Biology 12

Chapter 15 Human Ecology • MHR 515

In June 2001, the city of Ottawa held a Smart
Growth Summit to explore these ideas and make
them more accessible to its citizens. Like many
Ontario cities, Ottawa grew rapidly during the last
half of the twentieth century. The city leapt over a
greenbelt (a reserve of open space) that had been
created around Ottawa in the 1950s and 1960s to
limit its growth. In 2001, Ottawa was at a
crossroads, attempting to plan a city that would
ensure quality of life while still encouraging
population growth (see Figure 15.11). In other
words, it was attempting to ensure ecologically and
economically sustainable growth — a difficult
balancing act faced by cities all over the world. For
population growth to be sustainable, it must not
take a population past the carrying capacity of its
environment. The first step in ensuring that this
does not happen is to determine the carrying
capacity for a particular population. This
challenging task will be discussed in the
next section.
Figure 15.11Why do you think so many cities are built on
waterways — rivers, lakes, or oceans?

SECTION REVIEW

1. (a)What features of human life history suggest
   that Homo sapiensis a K-selected species?
   (b)Why did humans evolve these particular features?


2. What effect did the Agricultural Revolution have
   on the rate of growth of the human population?


3. How might you determine the positive and
   negative effects of monoculture farming on the
   human population? What factors would you have
   to consider and what variables would you measure?
   Design a study that will allow you to prepare such a
   balance sheet for a crop of your choice.


4. Compare the birth and death rates during each
   of the four stages of a demographic transition.


5. How did the Industrial Revolution have an impact
   on the rate of population growth?


6. Define the term “zero population growth.”


7. If the fertility rate is at replacement level, can a
   population still be growing? Explain your answer.


8. What is the replacement fertility rate for
   humans? Explain why it is called this.


9. Compare more industrialized nations with less
   industrialized nations with respect to typical age
   structure, fertility rate, and stage of demographic
   transition. What aspects of being more industrialized
   do you think have contributed to differences in these
   demographic features?


10. How does the age structure of a population
    influence its rate of growth?


11. How might you measure the impact of large
    urban areas on surrounding ecosystems?


12. If it is not there already, how might your school
    or community come closer to the circular metabolism
    model for water use? In your answer, consider the
    volume of water used (could it be less?), where
    the water ends up, how the used water is treated
    (is the method effective?), and the various uses to
    which water is put (should it all be treated to the
    same extent?).


13. Describe some of the impacts of urban sprawl
    on the ecosystems surrounding a city. What would
    you consider to be the most serious of these?

As you have seen, the Agricultural and Industrial

Revolutions significantly impacted human population

growth. This growth, along with the effects of

urbanization, had a number of environmental impacts

on Earth. When choosing your environmental issue,

consider these events and their potential impact.

UNIT ISSUE PREP

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