Structure-Function Relations of Warm Desert Plants - Gibson, Arthur C.

. .

Résumé :
For centuries biologists have been extremely interested in the structure of desert plants as examples of natural selection to harsh environmental conditions. Indeed, desert plants are frequently used as examples in many biology classes and textbooks to illustrate natural selection, but this has led to an unfortunate litany of errors and misconceptions about desert plant adaptations. This new synthesis focuses on plants of lowland tropical and subtropical arid deserts. Readers will be surprised to discover that many features commonly ascribed to desert plants are rareley observed in the most common species. Instead, the typical structural adaptations of nonsucculent warm desert plants are now viewed as ways to maximize photosynthetic rate.

Sommaire:
1 Plant Life Forms of Warm Desert Climates.- 1.1 Distribution and Climates of Warm Deserts.- 1.2 Physiological Problems for Plants.- 1.3 Conceptual Models for Desert Plant Adaptations.- 1.4 Plants of Warm Deserts.- 2 Functional Morphology of Nonsucculent Leaves.- 2.1 Energy Balance of a Leaf.- 2.2 Leaf Size.- 2.3 Encelia as a Model System.- 2.4 Structural Nature of Surface Reflectance.- 2.5 Leaf Orientation and Display.- 2.6 Leaf Rolling and Revolute Margins.- 3 Functional Morphology of Nonsucculent Leaves.- 3.1 Gas Diffusion Pathway.- 3.2 Physiological Anatomy of Nonsucculent Leaves of Desert Plants.- 3.3 Phreatophytes.- 3.4 Herbaceous Species.- 3.5 Fruit Photosynthesis.- 4 Photosynthetic Stems of Nonsucculent Plants.- 4.1 Functional Morphology.- 4.2 Anatomy of Woody Plants.- 4.3 Special Cases.- 5 Succulent Photosynthetic Organs.- 5.1 General Properties of Succulent Photosynthetic Organs.- 5.2 Taxon-Specific Adaptations.- 5.3 Fleshy Leaves.- 6 Special Topics in Water Relations.- 6.1 Xerohalophytes.- 6.2 Water Uptake.- 6.3 Vascular Tissues.- 7 Origins of Desert Structural Adaptations.- 7.1 Where Desert Adaptations Evolved.- 7.2 Warm Desert Versus Semiarid Habitats.- 7.3 Future Directions of Structure-Function Research.- References.- Taxonomic Index.