Chapter 20 | Populations, Communities, and Ecosystems
- Ecologists often collaborate with other researchers interested in ecological questions. Describe the levels of ecology that would be easier for collaboration because of the similarities of questions asked. What levels of ecology might be more difficult for collaboration?
- The population is an important unit in ecology as well as other biological sciences. How is a population defined, and what are the strengths and weaknesses of this definition? Are there some species that at certain times or places are not in populations?
- Compare and contrast ocean upwelling and spring and fall turnovers.
- Many endemic species are found in areas that are geographically isolated. Suggest a plausible scientific explanation for why this is so.
- Describe the rate of population growth that would be expected at various parts of the S-shaped curve of logistic growth.
- Describe the age structures in rapidly growing countries, slowly growing countries, and countries with zero population growth.
- Describe the competitive exclusion principle and its effects on competing species.
- Compare and contrast food chains and food webs. What are the strengths of each concept in describing ecosystems?
- Describe freshwater, ocean, and terrestrial ecosystems.
- Compare grazing and detrital food webs. Why would they both be present in the same ecosystem?
- Compare the three types of ecological pyramids and how well they describe ecosystem structure. Identify which ones can be inverted and give an example of an inverted pyramid for each.
