Download Chapter 6 – Population and Community Ecology

Chapter 6 – Population and Community Ecology
Directions: After reading Chapter 6 and reviewing the in-class material, you should be able to:
1.
Identify and describe characteristics of the five levels of complexity within nature: individuals, populations, communities,
ecosystems, and the biosphere.
2.
Explain why populations are said to be dynamic. Identify the two factors that increase a population and the two factors that lower
a population. Define immigration and emigration. Complete the following diagram:
3.
Define the 5 characteristics that are used to distinguish populations:
a. Population size
b.
Population density
c.
Population distribution (clumped, random, & uniform)
d.
Population sex ratio
e.
Population age structure
POPULATION ECOLOGY
4. Define the two factors that influence population size. Give examples of each.
a. Density-dependent factors
b.
Density-independent factors
5.
Describe a limiting resource. Give two examples of limiting resources for plants and two examples of limiting resources for
animals.
6.
Define the term carrying capacity (K). Use the blank axes below to illustrate a carrying capacity:
7.
Describe a population’s growth rate using the exponential growth model. List the factors that are used to calculate the growth rate.
Explain what intrinsic growth rate means. Use the blank axes below to illustrate exponential growth of a population:
8.
Describe a population’s growth rate using the logistic growth model. Use the blank axes below to illustrate logistic growth of a
population and indicate the carrying capacity:
9.
Use the blank axes below to illustrate a population undergoing periods of growth and decline. Describe why this is called a
population oscillation. Use the second blank axes to illustrate the growth and decline of the reindeer population.
Population oscillation
Reindeer population growth and decline
10. Use the blank axes below to illustrate the oscillations in lynx and hare populations. Describe why the peak of one population does
not correspond to the peak of the other population.
11. Explain the reproductive strategy known as “K-selected”. Give several characteristics and examples of organisms that exhibit this
strategy. Describe the population graph of a K-selected species.
12. Explain the reproductive strategy known as “r-selected”. Give several characteristics and examples of organisms that exhibit this
strategy. Describe the population graph of an r-selected species.
13. Compare the different patterns of survivorship as illustrated by a survivorship curve. Explain what the curves illustrate and give
one example of each type.
14. Define a metapopulation. What term that is used to describe the strips of habitat that connect distinct metapopulations?
COMMUNITY ECOLOGY
15. Describe the population interaction known as competition. Define the term competitive exclusion.
16. Explain how competition can be limited by resource partitioning. Use the two graphs below to illustrate two populations that are
competing for a resource (left) and then those populations after resource partitioning has occurred (right).
BEFORE PARTIONING
AFTER PARTITIONING
17. Define predation. Give an example and definition for the four types of predation:
a. True predators
b.
Herbivores
c.
Parasites & pathogens
d.
Parasitoids
18. Define and give two examples of mutualism.
19. Define and give two examples of commensalism.
20. Define symbiotic relationships. List the three population interactions that are examples of symbiotic relationships. Use the blank
table below to indicate the effects on both partners in the four relationships listed:
Type of Interaction
Competition
Predation
Mutualism
Commensalism
Species 1
Species 2
21. Define and give one example of a keystone species. Describe a keystone predator and its effects on other populations. Describe
the role of a keystone engineer.
COMMUNITIES CHANGE OVER TIME
22. Define ecological succession.
23. Describe the process of primary succession. Give the meaning for the terms: early-succession, mid-succession, and latesuccession. Identify the reproductive strategies (“r” or “K”) for some of the organisms found at each stage.
24. Describe the process of secondary succession. Discuss how it is different from primary succession.
25. Identify the steps of aquatic succession.
26. Explain how the following factors determine species richness:
a. Latitude
b.
Time
27. Describe how the theory of island biogeography helps determine species richness. Discuss the factors of habitat size and distance
from a source that determine species richness.
28. Explain how the theory of island biogeography can help in the conservation of endangered species.