© 2009 Delmar, Cengage Learning Chapter 3 Ecosystem Management

© 2009 Delmar, Cengage Learning Humans and Their Environment People have always lived in an environment –In the past, our impact was smaller hand tools, smaller populations, etc. –With technology, our impact has increased

© 2009 Delmar, Cengage Learning Managing Natural Resources Active role in caring for environment –Need to understand how environment works –Must gather information about environment health

© 2009 Delmar, Cengage Learning Managing Natural Resources Environmental issues require their own solutions –Each issue is different –Each issue should be considered separately

© 2009 Delmar, Cengage Learning Natural Resources Everything in environment is a natural resource –Any object used to perform work –Any object with potential to perform work

© 2009 Delmar, Cengage Learning Natural Resources Nonexhaustible resources –could last forever –continuously renewed –does not mean they are not limited Human misuse can still damage resource Examples –water and air

© 2009 Delmar, Cengage Learning Natural Resources Renewable resources –Resource can be replaced by human efforts –Use should be restricted used no faster than can be regenerated –Does not mean it will never be used up –Examples forests, fish populations, wildlife populations

© 2009 Delmar, Cengage Learning Natural Resources Nonrenewable or exhaustible resources –resources that cannot be replaced or reproduced –exist in finite amounts –do not renew themselves –We can learn to conserve, use less, and recycle

© 2009 Delmar, Cengage Learning Natural Resources Although a natural resource may be finite, it is not necessarily limited

© 2009 Delmar, Cengage Learning Nonrenewable and Exhaustible Resources Examples –oil, lead, cobalt, zinc –even soil constantly being formed Why not a nonexhaustible resource? Nature makes soil too slowly

© 2009 Delmar, Cengage Learning Nonrenewable and Exhaustible Resources Nonrenewable also means renewed too slowly

© 2009 Delmar, Cengage Learning Balance of Nature No such thing as balance of nature Forces of nature constantly produce change: continuous and natural It is essential that change be gradual Managing resources wisely requires careful use –using resources slowly and gradually

© 2009 Delmar, Cengage Learning Carrying Capacity Population –number of individuals in given area Carrying capacity –population level an ecosystem can support number of individuals that can get resources Populations that exceed carrying capacity –experience disease, predation, starvation

© 2009 Delmar, Cengage Learning Human Population Human population through the years –6000 B.C. = approximately 10 million people –Birth of Christ = approximately 300 million –A.D = almost 1 billion people –1900 = 1.6 billion –1979 = 4.3 billion –1999 = 6 billion –2009= 7+ billion

© 2009 Delmar, Cengage Learning Human Population What is the Earth’s carrying capacity?

© 2009 Delmar, Cengage Learning Conservation Protecting natural resources against harm and waste Involves –using less so resource available in future –not using resources wastefully or carelessly

© 2009 Delmar, Cengage Learning Conservation Resources are not to be set aside –should be used –should be managed for future use, too

© 2009 Delmar, Cengage Learning Conservation Soil necessary for –farms, human use –maintaining wildlife habitats –Soil erosion greatest source of water pollution

© 2009 Delmar, Cengage Learning Conservation Soil conservation –protecting soil from wind and water –minimizing erosion –keeping soils fertile and productive

© 2009 Delmar, Cengage Learning Preservation Maintaining resource in natural state –simply because we value it We must balance our desires –for preservation with needs as a people

© 2009 Delmar, Cengage Learning Preservation Questions for this generation: –Can we set aside certain resources? –Which is more important: economic growth or preservation?

© 2009 Delmar, Cengage Learning Protecting Resources Pollution –must find origin and reduce release –may even involve cleanup

© 2009 Delmar, Cengage Learning Protecting Resources Water Pollution –mostly from untreated sewage and industrial waste –Clean Water Act of 1972 did much to reduce water pollution

© 2009 Delmar, Cengage Learning Protecting Resources Air pollution –acid rain caused by weak acids forming in rain –smog pollution reacts with UV radiation forms cloud of polluted air

© 2009 Delmar, Cengage Learning Protecting Resources Main sources of air pollution –exhaust –coal and petroleum combustion Must reduce amount of exhaust and combustion products