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| Author | Clair, B.; Alteyrac, J.; Gronvold, A.; Espejo, J.; Chanson, B.; Alméras, T. | ||||
| Title | Patterns of longitudinal and tangential maturation stresses in Eucalyptus nitens plantation trees | Type | Journal Article | ||
| Year | 2013 | Publication  |
Annals of Forest Science | Abbreviated Journal | Ann. Forest Sci. |
| Volume | 70 | Issue | 8 | Pages | 801-811 |
| Keywords | Eucalyptus nitens; G-layer; Longitudinal maturation stress; Maturation strain; Tangential maturation stress; Tension wood | ||||
| Abstract | Context: Tree orientation is controlled by asymmetric mechanical stresses set during wood maturation. The magnitude of maturation stress differs between longitudinal and tangential directions, and between normal and tension woods. Aims: We aimed at evaluating patterns of maturation stress on eucalypt plantation trees and their relation with growth, with a focus on tangential stress evaluation. Methods: Released maturation strains along longitudinal and tangential directions were measured around the circumference of 29 Eucalyptus nitens trees, including both straight and leaning trees. Results: Most trees produced asymmetric patterns of longitudinal maturation strain, but more than half of the maturation strain variability occurred between trees. Many trees produced high longitudinal tensile stress all around their circumference. High longitudinal tensile stress was not systematically associated with the presence of gelatinous layer. The average magnitude of released longitudinal maturation strain was found negatively correlated to the growth rate. A methodology is proposed to ensure reliable evaluation of released maturation strain in both longitudinal and tangential directions. Tangential strain evaluated with this method was lower than previously reported. Conclusion: The stress was always tensile along the longitudinal direction and compressive along the tangential direction, and their respective magnitude was positively correlated. This correlation does not result from a Poisson effect but may be related to the mechanism of maturation stress generation. © 2013 # The Author(s) 2013. This article is published with open access at Springerlink.com. | ||||
| Address | Facultad de Ciencias Forestales, Universidad de Concepcion, Ciudad Universitaria, Concepcion, Chile | ||||
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| ISSN | 12864560 (Issn) | ISBN | Medium | ||
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| Notes | Export Date: 16 December 2013; Source: Scopus; Coden: Afosf; doi: 10.1007/s13595-013-0318-4; Language of Original Document: English; Correspondence Address: Clair, B.; CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 701, 97387 Kourou, French Guiana; email: bruno.clair@univ-montp2.fr; Funding Details: ANR-12-BS09-0004, French National Research Agency; References: Alméras, T., Fournier, M., Biomechanical design and long-term stability of trees: Morphological and wood traits involved in the balance between weight increase and the gravitropic reaction (2009) J Theor Biol, 256, pp. 370-381. , 19013473 10.1016/j.jtbi.2008.10.011; Alméras, T., Thibaut, A., Gril, J., Effect of circumferential heterogeneity of wood maturation strain, modulus of elasticity and radial growth on the regulation of stem orientation in trees (2005) Trees, 19, pp. 457-467. , 10.1007/s00468-005-0407-6; Archer, R.R., (1986) Growth Stresses and Strains in Trees, , Springer Verlag Berlin/Heidelberg/New York; Archer, R.R., On the origin of growth stresses in trees. Part 1: Micro mechanics of the developing cambial cell wall. Wood Sci (1987) Technol., 21, pp. 139-154; Baillères, H., Chanson, B., Fournier, M., Tollier, M.T., Monties, B., Structure, composition chimique et retraits de maturation du bois chez les clones d' Eucalyptus (1995) Ann Sci for, 52, pp. 157-172. , 10.1051/forest:19950206; Bergman, R., Cai, Z., Carll, C.G., Clausen, C.A., Ma, D., Falk, R.H., Frihart, C.R., Star, (2010) Wood Handbook: Wood As An Engineering Material, , U.S. Department of Agriculture, Forest Service, Forest Products