| Home | [61–70] << 71 72 73 74 75 76 77 78 79 80 >> [81–90] |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | de Grandcourt, A.; Epron, D.; Montpied, P.; Louisanna, E.; Bereau, M.; Garbaye, J.; Guehl, J.M. | ||||
| Title | Contrasting responses to mycorrhizal inoculation and phosphorus availability in seedlings of two tropical rainforest tree species | Type | Journal Article | ||
| Year | 2004 | Publication | New Phytologist | Abbreviated Journal | New Phytol. |
| Volume | 161 | Issue | 3 | Pages | 865-875 |
| Keywords | phosphorus; growth; efficiency; Paris-type arbuscular mycorrhizas; tropical rainforest; seedlings; Dicorynia guianensis; Eperua falcata | ||||
Abstract  |
This work aimed at understanding the role of mycorrhizal status in phosphorus efficiency of tree seedlings in the tropical rainforest of French Guyana. Mycorrhizal colonization, growth, phosphorus content, net photosynthesis and root respiration were determined on three occasions during a 9-month growth period for seedlings of two co-occurring species (Dicorynia guianensis and Eperua falcata) grown at three soil phosphorus concentrations, with or without inoculation with arbuscular mycorrhizas. Seedlings of both species were unable to absorb phosphorus in the absence of mycorrhizal association. Mycorrhizal seedlings exhibited coils that are specific of Paris-type mycorrhizae. Both species benefited from the mycorrhizal symbiosis in terms of phosphorus acquisition but the growth of E. falcata seedlings was unresponsive to this mycorrhizal improvement of phosphorus status, probably because of the combination of high seed mass and P reserves, with low growth rate. The two species belong to two different functional groups regarding phosphorus acquisition, D. guianensis being an obligate mycotrophic species. | ||||
| Address | Univ Franche Comte, Lab Biol & Ecophysiol, F-25211 Montbeliard, France, Email: daniel.epron@scbiol.uhp-nancy.fr | ||||
| 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 | 0028-646X | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | ISI:000188646500022 | Approved | no | ||
| Call Number | EcoFoG @ eric.marcon @ | Serial | 239 | ||
| Permanent link to this record | |||||
| Author | Paine, C.E.T.; Harms, K.E. | ||||
| Title | Quantifying the effects of seed arrival and environmental conditions on tropical seedling community structure | Type | Journal Article | ||
| Year | 2009 | Publication | Oecologia | Abbreviated Journal | Oecologia |
| Volume | 160 | Issue | 1 | Pages | 139-150 |
| Keywords | Community assembly; Dispersal; Niche differentiation; Seed addition; Variance partitioning | ||||
| Abstract |
Though it is recognized that both stochastic and deterministic processes structure all communities, empirical assessments of their relative importance are rare, particularly within any single community. In this paper, we quantify the dynamic effects of dispersal assembly and niche assembly on the seedling layer in a diverse neotropical rain forest. The two theories make divergent predictions regarding the roles of seed arrival and environmental heterogeneity in generating community structure. Put simply, dispersal assembly posits that the stochasticity inherent to seed arrival structures communities, whereas niche assembly suggests that heterogeneity in post-dispersal environmental conditions is more important. We experimentally sowed 15,132 seeds of eight tree species at varying levels of density and diversity. Every six months we censused the seedlings that germinated and assessed the abiotic and biotic conditions of each plot. We assessed the density, diversity, and species composition of three nested subsets of the seedling layer: seedlings germinated from sown seeds, all seedlings germinated between July 2003 and 2004, and all woody seedlings. We partitioned the variance in density and diversity of each subset of the seedling layer into components representing seed-addition treatments and