cycles within ecosystems

Question 1

how is carbon dioxide cycled through an ecosystem

Answer 1

• carbon dioxide is fixed through photosynthesis
• respiration released carbon dioxide
• decomposition releases carbon dioxide
• combustion releases carbon dioxide

Question 2

how is nitrogen cycled through an ecosystem

Answer 2

• nitrogen is fixed by lightning, the Haber process and bacteria
• decomposers break dead matter down into ammonia
• nitrifying bacteria convert ammonia into nitrites and nitrates
• denitrifying bacteria release nitrogen back into the atmosphere