Chapter 16 Human Impact on Ecosystems 16 1

Chapter 16 Human Impact on Ecosystems

16. 1 Objectives �Summarize the current state and effects of human population growth. �Explain the importance of effective resource management.

Human population �Earth’s carrying capacity is unknown

Two technological advancements that have contributed to population growth: �Gas-powered farm equipment �Medical advances (lower infant mortality rates)

Types of Resources �Nonrenewable: resources that are used faster than they are formed �Ex. Oil and coal

Types of Resources �Renewable: resources that cannot be used up or that replenish themselves over time �Ex. Wind and solar energy, plants and animals

Sustainable Use �Using resources in a way so that they are available for future generations

Ecological footprint �The amount of land needed to support a person �Land must produce and maintain enough food, water, shelter, energy and waste

Ecological footprint �Size depends on: �Amount and efficiency of resource use and amount and toxicity of waste produced

On the back of notes: �Currently, water is considered a renewable resource. Explain how water could become a nonrenewable resource. �Why is our ecological footprint related to an area of land?

Biodiversity �Brainstorm with your partner: �What are some of the products we get from living organisms? �Try to come up with at least 10 items

Threats to Biodiversity �Human activity can reduce biodiversity by: 1. Altering habitats 2. Hunting to extinction 3. Pollution 4. Introducing new species to an area

Altering habitats �As humans destroy habitats, species die out �Can lead to extinction: �Disappearance of species �Endangered species: in danger of becoming extinct http: //www. earthsendangered. com/continent. asp? gr=&v iew=&ID=9

Habitat Fragmentation �Splits ecosystems into pieces

16. 2 Objectives �Describe the sources, types, and effects of air pollution. �Explain how air pollution contributes to acid rain.

Pollution �Toxic compounds released to environment �Ex. DDT – pesticide �Nonbiodegradable

DDT (dichlorodiphenyltrichloroethane) �DDT is a pesticide that is sprayed onto crops �It drains into rivers and streams �Important properties of DDT: �Nonbiodegradable (cannot be broken down) �Will be stored in plants and animals that take it in �A plant may only store a low quantity of DDT �Herbivores will eat many plants, and store all the DDT from each plant in their tissues �Carnivores will eat those herbivores and store all the DDT from the herbivores in their tissues

Make a prediction… �Based on the information on DDT, what trophic level (primary, secondary, tertiary, etc) will be most affected by DDT? �Why? ? ?

Biological Magnification �Process where concentrations of a harmful substance increase in orgs. at higher trophic levels

Invasive Species �Plants and animals transported around the world �Can reproduce rapidly because they lack parasites and predators that control their population �Drive out native species

�Nutria: Human activity can reduce biodiversity by introducing foreign species to new environments. Native to South America, nutrias have become pests in coastal areas of the southeastern United States. These furry rodents eat water plants that protect fragile shorelines from erosion. This destroys the habitats of species native to those ecosystems.

Article – Zebra Mussells �Read the article �Answer the questions with your partner

Conservation �Wise management of natural resources �Protect single species �Protect entire ecosystems – biodiversity “hot spots” �Ensures that natural habitats and interactions of species are preserved

Section 16. 4 Charting a Course for the Future

Objectives �Describe two types of global change that are of concern to biologists.

Ozone Layer �Layer high in the atmosphere where ozone (O 3) is concentrated �Protects Earth from harmful radiation �Has been damaged by CFCs found in: �Aerosol sprays �Coolants (fridge, AC) �CFCs now banned

Global Warming �Increase in the average temp of biosphere �Caused by burning of fossil fuels �Adds CO 2 to atmosphere �Traps heat �May lead to rise in sea level and coastal flooding �What does this mean for Florida?