environmental conditions at 6- to 12-month intervals. Seed additions initially explained more variance in the density and diversity than did environmental heterogeneity for seven of eight sown species, but explained little variance in the density or diversity of the entire seedling layer. Species composition was better explained by seed-addition treatments than by environmental heterogeneity for all three subsets and in all time periods. Nevertheless, the variance in community structure explained by seed-addition treatments declined over the two years following germination, presaging shifts in the relative importance of dispersal assembly and niche assembly. Our study quantifies how dispersal assembly and niche assembly may vary among the components of an ecological community and shift dynamically through time. | ||||
| Address | [Paine, C. E. Timothy; Harms, Kyle E.] Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA, Email: timothy.paine@ecofog.gf | ||||
| Corporate Author | Thesis | ||||
| Publisher | SPRINGER | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0029-8549 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | ISI:000265100500014 | Approved | no | ||
| Call Number | EcoFoG @ eric.marcon @ | Serial | 116 | ||
| Permanent link to this record | |||||
| Author | Stahl, C.; Herault, B.; Rossi, V.; Burban, B.; Bréchet, C.; Bonal, D. | ||||
| Title | Depth of soil water uptake by tropical rainforest trees during dry periods: Does tree dimension matter? | Type | Journal Article | ||
| Year | 2013 | Publication | Oecologia | Abbreviated Journal | Oecologia |
| Volume | 173 | Issue | 4 | Pages | 1191-1201 |
| Keywords | Deuterium; Oxygen; Root; Soil water; Tropical rainforest | ||||
| Abstract |
Though the root biomass of tropical rainforest trees is concentrated in the upper soil layers, soil water uptake by deep roots has been shown to contribute to tree transpiration. A precise evaluation of the relationship between tree dimensions and depth of water uptake would be useful in tree-based modelling approaches designed to anticipate the response of tropical rainforest ecosystems to future changes in environmental conditions. We used an innovative dual-isotope labelling approach (deuterium in surface soil and oxygen at 120-cm depth) coupled with a modelling approach to investigate the role of tree dimensions in soil water uptake in a tropical rainforest exposed to seasonal drought. We studied 65 trees of varying diameter and height and with a wide range of predawn leaf water potential (Ψpd) values. We confirmed that about half of the studied trees relied on soil water below 100-cm depth during dry periods. Ψpd was negatively correlated with depth of water extraction and can be taken as a rough proxy of this depth. Some trees showed considerable plasticity in their depth of water uptake, exhibiting an efficient adaptive strategy for water and nutrient resource acquisition. We did not find a strong relationship between tree dimensions and depth of water uptake. While tall trees preferentially extract water from layers below 100-cm depth, shorter trees show broad variations in mean depth of water uptake. This precludes the use of tree dimensions to parameterize functional models. © 2013 Springer-Verlag Berlin Heidelberg. | ||||
| Address | INRA, UMR EEF 1137, 54280 Champenoux, France | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 00298549 (Issn) | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Export Date: 6 December 2013; Source: Scopus; Coden: Oecob; doi: 10.1007/s00442-013-2724-6; Language of Original Document: English; Correspondence Address: Bonal, D.; INRA, UMR EEF 1137, 54280 Champenoux, France; email: bonal@nancy.inra.fr; References: Améglio, T., Archer, P., Cohen, M., Valancogne, C., Daudet, F.A., Dayau, S., Cruiziat, P., Significance and limits in the use of predawn leaf water potential for tree irrigation (1999) Plant Soil, 207, pp. 155-167; Baraloto, C., Morneau, F., Bonal, D., Blanc, L., Ferry, B., Seasonal water stress tolerance and habitat associations within four Neotropical tree genera (2007) Ecology, 88, pp. 478-489; Bonal, D., Barigah, T.S., Granier, A., Guehl, J.