CHAPTER
15Reflecting
Questions
Human Ecology
502
Corn has long been an important
agricultural crop in Ontario.
Archeological evidence shows that
Aboriginal people grew corn near
Campbellville, Ontario before A.D. 1200.
In 2000, Ontario farmers planted
829 600 ha of corn (approximate value
$5.2 billion), with the majority grown
in monoculture — an agricultural
system in which only one crop at a
time is planted over a large area. In
contrast, early Aboriginal people and
European settlers typically grew a
variety of crops in small fields. Why
the difference?
The answer is related to the
number and distribution of people
who rely on this resource. Canada’s
population is much larger now, with
the majority of it being concentrated
in cities and towns. This results in
fewer opportunities for individual
families to grow crops. In industrial
societies, jobs are specialized — only
a few people grow produce while
others transport, process, market, and
research the product. Most of us
simply eat this product, knowing little
about how it got to the grocery store.
In the past, produce from a garden
plot commonly fed a single family,
who would then sell any excess to
neighbours or local markets. Today,
70 percent of Canada’s corn comes
from Ontario. Large amounts of energy
are expended to plant, harvest, and
transport the crop, since much of it
ends up far from where it was grown.
Large amounts of fertilizer and
pesticides are used to increase the
yield. A recent decline in the rate ofuse for some pesticides may be due
to the availability of new types of
corn, including genetically modified
forms. Some people express concern
regarding use of these new forms,
noting that they may cause as yet
unknown problems.
About 60 percent of Ontario’s corn
feeds farm animals, with the remainder
used to manufacture products
including clothes and fuel. Very little
is directly consumed by humans. Are
these practices sustainable? Do they
echo some of the mistakes made by
the inhabitants of Easter Island? In
this chapter, you will examine issues
related to the demands placed on
Earth by the global human population
and the ecological consequences of
human population growth.
In the past, a garden like this might
have supplied the needs of one family.
Probably, little was added to the soil
other than manure for fertilizer.How do you determine
the carrying capacity of
Earth for humans?
Is the human population
already exceeding its
carrying capacity, or
will it do so soon?
What effect does the
human population
have on Earth?Prerequisite
Concepts
and Skills
Before you begin this chapter,
review the following concepts
and skills:
evaluating how a change in
one population can affect
the entire hierarchy of
living things (Chapter 13,
section 13.3),
explaining the concept
of interaction among
different species
(Chapter 14, sections 14.3
and 14.4),
describing characteristics
of a population, such
as growth, density,
distribution, and carrying
capacity (Chapter 14,
sections 14.2 and 14.3),
and
analyzing the components
of population growth and
explaining the factors that
affect the growth of
various populations
(Chapter 14, sections 14.3
and 14.4).