1. Human Impact on Ecosystems 7 th Grade Life Science Woodstock Middle School

2. Ecology Ecology is the study of the interactions of an organism with its environment

3. Human Impact Humans are part of the Earth’s ecosystem. They can intentionally or unintentionally impact the ecosystem in which they live.

4. Pollution Pollution is a change in the environment that is not wanted and caused by waste substances or forms of energy Form of energy= radiation Pollutant- something that causes pollution Most pollutants are human made May harm plants, animals and humans

5. Garbage The average American throws away 12 kg of trash a week. More than the average person in every other nation Trash gets taken to a landfill Hazardous wastes are any wastes that can catch fire, corrode (eat through metal), explode or make people sick Paper mills and oil refineries produce hazardous waste

6. Chemicals Fertilizers and pesticides pollute water and soil. CFCs Destroy the ozone Used in aerosols, refrigerators, and plastics PCBs Appliances and pants Poisonous and may cause cancer Use of CFCs and PCBs are banned, but still found in remote areas and the atmosphere.

7. High Powered Wastes Nuclear power provides electricity to many homes and businesses. Plants for nuclear power produce radioactive waste. These wastes can take thousands of years to become harmless.

8. Gases The atmosphere of Earth is made up of a mixture of gasses Carbon dioxide is one of these gasses Makes the Earth warm enough for life to exist Acts as a blanket Amount of Carbon Dioxide in the earth has increased since the Industrial Revolution CO2 and other gasses act as greenhouse (trapping the heat around the earth) Scientists believe this had led to an increase in global temperatures

9. Resource Depletion Renewable resource- a resource can be replaced at the same rate as which it is used Solar, wind, some types of trees Nonrenewable resource- resource that cannot be replaced, or that can only be replaced over thoundsands or millions of years Most minerals, fossil fuels (oil and coal)

10. Exotic Species Since people are constantly on the move, they sometimes carry organisms with them Plant seeds, animal eggs, adult organisms Exotic Species- an organism that makes a new home for itself outside of its original environment Often thrive in the new places Free from predators found in native home Become pests and compete with native species

11. Human Population Growth 1800- 1 billion people on Earth 2000- more than 6 billion people Some people say there may be too many people on earth one day. Scientists think it will level off Overpopulation- number of humans becomes more than the resources can support

12. Habitat Destruction When land is cleared for construction, crops, mines or lumber the soil may begin to erode. Chemicals can pollute steams and rivers Organisms may be left without food and shelter Biodiversity- an habitat’s number and variety of organisms When the habitat is destroyed then biodiversity is lost

13. Deforestation The cutting of trees in a forest ecosystem. This is caused by the human need for wood products, space, farming land, and roads. Deforestation impacts habitats Animals and plants are forced into other areas.

14. Marine Habitats Oil spills- point source pollution (pollution that comes from one source) Non-point source pollution- pollution comes from many different sources Plastics are sometimes dumped into oceans also Animals can mistake these for food May become tangled in the plastics Dumping plastics into the oceans is against the law

15. What can you do? Conservation- preservation and smart use of natural resources Ride your bike Use of organic compost Using fewer natural resources Reduce waste and pollution Prevent habitat destruction Reduce, Reuse, Recycle

16. Reduce Reducing Waste and Pollution 1/3 of the waste produced is from packaging materials Biodegradable- means that the material can be broken down by living organisms Using less hazardous materials in making products Reducing the use of nonrenewable resources Scientists looking for other sources of energy (not just fossil fuels) Wind, tides, falling waters, electric and hydrogen automobiles

17. Reuse Reusing Products Reusing plastic bags at the grocery store Some building materials Reusing Water Using organisms to clean the water Filter feeding animals (clams) Some not safe to drink, but can be used to water crops and lawns

18. Recycle Recycling- recovery of materials that were considered waste Recyclable materials: Plastics, glass, paper, aluminum, wood, cardboard Recycling trash Recycling newspapers could save millions of trees Save energy from changing ore into aluminum Recycling Resources Waste that can be burned can be used to create electricity Resource Recovery- Using garbage to make electricity Does this pollute the air?

19. Maintaining Biodiversity Losing one species could destroy the entire ecosystem Protecting Species Endangered Species Act- passed in the USA, endangered species are placed on a list, does not allow anything that could put the species in danger Protecting Habitats Nature preserves and parks

20. Strategies to protect the environment…. Reduce Pollution Reduce pesticide use Protect habitats Learn about local issues Develop alternative energy sources