CONIFER ADAPTATIONS

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CONIFER ADAPTATIONS
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ADVANTAGES OF ANGIOSPERMS

• vessels

• flowers

diverse pollination strategies
fruit diverse dispersal strategies

• abundant vegetative propagation

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What is special about conifers?

• Evolutionary relationships
• Adaptations
• Dominance in PNW

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EVOLUTIONARY RELATIONSHIPS
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Cycads
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Ginkgo biloba
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Welwitchia
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Ephedra
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Taxus
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Why are conifers successful in stressful
environments?

• cold
• dry

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1) photosynthesis at low temperatures
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2) Evergreen foliage
opportunistic photosynthesis
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3) Structure of stomates
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Wax deposits next to stomates
stomatal band
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• Structure of stomates reduces water loss

dry
cold winter desiccation
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4) TRACHEIDS ARE SAFE WATER-CONDUCTIONG CELLS
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Narrow tracheids and bordered pits prevent
embolism and cavitation
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5) Fire adaptations
Thick bark
Serotinous cones
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Why do evergreen conifers dominate the PNW?
Warm moist climate
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Strong seasonal variation in temperature and
precipitation
Dry summers and warm, wet winters favor evergreens
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Evergreen Species are Capable of Winter
Photosynthesis
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Why are PNW trees so large?

• Water storage in large sapwood volume

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