Chapter 54: Community Ecology Flashcards
What is biodiversity?
The variety of life across all levels of biological organization
- genetic diversity
- species diversity
- ecosystem diversity
What is genetic diversity?
Varying genes that make up the characteristics of a species
What is species diversity?
Number of different species in a particular region
Two parts:
Species richness
Species evenness
What is ecosystem diversity?
Variety of habitats and communities in the world
What is species richness?
The number of species
What is species evenness?
The relative abundance of the species in that environment
How many there are for that environment
Answer the following for each location:
a) What is the species richness?
b) What is the species evenness?
Location 1:
- One tree
- Nine of the same shrub
Location 2:
- Five of the same tree
- Five of the same shrub
Location 1:
a) Species richness = 2
b) Species evenness = low
Location 2:
a) Species richness = 2
b) Species evenness = high
What does the Berger-Parker Index say about diversity?
The sample with greater evenness is more diverse than the sample with greater richness
How are community interactions classified?
By whether they help, harm, or have no effect on the species involved.
What are the 4 community interactions?
- Competition
- Predation
- Herbivory
- Symbiosis
- parasitism
- mutualism
- commensalism
What is competition?
When two or more species try to obtain the same limited resources
What is predation?
An interaction between species where the predator kills the prey
What is herbivory?
When plants are consumed by animals
What is symbiosis?
When individuals of 2 or more species live in direct and intimate contact with one another
What is parasitism?
When one organism feeds on the other (host)
- host receives no benefit
What is mutualism?
When both individuals benefit from the relationship
E.g., ants feed off of acacia plants for nutrients, and the acacia plants are protected by the ants.
What is commensalism?
An interaction in which one species benefits and the other is neither benefited or harmed
E.g., birds nest in trees, tree is not benefited or harmed.
What are hitchhiking species?
Species that partake in commensalism on the go.
E.g., algae on turtle shells, barnacles on whales etc.
Does competition have a positive or negative effect on both species?
Negative on both
Does predation have a positive or negative effect on both species?
Positive for the predator
Negative for the prey
Does parasitism have a positive or negative effect on both species?
Positive for the parasite
Negative for the host
Does mutualism have a positive or negative effect on both species?
Positive on both
Does commensalism have a positive or negative effect on both species?
Positive for one species
Neither +/- for other
What is the competitive exclusion principle?
Principle which states that the species that acquires more of the resources will win and the other species will die out