Sci.
Volume 53 Issue 6 Pages 505-509
Keywords Engineering
Abstract This article presents a theoretical verification of the reinforced-matrix hypothesis derived from tensor equations, σ W = σ f + σ m and ε W = ε f = ε m (Wood Sci Technol 32:171–182, 1998; Wood Sci Technol 33:311–325, 1999; J Biomech Eng 124:432–440, 2002), using classical Mori-Tanaka theory on the micromechanics of fiber-reinforced materials (Acta Metall 21:571–574, 1973; Micromechanics — dislcation and inclusions (in Japanese), pp 141–147, 1976). The Mori-Tanaka theory was applied to a small fragment of the cell wall undergoing changes in its physical state, such as those arising from sorption of moisture, maturation of wall components, or action of an external force, to obtain ⟨σ A⟩D = ϕ·⟨σ F⟩I + (1−ϕ)·⟨σ M⟩D−I. When the constitutive equation of each constituent material was applied to the equation ⟨σ A⟩D = ϕ·⟨σ F⟩I + (1−ϕ)·⟨σ M⟩D−I, the equations σ W = σ f + σ m and ε W = ε f = ε m were derived to lend support to the concept that two main phases, the reinforcing cellulose microfibril and the lignin-hemicellulose matrix, coexist in the same domain. The constitutive equations for the cell wall fragment were obtained without recourse to additional parameters such as Eshelby’s tensor S and Hill’s averaged concentration tensors AF and AM. In our previous articles, the coexistence of two main phases and σ W = σ f + σ m and ε W = ε f =ε m had been taken as our starting point to formulate the behavior of wood fiber with multilayered cell walls. The present article provides a rational explanation for both concepts.
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Publisher Springer Japan Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1435-0211 ISBN Medium
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Notes Approved no
Call Number EcoFoG @ eric.marcon @ Serial 215
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Author Almeras, T.; Yoshida, M.; Okuyama, T.
Title The generation of longitudinal maturation stress in wood is not dependent on diurnal changes in diameter of trunk Type Journal Article
Year 2006 Publication (down) Journal of Wood Science Abbreviated Journal J. Wood Sci.
Volume 52 Issue 5 Pages 452-455
Keywords maturation stress; growth stress; cell-wall maturation; continuous lighting; diurnal strains
Abstract A hypothetical mechanism for the generation of maturation stress in wood was tested experimentally. The hypothesis was that the maturation stress could partly originate in a physical mechanism related to daily changes in water pressure and associated diurnal strains. The matrix of lignin and hemicellulose, deposited in the cell wall during the night, would be put in compression by the effect of water tension during the next day. The cellulose framework, crystallizing during the day, would be put in tension by the decrease in tension at night and subsequent cell-wall swelling. This was tested on young saplings of sugi and beech. Half of the saplings were submitted to continuous lighting, which canceled diurnal strains. Saplings were tilted 40 degrees, and their uprighting movement was measured. The uprighting movement is directly due to the production of reaction wood and the concomitant development of large longitudinal maturation stress. It occurred in the continuously lighted plants at least as much as in control plants. We conclude that the generation of longitudinal maturation stress in tension or compression wood is not directly related to variations in water pressure and diurnal strains.
Address Nagoya Univ, Grad Sch Bioagr Sci, Lab Biomat Phys, Chikusa Ku, Nagoya, Aichi 4648601, Japan, Email: t_almeras@hotmail.com
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Publisher SPRINGER TOKYO Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1435-0211 ISBN Medium
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Notes ISI:000241010600012 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 222
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Author Zhang, T.; Bai, S.-L.; Bardet, S.; Almeras, T.; Thibaut, B.; Beauchene, J.
Title Radial variations of vibrational properties of three tropical woods Type Journal Article
Year 2011 Publication (down) Journal of Wood Science Abbreviated Journal J. Wood Sci.
