L14 - Succession

Question 1

what is disturbance?

Answer 1

a discrete event in space and time that disrupts ecosystem community or population structure and changes the physical environment.

Question 2

how do disturbances vary?

Answer 2

spatially and temporally

Question 3

what is a fine scale disturbance?

Answer 3

spatially small, and typically temporally short
- tree death
- frost boils
- animal burrows

Question 4

what is a Broad- scale Disturbance

Answer 4

spatially large, and typically temporally long
-Forest fire
- severe pathogen outbreaks
- hurricanes

Question 5

how can an individual disturbance be descirbed?

Answer 5

Spatial extent
Intensity
Regularity
Timing

Question 6

what makes up a disturbance regime

Answer 6

intensity and frequency

Question 7

what is the relationship between frequency and severity of disturbances?

Answer 7

inversely proportional.
- high frequency = low severity
- low frequency = High severity

Question 8

what is succession?

Answer 8

Cumulative directional change in community composition through time.

Question 9

what is the problem with modern views of succession?

Answer 9

succession is a series of stages that result in a stable climax community.
changes are predictable.

Question 10

what is the modern view of succession?

Answer 10

Succession doesn’t proceed to a single endpoint

Question 11

What are the three components of modern views of succession

Answer 11

Polyclimaxes
- succession with multiple end points
Disclimaxes
- frequent disturbance limits
Edaphic Climax
- local variation in soils limits succession

Question 12

What is an alternative stable states

Answer 12

Different ecological configurations that occur in the same place under similar environmental conditions. occurs due to disturbance

Question 13

what is the ball and cup diagram used for

Answer 13

representing alternative stable states with tipping points and thresholds

Question 14

what is ecological resilience?

Answer 14

the magnitude of the disturbance that an ecosystem can absorb without exhibiting a fundamental shifts structure and function.

Question 15

what is the facilitation model of succession?

Answer 15

early successional stages create conditions that favor new assemblages of species.
EX. arrival of gulls on a desert island bringing seeds.

Question 16

what is the Tolerance Model of succession?

Answer 16

species have different competitive abilities. early successional stages are dominated by better colonists.
r- adapted, k-adapted

Question 17

What is the Inhabitation Model of succession?

Answer 17

First species to establish alter the environment in ways that inhibit other species.