week 12

Question 1

What are the two most listing elements to terrestrial vegetation?

Answer 1

Nitrogen (N) and phosphorus(P)

Question 2

Where do plants take up essential nutrients?

Answer 2

through the roots

Question 3

What do elements undergo for nutrients to be available for plant uptake?

Answer 3

mineralisation

Question 4

What do the pH and redox state affect?

Answer 4

availability of nutrients for plants

Question 5

Land plants key features?

Answer 5

• Vascular System (wood/lignin/cellulose)
• Roots (wood/lignin/cellulose)
• Structure (wood/lignin/cellulose)
• Storage (starch)

Question 6

N:P ratios of terrestrial plants are similar to the Redfield ratio found in?

Answer 6

marine phytoplankton. But there is a lot more C.

Question 7

What does the N/P ratio do as it heads towards the equator?

Answer 7

increases

Question 8

nutrients and C leaves in Australian foliage?

Answer 8

Low on nutrients

High on C

Question 9

What are the effects of Excess C?

Answer 9

Affects pollination
Affects herbivory
Sclerophylly

Question 10

What is Sclerophylly?

Answer 10

Hard, tough, stiff leaves: efficient biomass partitioning in stressful environments, increased likelihood of leaves reaching the optimal lifespan.

Question 11

Ideal leaf traits

Answer 11

Thin
large
low C:N ratio
high turgor
high photosynthetic capacity

Question 12

What are heavy metals?

Answer 12

Heavy metals are elements that exhibit metallic properties such as ductility, malleability, conductivity, cation stability, and ligand specificity. Relatively high density and high relative atomic weight with an atomic number greater than 20

Question 13

What happens when heavy metals concentrations get above 0.1%?

Answer 13

With the exception of Fe, all heavy metals above a concentration of 0.1% in the soil become toxic to most plants

Question 14

What is Tolerance?

Answer 14

the ability to survive, grow and reproduce in areas with high levels of heavy metal in the soil

Question 15

What are the two different tolerance methods?

Answer 15

Accumulation

Exclusion– (most plants)

Question 16

Key details Accumulation?

Answer 16

(1) root uptake to the cell (not exclusion)
(2) root-to-shoot translocation (move the
metal from the root to the shoot)
(3) Heavy metal binding to the cell walls and/or cell exudates
(4) chelation in the cytosol and/or
sequestration in vacuoles,

Question 17

What are hyper accumulators?

Answer 17

• strongly enhanced rate of heavy metal uptake
• faster root-to-shoot translocation
• greater ability to detoxify and sequester heavy metals in leaves

Question 18

What are the criteria for a hyper accumulator?

Answer 18

-the concentration of metal in the shoot must be higher than 0.1% for Al, As, Co, Cr, Cu, Ni, and Se, higher than 0.01% for Cd, and higher than 1.0% for Zn
-the ratio of shoot to root concentration must be consistently higher than 1; this indicates the capability to transport metals from roots to shoot and the existence of
hypertolerance ability
-the ratio of shoot to root indicates the degree of plant metal uptake (a higher ratio indicates more accumulation)

Question 19

What is Phytoremediation?

Answer 19

Using hyperaccumlators ti take up heavy metals improving the soil

Question 20

What is Phytoremediation used for?

Answer 20

Wastewater treatment, heavy metals and metalloids, organic pollutants (TNT, PCB) and radionucleotides.

Question 21

What are the advantages of Phytoremediation?

Answer 21

Perceived to occur via natural processes
Aesthetically pleasing
Inexpensive

Question 22

What are the Limitations of Phytoremediation?

Answer 22

Effective only where contamination of soil and water is shallow (< 5 m)
Takes time and affected by growing conditions
Can transfer toxins up the food chain

Question 23

Why did Phytoremediation fail at Fukushima?

Answer 23

Genetic differences between the sunflower genotypes used in the Ukraine and Japan could account for the success and failure of phytoremediation projects in these countries

Question 24

What is Phyto (biogeochemical, geo-botanical) exploration?

Answer 24

using plants for mapping geology, mineral deposits, petroleum seeps

Question 25

Plant criteria for Phyto (biogeochemical, geo-botanical) exploration?

Answer 25

Easy to identify
Sufficiently common
Root system reaches at least a few meters depth
Roots that explore a large area ofsoil
Bark, leaves