Laboratory., Washington D.C. (USA)/Madison, WI, (USA); Biechele, T., Nutto, L., Becker, G., Growth strain in Eucalyptus nitens at different stages of development (2009) Silva Fennica, 43, pp. 669-679; Bonser, R.H.C., Ennos, A.R., Measurement of prestrain in trees:implications for the determination of safety factors (1998) Funct Ecol, 12, pp. 971-974. , 10.1046/j.1365-2435.1998.00279.x; Boyd, J.D., Tree growth stresses – Part I: Growth stress evaluation (1950) Austr. J. Sci. Res. Series B, Biological Sciences, 3, pp. 270-293; Boyd, J.D., Tree growth stresses – Part II: The development of shakes and other visual failure in timber (1950) Aust. J. App. Sci., 1, pp. 296-312; Clair, B., Alméras, T., Sugiyama, J., Compression stress in opposite wood of angiosperms: Observations in chestnut, mani and poplar (2006) Ann for Sci, 63, pp. 507-510. , 10.1051/forest:2006032; Clair, B., Ruelle, J., Beauchêne, J., Prevost, M.F., Fournier, M., Tension wood and opposite wood in 21 tropical rain forest species. 1. Occurence and efficiency of G-layer (2006) IAWA J, 27, pp. 329-338; Clair, B., Ruelle, J., Thibaut, B., Relationship between growth stress, mechano-physical properties and proportion of fibre with gelatinous layer in Chestnut (Castanea sativa Mill.) (2003) Holzforschung, 57, pp. 189-195. , 1:CAS:528:DC%2BD3sXjs1ensr8%3D; Coutand, C., Fournier, M., Moulia, B., The gravitropic response of poplar trunks: Key roles of prestressed wood regulation and the relative kinetics of cambial growth versus wood maturation (2007) Plant Physiol, 144, pp. 1166-1180. , 17468227 10.1104/pp.106.088153 1:CAS:528:DC%2BD2sXmvValtbg%3D; Fang, C.-H., Clair, B., Gril, J., Liu, S.-Q., Growth stresses are highly controlled by the amount of G-layer in poplar tension wood (2008) IAWA J, 29, pp. 237-246. , 10.1163/22941932-90000183; Ferrand, J.C., Study of growth stresses. 1. Measurement method on increment cores (1982) Ann Sci for, 39, pp. 109-142. , 10.1051/forest:19820201 (in French with English summary); Ferrand, J.C., Study of growth stresses. 2. Variations in the forest of growth stresses of beech (Fagus sylvatica) (1982) Ann Sci for, 39, pp. 187-218. , 10.1051/forest:19820301 (in French with English summary); Ferrand, J.C., Study of growth stresses. 3. Eucalyptus dedegatensis and Eucalyptus nitens – Influence of sylviculture and site index (1982) Ann Sci for, 39, pp. 355-378. , 10.1051/forest:19820402 (in French with English summary); Fournier, M., Chanson, B., Thibaut, B., Guitard, D., Measurement of residual growth strains at the stem surface. Observations of different species (1994) Ann. For. Sci., 51, pp. 249-266. , 10.1051/forest:19940305 (in French with English summary); Gerard, J., Bailleres, H., Fournier, M., Thibaut, B., Wood quality in plantation Eucalyptus – A study of variation in three reference properties (1995) Bois For. Trop, 245, pp. 101-110. , (in French with English summary); Giordano, G., Curro, P., Ghisi, G., Contribution of internal stresses in wood of Eucalyptus (1969) Wood Sci Technol, 3, pp. 1-13. , 10.1007/BF00349980; Jacobs, M.R., The fibre tension of woody stems, with special reference to the genus Eucalyptus (1938) Bull. Com. For. Bur, 22, p. 37; Jacobs, M.R., (1945) The Growth Stresses of Woody Stems, , Commonwealth Forestry Bureau Canberra, Australia; Jullien, D., Laghdir, A., Gril, J., Modelling log-end cracks due to growth stresses: Calculation of the elastic energy release rate (2003) Holzforschung, 57, pp. 407-414. , 10.1515/HF.2003.060 1:CAS:528:DC%2BD3sXntFeksrk%3D; Jullien, D., Gril, J., Growth strain assessment at the periphery of small-diameter trees using the two-grooves method: Influence of operating parameters estimated by numerical simulations (2008) Wood Sci. Technol., 42, pp. 551-565. , 10.1007/s00226-008-0202-9 1:CAS:528:DC%2BD1cXhtVOiu7jL; Jullien, D., Widmann, R., Loup, C., Thibaut, B., Relationship between tree morphology and growth stress in mature European beech stands (2013) Ann for Sci, 68, pp. 681-688; Kubler, H., Studies on growth stresses in trees – Part I: The origin of growth stresses and the stresses in transverse direction (1959) Holz Als Roh- Und Werkstoff, 17, pp. 