Volume 57 Issue 5 Pages 377-386
Keywords Damping coefficient; Dynamic modulus; Extractives; Microfibril angle; Tropical woods
Abstract The radial trends of vibrational properties, represented by the specific dynamic modulus (E′/ρ) and damping coefficient (tan δ), were investigated for three tropical rainforest hardwood species (Simarouba amara, Carapa procera, and Symphonia globulifera) using free-free flexural vibration tests. The microfibril angle (MFA) was estimated using X-ray diffraction. Consistent patterns of radial variations were observed for all studied properties. E′/ρ was found to decrease from pith to bark, which was strongly related to the increasing pith-bark trend of MFA. The variation of tan δ along the radius could be partly explained by MFA and partly by the gradient of extractives due to heartwood formation. The coupling effect of MFA and extractives could be separated through analysis of the log(tan δ) versus log(E′/ρ) diagram. For the species studied, the extractive content putatively associated with heartwood formation generally tends to decrease the wood damping coefficient. However, this weakening effect of extractives was not observed for the inner part of the heartwood, suggesting that the mechanical action of extractives was reduced during their chemical ageing. © 2011 The Japan Wood Research Society.
Address CIRAD, UMR Ecofog, BP 701, 97387 Kourou Cedex, Guyane Française, France
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ISSN 14350211 (Issn) ISBN Medium
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Notes Export Date: 26 October 2011; Source: Scopus; Coden: Jwscf; doi: 10.1007/s10086-011-1189-7; Language of Original Document: English; Correspondence Address: Bai, S.-L.; Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871, China; email: slbai@pku.edu.cn Approved no
Call Number EcoFoG @ webmaster @ Serial 363
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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 (down) 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
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ISSN 1100-9233 ISBN Medium
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Notes ISI:000279450200005 Approved no
Call Number EcoFoG @ eric.marcon @ Serial 52
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Author Traissac, S.; Pascal, J.-P.
Title Birth and life of tree aggregates in tropical forest: Hypotheses on population dynamics of an aggregated shade-tolerant species Type Journal Article
Year 2014 Publication (down) Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.
Volume 25 Issue 2 Pages 491-502
Keywords Clusters; Colonization strategy; Janzen-Connell; Spatial analysis; Spatial pattern; Vouacapoua americana
Abstract Questions: Several studies have described aggregated spatial patterns in tropical tree species. This study investigates aggregate dynamics of Vouacapoua americana (Aublet), a climax species whose spatial pattern is not simply related to light and soil conditions or to its short seed dispersal range. Location: Two rain forest sites: Nouragues and Paracou, in the Guiana Shield. Methods: We described the spatial pattern of tree locations and spatial autocorrelation of tree diameters, using statistics derived from Ripley's K. We particularly used methods to define analysis subplots according to local density or local mean diameter. We investigated relationships between spatial distributions of adults and saplings. Results: At both sites, populations of Vouacapoua demonstrated several nested levels of aggregation. Tree diameters were spatially autocorrelated, revealing the existence of clusters with similar diameters. In the largest aggregates, tree diameters declined from the centre to the edge. Regeneration was aggregated and occurred mainly at cluster edges and around rare isolated trees, and sapling densities and basal area of adults were negatively correlated. We show that long-distance dispersal events are rare. Conclusions: Environmental factors and seed dispersal only explain part of the observed spatial patterns. We provide two main hypotheses about Vouacapoua population dynamics. First, the lack of regeneration in aggregate centres results in the ageing of existing aggregates. We suggest that this lack of recruitment close to mature trees is due to a Janzen-Connell effect. However, aggregates can continue to grow along colonization fronts. Second, long-distance dispersal events allow the formation of new clusters and play a crucial role in the colonization process. We investigate aggregate dynamics of Vouacapoua americana (Aublet) whose spatial pattern is not simply related to environmental conditions or to its seed dispersal. Regeneration does not occur in centers of aggregate of adults. We suggest that rare long-distance dispersal events and density-dependence predation of seeds and seedlings play a crucial role in formation of new clusters and structuration of larger aggregates. © 2013 International Association for Vegetation Science.
