#21-Nutrient Supply And Cycling

Question 1

What are nutrients?

Answer 1

Chemical elements required for metabolism and growth

- has to be in certain forms for uptake

Question 2

Do animals or plants have a higher C:N ratio?

Answer 2

Animals have lower ratios

Question 3

How do plants take up nutrients?

Answer 3

In simple soluble forms

Question 4

How do animals take up nutrients ?

Answer 4

As large complex molecules that are broken down through digestion
-some can just be absorbed

Question 5

What are minerals?

Answer 5

Solid substances with characteristic chemical properties

Question 6

What is mechanical weathering?

Answer 6

The physical breakdown of rocks

Question 7

What is chemical weathering?

Answer 7

Chemical reactions release soluble forms of the mineral element

Question 8

What is soil?

Answer 8

A mix of organic matter and mineral particles water and organisms

Question 9

What is a soil solution?

Answer 9

Water contains dissolved organic matter morals and gases

-plant roots absorb this solution

Question 10

What is sand?

Answer 10

The coarsest particles

Question 11

What is clay?

Answer 11

The smallest particles

Question 12

What is the cation exchange capacity?

Answer 12

The ability of s soil to hold and exchange cations

- related to the amount and type of clay present

Question 13

What happens to soil with a high portion of sand?

Answer 13

Can’t hold water well, all drains through

Question 14

What is parent material?

Answer 14

The Rock and mineral material that was broken down by weathering to form soil

Question 15

What does the structure of the parent material determine?

Answer 15

Rate of weathering
Amount of chemical released
- can influence abundance, growth and diversity of plants

Question 16

Where is soil development the fastest?

Answer 16

Warm and wet conditions

Question 17

Can nutrients be reused and recycled?

Answer 17

Yes

Question 18

What is litter?

Answer 18

Fresh undecomposed organic matter on the soil surface

Question 19

What is mineralization?

Answer 19

Chemical conversions or organic matter into inorganic nutrients

Question 20

What controls decomposition?

Answer 20

Abiotic and biotic

Question 21

What does mineralization determine?

Answer 21

Nutrient availability

Question 22

What inhibits detrivores in soil?

Answer 22

Low O2 concentration in wet soils

Question 23

What is lignin?

Answer 23

Strengthens plant cell walls

- can affect how well it can be broken down by detrivores

Question 24

What is Nitrification?

Answer 24

NH3 and 4 –> NO3-

By bacteria in anaerobic conditions

Question 25

What is denitrification?

Answer 25

NO3- --> N2 | Under anoxic conditions

Question 26

How do you estimate soil fertility?

Answer 26

Concentration of inorganic forms of Nitrogen

Question 27

How can plants avoid competition of nitrogen?

Answer 27

Can take up different forms of it

Question 28

What is nutrient cycling?

Answer 28

Movement of nutrients in ecosystems as they undergo biological and chemical and physical transformations

Question 29

What are pools?

Answer 29

Total amount of nutrients in a component of the ecosystem

Question 30

What is the mean residence time?

Answer 30

Turnover rate | - amount of time on average that a molecules lens in the pool

Question 31

How are nutrients lost from an ecosystem?

Answer 31

Leach out of the root zone into ground water and streams Lost as gases Converted to chemical forms

Question 32

What is a watershed?

Answer 32

The land area that is drained by a single stream is often used

Question 33

How do nutrients get into a watershed?

Answer 33

Atmospheric deposition and nitrogen fixations

Question 34

How are nutrients transferred through ecosystems?

Answer 34

Herbivory Predation Decomposition Weathering

Question 35

How does an ecosystem lose nutrients?

Answer 35

Streams Atmosphere Organisms moving

Question 36

What is atmospheric deposition?

Answer 36

Elements in precipitation or aerosols and fine dust

Question 37

Equation for the total amount of element entering the watershed

Answer 37

Concentration of element x volume of precipitation in watershed

Question 38

What's harder to measure, dry or wet deposition?

Answer 38

Dry | - done less often

Question 39

What is primary succession?

Answer 39

Little organic matter in soil and little N

Question 40

Where does P originate?

Answer 40

From weathering of the mineral apatite

Question 41

What is occlusion?

Answer 41

Soluble P may combine with iron, calcium or aluminum to form insoluble compounds that are unavailable as nutrients

Question 42

What is biogeochemistry?

Answer 42

The study of physical chemical and biological factors that influence the movement and transformation of elements