1-9. , 10.1007/BF02608827; Kubler, H., Growth stresses in trees and related wood properties (1987) For. Abst., 48, pp. 131-189; Moulia, B., Coutand, C., Lenne, C., Posture control and skeletal mechanical acclimation in terrestrial plants: Implications for mechanical modelling of plant architecture (2006) Am J Bot, 93, pp. 1477-1489. , 21642095 10.3732/ajb.93.10.1477; Nicholson, J., A rapid method for estimating the longitudinal growth stress in logs (1971) Wood Sci. Technol., 5, pp. 40-48. , 10.1007/BF00363119; Nicholson, J.E., Growth stress differences in Eucalypts (1973) For Sci, 19, pp. 169-174; Okuyama, T., Sasaki, Y., Kikata, Y., Kawai, N., The seasonal change in growth stress in the tree trunk (1981) Mokuzai Gakkaishi, 27, pp. 350-355; Okuyama, T., Yamamoto, H., Yoshida, M., Hattori, Y., Archer, R.R., Growth stresses in tension wood: Role of microfibrils and lignification (1994) Ann for Sci, 51, pp. 291-300. , 10.1051/forest:19940308; Onaka, F., Studies on compression and tension wood (traduction) (1949) Wood Res, 1, pp. 1-88. , traduction n.p; Sasaki, Y., Okuyama, T., Kikata, Y., The evolution process of the growth stress in the tree. The surface stresses on the tree (1978) Mokuzai Gakkaishi, 24, pp. 140-157. , (in Japenese with English summary); Scurfield, G., Histochemistry of reaction wood cell walls in two species of Eucalyptus and in Tristania Conferta R (1972) Br. Aust. J. Bot., 20, pp. 9-26. , 10.1071/BT9720009 1:CAS:528:DyaE38XltFWksLk%3D; Yamamoto, H., Generation mechanism of growth stresses in wood cell walls: Roles of lignin deposition and cellulose microfibril during cell wall maturation (1998) Wood Sci. Technol., 32, pp. 171-182. , 1:CAS:528:DyaK1cXktlKhsb0%3D; Yamamoto, H., Abe, K., Arakawa, Y., Okuyama, T., Gril, J., Role of the gelatinous layer on the origin of the physical properties of the tension wood of Acer sieboldianum (2005) Wood Sci. Technol., 51, pp. 222-233. , 10.1007/s10086-004-0639-x 1:CAS:528:DC%2BD2MXpslOqurs%3D; Yamamoto, H., Yoshida, M., Okuyama, T., Growth stress controls negative gravitropism in woody plant stems (2002) Planta, 216, pp. 280-292. , 12447542 10.1007/s00425-002-0846-x 1:CAS:528:DC%2BD3sXktFOiug%3D%3D; Yang, J.L., Waugh, G., Growth stress, its measurement and effects (2001) Autr. For., 64, pp. 127-135; Yoshida, M., Ohta, H., Yamamoto, H., Okuyama, T., Tensile growth stress and lignin distribution in the cell walls of yellow poplar, Liriodendron tulipifera Linn (2002) Trees, 16, pp. 457-464. , 10.1007/s00468-002-0186-2 1:CAS:528:DC%2BD38XosFWltro%3D; Yoshida, M., Okuyama, T., Techniques for measuring growth stress (2002) Holzforschung, 56, pp. 461-467. , 10.1515/HF.2002.071 1:CAS:528:DC%2BD38XovVaru7c%3D | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 519 | ||
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| Author | Lefèvre, F.; Boivin, T.; Bontemps, A.; Courbet, F.; Davi, H.; Durand-Gillmann, M.; Fady, B.; Gauzere, J.; Gidoin, C.; Karam, M.-J.; Pichot, C.; Oddou-Muratorio, S.; Pichot, C. | ||||
| Title | Considering evolutionary processes in adaptive forestry | Type | Journal Article | ||
| Year | 2013 | Publication |
Annals of Forest Science | Abbreviated Journal | Ann For Sci |
| Volume | 71 | Issue | 7 | Pages | 723-739 |
| Keywords | Adaptation; Climate change; Evolution-oriented forest management; Genetic resources; Silviculture | ||||
| Abstract | Context: Managing forests under climate change requires adaptation. The adaptive capacity of forest tree populations is huge but not limitless. Integrating evolutionary considerations into adaptive forestry practice will enhance the capacity of managed forests to respond to climate-driven changes.
