Tropical Forest Community Ecology

Patterns of Herbivory and Defense in Tropical Forests 69

Predicted plant

responses

Episodic

Lower

Restricted

Lower

Lower

Higher

Water table Light availability

Physical

environment:

precipitation

Ecological driver of basic plant

phenological patterns

Resource

availability for

herbivores

(foliage)

Strongly seasonal:

Tropical dry forests:

(deciduous)

Plant responses

Slow

growth

Evergreen Rapid growth

Deciduous

Continuous

Higher

Continuous

Higher

Higher

Lower

Foliage availability

Risk of attack

Potential impact of herbivores

Selective pressure for defense

Investment in defense

Herbivory

Less seasonal:

Tropical rain forests:

(evergreen)

Figure 5.1 Diagrammatic model of the water availability/phenology hypothesis to explain how foliage availability
leads to a series of contrastin gresponses between plants of seasonally dry tropical forest (TDF) and ever green tropical
rain forest (TRF), regarding herbivory and defense. A further subdivision of TDF plants into deciduous and evergreen,
and TRF plants into rapid-growth and slow-growth species, shows relevant interspecific heterogeneity within each
major forest type, and size of boxes are indicative of the relative representation of these four types of plants.
Ascendin garrows indicate the predicted responses for plants of each of the four groups. See text for details.