Address Université Claude Bernard Lyon 1, 43 Boulevard 11 Novembre 1918, Villeurbanne, 69100, France
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ISSN 11009233 (Issn) ISBN Medium
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Notes Export Date: 10 March 2014; Source: Scopus; Coden: Jvese; Language of Original Document: English; Correspondence Address: Traissac, S.; AgroParisTech, UMR ECOlogie des Forêts de Guyane, Campus Agronomique, BP 709, Kourou, 97387, France; email: stephane.traissac@ecofog.gf Approved no
Call Number EcoFoG @ webmaster @ Serial 532
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Author Vleminckx, J.; Bauman, D.; Demanet, M.; Hardy, O.J.; Doucet, J.-L.; Drouet, T.
Title Past human disturbances and soil fertility both influence the distribution of light-demanding tree species in a Central African tropical forest Type Journal Article
Year 2020 Publication (down) Journal of Vegetation Science Abbreviated Journal J. Veg. Sci.
Volume 31 Issue 3 Pages 440-453
Keywords light-demanding species; moist tropical forests; past human disturbances; shade-bearer species; soil charcoal abundance; soil properties; tree community assemblages; wood-specific gravity; anthropogenic effect; forest canopy; forest ecosystem; shifting cultivation; soil fertility; soil property; tree; tropical forest; Cameroon
Abstract Questions: In vast areas of Central African forests, the upper canopy is presently dominated by light-demanding tree species. Here, we confront three hypotheses to explain this dominance: (a) these species have expanded their distribution because of widespread past slash-and-burn activities, as suggested by important charcoal amounts recorded in the soils of the region; (b) their abundance is rather explained by soil properties, as this guild establishes preferentially on favourable physico-chemical conditions for rapid growth; (c) soil properties have been substantially influenced by past human disturbances and those two effects cannot be disentangled. Location: Pallisco-CIFM logging concession, southeastern Cameroon (300,000 ha). Methods: We quantified soil charcoal abundance and measured ten soil variables at the basis of 60 target trees that belonged to a list of three long-living pioneer light-demanding (LLP) and four shade-bearer (SB) species. We identified all stems with a diameter at breast height (DBH) ≥ 20 cm within a distance of 15 m around each target tree. Species were characterised by their wood-specific gravity (WSG), which reflected their light requirement. Multiple regression models were used to quantify and test the relative effects of charcoal abundance and soil variables on the mean WSG of the 60 tree communities, as well as the abundance of three guilds: LLP, SB, and non-pioneer light demanders (NPLD). Results: The mean WSG was the only response variable significantly explained by soil variables and charcoal abundance combined. It was significantly negatively associated with soil calcium and Mg content and with charcoal abundance, with soil and charcoal influencing the mean WSG independently. Conclusion: Our study provides evidence that past human disturbances and soil fertility have independently promoted the establishment of light-demanding species in western Central African forests, thereby shedding light on tree community assembly rules in these ecosystems which remain considerably understudied compared to the tropical forests of other continents. © 2020 International Association for Vegetation Science
Address Forest is life, TERRA Teaching and Research Centre, Université de Liège – Gembloux Agro-Bio Tech, Gembloux, Belgium
Corporate Author Thesis
Publisher Wiley-Blackwell Place of Publication Editor
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ISSN 11009233 (Issn) ISBN Medium
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Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 970
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Author Schmitt, Sylvain ; Raevel, Valérie ; Réjou-Méchain, Maxime ; Ayyappan, Narayanan ; Balachandran, Natesan ; Barathan, Narayanan ; Rajashekar, Gopalakrishnan ; Munoz, François
Title Canopy and understorey tree guilds respond differently to the environment in an Indian rain forest Type Journal Article
Year 2021 Publication (down) Journal of Végétation Science Abbreviated Journal
Volume 32 Issue 5 Pages e13075
Keywords
Abstract Questions Changes in the functional composition of tree communities along resource availability gradients have received attention, but it is unclear whether understorey and canopy guilds respond similarly to different light, biomechanical, and hydraulic constraints. Location An anthropically undisturbed, old-growth wet evergreen dipterocarp forest plot located in Karnataka State, India. Methods We measured leaf and wood traits of 89 tree species representing 99% of all individuals in a 10-ha permanent plot with varying topographic and canopy conditions inferred from Light Detection And Ranging (LiDAR) data. We assigned tree species to guilds of canopy and understorey species and assessed the variation of the guild-weighted means of functional-trait values with canopy height and topography. Results The functional-trait space did not differ between canopy and understorey tree species. However, environmental filtering led to significantly different functional composition of canopy and understorey guild assemblages. Furthermore, they responded differently along environmental gradients related to water, nutrients, light, and wind exposure. For example, the canopy guild responded to wind exposure while the understorey guild did not. Conclusions The pools of understorey and canopy species are functionally similar. However, fine-scale environmental heterogeneity impacts differently on these two guilds, generating striking differences in functional composition between understorey and canopy guild assemblages. Accounting for vertical guilds improves our understanding of forest communities' assembly processes.
