Functional relationships between leaf structure and photosynthetic traits as modulated by irradiance and nutrient availability in a sclerophyllous and a non-sclerophyllous mediterranean oak species
2011
Daas-Ghrib, Chiraz | Montpied, Pierre | Ksontini, Mustapha | Dreyer, Erwin | Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Institut National de Recherche en Génie Rural Eaux et Forêts (INRGREF) ; Ecole Nationale du Génie Rural, des Eaux et des Forêts (ENGREF)-Institution de la Recherche et de l'Enseignement Supérieur Agricoles [Tunis] (IRESA)
International audience
显示更多 [+] 显示较少 [-]英语. Plasticity of structural and physiological leaf traits elicited by irradiance and soil nutrients was investigated in two sympatric mediterranean oaks: a sclerophyllous (Quercus suber L.) and a non-sclerophyllous species (Q. canariensis Willd.). Seedlings were grown for 2 years in pots in a 2-way crossed factors design. Leaf mass-to-area ratio (LMA) and nitrogen were recorded, and photosynthetic capacity (i.e. the apparent maximal carboxylation rate by rubisco, Vcmax) was derived from response curves of net CO2 assimilation (A) versus intercellular CO2 mol fraction (Ci). Structural equation modelling was applied to the data for disentangling the complex correlation structure between variables. The two species differed significantly in photosynthetic nitrogen use efficiency (PNUE). They displayed the expected responses to irradiance, with large increases in LMA, Vcmax and nitrogen per unit leaf area and decreases in mass-based nitrogen content. Nutrient availability modulated severely leaf N content (mass- and areabased) and mass-based maximal carboxylation rate, but not the plastic response of all these parameters to irradiance. Irradiance primarily modulated leaf structure (LMA), and secondarily nitrogen content, while nutrient availability
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