Aims: Focusing on natural regeneration systems, we propose a general framework that can be used in various and complex local situations by forest managers, in combination with their own expertise, to integrate evolutionary considerations into decision making for the emergence of an evolution-oriented forestry. Methods: We develop a simple process-based analytical grid, using few processes and parameters, to analyse the impact of forestry practice on the evolution and evolvability of tree populations. Results: We review qualitative and, whenever possible, quantitative expectations on the intensity of evolutionary drivers in forest trees. Then, we review the effects of actual and potential forestry practice on the evolutionary processes. We illustrate the complexity of interactions in two study cases: the evolutionary consequences for forest trees of biotic interactions and of highly heterogeneous environment. Conclusion: Evolution-oriented forestry may contribute adapting forests to climate change. It requires combining short-term and long-term objectives. We propose future lines of research and experimentation. |
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| Address | INRA, UR629 Ecologie des Forêts Méditerranéennes, URFM, Domaine Saint Paul, Site AgroparcAvignon Cedex 9, France | ||||
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| Notes | Cited By :2; Export Date: 13 January 2015 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 580 | ||
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| Author | Leclerc, T.; Vimal, R.; Troispoux, V.; Périgon, S.; Scotti, I. | ||||
| Title | Life after disturbance (I): changes in the spatial genetic structure of Jacaranda copaia (Aubl.) D. Don (Bignonianceae) after logging in an intensively studied plot in French Guiana | Type | Journal Article | ||
| Year | 2015 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 72 | Issue | 5 | Pages | 509-516 |
| Keywords | Amazon; Bayesian clustering; Demogenetics; Guiana shield; Parentage analysis; Regeneration; Spatial genetic structure; Tropical rainforest | ||||
| Abstract | Key message: Forest disturbance affects the within-population distribution of genetic diversity, but not its overall levels, in a tropical pioneer tree species. In particular, clumps of related saplings with impoverished diversity are found in canopy gaps but not under forest cover. Context: Forest disturbances can have long-term consequences on the genetic structure of tree populations, because they can alter the demographic properties of the regeneration process and favour some subpopulations/genotypes, both by stochastic processes and by selection. Intermediate disturbances tend to favour species diversity, at least in highly diverse communities, but their effect on intra-specific diversity is unknown. Aims: In this study, we have looked at the genetic consequences of forest disturbance in a stand of the long-lived Neotropical pioneer species, Jacaranda copaia. Methods: The study site was experimentally logged in 1984, and the canopy gaps generated by the logging were mapped. Seedlings of J. copaia colonised the gaps, as expected, at a higher density than in the surrounding forest. In 2006, we exhaustively sampled all saplings and adult trees available in a 25-ha area. The samples were genotyped at nine microsatellite loci, and the distribution of genetic diversity was inspected by analyses of spatial autocorrelation, automated Bayesian assignment and comparisons of diversity between cohorts by bootstrap (RaBoT). Results: Spatial autocorrelation was found to extend farther in post-disturbance saplings than in the undisturbed population (100 m and beyond versus less than 50 m), and divergent clumps (F<inf>ST</inf> = 0.05) of related genotypes were found; genetic diversity was found to be impoverished in each clump relative to the global population at about half of the loci. Conclusion: Overall, our results suggest that forest disturbance has changed the patterns of distribution of genetic diversity, with potential consequences on long-term population viability. © 2015, INRA and Springer-Verlag France. | ||||
| Address | INRA, URFM « Ecologie des Forêts Méditerranéennes », Domaine de Saint-Paul, Avignon, France | ||||
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| Notes | Export Date: 16 July 2015 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 611 | ||
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| Author | Scotti, I.; Montaigne, W.; Cseke, K.; Traissac, S. | ||||
