Wernsdorfer, H., Caron, H., Gerber, S., Cornu, G., Rossi, V., Mortier, F., et al. (2011). Relationships between demography and gene flow and their importance for the conservation of tree populations in tropical forests under selective felling regimes. Conserv. Genet., 12(1), 15–29.
Abstract: Determining how tropical tree populations subject to selective felling (logging) pressure may be conserved is a crucial issue for forest management and studying this issue requires a comprehensive understanding of the relationships between population demography and gene flow. We used a simulation model, SELVA, to study (1) the relative impact of demographic factors (juvenile mortality, felling regime) and genetic factors (selfing, number and location of fathers, mating success) on long-term genetic diversity; and (2) the impact of different felling regimes on population size versus genetic diversity. Impact was measured by means of model sensitivity analyses. Juvenile mortality had the highest impact on the number of alleles and genotypes, and on the genetic distance between the original and final populations. Selfing had the greatest impact on observed heterozygote frequency and fixation index. Other factors and interactions had only minor effects. Overall, felling had a greater impact on population size than on genetic diversity. Interestingly, populations under relatively low felling pressure even had a somewhat lower fixation index than undisturbed populations (no felling). We conclude that demographic processes such as juvenile mortality should be modelled thoroughly to obtain reliable long-term predictions of genetic diversity. Mortality in selfed and outcrossed progenies should be modelled explicitly by taking inbreeding depression into account. The modelling of selfing based on population rate appeared to be oversimplifying and should account for inter-tree variation. Forest management should pay particular attention to the regeneration capacities of felled species.
Keywords: Genetic diversity; Gene flow; Population dynamics; Simulation model; Conservation; Forest management
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Meyer-Sand, B. R. V., Blanc-Jolivet, C., Mader, M., Paredes-Villanueva, K., Tysklind, N., Sebbenn, A. M., et al. (2018). Development of a set of SNP markers for population genetics studies of Ipe (Handroanthus sp.), a valuable tree genus from Latin America. Conserv. Gen. Res., 10(4), 779–781.
Abstract: A combination of restriction associated DNA sequencing (RADSeq) and low coverage MiSeq genome sequencing was used for the development of single nucleotide polymorphisms (SNP) and INDEL (insertion/deletions) genetic markers for Ipe (Handroanthus sp.). Of the 402 putative loci identified, 389 SNPs and INDELs (315 nuclear SPNs, six chloroplast INDELs, 15 chloroplast SNPs, 12 mitochondrial INDELs and 41 mitochondrial SNPs) were successfully genotyped at 93 individuals from Brazil, Bolivia and French Guiana using a MassARRAY® iPLEX™ platform. This set of markers will be invaluable for population genetics, phylogeography and DNA fingerprinting studies. © 2017, Springer Science+Business Media B.V., part of Springer Nature.
Keywords: Handroanthus sp; MassARRAY; Single nucleotide polymorphism
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Sebbenn, A. M., Blanc-Jolivet, C., Mader, M., Meyer-Sand, B. R. V., Paredes-Villanueva, K., Honorio Coronado, E. N., et al. (2019). Nuclear and plastidial SNP and INDEL markers for genetic tracking studies of Jacaranda copaia. Conserv. Gen. Res., 11(3), 341–343.
Abstract: Nuclear and plastidial single nucleotide polymorphism (SNP) and INDEL markers were developed using restriction associated DNA sequencing (RADSeq) and low coverage MiSeq genome sequencing for population genetics and timber tracking purposes in the Neotropical timber species Jacaranda copaia. We used 407 nuclear SNPs, 29 chloroplast, and 31 mitochondrial loci to genotype 92 individuals from Brazil, Bolivia, French Guiana, and Peru. Based on high amplification rates and genetic differentiation among populations, 113 nuclear SNPs, 11 chloroplast, and 4 mitochondrial loci were selected, and their use validated for genetic tracking of timber origin.
