Elemental Flux

Question 1

element cyclying

Answer 1

Transport and transofrmatuon of chemicals within and among ecosytsmes

Major focal area of ecosystem beacuse:
- elements are required by all living organisms
- Element cycles link living and non lving parts of ecosystem
- Many envirnmental mangment issues arise from too much or too little of particular elements in a system and humans have altered cycling of elements

involves the movement and trasnormation of abiotic and biotic forms of elements (production is inorganic to organic and decomp is organic to inorganic)
- includes inputs, outputs and interal cycling in an ecosystem
- obeys 1st law of thermocunci thats matetr cant be created or destroyed
- think of carbon cycle (plants intaking co2, dying to release, then decomp and minerlition for it to go bakc into soil)

Question 2

Element cycles and resevoirs

Answer 2

Main resevoirs are atmosphere, hydrosphere, biosphere and lithosphere

• two types of elemts cycles based on major resecoir where elemt rsides

Gaseous cycles: main resevoirs are atmosphere and ocean (n and o)

Sedimentary ccles: main resevoir is lthosphere - soil rocks and minerals (ex. P)

Hybrd: gaseous and sedimentary (ex. s and c; the ocean is a signifant carbon sink)

Question 3

Move Stick and Change

Answer 3

Framework of elemetal cycling

Material move within and between ecosystems - FLUX is the moevemnt between diff compartments - moveemnt of energy or materials between system

Sticlk for periods of time within pools or resevoirs

Change from on chem state to another (and the form it is infleunces its moevemnt and stcking)

Question 4

Flux

Answer 4

Moevemnt of elemets = internal movements and inpits and outputs to the system

Elements move between within ecosystems due to

Physical gradients - water moevemnts erode soil and transport elements down slope and downstream

Chemical gradients – e.g., diffusion of CO2 from areas of net respiration in soil to the atmosphere

Biological vectors – e.g., salmon migrating upstream from oceans to lakes; invertebrate larvae hatching out of lakes and moving to land; bioaccumulation of a toxin through a foodweb.

Question 5

Phosphorous

Answer 5

Phosphorus held in lithosphere – in rocks, soil etc

Erosion from phosphrous rocks, to stream system, abrosbed into organis, coverted to bioavalble forms, works way up to eating system

The main reservoirs of P are rock, soil and sediments.
P has no gaseous phase, thus it is not normally found in the atmosphere (except in dust particles, sea spray).
P can follow the hydrological cycle only part way, from land to sea – but not rapidly back to land!

P is released very slowly from rock/soil by processes of weathering, leaching and erosion (sped up by humans).

P is not very abundant in the biosphere, and limits productivity in many ecosystems (inland waters, estuaries, agricultural systems)

Movement of P from rock through soils to oceans takes ~500 million years

P is used in fertilizers
Use of P has increased crop yields 2x – 3x, its depletion would mean the loss of food security
Meat and dairy products are more phosphate intensive
Before P fertilizers, farmers are reliant on locally sourced manure

China, Morocco, Algeria, South Africa, Syria and Jordan = 85% of global P reserves (obtained through Phosphate mines

Question 6

Phosphorous Flux

Answer 6

Movement of terrestrial P has decreased significantly over the last 15k years as a result of megafaunal extinction

They would release P through feces and urine in diff areas

Sub-Saharan Africa remains at nearly 100% of its late quaternary nutrient distribution capacity
Ever continent outside of Africa (~46%) is less than ~5% of its original value
South America is at ~1%

Movement of oceanic P has decreased significantly over the last 15k years as a result of overfishing
Whaling has caused teh decrease in P movement
Southern Ocean is 2% of its historical capacity
North Pacific ~10%
North Atlantic ~14%
90% reduction in amount of P flux in whale systems

Sperm whale: named for spermaceity which is oily susbtance in theri heads used as oil in lamps, candles or lubes - used in echolocation - deep diving anmial - also harvested fro ambergris in perfume - resulted in pop decrease form 1.1 m to 360k

Also seeing massive decreases in the movement of P from anadromous fishes and seabirds
P flux from seabirds has declined. Some birds have switched to more terrestrial prey
Gong into ocean to grow bigger, when you return back to spawn (after placing eggs), die at spawn and deposit all these things In freshwater systems – nitogeen and P is increased in freshwater during these phases