| Title | Life after disturbance (II): the intermediate disturbance hypothesis explains genetic variation in forest gaps dominated by Virola michelii Heckel (Myristicaceae) | Type | Journal Article | ||
| Year | 2015 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 72 | Issue | 8 | Pages | 1035-1042 |
| Keywords | Amazon; Bayesian clustering; Demogenetics; Guiana shield; Parentage analysis; Regeneration; Spatial genetic structure; Tropical rainforest | ||||
| Abstract | Key message: Genetic diversity appears to be unaffected by disturbance in a stand of the light-demanding Neotropical treeV. michelii. Although spatial genetic structure is modified in post-disturbance cohorts, mixing of seeds from different mother trees in canopy gaps appears to efficiently maintain genetic admixture. Context: The interplay between genetic and demographic processes has major consequences on population viability. Population size affects demographic trends, while genetic diversity insures viability by reducing risks of inbreeding depression and by maintaining adaptive potential. Yet, the consequences of increases in census size (as opposed to effective size) on genetic diversity of forest populations are poorly known. Aims: We have studied the structure of genetic diversity in populations of saplings of the light-responsive tree, Virola michelii (Myristicaceae, the nutmeg family), in two plots having undergone different levels of canopy-gap opening disturbance. This allowed us to test the “intermediate disturbance” hypothesis, which generally applies to species diversity, at the intra-specific scale. Methods: Levels and distribution of genetic diversity were compared between plots and between life stages. Sapling parentage was analysed to infer each adult tree’s contribution to regeneration. Results: Genetic diversity was higher, and spatial genetic structure was stronger in the post-disturbance than in the control seedling population. Parentage analysis suggested that a limited number of parents contributed to most of the regeneration, but that efficient mixing of their progeny may have enhanced the diversity of saplings occupying canopy gaps. Conclusion: A mixture of demo-genetic processes may contribute to maintain genetic diversity in spite of, or possibly due to, ecosystem disturbance in V. michelii. © 2015, INRA and Springer-Verlag France. | ||||
| Address | Solicaz, Guyane Technopôle, 16 bis Rue du 14 Juillet, Cayenne, French Guiana | ||||
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| Notes | Export Date: 14 December 2015 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 642 | ||
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| Author | Scotti, I.; González-Martínez, S.C.; Budde, K.B.; Lalague, H. | ||||
| Title | Fifty years of genetic studies: what to make of the large amounts of variation found within populations? | Type | Journal Article | ||
| Year | 2016 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 73 | Issue | 1 | Pages | 69-75 |
| Keywords | Intra-specific variation; Microgeography; Natural selection; Population genomics | ||||
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| Address | INRA, UMR745 Ecologie des Forêts de Guyane, Campus Agronomique, Kourou, French Guiana | ||||
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| Notes | Export Date: 7 March 2016 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 667 | ||
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| Author | Thibaut, B.; Denaud, L.; Collet, R.; Marchal, R.; Beauchene, J.; Mothe, F.; Méausoone, P.-J.; Martin, P.; Larricq, P.; Eyma, F. | ||||
| Title | Wood machining with a focus on French research in the last 50 years | Type | Journal Article | ||
| Year | 2016 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 73 | Issue | 1 | Pages | 163-184 |
| Keywords | Primary conversion; Secondary processing; Surface quality; Tool wear | ||||
