Journal Article

Scale dependence in the effects of leaf ecophysiological traits on photosynthesis: Bayesian parameterization of photosynthesis models

Michael Dietze, Xiaohui Feng

2013

Overview

Relationships between leaf traits and carbon assimilation rates are commonly used to predict primary productivity at scales from the leaf to the globe. We addressed how the shape and magnitude of these relationships vary across temporal, spatial and taxonomic scales to improve estimates of carbon dynamics. Photosynthetic CO2 and light response curves, leaf nitrogen (N), chlorophyll (Chl) concentration and specific leaf area (SLA) of 25 grassland species were measured. In addition, C3 and C4 photosynthesis models were parameterized using a novel hierarchical Bayesian approach to quantify the effects of leaf traits on photosynthetic capacity and parameters at different scales. The effects of plant physiological traits on photosynthetic capacity and parameters varied among species, plant functional types and taxonomic scales. Relationships in the grassland biome were significantly different from the global average. Within-species variability in photosynthetic parameters through the growing season could be attributed to the seasonal changes of leaf traits, especially leaf N and Chl, but these responses followed qualitatively different relationships from the across-species relationship. The results suggest that one broad-scale relationship is not sufficient to characterize ecosystem condition and change at multiple scales. Applying trait relationships without articulating the scales may cause substantial carbon flux estimation errors.

• Publisher: New Phytologist Trust,Wiley Subscription Services, Inc
• Subject: A max / Bayes Theorem / Bayesian analysis / Bayesian model parameterization / Bayesian theory / Carbon / Carbon dioxide / carbon dioxide fixation / Carbon fixation / Chlorophyll / Chlorophylls / Confidence Intervals / Ecological modeling / Ecophysiology / ecosystems / Forbs / Grasslands / Growing season / Kinetics / Leaf area / leaf ecophysiological traits / leaf nitrogen / Leaves / Legumes / Light effects / Mathematical models / Model testing / Modeling / Models, Biological / Nitrogen / Nitrogen - pharmacology / Parameterization / Parameters / Parametric models / Photosynthesis / Photosynthesis - drug effects / Physiological effects / Plant Leaves - drug effects / Plant Leaves - physiology / Plants / Primary production / primary productivity / Probability theory / Quantitative Trait, Heritable / Quantum efficiency / Seasonal variation / Seasonal variations / Seasons / Species / specific leaf area / Taxonomy / V cmax