Chapter 13 Ecological Principles • MHR 439
SECTION REVIEW
- In ecological terms, describe the difference
between a population and a community.
- Many wolf families are found within the
boundaries of Ontario’s Algonquin Park. Should all
these animals be considered members of a single
population or more than one population? Explain
your answer.
- Explain why it almost always takes longer to
achieve climax stage through primary succession
rather than through secondary succession in the
same region.
- On May 18, 1980, the eruption of the Mount
St. Helens volcano (in Washington State) caused
widespread environmental destruction. Over the
years, many plant and animal species have returned
to the region. What type of succession is
demonstrated by this chain of events? Why would
you not expect to find exactly the same variety of
plant and animal species inhabiting the region now
as compared with the period before the eruption?
- Occasionally a volcano on the sea floor erupts
and forms a new island above the water’s surface.
Over time, the bare lava often becomes colonized by
various plant and animal species. Identify the kind of
succession described in this example. Speculate
about the origin of the flora and fauna that eventually
make their homes on these new islands.
- Describe how simple organisms (such as
lichens) can survive on bare rock substrate. How do
they alter their environment to make it more suitable
for higher organisms?
- (a)Explain how a fallen tree in a forest can
be regarded as an entire ecosystem.
(b)Is this or any other ecosystem completely
separated from other ecosystems?
- Does Earth’s biosphere ever change, or has it
remained constant over time? Explain your answer.
- Would you expect that physical conditions on
the other planets in our solar system vary as they do
on Earth? Explain your answer.
- Identify the distinguishing features of two different
climatic zones that are found in the Great Lakes
region of Canada.
- Identify the features that ecologists use to
distinguish populations of barren-ground caribou from
populations of woodland caribou.
- In ecological terms, explain how a particular
species of fish found in the Great Lakes (such as the
northern pike) is not only part of a population but also
part of a community, an ecosystem, and a biome.
- The whooping crane (Grus americana), an
endangered species in North America, spends the
summer months in northern Canada. Use references
to locate and identify the biome or biomes that lie
within the summer or breeding range of this species.
Describe the general biotic and abiotic features of the
biome(s) you have identified.
- The ranges of two distinct species of birds — the
Baltimore oriole (Icterus galbula) and the grasshopper
sparrow (Ammodramus savannarum) — seem to
overlap in many parts of North America. Research
and describe the differences between the ecological
niches of the two species that make it possible for
them to co-exist within the same ecosystem.
- Explain why ecologists might consider
members of the species Homo sapiensto be
generalists rather than specialists.
- (A) The tree swallow (Iridioprocne bicolor) and
(B) the little brown bat (Myotis lucifigus) breed in
similar habitats in Ontario, and both feed on insects
they catch while in flight. What differentiates their
ecological niches?
- The great-horned owl (Bubo virginianus) is a
ubiquitous predator species that generally inhabits
rural areas. Some populations survive on a rather
limited diet, while others feed on an extremely varied
number of prey species. Research and compare the
feeding habits of different populations of great-
horned owls (such as a population found in western
Canada versus one in the southern United States).
You have just learned that an organism’s environment
includes biotic and abiotic components. When researching
your environmental issue, consider these components
and the effect they have on human populations.
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