1.6 phosphorus cycle

phosphorus cycle

movement of p through sources and sinks (reservoirs).

what resources contain P minerals

rocks and sediments

how fast/slow is the p cycle

slow compared to c/water/n cycles, takes a long time for minerals to weather

why is the process considered a limiting nutrient

bc the process is so slow and it creates plant growth

what does it produce for organisms

dna, atp, bone and tooth, etc

phosphorus sources

weathering rocks

how does minerals shift into water

• wind and rain break down rock and phosphate

• and then it is released and dissolved into water

  • rain water carries phosphate into nearby soils/bodies of water

synthetic(human) sources of p

mining phosphate minerals

what is the cause/effect of mining synthetic p

• adding products like synthetic fertilizers/detergents/cleaners

• extracting nitrogen in an efficient way and add it to lawns/ag fields

  • runoffs carries p into nearby bodies of water and creates eutrophication

the process where a body of water becomes excessively enriched with nutrients, primarily phosphorus and nitrogen, leading to an explosion of aquatic plant and algal growth, known as algal blooms

assimiliation and excreption/decomp.

just like n, p is absorbed by plant roots and assimilate into tissues

how do animals assimilate p

by eating other animals

p sources from organisms

animal waste(birds), plant matter and other biomass

by bacteria/soil decomposers that return phosphate to soil

how is the p sources from organisms broken down

sedimentation & geological uplift cause

phosphate doesn’t dissolve very well in water; much of it forms solid bits of phosphate that fall to the bottom as sediment

what happens to p over long periods

pressure of the overlying water turns the p mineral into sediment

geological uplift cause and effect

tectonic plate collision forcing up rock layers that form mountains; p cycle starts over again w weathering and release of p from rock

no

is there an atmospheric component of the p cycle

what happens if the plant growth is limited by the lack of phosphorus?

when it IS provided, the plants/algae grow quickly

first part of p cycle

weathering of uplifted rocks contributes phosphates to the land. some phosphates make their way back to the ocean

second part of p cycle

phosphate fertilizer applied to fields can run off directly into streams, become part of a soil pool, or be absorbed by plants

third part of p cycle

excretion by animals and decomposition of both animals and plants release p on land/in water

fourth part of p cycle

dissolved phosphate precipitate out of solution and contribute to ocean sediments. conversion of sediments into p rocks is a very slow process

fifth part of p cycle

geologic forces slowly lift up p rocks from the ocean floor to form mountains

eutrophication (too much n/p)

bc they're limited nutrients in an aq. ecosystem, extra input of n/p lead to eutrophication which fuels algae growth

what does algae growth/bloom do?

• covers surface water

• blocks sunlight

• kills plants beneath the surface

  algae eventually dies off bc they run out of nutrients

• bc it takes o2 to decompose dead animals, it is an endless cycle of minimal o2

what does lower levels of dissolved oxygen (o2) mean in water

kills aquatic animals, especially fish

ex of pos feedback loop in algae bloom

less o2 > more dead organisms > more bacterial decomposition > even more less o2