L6-competition,predation,supply-side ecology Flashcards
What is idea of Intertidal zonation?
Physiological tolerances of different species lead to their distribution?(species live where they can survive)
How did Connell’s findings not fit intertidal zonation?
Cthalamus settles everywhere
But adults only in top zone
Transplant Cthalamus to lower level can still survive
What is competitive exclusion?
species may be able to live somewhere but get out competed by other species.
eg. Cthalamus was
undercut/overgrown by Balanus but could survive where balanus was not present
Whys is competitive exclusion important?
its an important structuring force in communities
How do competitive ability and colonizing ability interact?
Early species good colonisers (‘weeds’)
Late species poor colonisers but good competitors
What type of larvae do colonizers typically have?
plantonic
What happens when new environment appears after disturbance?
starts with colonizers then competitors
What is the intermediate disturbance hypothesis?
highest species diversity happens at medium disturbance where both good competitors and good colonizers can flourish. to little or to much disturbance selects for only one
What happens at vary disturbed sites?
often same disturbance but select for colonisers
how do predators affect colonization?
Predation opens up space
Predation can act like disturbance
What was the 80’s view of marine communities?What assumptions?
• Competition
• Disturbance
• Predation
Hidden assumption:All space taken up
How does australian compare to us?
australia less productive
less competitive environments
limited larvae supply
less feeding larvae
What is supply-side ecology?
Recruitment into a population has the
potential to affect the dynamics of that
population
less recruitment
What does less larvae supply mean?
less Post-settlement factors
What affects recruitment?
- Recruitment = (Larval supply x Larval Behaviour) – Post-settlement mortality
- Larval supply = production of larvae x delivery of larvae
