How does supply side ecology affect rocky shore communities ?

Question 1

Dispersal

Answer 1

Describes how far individuals are carried by the currents and affects how genes move between populations

Question 2

Settlement

Answer 2

Describes when pelagic larvae settle onto the benthos

Question 3

Recruitment

Answer 3

Describes when a new individual joins the population

Question 4

What affects the survival of larvae? (3)

Answer 4

Suitable environmental conditions
Availability of food for larvae
Predators

Question 5

Important Factors for Dispersal (3)

Answer 5

Reproductive outputs of adults: fecundity and density

Larval life stage (planktonic vs non-lecithotrophic)
How much fuel do they have and how reliant are they on other resources

Currents: How far do they get and where do they go

Question 6

What promotes settlement? (2)

Answer 6

Larvae detect appropriate surfaces via chemical means
Chemical cues of adults conspecifics (gregariousness)

Differences in light, food, concentrations, presence of appropriate surface to attach, beach angle, surface texture

Question 7

Menge-Sutherland model

Answer 7

When physical conditions are stressful, biological interactions are less important than environmental factors (environmental tolerance)

When physical conditions are benign, biological forces are more important than environmental forces (competition/predation)

Predators are more sensitive to environmental stress, so predation requires more benign environmental conditions than competition to be important

Question 8

Using the Menge-Sutherland model to explain zonation

Answer 8

Tolerance to abiotic conditions sets the upper limit of distribution (how high up the shore the organisms are found), while ecological (biotic) interactions set the lower limit (how far down the intertidal the organisms are found)

Question 9

Menge-Sutherland model under low recruitment

Answer 9

Environmental tolerance is most important under harsh conditions, with it slowly decreasing

Competition is a bell curve with its peak at intermediate conditions

Predation is a slow linear increase starting at intermediate conditions and peaking at benign

Question 10

Menge-Sutherland model under high recruitment

Answer 10

Environmental tolerance is most important under harsh conditions with a fast decrease

Competition is a bell curve with a peak at intermediate conditions

Predation begins at intermediate with its increase into the benign conditions before slowly decreasing as competition becomes important.