-M., Late-stage canopy tree species with extremely low delta C-13 and high stomatal sensitivity to seasonal soil drought in the tropical rainforest of French Guiana (2000) Plant Cell Environ, 23, pp. 445-459; Bonal, D., Atger, C., Barigah, T.S., Ferhi, A., Guehl, J.-M., Ferry, B., Water acquisition patterns of two wet tropical canopy tree species of French Guiana as inferred from H218O extraction profiles (2000) Ann For Sci, 57, pp. 717-724; Bonal, D., Bosc, A., Ponton, S., Goret, J.-Y., Burban, B., Gross, P., Bonnefond, J.-M., Granier, A., Impact of severe dry season on net ecosystem exchange in the Neotropical rainforest of French Guiana (2008) Glob Chang Biol, 14, pp. 1917-1933; Cao, K.F., Water relations and gas exchange of tropical saplings during a prolonged drought in a Bornean heath forest, with reference to root architecture (2000) J Trop Ecol, 16, pp. 101-116; Carvalheiro, K.O., Nepstad, D.C., Deep soil heterogeneity and fine root distribution in forests and pastures of eastern Amazonia (1996) Plant Soil, 182, pp. 279-285; Chmura, D.J., Anderson, P.D., Howe, G.T., Harrington, C.A., Halofsky, J.E., Peterson, D.L., Shaw, D.C., Brad St Claire, J., Forest responses to climate change in the northwestern United States: ecophysiological foundations for adaptive management (2011) For Ecol Manage, 261, pp. 1121-1142; da Rocha, H.R., Goulden, M.L., Miller, S.D., Menton, M.C., Pinto, L.D.V.O., de Freitas, H.C., e Silva Figueira, A.M., Seasonality of water and heat fluxes over a tropical forest in eastern Amazonia (2004) Ecol Appl, 14, pp. 22-32; Davidson, E., Lefebvre, P.A., Brando, P.M., Ray, D.M., Trumbore, S.E., Solorzano, L.A., Ferreira, J.N., Nepstad, D.C., Carbon inputs and water uptake in deep soils of an eastern Amazon forest (2011) For Sci, 57, pp. 51-58; Engelbrecht, B.M.J., Kursar, T.A., Comparative drought-resistance of seedlings of 28 species of co-occurring tropical woody plants (2003) Oecologia, 136, pp. 383-393; Engelbrecht, B.M.J., Wright, S.J., De Steven, D., Survival and ecophysiology of tree seedlings during El Nino drought in a tropical moist forest in Panama (2002) J Trop Ecol, 18, pp. 569-579; Fisher, R.A., Williams, M., Do Vale, R.L., Da Costa, A.L., Meir, P., Evidence from Amazonian forests is consistent with isohydric control of leaf water potential (2006) Plant Cell Environ, 29, pp. 151-165; Goulden, M.L., Miller, S.D., da Rocha, H.R., Menton, M.C., De Freitas, H.C., Silva Figueira, A.M.E., De Sousa, C.A.D., Diel and seasonal patterns of tropical forest CO2 exchange (2004) Ecol Appl, 14, pp. 42-54; Gourlet-Fleury, S., Ferry, B., Molino, J.F., Petronelli, P., Schmitt, L., Experimental plots: key features (2004) Ecology and management of a Neotropical Rainforest, pp. 3-60. , In: Gourlet-Fleury S, Guehl JM, Laroussinie O (eds) Lessons drawn from Paracou, a long-term experimental research site in French Guiana. Elsevier, Paris; Huc, R., Ferhi, A., Guehl, J.M., Pioneer and late stage tropical rainforest tree species (French Guyana) growing under common conditions differ in leaf gas exchange regulation, carbon isotope discrimination and leaf water potential (1994) Oecologia, 99, pp. 297-305; Hutyra, L.R., Munger, J.W., Saleska, S., Gottlieb, E., Daube, B.C., Dunn, A.L., Amaral, D.F., Wofsy, S.C., Seasonal controls on the exchange of carbon and water in an Amazonian rain forest (2007) J Geophys Res, 112, pp. G03008. , doi:10.1029/2006JG000365; Jackson, R.B., Canadell, J., Ehleringer, J.R., Mooney, H.A., Sala, O.E., Schulze, E.D., A global analysis of root distributions for terrestrial biomes (1996) Oecologia, 108, pp. 389-411; Jobbagy, E.G., Jackson, R.B., The distribution of soil nutrients with depth: global patterns and the imprint of plants (2001) Biogeochemistry, 