Download Biodiversity

Chapter 5: Biomes and
Biodiversity
Principles of Environmental
Science - Inquiry and Applications,
3rd Edition
by William and Mary Ann Cunningham
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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Part 1: Biomes
Biomes
• Broadly defined life zones
• Environments with similar climates,
topographies, soil conditions, and
biological communities
• Distribution mainly dependent on
temperature and precipitation
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ADD FIG. 5.1
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Biomes of the World
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ADD FIG. 5.4
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Part 2: Biodiversity
Biodiversity - the variety of living things - three
types essential:
• Genetic diversity - variety of different
versions of the same genes within a species
• Species diversity - number of different kinds
of organisms within an ecosystem
• Ecological diversity - complexity of a
biological community (number of niches,
trophic levels, etc.)
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How many
species are
there?
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Biodiversity Hotspots
Most of the world's biodiversity concentrations are near
the equator (tropical rainforests, coral reefs).
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Part 3: How do we benefit
from biodiversity?
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Food
Drugs and medicines
Ecological benefits
Aesthetic and cultural benefits
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Fig. 5.21
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Aesthetic
and cultural
benefits
Bird watching and
other wildlife observation
contribute more than $29
billion each year to the
U.S. economy.
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Part 4: What Threatens
Biodiversity?
Extinction - the elimination of a species
• Natural process - one species lost every
10 years
• Process been accelerated by human
impacts on populations and ecosystems
• E.O. Wilson - we are currently losing
thousands of species a year
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Part 5: Human-Caused
Reductions in Biodiversity
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Habitat destruction and fragmentation
Hunting and fishing
Commercial products and live specimens
Predator and pest control
Exotic species introduction
Diseases
Pollution
Genetic assimilation
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About 200 years ago,
the American passenger
pigeon was probably the
world's most abundant
bird.
Population: 3-5 billion
Over hunting and
habitat destruction
caused its extinction.
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Trade in Products from Endangered Species
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Trade in Wildlife
About 75% of all saltwater tropical aquarium fish sold come from coral reefs of the Philippines
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and Indonesia, where they are commonly caught with dynamite or cyanide.
Part 6: Protecting Biodiversity
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Hunting and fishing laws
The Endangered Species Act (ESA)
Recovery plans
Reintroductions
Minimum viable population
Private land and critical habitat
Reauthorization of the ESA
International wildlife treaties
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