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

impacts of human activites on carbon cycle

Answer 2

• 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 3

impacts of human activites on nitrogen cycle

Answer 3

• 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