53, pp. 51-77; Kozlowski, T.T., Pallardy, S.G., Acclimation and adaptive responses of woody plants to environmental stresses (2002) Bot Rev, 68, pp. 270-334; Malhi, Y., Wright, J., Spatial patterns and recent trends in the climate of tropical rainforest regions (2004) Phil Trans R Soc Lond B, 359, pp. 311-329; Markewitz, D., Devine, S., Davidson, E.A., Brando, P., Nepstad, D.C., Soil moisture depletion under simulated drought in the Amazon: impacts on deep root uptake (2010) New Phytol, 187, pp. 592-607; Meinzer, F.C., Andrade, J.L., Goldstein, G., Holbrook, N.M., Cavelier, J., Wright, S.J., Partitioning of soil water among trees in a seasonally dry tropical forest (1999) Oecologia, 121, pp. 293-301; Merbold, L., Ardo, J., Arneth, A., Scholes, R.J., Nouvellon, Y., de Grandcourt, A., Archibald, S., Kutsch, W.L., Precipitation as driver of carbon fluxes in 11 African ecosystems (2009) Biogeosciences, 6, pp. 1027-1041; Moreira, M., Sternberg, L., Nepstad, D., Vertical patterns of soil water uptake by plants in a primary forest and an abandoned pasture in the eastern Amazon: an isotopic approach (2000) Plant Soil, 222, pp. 95-107; Nepstad, D.C., De Carvalho, C.R., Davidson, E.A., Jipp, P.H., Lefebvre, P.A., Negreiros, G.H., Da Silva, E.D., Vieira, S., The role of deep roots in the hydrological and carbon cycles of Amazonian forests and pastures (1994) Nature, 372, pp. 666-669; Oliveira, R., Dawson, T., Burgess, S., Nepstad, D., Hydraulic redistribution in three Amazonian trees (2005) Oecologia, 145, pp. 354-363; Poorter, L., Markesteijn, L., Seedling traits determine drought tolerance of tropical tree species (2008) Biotropica, 40, pp. 321-331; (2010) R: A Language and Environment for Statistical Computing, , R Development Core Team, Vienna: R Foundation for Statistical Computing; Romero-Saltos, H., LdSL, S., Moreira, M.Z., Nepstad, D.C., Rainfall exclusion in an eastern Amazonian forest alters soil water movement and depth of water uptake (2005) Am J Bot, 92, pp. 443-455; Sobrado, M.A., Embolism vulnerability in drought-deciduous and evergreen species of a tropical dry forest (1997) Acta Oecol, 18, pp. 383-391; Stahl, C., Burban, B., Bompy, F., Jolin, Z.B., Sermage, J., Bonal, D., Seasonal variation in atmospheric relative humidity contributes to explaining seasonal variation in trunk circumference of tropical rain-forest trees in French Guiana (2010) J Trop Ecol, 26, pp. 393-405; Stahl, C., Burban, B., Goret, J.-Y., Bonal, D., Seasonal variations in stem CO2 efflux in the Neotropical rainforest of French Guiana (2011) Ann For Sci, 68, pp. 771-782; Stahl, C., Burban, B., Wagner, F., Goret, J.-Y., Bompy, F., Bonal, D., Influence of seasonal variations in soil water availability on gas exchange of tropical canopy trees (2013) Biotropia, 45, pp. 155-164; Sternberg, L., Green, L., Moreira, M.Z., Nepstad, D.C., Martinelli, L.A., Victoria, R., Root distribution in an Amazonian seasonal forest (1998) Plant Soil, 205, pp. 45-50; Sternberg, L., Moreira, M., Nepstad, D.C., Uptake of water by lateral roots of small trees in an Amazonian tropical forest (2002) Plant Soil, 238, pp. 151-158; Wagner, F., Hérault, B., Stahl, C., Bonal, D., Rossi, V., Modeling water availability for trees in tropical forests (2011) Agric For Meteorol, 151, pp. 1202-1213; Wagner, F., Rossi, V., Stahl, C., Bonal, D., Hérault, B., Water availability is the main climate driver of Neotropical tree growth (2012) PLoS ONE, 7, pp. e34074; Wang, G., Alo, C., Mei, R., Sun, S., Droughts, hydraulic redistribution, and their impact on vegetation composition in the Amazon forest (2011) Plant Ecol, 212, pp. 663-673; Williams, M., Malhi, Y., Nobre, A.D., Rastetter, E.B., Grace, J., Pereira, M.G.P., Seasonal variation in net carbon exchange and evapotranspiration in a Brazilian rainforest: a modelling analysis (1998) Plant Cell Environ, 21, pp. 953-968; Yavitt, J.B., Wright, S.J., Drought and irrigation effects on fine root dynamics in a tropical moist forest, Panama (2001) Biotropica, 33, pp. 421-434; Zapater, M., Hossann, C., Bréda, N., Bréchet, C., Bonal, D., Granier, A., Evidence of hydraulic lift in a young beech and oak mixed forest using 18O soil water labelling (2011) Trees Struct Funct, 25, pp. 885-894; Zhang, Y., Tan, Z., Song, Q., Yu, G., Sun, X., Respiration controls the unexpected seasonal pattern of carbon flux in an Asian tropical rain forest (2010) Atmos Environ, 44, pp. 3886-3893 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 514 | ||