| Abstract | Key message: Wood machining is compulsory both for timber separation and the surfacing of wooden objects. The anisotropy, cellular nature and multi-scale level organisation of wood make its cutting complicated to study. During the last 50 years, most of the wood machining subjects were covered by French teams. Context: Woodcutting is a very old technology but scientific research is scarce on the subject. In the last 50 years, much work on basic mechanisms as well as on industrial processes has been done in France. Aims: The specific nature of wood introduces strong differences between wood and metal cutting processes. The paper focuses on French teams’ contributions. Results: The basic aspects of the tool–material interaction for different basic modes in woodcutting are highlighted. In primary conversion such as sawing, veneer cutting or green wood chipping, huge progress comes from automation and the possibility of linking the process to log and product quality through new sensors. In secondary processing, much has been done on the links between the cutting process, surface qualification and the properties of these surfaces for further processing, such as gluing or coating. Tool wear depends on the cutting process, timber quality and species. Trade-offs are required in tool technology and coating technologies may improve tool life. Conclusion: A large amount of knowledge and innovation has come from 50 years of worldwide research effort, with France being particularly active in this period. The transfer of skills from metals cutting industry was often a key, but much is needed to move closer to both metal cutting sector and woodcutting skills among craftsmen. © 2015, INRA and Springer-Verlag France. | ||||
| Address | ICA, Université Paul Sabatier Toulouse III, Toulouse, France | ||||
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| Notes | Export Date: 7 March 2016 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 668 | ||
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| Author | Bonal, D.; Burban, B.; Stahl, C.; Wagner, F.; Herault, B. | ||||
| Title | The response of tropical rainforests to drought—lessons from recent research and future prospects | Type | Journal Article | ||
| Year | 2016 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 73 | Issue | 1 | Pages | 27-44 |
| Keywords | Carbon; Climate; Drought; Global change; Growth; Mortality; Soil; Tropical; Water | ||||
| Abstract | Key message: We review the recent findings on the influence of drought on tree mortality, growth or ecosystem functioning in tropical rainforests. Drought plays a major role in shaping tropical rainforests and the response mechanisms are highly diverse and complex. The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical rainforests on the three continents. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance. Context: Tropical rainforest ecosystems are characterized by high annual rainfall. Nevertheless, rainfall regularly fluctuates during the year and seasonal soil droughts do occur. Over the past decades, a number of extreme droughts have hit tropical rainforests, not only in Amazonia but also in Asia and Africa. The influence of drought events on tree mortality and growth or on ecosystem functioning (carbon and water fluxes) in tropical rainforest ecosystems has been studied intensively, but the response mechanisms are complex. Aims: Herein, we review the recent findings related to the response of tropical forest ecosystems to seasonal and extreme droughts and the current knowledge about the future of these ecosystems. Results: This review emphasizes the progress made over recent years and the importance of the studies conducted under extreme drought conditions or in through-fall exclusion experiments in understanding the response of these ecosystems. It also points to the great diversity and complexity of the response of tropical rainforest ecosystems to drought. Conclusion: The numerous gaps identified here require the international scientific community to combine efforts in order to conduct comprehensive studies in tropical forest regions. These results are essential to simulate the future of these ecosystems under diverse climate scenarios and to predict the future of the global earth carbon balance. © 2015, INRA and Springer-Verlag France. | ||||
| Address | National Institute for Space Research (INPE), São José dos Campos, SP, Brazil | ||||
