Succession

Question 1

What is succession?

Answer 1

The directional change in the structure of a community over time

Question 2

What is each sequence of succession called?

Answer 2

A sere, or a seral stage

Question 3

How is succession different from zonation?

Answer 3

Succession is in one location, zonation is across the landscape

Question 4

What is the end stage of succession?

Answer 4

The climax community

Question 5

Are changes during succession random or do they follow a predictable pattern?

Answer 5

Both, depends on the community

Question 6

Who is the guy who came up with the relay floristics mechanism of succession? What is it?

Answer 6

Clements

Succession proceeds by predictable changes, inhibition, facilitation, and tolerance “pathways”

Question 7

What is the facilitation “pathway” in relay floristics?

Answer 7

Early species facilitate the arrival of late species. Resident species don’t change the environment in any way that favours other species

Question 8

What is the tolerance “pathway” in relay floristics?

Answer 8

Environment is unsuitable for early species, but neither favourable or unfavourable for late species. Resident species are the ones able to tolerate the conditions

Question 9

What is the inhibition “pathway” in relay floristics?

Answer 9

Environment is less suitable for establishment by all species. Resident species inhibit the establishment of all other species

Question 10

Who is the guy who came up with the initial floristics mechanism of succession? What is it?

Answer 10

Egler

What matters is who gets there first, if its pioneer species or species that survived the disturbance that reestablish

Question 11

Who is the guy who came up with the idea that all successional changes are random?

Answer 11

Gleason

Question 12

What are the 3 successional stages?

Answer 12

Early, mid, late

Question 13

What species are in the early successional stages?

Answer 13

The pioneer community. Species with high growth rates, high dispersal, small size, potential for high population growth, r species

Question 14

What species are in the late successional stages?

Answer 14

Species that are better at competition, lower dispersal, lower colonization, slower growth, longer lived, K species

Question 15

What is primary succession?

Answer 15

Occurs on newly exposed substrates with no previous plant communities

Question 16

What are the steps of primary succession? How long does it take?

Answer 16

1. Rock weathering
2. Soil formation from lichens and mosses that die, leave behind organic matter
3. Successional stages
   Hundreds of years

Question 17

When does primary succession occur?

Answer 17

When no soil is initially present. Glacial retreat, volcanic rocks, sand dunes, etc

Question 18

What is secondary succession?

Answer 18

Occurs on previously vegetated surfaces, with the first pioneer species already there

Question 19

When does secondary succession occur?

Answer 19

After a disturbance, when soil is already present

Question 20

What is the difference between primary and secondary succession?

Answer 20

The initial presence of soil

Question 21

How do climax communities and pioneer communities differ in terms of seed dispersal?

Answer 21

Pioneer communities have wind dispersal, climax communities have animal dispersal

Question 22

What are autogenic environmental changes?

Answer 22

Results from species within a community

Question 23

What are allogenic environmental changes?

Answer 23

Results from physical environment

Question 24

What drives succession in a terrestrial environment?

Answer 24

Species colonization and replacement

Question 25

How can speed of replacement be decreased during succession?

Answer 25

Slow competition, disturbances (fire, insect outbreaks, human activity

Question 26

What drives succession in aquatic systems? Where does it tend to happen?

Answer 26

Sedimentation and eutrophication. Common in eutrophic lakes

Question 27

What are the successional stages in aquatic systems?

Answer 27

Shallow lake -> marsh -> bog/fen -> terrestrial environment

Question 28

How can succession be reversed?

Answer 28

Disturbances will set back succession to earlier stages, and knock back the abundance of dominant species, creating stability

Question 29

How can stability be created (2 ways)? What determines those?

Answer 29

Resistance: maintaining structure/function in face of a potential disturbance
Resilience: how fast a community comes back after a disturbance
Both are determined by biodiversity