8.5 Community Ecology
in AP Biology
A biological community is an assemblage of populations of various species living close enough for potential interaction.
To Think About:
In what ways do communities and ecosystems change on the basis of interactions among populations and disruptions in the environment? How is the structure of a community measured? What determines whether communities change over time? How do populations access energy and matter in the community? How are relationships between populations characterized? What types of interactions drive population dynamics? How is community structure related to energy availability in the environment?
Watch: AP Daily Video Community Ecology
Answer the Following Questions:
- What is a community?
- How do we describe communities?
- How is species diversity different from species composition?
- The Simpson’s Diversity Index measure the ________________ of a habitat. Higher SDI values mean the community is _____________ diverse.
- Competition can occur _______________ or _______________ species
- Interactions between organisms can be _______________, ______________ or ____________
- Describe two examples of positive interactions between species.
- Describe two examples of negative interactions between species.
- Describe one example of a neutral interaction between species.
- Why is the interaction between shelf fungi and trees considered negative? What positive effects on the community could it have?
- How are increases in prey and predator populations related?
- What is a trophic cascade?
- What is niche partitioning?
- STOP the video at 13:10. Which stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams?
Supplementary Resources:
- Bozeman Science: Mr. Andersen’s “Communities” video
- Bozeman Science: Mr. Andersen’s “Niche” video
- Steve Hammack, Los Gatos HS, California: Community Ecology
