modules38-04to38-05 the geographic distribution of biodiversity
TRANSCRIPT
BIOLOGYCONCEPTS & CONNECTIONS
Fourth Edition
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
From PowerPoint® Lectures for Biology: Concepts & Connections
CHAPTER 38Conservation Biology
Modules 38.4 – 38.5
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• Burning of fossil fuels is increasing the amount of CO2 and other greenhouse gases in the air
38.4 Connection: Rapid global warming could alter the entire biosphere
Figure 38.4A
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Figure 38.4B
Light
Heat
GREENHOUSE EFFECT:CO2 lets sunlight through butretains the heat generatedby the sun
CO2
Adding CO2 to the airincreases the greenhouse effect
Removal of CO2 from the air byphotosynthesizing plants and
algae decreases the greenhouse
effect
CO2 CO2
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• Projected atmospheric temperatures indicate an increase in greenhouse gases
Figure 38.4C
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• An increase in global temperature could have many negative effects
– Change in climate patterns
– Melting of polar ice
– Flooding of coastal regions
– Increase in the rate of species loss
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• Environments are patchy– As a result, species are not evenly
distributed
• Geographic distribution patterns for many species indicate an uneven density
– Example: terrestrial birds in North and Central America
38.5 Some locations in the biosphere are especially rich in biodiversity
THE GEOGRAPHIC DISTRIBUTION OF BIODIVERSITY
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• Density of bird species
Figure 38.5A
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• Biodiversity hot spots are relatively small areas with a large concentration of species
• Many species in these hot spots are endemic
– They are found nowhere else
• Biodiversity hot spots can also be hot spots of extinction
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• Location of some biodiversity hot spots
Figure 38.5B
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• Endemic species are highly sensitive to habitat degradation and thus prone to extinction
• Many migratory species, both terrestrial and aquatic, require international protection
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
• Monarch butterflies migrate throughout Canada and the United States during the summer months
– In the autumn months, they migrate to local sites in Mexico and California
– Such overwintering populations are susceptible to habitat disturbances Figure 38.5C
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• Sea turtles, such as the loggerhead turtle, are threatened in their ocean feeding grounds and on land
Figure 38.5D