Coste, Sabrina (2008) Diversity and plasticity of leaf traits in tropical rain forest : a cost/benefit analysis of carbon gain. PhD thesis Sciences forestières, UMR Ecologie des forêts de Guyane (Ecofog) ENGREF, AgroParistech 08AGPT0046 p.320.
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Abstract
The aim of this research were (i) identify the main trade-off and covariations of a group of leaf traits related to carbon assimilation, and (ii) assess the irradiance-elicited plasticity, and test whether this plasticity differs among species of tropical rain forest. Measurements were made with saplings from 13 species growing under three levels of irradiance, provided by shading nets, in an open green-house. A cost benefit analysis was undertaken to quantify carbon balance of leaves metamers. Construction costs of metamers (CCmetm), payback time of the investment of carbon into leaf and metamer structure (PBT), and leaf life span (LLS) were recorded on the saplings. A large inter-specific diversity was recorded for all the traits, the species are scattered along a principal component axis opposing on one hand LSS and leaf mass-to-area ratio (LMA), and on the other hand, photosynthetic capacity, photosynthetic nitrogen use efficiency (angnp1033PNUE), respiration (Rd) and leaf nitrogen content (N). These results are in agreement with the concept of “leaf economics spectrum” suggested by Wright et al. (2004). The relationship between LLS and PBT were very loose, which shows that all species fully cover the construction costs, even under very low irradiance. Species ranking was not modified by irradiance whatever the trait, and, except for specific construction costs, only very weak interactions were found between species and irradiance. The computation of a plasticity index allowed to demonstrate that despite some inter-specific diversity of the values taken by the index for some traits, there was no consistent difference among species, and none of them appeared consistently more plastic than the others. Even if the two pioneer species analysed here differed largely from the others, from the point of view of trait values, they displayed similar levels of plasticity.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| PhD Supervisor: | Dreyer, Erwin and Jean-Christophe, Roggy |
| Date: | 02 July 2008 |
| Board of examiners: | Bongers, Frans and Navas, Marie-Laure and Collet, Catherine and Dreyer, Erwin and Epron, Daniel and Heuret, Patrick and Fournier, Meriem |
| Ecole Doctorale: | ED 410 SCIENCES ET INGENIERIE DES RESSOURCES PROCEDES PRODUITS ENVIRONNEMENT |
| Discipline: | Sciences forestières |
| Collection (Fonds): | AgroParisTech ENGREF AgroParistech |
| Institution: | AgroParistech |
| Department: | UMR Ecologie des forêts de Guyane (Ecofog) ENGREF |
| Subjects: | 7. Life Sciences and Engineering |
| Uncontrolled Keywords: | Capacités photosynthétiques, Azote, Durée de vie des feuilles, Plasticité phénotypique, Éclairement relatif, Bilan de carbone, Temps de remboursement, Coûts de constructions |
| ID Code: | 4645 |
| Deposited By: | Sabrina Coste |
| Deposited On: | 12 May 2009 |
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