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Publisher International Association for Vegetation Science Place of Publication Editor
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Call Number EcoFoG @ webmaster @ Serial 1038
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Author Millet, J.; Pascal, J.P.; Kiet, L.C.
Title Effects of Disturbance Over 60 Years on a Lowland Forest in Southern Vietnam Type Journal Article
Year 2010 Publication (down) Journal of Tropical Forest Science Abbreviated Journal J. Trop. For. Sci.
Volume 22 Issue 3 Pages 237-246
Keywords Lowland tropical forest; disturbance impact; floristic composition; forest structure; Tan Phu forest
Abstract MILLET J, PASCAL JP & MET LC. 2010. Effects of disturbance over 60 years on a lowland forest in southern Vietnam. Tropical lowland forests are some of the most threatened in the world and this is particularly the case in Vietnam. This study aimed to identify changes in species composition and forest structure in the Tan Phu lowland forest resulting from disturbance over a 60 year period. Analysis of forest composition and structure rely on data from 25 plots of 0.5-ha size established in a lowland secondary forest. The five forest stands described differed greatly from the three forest stand types described in 1943. Some long-lived shade-tolerant species had been replaced by pioneer species, such as Cratoxylon formosum and Shorea roxburghii. In addition to altering composition, forest disturbances had resulted in large changes in forest structure. While in the past, forest stands had a large number of exploitable trees, current forest stands have few trees in the diameter class > 50 cm and sometimes no trees in the diameter class > 80 cm. This paper provides notable results on forest tree ecology, forest dynamics and on the state of secondary forests in Vietnam. This is particularly important as future goods and services will increasingly have to come from such forests.
Address [Millet, J.] Univ Lyon 1, F-69622 Villeurbanne, France, Email: jerome.millet@ird.if
Corporate Author Thesis
Publisher FOREST RESEARCH INST MALAYSIA Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0128-1283 ISBN Medium
Area Expedition Conference
Notes ISI:000280653200003 Approved no
Call Number EcoFoG @ webmaster @ Serial 283
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Author Sellan, G. ; Brearley, FQ. ; Nilus, R. ; Ttin, J. ; Majalap-Lee, N.
Title Differences in soil properties among contrasting soil types in Northern Borneo Type Journal Article
Year 2021 Publication (down) Journal of Tropical Forest Science Abbreviated Journal
Volume 33 Issue 2 Pages 191-202
Keywords
Abstract Soil in the tropics is high in diversity, and despite the diversity of Borneo’s forest–soil associations, there is a paucity of data on its soil properties. We investigated the differences between three soil types in the Kabili–Sepilok Forest Reserve, Sabah, Malaysia, encompassing the contrasting alluvial, sandstone and heath forest typologies. We examined the distribution of nutrients between soil types and through soil depths, and assessed the extent of spatial autocorrelation in the three soil types. We confirmed the fertility gradient from alluvial to heath forest soil found by others. Soil elemental concentrations declined in deeper horizons with the exception of exchangeable sodium and aluminium that remained constant through alluvial and sandstone soil profiles. Spatial autocorrelation was present in all three soil types and strongest in the sandstone soil. Overall, we show how bedrock, erosion, leaching and topography influence soil properties across this mosaic of soil types and note their importance in influencing tree communities and their ecological functioning.
Address
Corporate Author Thesis
Publisher FOREST RESEARCH INST MALAYSIA Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0128-1283 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 1017
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