Coral Reef Succession
Coral Reef SuccessionCoral Reef Succession
Ecological SuccessionEcological Succession
The progressive change in the species composition of an ecosystem.
Ecological SuccessionEcological
Succession
Climax StageClimax Stage
New Bare SubstrateNew Bare Substrate
Colonizing StageColonizing Stage
Successionist StageSuccessionist Stage
PRIMARY SECONDARY
Growth occurs on newly exposed surfaces where no soil exists
Ex. Surfaces of volcanic eruptions
Growth occurring after a disturbance changes a community without removing the soil
2 types of succession
• For example, new land created by a volcanic eruption is colonized by various living organisms
• For example, new land created by a volcanic eruption is colonized by various living organisms
• Disturbances responsible can include cleared and plowed land, burned woodlands
• Disturbances responsible can include cleared and plowed land, burned woodlands
Mount St. Helens
prior 1980
Mount St. Helens
May 18, 1980
Sep. 24, 1980
Mount St. Helens
Fireweed 1980 after eruption
2004
2012
Hanauma Bay Tuff Ring(shield volcano)
Succession after Volcanic Eruption
What organisms would appear first?
How do organisms arrive, i.e., methods for dispersal?
Volcanic eruption creates sterile environment
Mechanisms of Succession
Facilitation
Inhibition
Tolerance
Early species improve habitat.
Ex. Early marine colonists provide a substrate conducive for settling of later arriving species.
As resources become scarce due to depletion and competition, species capable of tolerating the lowest resource levels will survive.
Competition for space, nutrients and light; allopathic chemicals.
First arrivals take precedence.
r & K Selected Species
Pioneer species- 1st species to colonize a newly disturbed area
r selected
Late successional species
K selected
low competitive abilityshort life spanhigh growth rate
higher maternal investment per offspringlow reproductive output
high reproductive output
slow growth ratelong life spanhigh competitive ability
r & K refer to parameters in logistic growth
equation
Ecological Succession on a Coral Reef
Ecological Succession on a Coral Reef
Successional Models and their Impacts (p.133)
Successional Models and their Impacts (p.133)
• Case 1: No Disturbance (Competitive Exclusion Model)
• Case 2: Occasional Strong Disturbance (Intermediate Disturbance Model)
• Case 3: Constant Strong Disturbance (Colonial Model)
• Case 1: No Disturbance (Competitive Exclusion Model)
• Case 2: Occasional Strong Disturbance (Intermediate Disturbance Model)
• Case 3: Constant Strong Disturbance (Colonial Model)
Case 1: No Disturbance(Competitive Exclusion Model)
• As the reef becomes complex, organisms compete for space.• Dominant organism outcompetes other species.• Occurs in stable environments. • Results in low species diversity.• Highly protected patch reefs within lagoons or protected bays• Deeper water
Case 2: Occasional Strong Disturbance(Intermediate Disturbance Model)
• Storms and hurricanes allow for other species to move in• Dominant species would not be allowed to reach competitive exclusion• After each disturbance have a recovery period• Area of high diversity
Case 3: Constant Strong Disturbance(Colonial Model)
• Constant exposure to disturbance• Shallow environment• High turnover of species• r-selected species
Reef
Case 3
Case 2
Case 1Deep reef slope
Reef slope beneath reef crest
Near reef crest
Ecological Succession on a Coral ReefThe Big Island
Ecological Succession on a Coral ReefThe Big Island
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Ecological Succession on a Coral ReefEcological Succession on a Coral Reef
Successional Models and their Impacts
Successional Models and their Impacts
a) The slopes of a newly formed volcanic island
b) Wetlands in Texas, following Hurricane Rita
c) A receding glacier
d) A dried up lake
e) Primary succession would not occur on any of these.
a) The slopes of a newly formed volcanic island
b) Wetlands in Texas, following Hurricane Rita
c) A receding glacier
d) A dried up lake
e) Primary succession would not occur on any of these.
Primary succession would take place on all of the following EXCEPT:
QUESTION: Review
A “K” selected species generally has all of the following characteristics EXCEPT:
a) Large sizeb) Short-livedc) Good competitord) Constant population sizee) Slow population growth