Keywords: DNA fingerprints; Geographical origin; Jacaranda copaia; MassARRAY; MiSeq; RADSeq; Tropical timber
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Chaves, C. L., Blanc-Jolivet, C., Sebbenn, A. M., Mader, M., Meyer-Sand, B. R. V., Paredes-Villanueva, K., et al. (2019). Nuclear and chloroplastic SNP markers for genetic studies of timber origin for Hymenaea trees. Conserv. Gen. Res., 11(3), 329–331.
Abstract: We developed nuclear and chloroplastic single nucleotide polymorphism (SNP) and INDEL (insertion/deletion) markers using restriction associated DNA sequencing (RADSeq) and low coverage MiSeq genome sequencing to set up a genetic tracking method of the geographical origin of Hymenaea sp. From two initial sets of 358 and 32 loci used to genotype at least 94 individuals, a final set of 75 nSNPs, 50 cpSNPs and 6 INDELs identifying significant population structure was developed. © 2018, Springer Nature B.V.
Keywords: DNA fingerprints; Geographical origin; MiSeq; RADSeq
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Tysklind, N., Blanc-Jolivet, C., Mader, M., Meyer-Sand, B. R. V., Paredes-Villanueva, K., Honorio Coronado, E. N., et al. (2019). Development of nuclear and plastid SNP and INDEL markers for population genetic studies and timber traceability of Carapa species. Conserv. Gen. Res., 11(3), 337–339.
Abstract: Low coverage MiSeq genome sequencing and restriction associated DNA sequencing (RADseq) were used to identify nuclear and plastid SNP and INDEL genetic markers in Carapa guianensis. 261 genetic markers including 237 nuclear SNPs, 22 plastid SNPs, and 2 plastid INDELs are described based on 96 genotyped individuals from French Guiana, Brazil, Peru, and Bolivia. The best 117 SNPs for identifying population structure and performing individual assignment are assembled into four multiplexes for MassARRAY genotyping.
Keywords: Carapa guianensis; Carapa surinamensis; DNA-fingerprints; Geographical origin; MassARRAY; MiSeq; RADSeq; Tropical timber
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Dejean, A., Petitclerc, F., Azémar, F., Pélozuelo, L., Talaga, S., Leponce, M., et al. (2018). Aquatic life in Neotropical rainforest canopies: Techniques using artificial phytotelmata to study the invertebrate communities inhabiting therein. Comptes Rendus – Biologies, 341(1), 20–27.
Abstract: In Neotropical rainforest canopies, phytotelmata (“plant-held waters”) shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns “artificial phytotelmata” whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations. We noted a difference between a riparian forest and a rainforest, whereas trees alongside a dirt road cutting through that rainforest corresponded to a subset of the latter. Because rarefied species richness was significantly lower when the phytotelmata were left for three weeks rather than for six or nine weeks, we recommend leaving the phytotelmata for twelve weeks to permit predators and phoretic species to fully establish themselves.
Keywords: Artificial phytotelmata; Epiphytes; French Guiana; Invertebrate diversity; Neotropical rainforests
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Le Guen, R., Corbara, B., Rossi, V., Azémar, F., & Dejean, A. (2015). Reciprocal protection from natural enemies in an ant-wasp association. Comptes Rendus – Biologies, 338(4), 255–259.
Abstract: Abstract We show that in French Guiana the large carton nests of Azteca chartifex, a territorially-dominant arboreal dolichoderine ant, are protected from bird attacks when this ant lives in association with Polybia rejecta, an epiponine social wasp. Because A. chartifex colonies are well known for their ability to divert army ant raids from the base of their host tree so that they protect their associated wasps from these raids, there is a reciprocal benefit for these two partners, permitting us to call this association a mutualism. We also show that P. rejecta nests are significantly less often attacked by birds than are those of two compared epiponine social wasp species. Furthermore, experimentation using a standardized protocol demonstrated the significantly higher aggressiveness of P. rejecta compared to seven other wasp species. We conclude that the efficacious protection of its associated ant nests is likely due to the extreme aggressiveness of P. rejecta. © 2015 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.
