The Phosphurus Cycle Flashcards
What are the important biological functions of phosphorus?
Component of bones
ATP (energy)
DNA
RNA
Cell membranes
Proteins
Why might phosphorus be a limiting factor on biological processes?
Most compounds of phosphorus have low solubility and there is no gaseous reservoir
How are absorption by roots aa part of the phosphorus cycle?
Plant Roots absorb phosphates to be used in metabolic processes
Not effective at absorbing phosphates so have symbiotic relationship with mycorrhizal fungi which increase surface area
How is decomposition a part of the phosphorus cycle?
Breakdown of phosphorylated proteins in DOM releases phosphates which are often made ore soluble by soil microbes so plants can absorb them
How does sedimentation form part of the phosphorus cycle?
Phosphorus in organisms that die becomes incorporated into sediments making it unavailable to other organisms (planktonic organisms that sink and die)
Reduces productivity of surface ocean
How do mountain building and weathering form part of the phosphorus cycle?
As these processes mobilise phosphorus and make it available to living organisms but are often slow
May not become available until continental drift forms new mountain ranges
How does Mining of phosphate rocks affect the phosphorus cycle?
Calcium phosphate is mined then treated to produce ammonium phosphate which is more soluble
Bird droppings were mined in dry regions where it built up (Peru) most of these areas are fully exploited
How does fertiliser use affect the phosphorus cycle?
Mobilises phosphorus compounds into environment in more soluble forms increasing crop production but can cause eutrophication
How is crop breeding helping the phosphorus cycle?
Increasing plant efficiency of phosphate absorption
What can biological waste be used as?
As fertilisers to maintain phosphate nutrient availability
What is the problem with phosphate shortages on Farmland?
Availability reduced be biomass removal during harvesting and erosion due to bare soil
Compensation by mining more phosphate is unsustainable
