Succession

Question 1

Succession

Answer 1

The process by which the mix of species and habitat in an area changes over time

• Established communities are replaced by more
  evolved natural communities

Question 2

Primary succession

Answer 2

The establishment of a community following a catastrophic disturbance (volcanic
eruption, glacial retreat, landslide) on land that was not previously vegetated

-Requires soil development
- Very slow process (100s of yrs)

Question 3

Secondary succession

Answer 3

The establishment of a community following a small disturbance (fire,
agricultural abandonment, hurricane) on land that was previously vegetated

• Doesn’t usually require soil development
• Relatively fast (10s of yrs)

Question 4

What happens post-fire recovery to ecosystems?

Answer 4

Cover and biomass increase rapidly after fire & reach a maximum

• Net primary production reaches a maximum value

Question 5

What do the changes in plant cover do during post-fire recovery?

Answer 5

Lead to changes in soil’s physical + chemical properties

Question 6

What are the 3 mechanisms of succession?

Answer 6

1. Facilitation
2. Tolerance
3. Inhibition

Question 7

Facilitation

Answer 7

Environment is less suitable for early species but more suitable for late successional species

• early successional species die out

Question 8

Tolerance

Answer 8

Environment less suitable for early species but neither less nor more favorable for later successional species

Question 9

Inhibition

Answer 9

Environment is less suitable for establishment across all species

Question 10

What do some species do in regards to facilitation?

Answer 10

They add organic matter and nutrients to the soil in the expansion of later successional species to make it more suitable for them

Question 11

How does later successional species affect other species in relation to inhibition?

Answer 11

Can shade shorter species, consume water and nutrients, or produce litter that inhibits the growth of other species

Question 12

Species that are present during all stages of succession are able to ?

Answer 12

Tolerate changes in resource availability and plant species composition

Question 13

What are the effects of fire frequency on plant communities?

Answer 13

Fire frequencies in chaparral that are too high have a low chance in shrub resprouting and deleted seedbanks

Question 14

What does the variation in frequency or magnitude of disturbance affect?

Answer 14

The rate and magnitude of the ecosystem response

Question 15

Climate climax

Answer 15

Is the last stage of ecological development of a particular area, such as a mountain top or plain

• Remains relatively unchanged until destroyed by an event such as fire or human interference.

Question 16

Monoclimax

Answer 16

Has only one type of climate in the beginning and end of succession

• Succession begins is diverse areas, but converges into one single climax community decided by their regional climate

Question 17

Polyclimax

Answer 17

Variable factors

• Not just the climate, but also animal activity, soil nutrients, moisture, and other factors affect these climaxes