topic 2

Question 1

Name the 5 stages of succession

Answer 1

1) First plant to establish is easily and widely dispersed, able to grow mature quickly (Pioneer species)
2) Plants that are properly dispersed and slower growing may become dominant (forbs and grass)
3) Woody plants become part of landscape, first with shrubs, then trees
4) Trees take over, first ones will be shade intolerant, then they will grow over our pioneer species
5) Reached climax community

Question 2

What is climax vegetation?

Answer 2

The vegetation that has reached steady state. No more major species replacements are occurring

Question 3

What are three micro-climate changes when a highly resistant community faces large scales disturbance

Answer 3

1) Surface temperature change due to dramatic change in albedo
2) Cleared forest tracts are slow to recover
3) Resilience is compromised for stability

Question 4

What is biome has very high resilience?

Answer 4

• Mid latitude grasslands

Question 5

What is a paradigm?

Answer 5

Ecosystems tend to move toward maximum biomass and stability
- Paradigm is upset in response to an accumulation of anomalies

Question 6

Explain main steps of succession in the Hubbard Brook in a gap

Answer 6

This is a broadleaf deciduous forest, and succession is impacted by size of gap
1) First birch grows - it has small light seeds that disperse 100m, that germinate well, but does not grow well in the shade of other trees.
2) Yellow birch grows, producing shade and adding OM to soil
3) Sugar maple will grow due to high seed production. Shade will kill original birch
4) Beech will grow, sprouting from seeds or roots of older beech

Question 7

Describe Pin cherry growth and large scale succession

Answer 7

Pin cherry is first shrub to colonize due to a seed bank.
- Seeds survive in the soil for >60 years “waiting fo right conditions”

Stabilizes nitrogen losses and returns OM to the system. Good for resilience

Question 8

Describe cause of gap in an equatorial rain forest - what is the name of this process?

Answer 8

Chablis:
- Fall of tree
- Hole in canopy
- Accumulated debris
- Disturbance to the soil

Question 9

What are the three zones created after chablis?

Answer 9

• Crown gap- gap in crown where lower trees and shrubs stay intact, but mineral soil is spread
• Epicentre- where the crown fell - lots OM is added to soil surface
• Peripheral zones - surrounding zones

Question 10

What is main difference between tropical rain forest and the Mid-latitude deciduous forest?

Answer 10

Climax species of tropical rain forest is not the same species that was originally in the location
Seeds that fall in vicinity of producing trees won’t sprout - due to high seed predation
OG species seeds will be available some distance away

Question 11

Describe succession in a boreal forest after a fire

Answer 11

Initially, depth of permafrost will drop, have a deep active layer, and an increase is mineralization
1) Pioneer species occurs NOT SHADE TOLERANT (fireweed, aspen and birch)
2) Litter from leaves produce nitrogen and lower lignin
3) Serotinous cones produce black spruce, which create shade and decrease soil temp, bringing permafrost back up. Increase in soil water content
4) Moss outcompetes spruce, and stops new spruce from growing

Question 12

Are climax vegetations of broadleaf forests self-perpetuating?

Answer 12

• Beech sprouts from it’s root and is shade tolerant!
• It is self perpetuating

Question 13

Are climax vegetations of rain forests self-perpetuating?

Answer 13

• If shade tolerant, they are self-perpetuating

Question 14

What is climax vegetation of boreal forest?

Answer 14

• Moss
• Not self-perpetuating- needs disturbance in order to go through steps of succession to be able to arrive