Biogeochemical cycles Flashcards
What are the carbon reservoirs
- atmosphere
- hydrosphere
- lithosphere (rocks and fossil fuel)
- living things
- dead organic matter
What is photosynthesis and how does carbon move from one reservoir to another
- plants use sunlight to synthesise nutrients from carbon dioxide and water
- atmosphere - biosphere
What is respiration and how does carbon move from one reservoir to another
- living organisms involving the production of energy intake of oxygen and release of CO2
- biosphere - atmosphere
What is food chain transfer and how does carbon move from one reservoir to another
- transfer of matter and energy in the form of food from organism to organism
- biosphere - biosphere
What is fossilisation and how does carbon move from one reservoir to another
- animal or plant becoming preserved in a hard form
- biosphere - lithosphere
What is combustion and how does carbon move from one reservoir to another
- chemical combination of a substance with oxygen, involving the production of heat and light
- lithosphere - atmosphere
What is decomposition and how does carbon move from one reservoir to another
- break up into constituent parts by or as if by a chemical process
- biosphere - atmosphere
What is volcanic activity and how does carbon move from one reservoir to another
- ranges from emissions of gases, non - explosive lava emissions to extremely violet explosive bursts that may last many hours
- lithosphere - atmosphere
How does deforestation affect process and what are the consequences
- decrease photosynthesis
- decrease food chain transfer
- increases amount of CO2 in atmosphere
- contributes to climate change
How does combustion of fossil fuels affect processes and what are the consequences
- increase combustion
- releases stored carbon into the atmosphere
- contributes to climate change
How does afforestation affect processes and what are the consequences
- increases photosynthesis
- increases food chain transfer
- decreases amount of CO2 in the atmosphere
How does intensive farming affect processes and what are the consequences
- increase decomposition
- can either increase or decrease photosynthesis
- increase CO2 in atmosphere
How does pollution of oceans affect carbon processes and what are the consequences
- increase in CO2
- decrease in respiration
- reduce amount of CO2 released
What are the nitrogen reservoirs
- atmosphere
- biosphere
- lithosphere
- hydrosphere
What is ionisation
- lightning provides energy for atmospheric nitrogen and oxygen to react and produce oxides of nitrogen
What is fixation
- microorganisms that can chemically reduce nitrogen to ammonia
What is nitrogen food chain transfer
- nitrogen passes between organisms as amino acids and proteins in food
What is nitrification
- involves the oxidation of ammonium ions to nitrites, then to nitrates, by nitrifying bacteria in the soil
What is denitrification
- chemical reduction of nitrates in soil to nitrogen and nitrogen oxide gases, by denitrifying bacteria in the soil
What is leaching
- the high solubility of nitrates means they are easily leached out of the soils and into water bodies where they act as nutrients for aquatic plants and algae
What is absorption by roots nitrogen
- plants absorb nitrogen as soluble ions, mainly as nitrate but also as ammonium ions
What is ammonification
- the amino groups in proteins are released as ammonium ions by the action of bacteria, fungi as they decompose dead organic matter
How does the Haber process impact the nitrogen reservoirs and availability
- turning air into fertilisers
- use large amounts of energy
- ammonia is then converted to nitrates
How does agricultural activities impact nitrogen reservoirs and availability
- use of fertilisers : nitrate fertilisers may increase problems caused by leaching
- drainage systems : makes soil more aerobic so increases the number of nitrifying bacteria
- soil disturbance : ploughing - increases rate of decomposition which releases more nitrogen oxides
How does pollution impact nitrogen reservoirs and availability
- combustion releases oxides of nitrogen
Explain the process of eutrophication
- nutrients are transported to a body of water - contains fertilisers
- build up of nutrients cause algae blooms
- stops light getting to the plants that photosynthesise
- these plants die which decreases oxygen levels
- water becomes anoxic
- causes all organisms to die
What are the phosphorus reservoirs
- animals and plants
- sediments and rocks
- water
Why is phosphorus often a limiting factor in plant growth
- no atmosphere reservoir: slower to cycle
What is absorption by roots with phosphorus
- phosphate ions in solution
- solution taken up by the roots of plants
- plants use it to make DNA & RNA etc
What is food chain transfer
- one organism consumes another
- phosphorus moves along and becomes more available
What is decomposition
- living organisms die
- microbes break down dead organic matter
- release phosphorus back to the soil
What is sedimentation in phosphate
- phosphate ends up in sediments
- become rocks
What is mountain building
- plate tectonics move from underground to the surface
What is weathering/erosion
- rocks exposed to the surface are weathered and eroded
What human activities causes the most impact on the movement and storage of phosphorus
- fertilisers : contain phosphate
- mining : obtaining phosphorus from fertilisers
Sustainable management of the carbon cycle
- afforestation : increase photosynthesis
- reduce combustion
- carbon capture
Sustainable management of the nitrogen cycle
- reduce use of combustion engines in vehicles
- reduce reliance of fertilisers
- educate farmers on weather conditions
Sustainable management of the phosphorus cycle
- increase in natural fertilisers
- crop breeding programmes
