EAR - Biophysical Interactions

Question 1

What is an example of a biospheric interactions in the GBR

Answer 1

• Zooxanthellae (algae) and coral polyp symbiotic relationship (endosymbiosis)
• Zooxanthellae provides 90% of the coral’s energy, therefore corals are reliant on photosynthesis
• Must be below low tide but shallow enough to photosynthesise
• When corals are under stress, the Zooxanthellae are released into the ocean and it bleaches. This is not lethal if it only occurs once since it will be recolonised

Question 2

What are important concepts within biophysical interactions (other than the 4 spheres)

Answer 2

• Carbon cycle
• Nutrient cycle
• Energy cycle (within an ecosystem)

Question 3

What is an example of a biospheric and lithospheric interaction in the GBR

Answer 3

Coral exoskeleton is secreted (calcium carbonate), damaged by ocean acidification or physical damage. This broken coral then forms the ocean substrate and sand

Question 4

What is an example of biospheric interactions in the TRHS

Answer 4

• Megafauna species present in the Sumatran Rainforest include the Sumatran Tiger, Sumatran Orangutan, Sumatran Elephant and the Sumatran Rhinosaurus
• These species are few in number since they are high in the food chain, and have specific requirements (e.g. tigers needs extensive range)

Question 5

What is an example of a lithospheric and hydrospheric interaction in the TRHS

Answer 5

• A tectonic subduction zone lies beneath Sumatra where the Sundra and Austro-Indian plates collide.
• Volcanic activity has formed the Bukit Barisan mountains stretching along Sumatra and creating orographic rainfalls
• Rivers run mostly Westward from the mountain range creating vast peatland marshes
• Temperature differences at the top of the mountain range

Question 6

What are examples of lithospheric and hydrospheric interactions in the GBR

Answer 6

• Reef sediments are mixtures of sediment and biogenic matter (sediment runoff and weathered coral) - “K’Gari”
• Sea levels and past reef structures are important for location.
• The Equatorial and East Australian Currents (E.A.C.) determine water temperatures

Question 7

What are examples of biogeographic processes in the GBR

Answer 7

• Predator - Prey dynamics (Crown of Thorns Starfish)
• Mass spawning events (Coral Polyps in Spring)
• Breeding practices (high mortality vs low mortality)
• Camouflage systems/territoriality (Potato Cod)
• Symbiotic relationships (Anemone fish)
• Migrations (Turtles)
• Territoriality (Hump headed Wrasse)