Week 4 Biogeochemical flows

Question 1

What is biogeochemical flows?

Answer 1

The movement of nutrients, nitrogen, phosphorous, and carbon through abiotic and biotic factors of the ecosystem

Question 2

What are the main nutrients?

Answer 2

Phosphorous
Nitrogen
Carbon (discussed in climate change)

Question 3

List the thre processes through which nitrogen is “fixed” into a reaction form?

Answer 3

N-fixation
nitrogen gas to ammonia
(done by microbes)

Nitrification
ammonia to nitrate
(done by lighting)

Decomposition break down organic matter and release NH4.

Question 4

Why is the phosphorous cycle the slowest of all?

Answer 4

It moves slowly through soil and ocean; one of the slowest. takes time to erode rocks

Question 5

How do human activities alter phosphorous and nitrogen biogeo cycles?

Answer 5

Industrial production of Nitrogen and mining of phosphorous all increase the rates at which they exist

Fertilizers made from nitrogen and phosphorous run off from land into the ocean causing eutrophication.

Question 6

What is eutrophication?

Answer 6

the accumulation of excess nutrients in water bodies due to runoff from land, causing dense growth of plants and death of animals/aquatic life from lack of O2 (hypoxia)

Question 7

Identify the control variables and planetary boundaries for biogeochemical flow

Answer 7

P global: phosphorous flow from freshwater systems into ocean

N global: industrial and intentional biological fixation of nitrogen

units: Teragram (Tg)

Question 8

Anthropogenic sources of eutrophication

Answer 8

-munical sewage
-livestock waste
-agricultural fertilizer
-aquaculture
-storm drainage

Question 9

Describe the environmental effects of excess nitrogen in the environment (“the nitrogen “cascade”) ?

Answer 9

overgrowth of algae and plants
death of animals lack of oxygen
ocean acidification creates anoxic environments
releases potent greenhouse gas trapping heat

Question 10

How can you reduce the amount of P and N entering waterways?

Answer 10

Filter in waterbodies, they absorb algae and the algae can then be used as fertilizers.