| Permanent link to this record | |||||
| Author | Cabanillas, B.J.; Le Lamer, A.C.; Castillo, D.; Arevalo, J.; Rojas, R.; Odonne, G.; Bourdy, G.; Moukarzel, B.; Sauvain, M.; Fabre, N. | ||||
| Title | Caffeic Acid Esters and Lignans from Piper sanguineispicum | Type | Journal Article | ||
| Year | 2010 | Publication | Journal of Natural Products | Abbreviated Journal | J. Nat. Prod. |
| Volume | 73 | Issue | 11 | Pages | 1884-1890 |
| Keywords | |||||
| Abstract |
Three new caffeic acid esters (1-3), four new lignans (4-7), and the known compounds (7'S)-parabenzlactone (8), dihydrocubebin (9), and justiflorinol (10) have been isolated from leaves of Piper sanguineispicum. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRCIMS, CD experiments, and chemical methods. Compounds 1-10 were assessed for their antileishmanial potential against axenic amastigote forms of Leishmania amazonensis. Caffeic acid esters 1 and 3 exhibited the best antileishmanial activity (IC50 2.0 and 1.8 μM, respectively) with moderate cytotoxicity on murine macrophages. | ||||
| Address | [Cabanillas, Billy Joel; Le Lamer, Anne-Cecile; Odonne, Guillaume; Bourdy, Genevieve; Moukarzel, Beatrice; Sauvain, Michel; Fabre, Nicolas] Univ Toulouse, UPS, UMR 152, Lab Pharmacochim Subst Nat & Pharmacophores Redox, F-31062 Toulouse 9, France, Email: michel.sauvain@ird.fr | ||||
| Corporate Author | Thesis | ||||
| Publisher | AMER CHEMICAL SOC | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0163-3864 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | ISI:000284559100024 | Approved | no | ||
| Call Number | EcoFoG @ eric.marcon @ | Serial | 74 | ||
| Permanent link to this record | |||||
| Author | Fox Ramos, A.E.; Alcover, C.; Evanno, L.; Maciuk, A.; Litaudon, M.; Duplais, C.; Bernadat, G.; Gallard, J.-F.; Jullian, J.-C.; Mouray, E.; Grellier, P.; Loiseau, P.M.; Pomel, S.; Poupon, E.; Champy, P.; Beniddir, M.A. | ||||
| Title | Revisiting Previously Investigated Plants: A Molecular Networking-Based Study of Geissospermum laeve | Type | Journal Article | ||
| Year | 2017 | Publication | Journal of Natural Products | Abbreviated Journal | |
| Volume | 80 | Issue | 4 | Pages | 1007-1014 |
| Keywords | |||||
| Abstract |
Three new monoterpene indole alkaloids (1-3) have been isolated from the bark of Geissospermum laeve, together with the known alkaloids (−)-leuconolam (4), geissolosimine (5), and geissospermine (6). The structures of 1-3 were elucidated by analysis of their HRMS and NMR spectroscopic data. The absolute configuration of geissolaevine (1) was deduced from the comparison of experimental and theoretically calculated ECD spectra. The isolation workflow was guided by a molecular networking-based dereplication strategy using an in-house database of monoterpene indole alkaloids. In addition, five known compounds previously undescribed in the Geissospermum genus were dereplicated from the G. laeve alkaloid extract network and were assigned with various levels of identification confidence. The antiparasitic activities against Plasmodium falciparum and Leishmania donovani as well as the cytotoxic activity against the MRC-5 cell line were determined for compounds 1-5. © 2017 The American Chemical Society and American Society of Pharmacognosy. | ||||
| Address | Équipe Chimiothérapie Antiparasitaire BioCIS, Univ. Paris-Sud, CNRS, Université Paris-Saclay, 5 Rue J.-B. Clément, Châtenay-Malabry, France | ||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Medium | |||
