Quiz 6 Flashcards
Summarize feeding relationships in a community
Food web
Dominant species have both: _________ and _________. on community structure.
high biomass
Strong influence
What is a keystone species?
What does it accomplish in communities?
Species that exerts strong effects on their community structure, despite low biomass
What would happen if you removed the Pisaster starfish from the community?
it would decrease the diversity in the community by 8-15
What interactions exist among green algae, red algae, crabs, snails and gulls?
Green algae outcompete the red algae
Snails eat the green algae
Crabs eat the dam snails
Gulls eat the dam crabs
What conditions do keystone species create between species in the same area?
They decrease the competitive exclusiveness between species, therefore increasing the number of co-existing species
Dominant species vs. Keystone species
- Biomass
- Influence on community
Dominant
- high
- strong
Keystone
- could be high or low
- strong relative to biomass
Gradual change in plant and animal communities in an area.
Succession
Succession on newly exposed geological substrates
Primary
Succession that follows disturbance, and does not destroy soil
Secondary
When do we first see the pioneer community?
“the weedy species that are first able to take advantage of that substrate” - Gerson
How does the pioneer community influence the soil in environments?
Increase soil depth and depth of each horizon layer
What is the model about ecosystem recovery?
Biomass Accumulation Model
What are the 4 phases of Biomass Accumulation Model?
- Re-organization - some species continue to decrease i guess [idk tbh]
- Aggradation - biomass start to build back up
- Transition - biomass declines from peak as later stage successional species exclude weaker competitor
- Steady-State - fluctuates around mean
Absence of change
Stability
