phosphorus cycle

Question 1

why is there no phosphorus in the atmosphere

Answer 1

soil conditions do not allow bacteria to convert chemical to gaseous forms of phosphorus

Question 2

why is phosphorus a limiting factor in plant growth

Answer 2

most soil contains little phosphorus unless it is directly applied to soil

Question 3

why is phosphorus a limiting factor in freshwater sources

Answer 3

phosphate salts are only slightly soluble in water = not much is available to aquatic plants

Question 4

how do humans affect the phosphorus cycle

Answer 4

mine large quantities of phosphate rock for commercial inorganic fertilizers, reduce available phosphate in soil due to agriculture and forestry, disrupt aquatic systems with phosphate runoff from animal waste, fertilizer, and discharge from sewage systems

Question 5

consequences of human effects on phosphorus cycle

Answer 5

acid mine drainage, tailings, habitat destruction, loss of nutrients reduce plant growth, increase in hypoxic zones

Question 6

marine sediments adding to phosphorus cycle

Answer 6

uplifted into rocks which dissolve into water sources, mined to become fertilizer used in agriculture and consumed into land food webs

Question 7

marine sediments taking from phosphorus cycle

Answer 7

sediment from food webs, phosphorus settles out into sediments

Question 8

ways that phosphorus moves between ocean and land cycles

Answer 8

mining, leaching and runoff, uplifiting of sediments

Question 9

marine food webs

Answer 9

excretion = dissolves into water to be consumed or become sediments

Question 10

land food webs

Answer 10

decompostion = dissolved into freshwater sources sand consumed again