Table des matières
1. Introduction générale
1.1 Mise en contexte
1.2 Espacement, compétition et productivité
1.2.1 Acclimatation
1.2.2 Compétition et allocation de biomasse
1.2.3 Compétition, morphologie aérienne et racinaire
1.2.4 Compétition et physiologie
1.3 Déploiement mixte vs monoclonal
1.3.1 La complémentarité ou ‘évitement de l’exclusion compétitive’
1.3.2 La facilitation
1.3.3 L’effet de sélection
1.4 Modélisation de l’assimilation de carbone et de la productivité
1.5 Objectifs de la thèse
2. Chapitre II: THE EFFECTS OF SPACING ON GROWTH, MORPHOLOGY AND BIOMASS PRODUCTION AND ALLOCATION IN TWO HYBRID POPLAR CLONES GROWING IN THE BOREAL REGION OF CANADA
2.1 Abstract
2.2 Introduction
2.3 Materials and methods
2.3.1 Study area and experimental design
2.3.2 Growth
2.3.3 Crown traits
2.3.4 Branch characteristics
2.3. 5 Spatial distribution of leaf area
2.3.6 Biomass allocation and coarse root morphology
2.3.7 Statistical Analyses
2.4 Results
2.4.1 Growth
2.4.2 Biomass predictions
2.4.3 Biomass production and allocation
2.4.4 Crown structure and foliage distribution
2.4. 5 Branch characteristics
2.4.6 Root characteristics
2.5 Discussion
2.5.1 Spacing effects on stem size
2.5.2 Spacing effects on biomass production
2.5.3 Spacing effects on biomass allocation
2.5.4 Spacing effects on branch size and orientation
2.6 Conclusion
2.7 Acknowledgements
3.Chapitre III: CHANGES IN SPECIFIC LEAF AREA AND PHOTOSYNTHETIC NITROGEN-USE EFFICIENCY ASSOCIATED WITH PHYSIOLOGICAL ACCLIMATION OF TWO HYBRID POPLAR CLONES TO INTRA-CLONAL COMPETITION
3.1 Abstract
3.2 Introduction
3.3 Materials and methods
3.3.1 Study area
3.3.2 Experimental design
3.3.3 Sampling
3.3.4 Gas exchange measurements
3.3.5 SLA and leafnitrogen content
3.3.6 Light measurement
3.3.7 Statistical analyses
3 .4 Results
3.4.1 Variation in crown light environments
3.4.2 Light-saturated photosynthesis (Amax) and stomatal conductance (Gs)
3.4.3 Specifie leaf area (SLA)
3.4.4 Leafnitrogen content (Narea) and PNUE
3.4.5 Light response curves
3.4.1 Leaf trait relationships
3.5 Discussion
3.6 Conclusion
3.7 Acknowledgements
4.Chapitre IV: COMPARING GROWTH AND FINE ROOT DISTRIBUTION IN MONOCULTURES AND MIXED PLANTATIONS OF HYBRID POPLAR AND SPRUCE
4.1 Abstract
4.2 Introduction
4.3 Materials and Methods
4.3.1 Study area
4.3.2 Growth
4.3.3 Foliage nitrogen
4.3.4 Fine roots distribution
4.3.5 Statistical analyses
4.4 Results
4.4.1 Growth
4.4.2 Leaf nitrogen
4.4.3 Fine roots distribution
4.5 Discussion
4.5.1 Growth and stand productivity: mixtures vs monocultures
4.5.2 Height growth and canopy stratification
4.5.3 Fine roots distribution
4.5.4 Leafnitrogen
4.6 Conclusion
4. 7 Acknowledgements
5. Chapitre V: A PROCESS-BASED MODEL OF GROSS PHOTOSYNTHESIS FOR TWO HYBRID POPLAR CLONES IN BOREAL CONDITIONS
5.1 Abstract
5.2 Introduction
5.3 Material and methods
5.3.1 Model description
5.3.2 Study area and physiological measurements
5.3.3 Statistical analysis
5.4 Results
5.4.1 Photosynthesis parameters (V cmax, Imax and Rd) in relation to Narea
5.4.2 Relationships between M. and proteins content, N area and Cbo
5.4.3 Canopy light environment
5.4.4 Model validation
5.4.5 Simulation of daily canopy photosynthetic rate
5.5 Discussion
5.5.1 Photosynthesis parameters measurement
5.5.2 Photosynthesis sub-model
5.5.3 Stomatal conductance sub model
5.5.4 Canopy photosynthesis
5.6 Acknowledgements
6. CONCLUSION GÉNÉRALE
7. RÉFÉRENCES
