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Summary
• One approach to using natural
resources is sustainable use.
• There are many approaches
used to conserve biodiversity
in the world.
• Biodiversity hotspots contain a
large number of endemic
species that are threatened
with extinction.
• Two techniques used to restore
an ecosystem are bioremedia-
tion and biological
augmentation.
• Since the 1970s, many forms of
legislation have been passed
to protect the environment.
Demonstrate Understanding
1.
Describe
three approaches used to slow down the
rate of extinction or to preserve biodiversity.
2.
Define
the two classes of natural resources.
3.
Choose
a human-caused disaster from
Figure 21
.
Discuss the methods that could be used to restore
biodiversity.
Explain Your Thinking
4.
Create
a script of dialogue that could occur between a
conservationist and a person who lives in a biodiversity
hotspot. The local person wants to use the natural
resources to provide a living for his or her family. The
dialogue should include a compromise in which both
sides are satisfied with the use of resources. Consider
the social, cultural, and environmental impacts of the
compromise.
5.
Connection
MATH
If Earth has 150,100,000 km
2
of
land area, how much land area is included in the
biodiversity hotspots?
Check Your Progress
Biological control of invasive species
Invasive species can have a profound effect on an
ecosystem’s biodiversity. In some cases, ecologists
attempt to control the invasive species by intro-
ducing another organism to the ecosystem. This
organism may be a natural predator of the inva-
sive species, or it may be likely to outcompete the
invasive species for resources.
For example, an invasive plant called
Hydrilla
has had a significant impact on Florida’s water-
ways.
Hydrilla
grows very quickly, and forms
dense mats that cover the surface of the water.
These mats decrease the growth of bot-
tom-dwelling native plants by preventing light from penetrating the water. In the early
1970s, researchers introduced the Asian grass carp shown in
Figure 23
to control
Hydrilla
. These fish eat large amounts of plants as part of their diets, and have been
effective in controlling the amount of
Hydrilla
. If too many carp are present in a body of
water, however, they will destroy natural vegetation, and can change water quality.
Therefore, ecologists are careful to monitor the number of carp in each body of water.
Figure 23
Carp can control
Hydrilla
populations.
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Module 5 • Biodiversity and Conservation