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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 ).
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Warning! Warning! Danger! • March 11: Lecture exam #2 1998 remake
Biotic • Biotic seed dispersal • Epizoochory: Diaspore Ex from lab #3 (weed lab)
Epizoochory • Ex, Devil’s claw (Proboscidea) Devil’s claw fruits) Extinct ground sloth with fruits attached Now?
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 Fremontodendron seeds Stylophorum seeds
Myrmecochory World distribution…. ? ?
Myrmecochory Bloodroot • Common: Eastern forest herbs ? ErythroniumTrout lily Viola ?
Biotic pollination vs biotic seed dispersal • Trait Pollen dispersal Seed dispersal • Animals
Biotic pollination vs biotic seed dispersal • Trait Pollen dispersal Seed dispersal • Animals • “Target” • Motivation to target • Cues to target
Biotic pollination vs biotic seed dispersal • Seeds: “Directed dispersal” (directly to safe site) unlikely
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