Freshwater Abiotic and Biotic Interactions Flashcards
Carboniferous
Forests, coal swamps, water versions of plants- giant ferns and horestails
Spore plants
need water to germinate, dominant in carboniferous, no seeds
First seed plants
seed ferns, all seed bearing plants evolved from these
Carboniferous trees
Lignin and cellulose had to break down, done so by fungi
Decomposers in carboniferous
poor habitat for fungi (water), main decomposer bacteria but can’t break down wood- material doesn’t get broken down
Plant growth in carboniferous
Lead to high atmospheric oxygen, the Second Oxygenation event, more plants photosynthesis = more oxygen, no decomposers using oxygen also lead to more oxygen
Animal life in carboniferous
dominated by large insects, , no vertebrate predators of the same size, high oxygen levels means more energy for size, few other animals on land
Emergence of reptiles
scales and thick skin to prevent desiccation, amniotic egg can be laid anywhere, no dependance on water
Coal
there is a lot from this time because no decomposers
Coalification
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
Deltic/ Estuarine Cycles Coal swamps
Change with sea level, allow organic material to build up then be drowned with sea level rise- mixed salinity
Meandering River Cycles coal swamps
plant material buried through cycles of freshwater flooding, peat accumulation in floodplain
Why do rivers meander?
appears on low gradient slopes, weathering-erosion-transport- deposition, eventual change to curve because of deposition and then further erosion
Weathering
weakening and breakdown of rock
Physical weathering
Mechanical break up of rock (ice, rain, physical contact)
Chemical weathering
mineral breakdown by chemical reaction (water combining with chemicals to make a substance that breaks stuff down)
Biological weathering
Mechanical and chemical with biological life
Erosion
weathered material is moved from its original location
Transport
eroded material is moved from one location to another (requires energy input such as fast running water)
Deposition
No more energy for transport, material deposited
Fluvial sediment transport
size of particle determines how far it travels- dissolved in water, suspended in water, rolling/ sliding along bed
Flow rate
determined by incline of slope, volume of water, obstacles
Why did the carboniferous end?
tectonic plate movement, climate change with glaciation
