Final Exam Flashcards
(32 cards)
Resource competition v. Interference competition
Resource: Shared resource is in short supply; indirect interaction
Interference: Shared resource is usually in short supply; direct interaction
2 Types of Competition
- Resource Competition
2. Interference Competition
Define Competition
One individual gains access to limited resources at the expense of another individual
What is the Competitive Exclusion Principle
Populations of two species with identical niches cannot coexist indefinitely (there will be competition)
What are the conditions for the Competitive Exclusion Principle?
One or more resources must be in short supply
The environment remains consistent
Must be a long enough time for equilibrium
How can you explain competition in nature?
Resource Partitioning
Character Displacement
Environmental Instability
Resource Partitioning v. Character Displacement
Resource Partitioning: 2+ species divide the resources to reduce competition
Character Displacement: competing species evolve traits to reduce competition
What are the types of exploitation?
Predation, Herbivory, Parasitism, Disease, Parasitoid
Hypothesized Dynamics of exploitation
Predator has negative effect on prey/host; Prey has positive effect on predator
Time lag between predator and prey
What can we conclude from predator-prey interactions?
Predator-prey interaction is unstable without external influence
What are the outcomes of predator-prey interactions?
Stable equilibrium
Stable cycles
Unstable cycles
Dampened oscillations
What is the Evolutionary Arms Race?
Predator: sharp claws, enhanced vision
Prey: size, camouflage, enhanced hearing
What is a prudent predator?
A predator that feeds at the maximum sustainable yield. “Cheaters” make this not happen
What are the emergent properties of a community?
Diversity Structure Number of Trophic Levels Number of links Stability
What are the measures of diversity?
Species Richness
Heterogeneity
Species Richness v. Heterogeneity
Species Richness: # Species in a community
Heterogeneity: relative proportion of species
How can you explain high and low diversity?
Habitat isolation and size (island example)
Resource Partitioning
Disturbance
What is the intermediate Disturbance Hypothesis?
A communities diversity is the greatest when there is an intermediate amount of disturbances
What is a keystone predator?
Predator whose removal results in a very different food web
What is a super-organism?
Clumped distribution of species ie. Coral reef
What is the facilitation mechanism of success?
Early species modify the environment and late species outcompete the early species
What is the inhibition mechanism of succession?
Early species prevent colonization of late species by creating physical or chemical barriers, and late species arrive following the death of the early species
What is the tolerance mechanism of succession?
All species colonize at the same time but late species outcompete the early species (not much evidence for this)
What is an ecosystem?
A community and its physical and chemical environment
