1. Human Impact on Ecosystems
Chapter 16
Human Impact on Ecosystems

2. 16.1 Objectives
Summarize the current state and effects of human population growth.
Explain the importance of effective resource management.

3. Human population
Earth’s carrying capacity is unknown

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

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

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

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

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

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

11. 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?

12. 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

13. Threats to Biodiversity
Human activity can reduce biodiversity by:
Altering habitats
Hunting to extinction
Pollution
Introducing new species to an area

14. Altering habitats As humans destroy habitats, species die out
Can lead to extinction:
Disappearance of species
Endangered species: in danger of becoming extinct

16. Habitat Fragmentation
Splits ecosystems into pieces

17. 16.2 Objectives
Describe the sources, types, and effects of air pollution.
Explain how air pollution contributes to acid rain.

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

19. 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

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

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

23. 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

24. 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.

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

26. 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

28. Section 16.4
Charting a Course for the Future

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

30. Ozone Layer
Layer high in the atmosphere where ozone (O3) is concentrated
Protects Earth from harmful radiation
Has been damaged by CFCs found in:
Aerosol sprays
Coolants (fridge, AC)
CFCs now banned

31. Global Warming Increase in the average temp of biosphere
Caused by burning of fossil fuels
Adds CO2 to atmosphere
Traps heat
May lead to rise in sea level and coastal flooding
What does this mean for Florida?