W1: L3 = Palaeo Ecosystem 1 [Terrestrialisation] (Prof. Bamford) Flashcards
Early Ecosystem attributes? (10)
• Aquatic only.
• Shallow seas.
• Invertebrates.
• Whole ecosystem of primary producers, prey & predators.
• Water cuts out harmful UV.
• Algae photosynthesising.
• Oxygen.
• Free oxygen + cosmic rays –> ozone.
• Land surface was empty.
Time period of Algae & Fungi?
Phanerozoic.
Earliest Terrestrial ecosystems attributes? (6)
• Seas very crowded.
• UV radiation harmful before ozone formed.
• Bare land was unoccupied & very tempting but was dry.
• Dry bare land.
• No soils & no water retention.
• Extreme hot/cold.
Adaptations required by Aquatic plants to colonize land? (4)
● Develop roots.
● Develop spores.
● Have cuticles & stomata.
● Have hydraulic system.
Why did Aquatic plants have to develop roots to colonize land?
For efficient water uptake.
Why did Aquatic plants have to develop/have spores to colonize land?
For reproduction.
Why did Aquatic plants have to have cuticles & stomata to colonize land? (2)
• To control water loss.
• To control CO2 intake.
Why did Aquatic plants have to have a hydraulic system to colonize land?
For efficient water transport through Tracheids.
Tracheids components? (2)
• Xylem.
• Phloem.
Tracheids attributes? (4)
• Efficient water transport.
• Have rigidity & talk stature above other plants.
• Enable long distance dispersal of spores.
• Made up of lignin & suberin.
Lignin & Suberin attributes? (4)
• Absent from aquatic plants.
• Strength to stems.
• Excretory material.
• Reduces cell wall permeability.
Thing to note on the different vascular structures in plants?
Through time, different patterns of xylem & phloem (vascular structure) were experimented by plants to adapt to the environment occupied.
Feedback: Effects of plants on the atmosphere? (3)
• Free O2 & O3
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• Increase in CO2
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• Greenhouse effect.
Feedback: Effects of plants on the landscape? (4)
• Soils formed (soil = sediment + organic matter)
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• Soils bound by roots
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• Nutrients available for plants
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• Microclimate & humidity
Thing to note about Feedback & effects of plants on the atmosphere & landscape?
Plants improve the Earth for their comfort, survival & reproduction.
Ancestor of land plants?
Charaphyceae.
Charaphyceae attributes? (7)
• Ancestral group within Algae.
• Gave rise to land plants.
• Complex morphology.
• Worldwide.
• Fresh & brackish water.
• Fossilised oogonium.
• Upper Silurian.
Charaphyceae time period?
Upper Silurian.
Oogonium?
= structure enclosing egg cells.
Plant classification techniques for living plants? (3)
● Based on reproductive structures.
● Molecular genetics/phylogeny changing some groupings.
● Molecular clocks.
Plant classification techniques for fossil plants? (5)
● Same as for living plants if possible, otherwise morphological only.
● Leaf shape & venation.
● Steles (vascular structure).
● Wood anatomy (distribution of tissues).
● Spore & pollen morphology.
Features of study in Palynology? (3)
• Size & shape.
• Pores & furrows.
• Surface texture.
Earliest Terrestrial ecosystems in terms of plants available attributes?
• Non-vascular Bryophytes occupied moist environments.
• Small vascular plants on drier land were ¹ simple,² small & ³ spore-producing.
• Charophyceae ancestor (monophyletic).
Charophyceae ancestor attributes? (6)
• Biochemistry same.
• Chlorophyll a & b.
• Cellulose.
• True starch stored.
• Life cycles same.
• Protostele.
Small vascular plants present in the Earliest Terrestrial ecosystems? (3)
• Rhyniophyta.
• Zosterophyllophyta.
• Trimerophyta.
Groups of Bryophytes (non-vascular plants during Earliest Terrestrial ecosystems)? (3)
• Liverworts.
• Mosses.
• Hornworts.
Liverworts attributes? (2)
• Grow in damp areas only.
• Common.