2.3 flows of energy and matter

Question 1

energy input into ecosystems

Answer 1

• main source of energy: sun (solar radiation or insolation)
• total reflection: 31%
• total absorption: 69%

Question 2

draw the carbon cycle

Answer 2

…

Question 3

draw the nitrogen cycle

Question 4

impacts of human activites on carbon cycle

Answer 4

• burning of fossil fuels –> excess CO2 –> disrupts natural carbon cycle balance
• deforestation –> reduces amount of CO2 that can be removed from atmosphere through photosynthesis (trees are carbon sinks)

Question 5

impacts of human activites on nitrogen cycle

Answer 5

• excessive use of nitrogen based fertilisers –> leads to runoff and causes eutrophication (depletes water O2 levels)
• fossil fuel combustion releases nitrogen oxides in atmosphere –> leads to acid rain

Question 6

deforestation and C and N cycles

Answer 6

C cycle:
- decrease in photosynthesis + increase in atmospheric carbon amounts

N cycle:
- change in soil nitrogen content (more lost)

solution: limit amount of land for agricultural processes (people still need food tho)

Question 7

urbanisation and C and N cycles

Answer 7

C cycle:
- deforestation, CO2 emissions, energy consumption

N cycle:
- fertiliser use, wastewater treatment

solutions:
- ashcrete instead of concrete (comes from coal so not long-term solution)
- C4 plants: higher photosynthesis rates