Freshwater Abiotic and Biotic Interactions

Question 1

Carboniferous

Answer 1

Forests, coal swamps, water versions of plants- giant ferns and horestails

Question 2

Spore plants

Answer 2

need water to germinate, dominant in carboniferous, no seeds

Question 3

First seed plants

Answer 3

seed ferns, all seed bearing plants evolved from these

Question 4

Carboniferous trees

Answer 4

Lignin and cellulose had to break down, done so by fungi

Question 5

Decomposers in carboniferous

Answer 5

poor habitat for fungi (water), main decomposer bacteria but can’t break down wood- material doesn’t get broken down

Question 6

Plant growth in carboniferous

Answer 6

Lead to high atmospheric oxygen, the Second Oxygenation event, more plants photosynthesis = more oxygen, no decomposers using oxygen also lead to more oxygen

Question 7

Animal life in carboniferous

Answer 7

dominated by large insects, , no vertebrate predators of the same size, high oxygen levels means more energy for size, few other animals on land

Question 8

Emergence of reptiles

Answer 8

scales and thick skin to prevent desiccation, amniotic egg can be laid anywhere, no dependance on water

Question 9

Coal

Answer 9

there is a lot from this time because no decomposers

Question 10

Coalification

Answer 10

dead plant material forms coal, plant material buried before decomposition (peat)- more sediment adds more pressure and increases temperature (squeeze out water)- chemical composition altered- you get coal

Question 11

Deltic/ Estuarine Cycles Coal swamps

Answer 11

Change with sea level, allow organic material to build up then be drowned with sea level rise- mixed salinity

Question 12

Meandering River Cycles coal swamps

Answer 12

plant material buried through cycles of freshwater flooding, peat accumulation in floodplain

Question 13

Why do rivers meander?

Answer 13

appears on low gradient slopes, weathering-erosion-transport- deposition, eventual change to curve because of deposition and then further erosion

Question 14

Weathering

Answer 14

weakening and breakdown of rock

Question 15

Physical weathering

Answer 15

Mechanical break up of rock (ice, rain, physical contact)

Question 16

Chemical weathering

Answer 16

mineral breakdown by chemical reaction (water combining with chemicals to make a substance that breaks stuff down)

Question 17

Biological weathering

Answer 17

Mechanical and chemical with biological life

Question 18

Erosion

Answer 18

weathered material is moved from its original location

Question 19

Transport

Answer 19

eroded material is moved from one location to another (requires energy input such as fast running water)

Question 20

Deposition

Answer 20

No more energy for transport, material deposited

Question 21

Fluvial sediment transport

Answer 21

size of particle determines how far it travels- dissolved in water, suspended in water, rolling/ sliding along bed

Question 22

Flow rate

Answer 22

determined by incline of slope, volume of water, obstacles

Question 23

Why did the carboniferous end?

Answer 23

tectonic plate movement, climate change with glaciation