| Area | Expedition | Conference | |||
| Notes | Export Date: 18 May 2017 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 752 | ||
| Permanent link to this record | |||||
| Author | Ramalho, M.O.; Duplais, C.; Orivel, J.; Dejean, A.; Gibson, J.C.; Suarez, A.V.; Moreau, C.S. | ||||
| Title | Development but not diet alters microbial communities in the Neotropical arboreal trap jaw ant Daceton armigerum: an exploratory study | Type | Journal Article | ||
| Year | 2020 | Publication | Scientific Reports | Abbreviated Journal | |
| Volume | 10 | Issue | 1 | Pages | 7350 |
| Keywords | |||||
| Abstract |
To better understand the evolutionary significance of symbiotic interactions in nature, microbiome studies can help to identify the ecological factors that may shape host-associated microbial communities. In this study we explored both 16S and 18S rRNA microbial communities of D. armigerum from both wild caught individuals collected in the Amazon and individuals kept in the laboratory and fed on controlled diets. We also investigated the role of colony, sample type, development and caste on structuring microbial communities. Our bacterial results (16S rRNA) reveal that (1) there are colony level differences between bacterial communities; (2) castes do not structure communities; (3) immature stages (brood) have different bacterial communities than adults; and 4) individuals kept in the laboratory with a restricted diet showed no differences in their bacterial communities from their wild caught nest mates, which could indicate the presence of a stable and persistent resident bacterial community in this host species. The same categories were also tested for microbial eukaryote communities (18S rRNA), and (5) developmental stage has an influence on the diversity recovered; (6) the diversity of taxa recovered has shown this can be an important tool to understand additional aspects of host biology and species interactions. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2045-2322 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | EcoFoG @ webmaster @ Ramalho2020 | Serial | 929 | ||
| Permanent link to this record | |||||
| Author | De Deurwaerder, H.; Hervé-Fernández, P.; Stahl, C.; Burban, B.; Petronelli, P.; Hoffman, B.; Bonal, D.; Boeckx, P.; Verbeeck, H. | ||||
| Title | Liana and tree below-ground water competition – evidence for water resource partitioning during the dry season | Type | Journal Article | ||
| Year | 2018 | Publication | Tree Physiology | Abbreviated Journal | |
| Volume | 38 | Issue | 7 | Pages | 1071-1083 |
| Keywords | |||||
| Abstract |
To date, reasons for the increase in liana abundance and biomass in the Neotropics are still unclear. One proposed hypothesis suggests that lianas, in comparison with trees, are more adaptable to drought conditions. Moreover, previous studies have assumed that lianas have a deeper root system, which provides access to deeper soil layers, thereby making them less susceptible to drought stress. The dual stable water isotope approach (δ18O and δ2H) enables below-ground vegetation competition for water to be studied. Based on the occurrence of a natural gradient in soil water isotopic signatures, with enriched signatures in shallow soil relative to deep soil, the origin of vegetation water sources can be derived. Our study was performed on canopy trees and lianas reaching canopy level in tropical forests of French Guiana. Our results show liana xylem water isotopic signatures to be enriched in heavy isotopes in comparison with those from trees, indicating differences in water source depths and a more superficial root activity for lianas during the dry season. This enables them to efficiently capture dry season precipitation. Our study does not support the liana deep root water extraction hypothesis. Additionally, we provide new insights into water competition between tropical canopy lianas and trees. Results suggest that this competition is mitigated during the dry season due to water resource partitioning. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0829-318x | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | 10.1093/treephys/tpy002 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 848 | ||
