1. Biology Chapter Sixteen: Human Impact on Ecosystems

2. Section One: Human Population Growth and Natural Resources
Earth’s Human Population
Continues to grow
What is the Earth’s carrying capacity?
Current World Population: 7.4 Billion
Carrying capacity has increased with agriculture, transportation, and medical advances and sanitation
Technology and antibiotics has also helped to increase carrying capacity

3. Section One: Human Population Growth and Natural Resources

4. Section One: Human Population Growth and Natural Resources
Human Population and Natural Resource Pressure
More humans= more use of natural resources
Nonrenewable resources: resources that are used faster than they are formed
Oil and Coal
Renewable Resources: cannot be used up or replenish themselves over time
Wind and Solar Energy
Pollution and over use threaten drinking water as a renewable resource

5. Section One: Human Population Growth and Natural Resources
Resource Management and Ecological Footprint
Practicing Sustainable Usage of Resources
Ecological Footprint: the amount of land necessary to produce and maintain enough food and water, shelter, energy, and waste

6. Section Two: Air Quality
Pollution: any undesirable factor that is added to air, water, or soil
Air Pollutants
Smog: a type of air pollution caused by the interaction of sunlight with pollutants produced by fossil fuel emissions
Particulates: microscopic bits of dust, metal, and unburned fuel that are produced by many different industrial processes
Can be inhaled
Ground Level Ozone
Produced by reaction of oxygen gas and nitrogen oxide
Can be harmful to humans

7. Section Two: Air Quality
Air Pollutants
Acid Rain: a type of precipitation produced when pollutants in the water cycle cause rain pH to drop below normal levels

8. Section Two: Air Quality
How Air Pollution Affects the Biosphere
Greenhouse Effect: occurs when greenhouse gases absorb reradiated energy by Earth’s surface and slow the release of this energy from Earth’s atmosphere
Greenhouse gases: carbon dioxide, water, CFCs, and methane
Make it harder for heat to be released back into the atmosphere
Contributes to excessive global warming
Global Warming: the trend of increasing global temperatures
Threatens ecosystems

9. Section Two: Air Quality

10. Section Two: Air Quality

11. Section Three: Water Quality
Water Pollution
Raw sewage, toxic chemicals, and trash can all enter the water system
Can lead to algal blooms and eutrophication
Indicator Species: a species that provides a sign of the quality of the ecosystem’s environmental condition
Amphibians

12. Section Three: Water Quality
Biomagnification
A process in which a pollutant moves up the food chain, as predators eat prey, accumulating in higher concentrations in the bodies of the predators
Has the greatest effect on top level consumers

13. Section Four: Threats to Biodiversity
Preserving Biodiversity
Decreasing biodiversity has an effect on all living organisms and ecosystems
Effects are long-term
Extinctions is forever

14. Section Four: Threats to Biodiversity
Causes of Loss of Biodiversity
Habitat Loss
Habitat Fragmentation: a barrier forms that prevents an organism from accessing its entire home range
Some states have built overpasses or underpasses for wildlife
Introduced (Invasive) Species
Any organism that was brought to the ecosystem as a result of human actions
Usually have no natural predators and can outcompete the native species
Can cause economic damage

15. Section Four: Threats to Biodiversity

16. Section Four: Threats to Biodiversity

17. Section Five: Conservation
Sustainable Development
A practice in which natural resources are used and managed in a way that meets current needs without hurting future generations
Selective cutting instead of clear cutting trees
Fishing industry examples:
Rotation
Fishing Gear Review
Harvest Reduction
Fishing Bans

18. Section Five: Conservation
Conservation through Umbrella Species
Conservation practices usually focus on one species but benefit entire ecosystems
Umbrella Species: protection of one species leads to protection of a wide range of other species
Ex. Manatees and marine ecosystems

19. Section Five: Conservation
Protecting Earth’s Resources and Our Future
Earth’s resource provide $30 trillion a year in services
Environmental Protection Agency (EPA)
Environmental Laws (Clean Air Act)
National Parks
Controlling Birth Rate
Using Less and Wasting Less