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| Notes | Export Date: 7 March 2016 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 669 | ||
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| Author | Anouhe, J.-B.S.; Niamké, F.B.; Faustin, M.; Virieux, D.; Pirat, J.-L.; Adima, A.A.; Kati-Coulibaly, S.; Amusant, N. | ||||
| Title | The role of extractives in the natural durability of the heartwood of Dicorynia guianensis Amsh: new insights in antioxydant and antifungal properties | Type | Journal Article | ||
| Year | 2018 | Publication |
Annals of Forest Science | Abbreviated Journal | Annals of Forest Science |
| Volume | 75 | Issue | 1 | Pages | |
| Keywords | Alkaloid; Antifungal; Antioxidant; Dicorynia guianensis; Heartwood; Natural durability; Phenols | ||||
| Abstract | Key message: The natural durability of Dicorynia guianensis Amsh’s Heartwood is conferred by the high content of antioxidant phenolic compounds, especially tannins and flavonoids combined with the presence of fungistatic alkaloids. The content of phenolic compounds increases according to the natural durability classes, from durable wood (class 2) to moderately durable wood (class 3) and correlated to the antioxidant capacity.
Context: The heartwood of Dicorynia guianensis Amsh is resistant to white rot fungi decay, but the mechanism of this natural durability is not fully elucidated. Aims: Biochemical studies were carried out in order to better understand the role of extractives in natural durability of D. guianensis. Methods: The powders from durable and moderately durable heartwood were extracted with methanol, ethanol, and hot water. The quantity of total phenols, tannins, and flavonoids as well as antioxidant activity, evaluated by 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) were determined using colorimetric methods. Antifungal activity was assessed by using two white rot fungi. The bioactive fractions and compounds were obtained using bio-guided fractionation, HPLC isolation, MS and RMN spectroscopic analyses. Results: Durable woods contain higher amounts of heartwood extract and antioxidant activity. Antioxidant activity was highly correlated with the content of phenolics. The purification of the most antioxidant fraction FII affords the characterization of (+)-catechin (−)-epicatechin, neoastilbin, astilbin, and isoastilbin. Alkaloid fraction FIII exhibits dose-dependent fungistatic activity against Pycnoporus sanguineus Linnaeus and Trametes versicolor Quelet. Conclusion: Phenolic antioxidants and fungistatic alkaloids positively impact the natural durability of D. guianensis. |
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| Address | AM2N, Institut Charles Gerhardt, UMR 5253, ENSCM 8 rue de l’Ecole Normale, Montpellier, France | ||||
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| Notes | Export Date: 19 February 2018 | Approved | no | ||
| Call Number | EcoFoG @ webmaster @ | Serial | 791 | ||
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| Author | Ghislain, B.; Alméras, T.; Prunier, J.; Clair, B. | ||||
| Title | Contributions of bark and tension wood and role of the G-layer lignification in the gravitropic movements of 21 tropical tree species | Type | Journal Article | ||
| Year | 2019 | Publication |
Annals of Forest Science | Abbreviated Journal | Ann. Forest Sci. |
| Volume | 76 | Issue | 4 | Pages | 107 |
| Keywords | Bark; Biomechanics; G-layer; Lignification; Tension wood; Tropical rainforest; Magnoliophyta | ||||
| Abstract | Key message: Gravitropic movements in angiosperm woody stems are achieved through the action of bark and/or wood motor, depending on the bark and wood fibre anatomy (with trellis structure or not; with G-layers or not). Bark motor is as efficient as wood motor to recover from tilting in young trees of 21 tropical species. Context: Angiosperm trees produce tension wood to control their orientation through changes in stem curvature. Tension wood is classified into 3 anatomical groups: with unlignified G-layer, with lignified G-layer and without G-layer. Aims: This study aimed at assessing whether this anatomical diversity reflects a diversity in