| Permanent link to this record | |||||
| Author | Odonne, G.; van den Bel, M.; Burst, M.; Brunaux, O.; Bruno, M.; Dambrine, E.; Davy, D.; Desprez, M.; Engel, J.; Ferry, B.; Freycon, V.; Grenand, P.; Jérémie, S.; Mestre, M.; Molino, J.-F.; Petronelli, P.; Sabatier, D.; Hérault, B. | ||||
| Title | Long-term influence of early human occupations on current forests of the Guiana Shield | Type | Journal Article | ||
| Year | 2019 | Publication | Ecology | Abbreviated Journal | Ecology |
| Volume | 100 | Issue | 10 | Pages | e02806 |
| Keywords | Amazonian forest; archaeology; ethnobotany; Guiana Shield; historical ecology; pre-Columbian settlements; ring-ditched hills; alluvial plain; anthropogenic effect; archaeology; basal area; database; ethnobotany; forest ecosystem; historical ecology; occupation; paleoecology; species diversity; Amazonia; French Guiana; Guyana Shield; Annonaceae; Arecaceae; Burseraceae; Lauraceae; Lecythidaceae; Brazil; forest; French Guiana; human; occupation; tree; Brazil; Forests; French Guiana; Humans; Occupations; Trees | ||||
| Abstract |
To decipher the long-term influences of pre-Columbian land occupations on contemporary forest structure, diversity, and functioning in Amazonia, most of the previous research focused on the alluvial plains of the major rivers of the Amazon basin. Terra firme, that is, nonflooded forests, particularly from the Guiana Shield, are yet to be explored. In this study, we aim to give new insights into the subtle traces of pre-Columbian influences on present-day forests given the archaeological context of terra firme forests of the Guiana Shield. Following archaeological prospects on 13 sites in French Guiana, we carried out forest inventories inside and outside archaeological sites and assessed the potential pre-Columbian use of the sampled tree species using an original ethnobotanical database of the Guiana Shield region. Aboveground biomass (320 and 380 T/ha, respectively), basal area (25–30 and 30–35 m2/ha, respectively), and tree density (550 and 700 stem/ha, respectively) were all significantly lower on anthropized plots (As) than on nonanthropized plots (NAs). Ancient human presence shaped the species composition of the sampled forests with Arecaceae, Burseraceae, and Lauraceae significantly more frequent in As and Annonaceae and Lecythidaceae more frequent in NAs. Although alpha diversity was not different between As and NAs, the presence of pre-Columbian sites enhances significantly the forest beta diversity at the landscape level. Finally, trees with edible fruits are positively associated with pre-Columbian sites, whereas trees used for construction or for their bark are negatively associated with pre-Columbian sites. Half a millennium after their abandonment, former occupied places from the inner Guiana Shield still bear noticeable differences with nonanthropized places. Considering the lack of data concerning archaeology of terra firme Amazonian forests, our results suggest that pre-Columbian influences on the structure (lower current biomass), diversity (higher beta diversity), and composition (linked to the past human tree uses) of current Amazonian forests might be more important than previously thought. © 2019 by the Ecological Society of America | ||||
| Address | Institut National Polytechnique Félix Houphouet-Boigny (INP-HB), Yamoussoukro, Ivory Coast, Cote d'Ivoire | ||||
| Corporate Author | Thesis | ||||
| Publisher | Ecological Society of America | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 00129658 (Issn) | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | EcoFoG @ webmaster @ | Serial | 919 | ||
