Chapter 3 Ecosystem Management 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 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. 1800 = almost 1 billion people – 1900 = 1. 6 billion – 1979 = 4. 3 billion – 1999 = 6 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 © 2009 Delmar, Cengage Learning