20: Nutrient Cycling & Biogeochemical Cycling

Question 1

Pathway of an element or nutrients through an ecosystem

Answer 1

Nutrient cycling (at the ecosystem level)

Question 2

The exchange and movement of elements or nutrients between the physical environment and living organisms. Much larger spatial scale the nutrient cycling.

Answer 2

Biogeochemical cycling (at the biosphere scale)

Question 3

What controls the availability of essential elements and minerals?

Answer 3

Their inputs, transformations, and outputs.

Question 4

What are the rates of inputs, transformations, and outputs related to?

Answer 4

The interactions among organisms and their interactions with the environment

Question 5

What is the original source for all essential elements?

Answer 5

The physical environment (big bang)

Question 6

What are the two types of biogeochemical cycles?

Answer 6

Gas and sedimentary

Question 7

What does the gaseous biogeochemical cycle include?

Answer 7

The atmosphere and the ocean

Question 8

What does the sedimentary biogeochemical cycle include?

Answer 8

Soils, rocks, and minerals move

Question 9

Where the three primary elements required for life?

Answer 9

Carbon, nitrogen, and phosphorus

Question 10

Major carbon pools

Answer 10

Atmosphere; marine and terrestrial soils; fossil fuels; autotrophs and heterotrophs

Question 11

What represent to the largest CO2 pools?

Answer 11

The atmosphere and water (mostly Ocean)

Question 12

What are the major processes that control the flux of carbon between the atmosphere and the living environment?

Answer 12

Photosynthesis and respiration

Question 13

The movement of nutrients between one nutrient pool and another

Answer 13

Flux

Question 14

What moves carbon from the atmosphere to autotrophs (or from the water to aquatic autotrophs)?

Answer 14

Photosynthesis

Question 15

What does photosynthesis do?

Answer 15

Transforms CO2 into organic carbon

Question 16

What moves carbon from autotrophs or heterotrophs to the atmosphere?

Answer 16

Respiration

Question 17

What does respiration do?

Answer 17

Transformed organic carbon into CO2

Question 18

What controls how much carbon will be stored in primary producers?

Answer 18

Gross primary production

Question 19

Which abiotic factors influence the rate of gross primary production and thus the flux of CO2 from the atmosphere to the living environment?

Answer 19

Nutrients, temperature, and precipitation

Question 20

What controls how much carbon will move up the food chain?

Answer 20

Consumption rates and production efficiency of consumers

Question 21

What controls how much carbon will be returned to the atmosphere or water as CO2?

Answer 21

Respiration rates

Question 22

Based on production efficiencies alone which taxa allows for more organic carbon to be cycled up the food web? Invertebrates (30-40%), ectothermic vertebrates (~ 10%), or endothermic vertebrates (1 to 2%)

Answer 22

Invertebrates

Question 23

What is the major control over returning organic carbon in fossil fuels to the atmosphere as CO2

Answer 23

The rate of fossil fuel use by humans

Question 24

Major nitrogen pools

Answer 24

Atmosphere (largest), soils, water, and organisms

Question 25

Convert N2 gas to nitrate + nitrate or ammonia, which are usable forms to plants

Answer 25

Nitrogen fixtures (Nitrification)

Question 26

List three nitrogen fixers

Answer 26

Cyanobacteria, Free living bacteria, root associated bacteria

Question 27

Generates enough high-pressure and energy to perform nitrogen fixation

Answer 27

Lightening

Question 28

What gets nitrogen into the food web?

Answer 28

Nitrification and Ammonification

Question 29

Transforms nitrate back to N2 gas

Answer 29

Denitrification (done by bacteria)

Question 30

How have humans altered the N cycle?

Answer 30

Haber-Bosch process (artificial N fixation for fertilizer)

Question 31

Major pools of phosphorus

Answer 31

Largest pools occur in mineral deposits and marine sediments

Question 32

What is the major way in which phosphorus is released from minerals?

Answer 32

Weathering. Once released into soils a can be taken up by plants

Question 33

A fungus that grows on plants roots. it has a symbiotic relationship with plants that help plants absorb nutrients

Answer 33

Mycorrhizae fungi

Question 34

Phosphorus can enter the food web once it has been?

Answer 34

taken-up by plants

Question 35

What are the major processes for P to enter the food web?

Answer 35

1-Weathering. 2-Mycorrhizae fungi transfer nutrients to plants. 3-Herbivory enters phosphorus into the heterotrophic food web

Question 36

not evenly distributed across the world, but we can make more available by mining it from rock

Answer 36

phosphorus

Question 37

How have humans altered the P cycle?

Answer 37

China, Morocco, and Western Sahara largest producers of mined phosphate. 80% US production comes from 10 mines in Florida and 1 mine (world largest) in North Carolina

Question 38

breakdown of chemical bonds that were formed during the constructions of plant and animal tissue

Answer 38

decomposition

Question 39

converts organic compounds into inorganic nutrients that can be taken up by plants

Answer 39

decomposition

Question 40

involves high rates of respiration that convert organic C to CO2 releasing it back to the atmosphere

Answer 40

decomposition

Question 41

Processes of Decomposition

Answer 41

Leaching, Fragmentation, Ingestion, and Excretion of Waste

Question 42

removal of soluble nutrients from a substance through the percolation of water

Answer 42

leaching

Question 43

breaking down of smaller parts. increases surface area allowing more bacteria to colonize , increasing rate of decomposition

Answer 43

fragmentation

Question 44

Major controls on decomposition

Answer 44

temperature and precipitation

Question 45

Which biome is the largest source of CO2 to the atmosphere due to high rates of decomposition? tundra, tropics, desert, or boreal forest

Answer 45

Tropics

Question 46

can be a major source of new nutrients

Answer 46

decomposition