Contents
XIII
15.7 Water Relations of Intertidal Aquatic Plants
in Relation to Photosynthesis ...................... 312
15.8 Conclusions.. . .. . . . . . .. . .. . .. . .. . .. . . .. . . ... . ... 314
References ...................................... 314
16
Photosynthesis in Poikilohydric Plants:
A Comparison of Lichens and Bryophytes
319
T. G. A. Green and O. L. Lange
16.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 319
16.2 CO 2 Exchange of Lichens and Bryophytes .......... 320
16.2.1 Net Photosynthetic Rates ......................... 320
16.2.2 Compensation Points and Photorespiration .......... 322
16.2.3 Dark Respiration Rates ........................... 323
16.2.4 Lichens and Bryophytes as Shade Plants ............ 325
16.2.5 Thallus Water Content and Photosynthesis .......... 326
16.2.6 Environmental CO 2 Concentration ................. 327
16.3 Plant Morphology and Photosynthesis .............. 328
16.3.1 Bryophytes ...................................... 329
16.3.2 Lichens......................................... 331
16.4 Water Location and Transport ..................... 332
16.4.1 Bryophytes ...................................... 332
16.4.2 Lichens ......................................... 332
16.5 An Upper Limit for Photosynthetic Rate? ........... 333
16.6 Lichens and Bryophytes as Early Land Plants? ...... 334
16.7 Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 335
References ...................................... 337
17
The Consequences of Sunflecks for Photosynthesis
and Growth of Forest Understory Plants ............ 343
R. W. Pearcy and W. A. Pfitsch
17.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 343
17.2 Sunflecks in Forest Understories ................... 344
17.3 Mechanisms Regulating the Utilization of Sunflecks .. 345
17.4 Photosynthesis in Natural Sun fleck Pegimes ......... 346
17.5 The Significance of Sunflecks to Annual Carbon Gain 349
17.6 Consequences of Sunflecks for Growth
and Reproduction ................................ 353
17.7 Conclusions .................................... , 356
References ...................................... 358
18
Variation in Gas Exchange Characteristics
Among Desert Plants ............................ , 361
1. R. Ehleringer
18.1 Introduction .................................... , 361