tailieunhanh - Báo cáo lâm nghiệp: "Variations of construction cost associated to leaf area renewal in saplings of two co-occurring temperate tree species (Acer platanoides L. and Fraxinus excelsior L.) along a light gradient"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài:"Variations of construction cost associated to leaf area renewal in saplings of two co-occurring temperate tree species (Acer platanoides L. and Fraxinus excelsior L.) along a light gradient" | Ann. For. Sci. 62 2005 545-551 545 INRA EDP Sciences 2005 DOI forest 2005047 Original article Variations of construction cost associated to leaf area renewal in saplings of two co-occurring temperate tree species Acer platanoides L. and Fraxinus excelsior L. along a light gradient Sandrine BARTHODa Daniel EPRONb a Université de Franche-Comté Laboratoire de Biologie Environnemental EA 3184 USC INRA Pôle universitaire BP 71427 25211 Montbéliard Cedex France b Université Henri Poincaré - Nancy 1 UMR 1137 INRA - UHP Écologie et Écophysiologie Forestières BP 239 54506 Vandreuvre Cedex France Received 15 June 2004 accepted 14 January 2005 Abstract - The yearly renewal of leaves and their holding organs the leafy shoot represent an energetic cost for saplings. The contribution of both biochemical tissue construction cost CC and morphological traits biomass partitioning and leaf mass per unit area LMA to the cost associated with leaf area renewal construction cost of the leafy shoot per unit leaf area shoot CCa was studied in saplings of Acer platanoides L. and Fraxinus excelsior L. growing in a natural light gradient below forest canopy. Decrease in LMA with shade and change in biomass partitioning from stems towards leaves and petioles accounted for the strong decrease in mass per unit area of the leafy shoot SMA with shade and for most of the plasticity of shoot CCa in both species. In addition a decrease in leaf CC in A. platanoides also contributed to the overall decrease of shoot CCa with shade in this species. Leaf CC was positively correlated with LMA in F. excelsior positively correlated with both LMA and epidermal absorbance of UV AUV in A. platanoides. Leaf CC was negatively correlated with ash content in both species. The strong negative correlation between AUV and nitrogen content might have damped variations in leaf CC in F. excelsior. Acer platanoides L. Fraxinus excelsior L. construction cost shade tolerance forest regeneration Résumé - Variations .