Chapter Outline   

These pictographs are located in a granite alcove in Baja California. Painted by prehistoric residents, their exact age and meaning are unknown.

Web Resources

Protecting Deserts introduces the Southwest's population growth and the impact on deserts. National Park Service.

Desertification describes the degradation of semiarid grasslands at the desert's edge. United States Geological Survey.

Study Questions

1. a) Describe the thermal budget of a human. This may be answered in the form of a diagram. b) Humans can regulate body temperature by both physiological and behavioral means. Describe the physiological mechanisms humans have to prevent hyperthermia.

2. Osmoregulation maintains the body's water and salt balance. a) Describe the essential role kidneys play in osmoregulation. b) Describe the danger of salt loss and depletion and how this can promote dehydration.  

The Kennicot Mine in Utah is the world's largest open pit copper mine. Mining has had a long history in the desert, though initial efforts were on a much smaller scale.

4. Describe the following illnesses: heat syncope, heat stroke, and heat cramps.

5. How is it that clothing can have a cooling effect for someone exposed to extreme heat and intense sun in the desert?

6. Human survival in the desert can be enhanced by acclimatization. Describe how humans acclimate to the desert.

7. Define desertification and describe the mechanisms by which humans bring about such changes.

8. The arid Southwest is a hotspot for threatened and endangered species in North America. a) What are the major causes of species endangerment in deserts? b) A partial explanation for the vulnerability of desert species may be that there are many endemic species in the desert. Explain how endemism might promote endangerment in the arid Southwest.