XVI
Contents
Part D: Global Aspects of Photosynthesis
22
22.1
22.2
22.3
22.3.1
Leaf Diffusive Conductances in the Major Vegetation
Types of the Globe .............................. .
Ch. Korner
The Significance of Leaf Conductances
in Vegetation Modeling .......................... .
Constraints of Utilizing Leaf Conductances
in Vegetation Modeling .......................... .
How Was the Data Set Compiled? ................ .
Definition of Maximum Leaf Conductance
463
463
463
464
for Water Vapor ................................. 466
22.3.2 Definition of Minimum Leaf Conductance
for Water Vapor ................................. 467
22.3.3 Definition of Stomatal Response Functions. . . . . . . . .. 468
22.4 Selection of Vegetation lYpes ...................... 469
22.5 Maximum Leaf Diffusive Conductances
in Important Vegetation Types ..................... 470
22.6 Maximum Leaf Diffusive Conductances
and Maximum Rate of Leaf Photosynthesis ......... 473
22.7 Minimum Leaf Diffusive Conductances ............. 474
22.8 Stomatal Responses in the Field ................... 475
22.8.1 Long-Term Trends and Seasonal Changes. . . . . . . . . . .. 475
22.8.2 Short-Term and Diurnal Changes ................... 478
22.9 Conclusions and Recommendations
for Further Research ............................. 484
References ...................................... 485
23
Predictions and Measurements of the Maximum
Photosynthetic Rate, A max , at the Global Scale ...... 491
EI. Woodward and T. M. Smith
23.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 491
23.2 Philosophy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 492
23.3. Experimental Evidence for the Soil N Supply
Constraint on Amax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 493
23.3.1 Introduction..................................... 493
23.3.2 Experimental Detail .............................. 494
23.3.3 Results ......................................... 496
23.3.4 Discussion ...................................... 497
23.4 Modeling Amax at the Global Scale ................. 498
23.4.1 Introduction..................................... 498
23.4.2 Method of Predicting Amax from Soil C ............ 498
23.4.3 Validating Amax Predictions ....................... 500
23.4.4 Predicting Amax from Soil C and Soil N ............ 500
23.5 Global Predictions and Tests of Soil-Based Amax ..... 501