Keywords: Aggressiveness; Arboreal ants; Azteca; Polybia; Protection mutualism; Social wasps
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Dejean, A., Groc, S., Herault, B., Rodriguez-Pérez, H., Touchard, A., Céréghino, R., et al. (2015). Bat aggregation mediates the functional structure of ant assemblages. Comptes Rendus – Biologies, 338(10), 688–695.
Abstract: In the Guianese rainforest, we examined the impact of the presence of guano in and around a bat roosting site (a cave). We used ant communities as an indicator to evaluate this impact because they occupy a central place in the functioning of tropical rainforest ecosystems and they play different roles in the food web as they can be herbivores, generalists, scavengers or predators. The ant species richness around the cave did not differ from a control sample situated 500m away. Yet, the comparison of functional groups resulted in significantly greater numbers of detritivorous fungus-growing and predatory ant colonies around the cave compared to the control, the contrary being true for nectar and honeydew feeders. The role of bats, through their guano, was shown using stable isotope analyses as we noted significantly greater δ15N values for the ant species captured in and around the cave compared to controls. © 2015 Académie des sciences.
Keywords: Ant functional groups; Bat roosts; Biogeochemical hotspots; Bioindicators; Stable isotopes
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Talaga, S., Dezerald, O., Carteron, A., Petitclerc, F., Leroy, C., Céréghino, R., et al. (2015). Tank bromeliads as natural microcosms: A facultative association with ants influences the aquatic invertebrate community structure. Comptes Rendus – Biologies, 338(10), 696–700.
Abstract: Many tank bromeliads have facultative relationships with ants as is the case in French Guiana between Aechmea aquilega (Salib.) Griseb. and the trap-jaw ant, Odontomachus haematodus Linnaeus. Using a redundancy analysis, we determined that the presence of O. haematodus colonies is accompanied by a greater quantity of fine particulate organic matter in the water likely due to their wastes. This increase in nutrient availability is significantly correlated with an increase in the abundance of some detritivorous taxa, suggesting a positive bottom-up influence on the aquatic macroinvertebrate communities living in the A. aquilega wells. On the other hand, the abundance of top predators is negatively affected by a lower number of available wells due to ant constructions for nesting, releasing a top-down pressure that could also favor lower trophic levels. © 2015 Académie des sciences.
Keywords: Aechmea; Ant-bromeliad associations; Aquatic communities; Odontomachus; Phytotelm
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Alméras, T., Gronvold, A., van der Lee, A., Clair, B., & Montero, C. (2017). Contribution of cellulose to the moisture-dependent elastic behaviour of wood. Composites Science and Technology, 138, 151–160.
Abstract: Wood has a hierarchical structure involving several levels of organisation. The stiffness of wood relies on its capacity to transfer mechanical stress to its stiffest element at the lowest scale, namely crystalline cellulose. This study aims at quantifying to what extend crystalline cellulose contributes to wood stiffness depending on its moisture content. The crystal strains of cellulose were measured using X-ray diffraction on wet and dry specimens of spruce, based on a previously published methodology. The comparison between crystal strain and macroscopic strain shows that, during elastic loading, cellulose strain is lower than macroscopic strain. The means ratio of crystal/macroscopic strain amounts 0.85 for dry specimens and 0.64 for wet specimens. This strain ratio cannot be explained just by the projection effect due to the difference in orientation between cellulose microfibrils and cell wall, but results from deformation mechanisms in series with cellulose. Analysis shows that this series contribution represents a non-negligible contribution to wood compliance and is strongly moisture-dependent. This contribution amounts 9% for dry specimens and 33% for wet specimens, corresponding to a 4-fold increase in compliance for the series contribution. The origin of these strains is ascribed to mechanisms involving bending or shear strain at different scales, due to the fact that reinforcing element are neither perfectly straight nor infinitely long. © 2016
Keywords: Cellulose; Crystal strain; Micromechanics; Wood; X-ray diffraction
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