| Permanent link to this record | |||||
| Author | Martin, J.M.; Roux, O.; Groc, S.; Dejean, A. | ||||
| Title | A type of unicoloniality within the native range of the fire ant Solenopsis saevissima | Type | Journal Article | ||
| Year | 2011 | Publication | Comptes Rendus Biologies | Abbreviated Journal | C. R. Biol. |
| Volume | 334 | Issue | 4 | Pages | 307-310 |
| Keywords | Ants; Solenopsis saevissima; Native range; Unicoloniality | ||||
| Abstract |
To determine if a type of unicoloniality exists in the fire ant Solenopsis saevissima in its native range, we conducted intraspecific aggressiveness tests in French Guiana between workers originating from 15 human-disturbed sites. We identified two “colonial groups” spread over 54 km and 12.5 km, respectively. Workers from the same group never attacked each other, but inter-group confrontations resulted in a high level of aggressiveness. These large “colonial groups” enhances the threat occasioned by S. saevissima for both agriculture and the environment. (C) 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved. | ||||
| Address | [Martin, Jean-Michel; Roux, Olivier; Groc, Sarah; Dejean, Alain] Ecol Forets de Guyane UMR CNRS 8172, F-97379 Kourou, France, Email: alain.dejean@wanadoo.fr | ||||
| Corporate Author | Thesis | ||||
| Publisher | Elsevier France-Editions Scientifiques Medicales Elsevier | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1631-0691 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | ISI:000290364200007 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 314 | ||
| Permanent link to this record | |||||
| Author | Christensen-Dalsgaard, K.K.; Ennos, A.R.; Fournier, M. | ||||
| Title | Are radial changes in vascular anatomy mechanically induced or an ageing process? Evidence from observations on buttressed tree root systems | Type | Journal Article | ||
| Year | 2008 | Publication | Trees-Structure and Function | Abbreviated Journal | Trees-Struct. Funct. |
| Volume | 22 | Issue | 4 | Pages | 543-550 |
| Keywords | wood; anatomy; mechanical loading; tree development; vessels | ||||
| Abstract |
To investigate the effect of changes in mechanical loading conditions on radial anatomical patterns, we here compare the trunk with the roots in two locations of three species of buttressed trees. The proximal part of the buttress roots is highly mechanically loaded throughout juvenile growth whereas the distal part of the buttresses is though to be mechanically unimportant at formation but become progressively more mechanically loaded during growth. We measured the frequency and diameter of the vessels and the vessel area fraction, and from this calculated the specific conductivity of tissue samples of the core-, intermediate- and outer wood. As in previous studies there was an increase in vessel size, vessel area fraction and specific conductivity from the pith to the bark in the trunk. In the proximal part of the buttress roots, however, there was no increase in vessel size and conductivity from core wood and out in agreement with the high mechanical loading found here throughout growth. There was instead a decrease in vessel size, vessel area fraction and specific conductivity from core- to outer wood in the distal part of the buttress roots in accordance with the increase in mechanical loading. Hence, it appears that the radial anatomical patterns are not a passive function of cambial ageing but may be modified in response to local mechanical loading. | ||||
| Address | [Christensen-Dalsgaard, Karen K.] Univ Alberta, Edmonton, AB T6G 2E3, Canada, Email: kkchrist@ualberta.ca | ||||
| Corporate Author | Thesis | ||||
| Publisher | SPRINGER | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0931-1890 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | ISI:000257385200014 | Approved | no | ||
| Call Number | EcoFoG @ eric.marcon @ | Serial | 136 | ||
| Permanent link to this record | |||||