Biology 12

Chapter 14 Population Ecology • MHR 499

CHAPTER 14 REVIEW

Summary of Expectations

Briefly explain each of the following points.

• The size and density of populations can be
  estimated using mathematical formulas. (14.1)


• Individuals in a population can be dispersed
  randomly, uniformly, or in a clumped pattern.
  (14.1)


• Four basic processes cause change in
  population size. (14.2)


• Population growth can be described using
  either an exponential or logistic (sigmoid)
  growth curve. (14.2)


• The rate of change in the size of populations
  growing exponentially or logistically can be
  determined mathematically. (14.2)


• The future size of exponentially growing
  populations with overlapping or non-
  overlapping generations can be predicted. (14.2)


• For populations growing in limited
  environments, the effect of population density
  on the rate of change in population size can be
  determined. (14.2)


• Density-dependent and density-independent
  regulating factors affect a given population.
  (14.3, 14.4)


• Various types of relationships exist among the
  members of different populations. (14.3)


• Different populations have characteristic life
  history features; certain features are typical of
  equilibrial life histories, while others are
  characteristic of opportunistic life histories.
  (14.4)


• Populations in unpredictable environments
  tends to be r-selected, whereas those in stable
  environments tend to be k-selected. (14.4)
  
  
  • Populations vary with respect to their age
    structure. (14.4)
  
  
  • Ecologists sometimes simplify explanations of
    complex phenomena. (14.2, 14.3, 14.4)
  
  
  
  

Language of Biology

State the biological significance of each of the

following terms. Create concept maps to show your

understanding of how they are related. Be prepared

to explain your rationale.

• demography •intraspecific competition


• density •interspecific competition


• dispersion •competitive exclusion


• census principle


• sample •symbiotic relationship


• transect •host


• quadrat •symbiont


• birth •parasitism


• immigration •mutualism


• death •commensalism


• emigration •environmental


• growth rate (r) resistance


• biotic potential •life history


• exponential growth •survivorship


• J-shaped curve •cohort


• non-overlapping •fecundity
  generations •mortality


• replacement rate (R) •life table


• overlapping generations •age structure


• logistic growth •age pyramid


• S-shaped curve •opportunistic life history


• carrying capacity (K) •r-selection


• density-independent •equilibrial life history
  factor •K-selection


• density-dependent factor

1.What factors contribute to determining how
individuals are dispersed in an area?

2.For the rate of population growth (r) to be
greater than zero, what has to be true of the
birth and death rates (band d) in the population?

3.In general terms, describe the rate of change in
the size of a logistically growing population in
each of the following situations, and explain
why the population size is changing at this rate.
(a)when the population is very small relative
to the carrying capacity of the environment

(b)when the population size is roughly one

half the carrying capacity (that is, near the

inflection point of the logistic growth curve)

(c)in the shoulder of the curve, when the

population is near the carrying capacity

4.Why might the carrying capacity of the

environment for a particular species change

as its population size increases?

5.Select an organism living in an environment

with which you are familiar, and list the things

that might limit the growth of its population.

6.In general terms, how does competition with

other species affect the growth of populations?

UNDERSTANDING CONCEPTS