XII
Contents
Part 3 Light Harvesting and Gas Exchange ........................................ 119
9
Leaf Traits and Canopy Organization
S. Sabate, A. Sala, and C.A. Gracia ........................................................ 121
9.1
Introduction ........................................................................................... 121
9.2
Total Leaf Biomass and Leaf Area Index ............................................. 121
9.3
Vertical Prome Organization ............................................................... 123
9.4
Morphological and Functional Leaf Traits ......................................... 125
9.4.1 Leaf Size and Leaf Specific Mass .......................................................... 125
9.4.2 Chlorophyll Content ............................................................................. 128
9.4.3 Nutrient Content ................................................................................... 129
References......................................................................................................... 131
10
Gas Exchange and Water Relations
R. Save, C. Castel!, and J. Terradas ........................................................ 135
10.1 Introduction ........................................................................................... 135
10.2 Sclerophylly and Water Stress .............................................................. 136
10.3 Transpiration and Water Status of Leaves in a Mesic Site ................. 136
10.4 Within-Canopy Variations .................................................................... 137
10.5 Ecophysiology of Stool Sprouts ........................................................... 139
10.6 Drought-Tolerance Mechanisms ......................................................... 141
10.7 Effects of Temperature on Plant Water Relations ............................... 141
10.8 Xylem Embolism ................................................................................... 142
10.9 Canopy Transpiration and Ecosystem Water Budgets ....................... 143
10.10 Biogeographical Implications .............................................................. 144
References ............................................................................ ................... .......... 144
11
Modelling Canopy Gas Exchange During Summer Drought
A. Sala ..................................................................................................... 149
11.1 Introduction........................................................................................... 149
11.2 Model Description ................................................................................ 150
11.3 Model Implementation at the Avic Catchment .................................. 151
11.3.1 Incorporating the Effects of Seasonal Water Deficits
on Stomatal Regulation ........................................ : ............................... 151
11.3.2 Model Performance............................................................................... 153
11.4 Physiological vs. Structural Adjustments
as Mechanisms to Cope with Summer Drought ................................ 156
11.5 Conclusions............................................................................................ 159
References ......................................................................................................... 160