efficiency of gravitropic movement. Methods: The study was conducted on tropical seedling from the three anatomical groups. Seedlings were staked and grown tilted. At the end of the experiment, changes in curvature when releasing the stem from the stake and when removing bark were measured. Three parameters were computed to compare the global efficiency of gravitropism (stem gravitropic efficiency) and the specific efficiency of motor mechanism based on wood (maturation strain of tension wood) and bark (standardized debarking curvature). Results: The maturation strain of tension wood was similar between species with unlignified and lignified G-layer. Species without G-layer exhibited low maturation strain and large debarking curvature, showing they rely on bark for gravitropism. Bark and wood achieved similar motor efficiency. Conclusion: Lignin does not affect the generation of tensile stress in the G-layer. Bark can be as efficient as wood as a motor of gravitropic movements. © 2019, The Author(s). | ||||
| Address | Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier, CNRS, Montpellier, 34095, France | ||||
| 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 | 12864560 (Issn) | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | EcoFoG @ webmaster @ | Serial | 900 | ||
| Permanent link to this record | |||||
| Author | Ziegler, C.; Coste, S.; Stahl, C.; Delzon, S.; Levionnois, S.; Cazal, J.; Cochard, H.; Esquivel-Muelbert, A.; Goret, J.-Y.; Heuret, P.; Jaouen, G.; Santiago, L.S.; Bonal, D. | ||||
| Title | Large hydraulic safety margins protect Neotropical canopy rainforest tree species against hydraulic failure during drought | Type | Journal Article | ||
| Year | 2019 | Publication |
Annals of Forest Science | Abbreviated Journal | Ann. Forest Sci. |
| Volume | 76 | Issue | 4 | Pages | 115 |
| Keywords | Amazon rainforest; Embolism resistance; Hydraulic safety margins; Turgor loss point; Water potential | ||||
| Abstract | Key message: Abundant Neotropical canopy-tree species are more resistant to drought-induced branch embolism than what is currently admitted. Large hydraulic safety margins protect them from hydraulic failure under actual drought conditions. Context: Xylem vulnerability to embolism, which is associated to survival under extreme drought conditions, is being increasingly studied in the tropics, but data on the risk of hydraulic failure for lowland Neotropical rainforest canopy-tree species, thought to be highly vulnerable, are lacking. Aims: The purpose of this study was to gain more knowledge on species drought-resistance characteristics in branches and leaves and the risk of hydraulic failure of abundant rainforest canopy-tree species during the dry season. Methods: We first assessed the range of branch xylem vulnerability to embolism using the flow-centrifuge technique on 1-m-long sun-exposed branches and evaluated hydraulic safety margins with leaf turgor loss point and midday water potential during normal- and severe-intensity dry seasons for a large set of Amazonian rainforest canopy-tree species. Results: Tree species exhibited a broad range of embolism resistance, with the pressure threshold inducing 50% loss of branch hydraulic conductivity varying from − 1.86 to − 7.63 MPa. Conversely, we found low variability in leaf turgor loss point and dry season midday leaf water potential, and mostly large, positive hydraulic safety margins. Conclusions: Rainforest canopy-tree species growing under elevated mean annual precipitation can have high resistance to embolism and are more resistant than what was previously thought. Thanks to early leaf turgor loss and high embolism resistance, most species have a low risk of hydraulic failure and are well able to withstand normal and even severe dry seasons. © 2019, The Author(s). | ||||
| Address | Smithsonian Tropical Research Institute, Balboa, Ancon, Panama | ||||
| 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 | 12864560 (Issn) | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes | Approved | no | |||
| Call Number | EcoFoG @ webmaster @ | Serial | 901 | ||
| Permanent link to this record | |||||