CHAPTER 38 Conservation Biology Modules 38.4 – 38.5

38.4 Connection: Rapid global warming could alter the entire biosphere Burning of fossil fuels is increasing the amount of CO2 and other greenhouse gases in the air Figure 38.4A

Adding CO2 to the air increases the greenhouse effect Removal of CO2 from the air by photosynthesizing plants and algae decreases the greenhouse effect GREENHOUSE EFFECT: CO2 lets sunlight through but retains the heat generated by the sun Light CO2 Heat CO2 CO2 Figure 38.4B

Projected atmospheric temperatures indicate an increase in greenhouse gases Figure 38.4C

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

THE GEOGRAPHIC DISTRIBUTION OF BIODIVERSITY 38.5 Some locations in the biosphere are especially rich in biodiversity 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

Density of bird species Figure 38.5A

Many species in these hot spots are endemic 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

Location of some biodiversity hot spots Figure 38.5B

Endemic species are highly sensitive to habitat degradation and thus prone to extinction Many migratory species, both terrestrial and aquatic, require international protection

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

Sea turtles, such as the loggerhead turtle, are threatened in their ocean feeding grounds and on land Figure 38.5D