key stages in the life-history of a plant
DESCRIPTION
Seed Maturation. Growth. Key Stages in the Life-History of a Plant. Dispersal. Flowering. seed phase. Dormancy. Pollination. Germination. Hitch-hikers. Dispersal by Frugivores. Disperse How Far?. Near Parent. Far From Parent. Advantages. Advantages. No competition with parent. - PowerPoint PPT PresentationTRANSCRIPT
Key Stages in the Life-History of a Plant
Growth
Flowering
Pollination
Seed Maturation
Dispersal
Dormancy
Germinationse
ed
ph
ase
Hitch-hikers
Dispersal by Frugivores
Disperse How Far?
Near Parent
Advantages
• Parent habitat was good
Disadvantages• Direct competition with parent
• Strong sib competition
• Habitat may deteriorate
• Random disaster may strike
• Disease burden may increase
• Seedlings easily found by predators
Far From Parent
Advantages
• Parent habitat was good
Disadvantages
• No competition with parent
• Weak sib competition
• Escape from potentially deteriorating habitat
• Potential colonization of new area
• Potentially less disease burden
• Seedlings harder to find by predators
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
Key Stages in the Life-History of a Plant
Growth
Flowering
Pollination
Seed Maturation
Dispersal
Dormancy
Germinationse
ed
ph
ase
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
End of Material covered on Exam #1!
Plant Population Ecology
What is a population?
“A collection of individuals of the same species living in the same area”
What we define to be a population is
often context dependent
Static Measures of
Population Structure
Numeric Status
Minneapolis/St. Paul
Alaska
Abundance
640,000
531,947
Area (sq. mi)
~70
591,000
Density
~9142
0.90
Population Density
• Scale independent
• Can be used to estimate numbers for areas of different size
Only true if individuals are distributed at random, with the same intensity over the entire study area