Environmental Problems, Their Causes, and Sustainability 1

Natural Capital DegradationWhen we try to pick out anything by itself, we find it hitchedto everything else in the universe.JOHN MUIRMountainsLandless poor migrating uphill tosurviveTimber extractionMineral resource extractionHydroelectric dams andreservoirsIncreasing tourism (such ashiking and skiing)Air pollution from industrial andurban centersIncreased ultraviolet radiationfrom ozone depletionSoil damage from off-roadvehiclesFigure 6-34 Natural capital degradation: major human impactson the world’s mountains.CRITICAL THINKING1. List a limiting factor for each of the following ecosystems:(a) a desert, (b) arctic tundra, (c) alpine tundra,(d) the floor of a tropical rain forest, and (e) a temperatedeciduous forest.2. Why do deserts and arctic tundra support a muchsmaller biomass of animals than do tropical forests?3. Some biologists have suggested restoring large herdsof bison on public lands in the North American plains asa way of restoring remaining tracts of tall-grass prairie.Ranchers with permits to graze cattle and sheep onfederally managed lands have strongly opposed thisidea. Do you agree or disagree with the idea of restoringlarge numbers of bison to the plains of North America?Explain.4. Why do most animals in a tropical rain forest live inits trees?5. What biomes are best suited for (a) raising crops and(b) grazing livestock?6. Congratulations! You are in charge of the world. Whatare the three most important features of your plan to helpsustain the earth’s terrestrial biodiversity?PROJECTS1. How has the climate changed in the area where youlive during the past 50 years? Investigate the beneficialand harmful effects of these changes. How have thesechanges benefited or harmed you personally?2. What type of biome do you live in? What have beenthe major effects of human activities over the past50 years on the characteristic vegetation and animal lifenormally found in the biome you live in? How is yourlifestyle affecting this biome?3. Use the library or the Internet to find bibliographic informationabout Robert H. MacArthur and John Muir,whose quotes appear at the beginning and end of thischapter.4. Make a concept map of this chapter’s major ideas, usingthe section heads, subheads, and key terms (in boldface).Look on the website for this book for informationabout making concept maps.LEARNING ONLINEThe website for this book contains study aids and manyideas for further reading and research. They include achapter summary, review questions for the entire chapter,flash cards for key terms and concepts, a multiple-choicepractice quiz, interesting Internet sites, references, and aguide for accessing thousands of InfoTrac ® College Editionarticles. Log on tohttp://biology.brookscole.com/miller14Then click on the Chapter-by-Chapter area, choose Chapter6, and select a learning resource.126 CHAPTER 6 Climate and Terrestrial Biodiversity