Costs Incurred in Employing Pollen Vectors Advertising Rewards Flower color Flower shape Fragrance Fragrance Nectar Pollen Bottom line: Pollinators benefit from the incentives provided; not from the services they give to plants  There are some cheaters! Bottom line: Pollinators benefit from the incentives provided; not from the services they give to plants

Movement of Pollen by an Animal Vector Only measures first visit

Outcrossing Increases Evidence for Costs Incurred in Outcrossing Outcrossing Increases

Key Stages in the Life-History of a Plant Seed Maturation Growth Dispersal Flowering seed phase Dormancy Pollination Germination

Ecology of Dispersal

Dispersal by Gravity

Wind Dispersal Pappus Wings

Effects of Specialized Dispersal Structures Not Plumed Plumed

Experimental Studies of Wind Dispersal Mechanisms

Self Propulsion Hygroscopic Awns Dry Wet

Explosive Seed Release Self Propulsion Explosive Seed Release (up to 15 m at 100 km/hr) Mistletoe

Hitch-hikers

Dispersal by Frugivores

Disperse How Far? Near Parent Far From Parent Advantages Advantages No competition with parent Parent habitat was good Weak sib competition Disadvantages Escape from potentially deteriorating habitat Direct competition with parent Strong sib competition Potential colonization of new area Habitat may deteriorate Potentially less disease burden Random disaster may strike Seedlings harder to find by predators Disease burden may increase Seedlings easily found by predators Disadvantages Parent habitat was good

Janzen-Connell Hypothesis Seed distribution Probability of escaping predation Surviving plants

Seed Survivorship in a Tropical Tree: Cecropia peltata Seed distribution Probability of surviving Surviving plants Fleming and Williams 1990. Journal of Tropical Ecology 6:163-178

Seed Dormancy: Dispersal in Time Ambrosia artemisifolia: a summer annual

Seed Dormancy: Dispersal in Time Patterns of dormancy as a function of local environment

Seed Dormancy: Dispersal in Time (1) A mechanism for timing germination when conditions are favorable for seedling survival (2) A tactic for dealing with environmental uncertainty

The Ecology of Seed Banks

Serotinous cones: an above ground seed bank