Éditeur(s) : HAL CCSD Walter de Gruyter
Résumé :  
A method for measuring shrinkage resulting from drying in the three anisotropic directions is developed and tested. Measurements are performed on sawn discs, a technique which simplifies preparation and enables large numbers of measurements. Shrinkage values can be represented as a map of the disc surface. The results indicate that comparisons between shrinkage distribution and tension wood distribution on the discs show a clear relationship and can be measured with relatively high accuracy in reference to the "shrinkage map". In the long term, this method could be useful in the timber industry as a means for choosing the direction in which logs are cut depending on their type of wood composition.
Holzforschung

hal-01032055
https://hal.archives-ouvertes.fr/hal-01032055
DOI : 10.1515/HF.2003.100

Éditeur(s) : HAL CCSD De Gruyter
Résumé : A method for measuring shrinkage resulting from drying in the three anisotropic directions is developed and tested. Measurements are performed on sawn discs, a technique which simplifies preparation and enables large numbers of measurements. Shrinkage values can be represented as a map of the disc surface; the results indicate that comparisons between shrinkage distribution and tension wood distribution on the discs show a clear relationship and can be measured with relatively high accuracy in reference to the "shrinkage map". In the long term, this method could be useful in the timber industry as a means for choosing the direction in which logs are cut depending on their type of wood composition.
ISSN: 0018-3830

hal-00004531
https://hal.archives-ouvertes.fr/hal-00004531
https://hal.archives-ouvertes.fr/hal-00004531/document
https://hal.archives-ouvertes.fr/hal-00004531/file/Holzforschung2003_Clair-Jaouen-Beauchene-Fournier_ccsd.pdf

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : The analysis of fine-scale spatial genetic structure (FSGS) within populations can provide insights into eco-evolutionary processes. Restricted dispersal and locally occurring genetic drift are the primary causes for FSGS at equilibrium, as described in the isolation by distance (IBD) model. Beyond IBD expectations, spatial, environmental or historical factors can affect FSGS. We examined FSGS in seven African and Neotropical populations of the late-successional rain forest tree Symphonia globulifera L. f. (Clusiaceae) to discriminate the influence of drift-dispersal vs. landscape/ecological features and historical processes on FSGS. We used spatial principal component analysis and Bayesian clustering to assess spatial genetic heterogeneity at SSRs and examined its association with plastid DNA and habitat features. African populations (from Cameroon and São Tomé) displayed a stronger FSGS than Neotropical populations at both marker types (mean Sp = 0.025 vs. Sp = 0.008 at SSRs) and had a stronger spatial genetic heterogeneity. All three African populations occurred in pronounced altitudinal gradients, possibly restricting animal-mediated seed dispersal. Cyto-nuclear disequilibria in Cameroonian populations also suggested a legacy of biogeographic history to explain these genetic patterns. Conversely, Neotropical populations exhibited a weaker FSGS, which may reflect more efficient wide-ranging seed dispersal by Neotropical bats and other dispersers. The population from French Guiana displayed an association of plastid haplotypes with two morphotypes characterized by differential habitat preferences. Our results highlight the importance of the microenvironment for eco-evolutionary processes within persistent tropical tree populations.
ISSN: 1932-6203

hal-01608324
https://hal.archives-ouvertes.fr/hal-01608324
DOI : 10.1371/journal.pone.0182515
PRODINRA : 403154
PUBMED : 28771629