Transcript Pinus albicaulis

Ch. 8: Plant
life histories
Warning! Warning! Danger!
• March 11: Lecture exam #2
1998 remake
Ch. 7: Plant Growth
and Reproduction
(Seed Dispersal)
Biotic
• Biotic seed dispersal
– Epizoochory: Diaspore
Ex from lab #3 (weed lab)
Epizoochory
– Ex, Devil’s claw (Proboscidea)
Devil’s claw fruits)
Now?
Extinct ground sloth with
fruits attached
Epizoochory
– 17 top “hitchhiker plants,” ranked by
SRDUs (Sock Removal Difficulty Units)
Dispersal Mutualisms
• Epizoochory: Some mutualisms.
• Ex, scatter hoarding animals
Dispersal Mutualisms
• Pinus albicaulis (white bark pine), Clark’s nutcracker
• 1 bird: 90,000 seeds in one season
Dispersal Mutualisms
• Endozoochory: fruit eaten
Dispersal Mutualisms
• Endozoochory: sometimes seed scarified
– Ex, dodo
– Flightless “pigeon”
– Calvaria
Dodo extinct 1680s!
So far, vertebrates…..
Myrmecochory
• Seed dispersal: ants (mutualism, epizoochory)
– Elaiosome: food body
Stylophorum seeds
Fremontodendron seeds
Myrmecochory
World distribution….
?
?
Myrmecochory
• Common: Eastern forest herbs
Bloodroot
?
Erythronium
Trout lily
?
Viola
Biotic pollination vs biotic seed dispersal
• Trait
• Animals
Pollen dispersal
Seed dispersal
Biotic pollination vs biotic seed dispersal
• Trait
• Animals
• “Target”
• Motivation
to target
• Cues to target
Pollen dispersal
Seed dispersal
Biotic pollination vs biotic seed dispersal
• Seeds: “Directed dispersal” (directly to safe site)
unlikely
Ch. 8: Plant
life histories
PLANTS!
• Use resources for:
– growth: add
– reproduction: produce
– maintenance: make tissues
Quercus geminata
Hard, stiff leaf…..
PLANTS!
• Use resources for:
– growth: add modules (roots, stems, leaves)
– reproduction: produce flowers/seeds
– maintenance: make tissues tough & resistant. Ex,
drought resistant leaves
• Allocation: How resources
Strategy
• Strategy: pattern
• Also called life history pattern
Strategy
• Why strategies differ?
Strategy
• Trade-offs (“choices”)
• Ex, seed size/seed dispersal/seedling
establishment
“Choices”: roots/shoots
• Allocation to roots or shoots?
– Shoots: compete for light
– Roots: compete for water/nutrients
Choices: roots/shoots
• Root:shoot ratio. Allocation roots vs. shoots
– Usually documented by drying/weighing
• High ratio: good
• Low ratio:
• Poor soil, lots of light: root:shoot ratio high or
low?
Choices: roots/shoots
Rich soil, lots of aboveground competition:
root:shoot ratio high or low?
Choices: when reproduce?
• Annuals: live 4• Biennials: Live 2
• Perennials: Live.
– Most polycarpic:
Choices: when reproduce?
• Perennials
– Some monocarpic: 1
Monocarpic perennials
• Advantages: 1) pollination (large display)
• Ex, Swertia radiata (monument plant: Gentianaceae)
Monocarpic perennials
• Century plants (Agave): U.S. & Mexico
deserts
Tony Danza!!
Baja California, Mexico
Monocarpic perennials
• Blue Agave: source of tequila
Monocarpic perennials
• Advantages: 2) predator satiation
• Many seeds:
Monocarpic perennials
• Ex, some bamboos
• Phyllostachys bambusoides:
Monocarpic perennials
• Giant Panda angle: eats bamboo
• Populations fragmented
Danza
as panda
Monocarpic perennials
• 1970s: 3 major species flowered
• Pandas starved
Monocarpic perennials
• Recall