Dendrology (FREC 2314)

True or False : As temperature increases photosynthesis increases (to an extent)

True

True or False : Photosynthesis decreases as water availability decreases

True

True or False : The lower the CO2 the higher the photosynthetic rate.

False

What is known to the have the greatest effect on WUE.

hi CO2 levels

Why do plants respirate?

to grow and maintain themselves.

Which leaf has a higher light compensation point? Sun leaf or shade leaf?

Sun Leaf

Which leaf invests more in light harvesting chlorophyll? sun or shade?

Shade leaf

Which leaf typically respirates more? Sun or shade?

Sun leaf

Which leaf has the lower light use efficiency? Sun or shade?

Sun leaf

Name all of the PHYSICAL factors related to plant growth.

Photosynthetic rate

Respiration rate

Allocation of Carbon

Leaf surface area

Seasonal patterns of the above processes

water moves from ____ to _____

high to low energy OR high to low water potential

What is the greatest abiotic factor which drives all productivity on earthen environments?

Water

List 4 qualities that make water unique/important

Solvent of everything

reactant in Ps

80-90% of growing tissues

Maintains pressure (turgidity)

What is the water potential of PURE WATER?

0

What. is cavitation?

a bubble of air in the water column

What theory explains the movement of water up a tree?

The Cohesion- Tension theory

What are some ways that trees resist drought?

Tolerance

Desiccation postponement

(of the root system, leaf adaptations, stomatal control, metabolic adaptations, water storage)

What kind of growth is auxin responsible for? (List 2)

Apical Dominance and stem elongation

Plants with few gibberellins typically lack what?

Stem length

If you want your tree to stay short or to not flower as much what would you spray on it?

Anti-Gibberellins ("Bonzai" is one type of anti-gibber.)

Which growth hormone can cause abnormally high cell division?

Cytokinin

You are working for a Christmas tree farm and you have been assigned to make the trees have a more classic Christmas tree look. What combination of hormones would you apply in addition to manual pruning?

an anti-gibberlin (auxin-inhibitor) to reduce stem elongation and cytokinin to make the base of the tree more "bushy" looking.

Which hormone has been named the "fruit ripening" hormone?

Ethylene (C2H4)

If sprayed on a plant, Abscisic acid will cause what result?

Dormancy

Briefly describe the conditions that will result in winter burn.

when a tree, planted on the south side of a building during the winter experiences a warm day while the root system remains in frozen soil. The needles will let water out and no water will be able to replenish from the roots.

is winter burn typically fatal on its own?

No, the buds have set by this time.

Name the 3 stages of dormancy?

Pre dormancy, true dormancy, post dormancy

Taking a plant out of its pre-dormancy stage is impossible. T or F?

False. this stage is reversible.

How can a tree in true dormancy be taken out of it?

It must be "wintered"

How does a tree develop dormancy.

Mainly by changes in day length. Also temperature, mineral availability, and water.

Briefly describe red belt disease

When the soil freezes, air temp increases and winter burn happens along a single "belt" on a mountain range. the weather phenomena is just so.

how do trees demonstrate cold tolerance?

1. Super cooling in the cell. (reducing their nucleating centers and this allows them remain liquid in the cell well below -39C

2. Intracellular dehydration. mechanisms in the plant are able to maintain their dehydrated cells. they can later be damaged by dehydration though.

True or False : a functioning plant membrane can be a solid.

False. must be FLUID

What kind of fatty acid is liquid at low temperatures?

unsaturated F.A

What kind of fatty acid is solid at relatively higher temperatures?

saturated F.A

Plants preparing for winter will make more _______ fatty acids.

unsaturated

Describe chilling injury

If the plant has not adjusted its cells and has too many saturated fatty acids and not enough unsaturated fatty acids. A large number of membranes become solid and burst