Human Impact on Ecosystems

1. Topic Seven Human Impact on Ecosystems

2. All living things affect the environment around them. As the human population grows and our need for the resources to sustain our technology expands, the possibility that we will harm Earth’s ecosystems increases.

3. Earth’s resources, which, given time, can be replaced are known as renewable resources

4. A nonrenewable resource is any resource which cannot be replaced.

5. A harmful change in the chemical makeup of the soil, water or air is pollution

6. Throughout the biosphere, animals take in oxygen and release carbon dioxide. Plants and algae take in carbon dioxide and release oxygen.

7. Soils form when weathering breaks down rocks and when organic materials from decaying plants and animals accumulate

8. The process by which water continuously moves from Earth’s surface to the atmosphere and back is known as the water cycle

9. Click on the water cycle below to see it animated

10. Waste is decomposed and the nutrients are recycled back into the environment

11. Food chains, food webs, and energy pyramids illustrate energy flow through ecosystems

12. Most species in new environments can have a period of rapid population growth. The population increase levels off as it approaches the ecosystem’s carrying capacity, which is the number of individuals the environment can support.

13. Some human activities that destroy habitats and degrade ecosystems do far more than damage individual organisms. They destroy diversity in both the living and nonliving parts of the environment.

14. The destruction or removal of species from their habitats is known as direct harvesting

15. In the past humans have caused the extinction of several species.

16. As human populations and needs increase, our use of land decreasesthe space and resources available for other species

17. Deforestation, or the destruction of forests resulting from human activity, is a land use decision that causes widespread habitat destruction

18. Habitat destruction, such as deforestation, can lead to loss of biodiversity.

19. Biodiversity is often reduced when people import and release a species from one environment into another

20. ZEBRA MUSSEL MIGRATION FROM1988 TO 2005

21. Biodiversity refers to the variety of life on earth. As habitats are lost and species become extinct, biodiversity is reduced. This is bad because • 1) ecosystems with low diversity take longer to recover from environmental changes and • 2) we use organisms for many things such as food and medicine; by reducing biodiversity we are losing potentially valuable resources.

22. Industrialization is the development of an economy in which machines produce many of the products people use

23. The higher energy demands in an industrialized society mean that more power plants must be built. Additional power plants especially those that burn coal add to the pollution of our air and water. AES Somerset Huntley

24. Nuclear fuelis an energy source that results from splitting atoms. Nuclear power plants do not pollute the air and water with toxic chemicals, but they can cause thermal pollution of waterways. Radioactive nuclear waste disposal presents a huge environmental problem

25. The addition of pollutants to natural environments causeswater pollution The pollution of our waterways became a national issue in June of 1969, the day that the Cuyahoga River, flowing through Cleveland, Ohio, on its way to Lake Erie, caught on fire because it was so polluted.

26. Click on image to see animation Toxic wastesdumped into waterways from cities, farms, or industries can be poisonous to the organisms

27. Click on image to see animation Thermal pollutionSome power plants and industries use water to cool their machines or materials. The warmed water is then released into a river or lake, and the water temperature in the river or lake rises. Because of the warm water oxygen levels drops suffocating some fish

28. Click on image to see video Just as wastes dumped into rivers and oceans cause water pollution, harmful substances released into the air causeair pollution

29. fossil fuela fuel, such as coal and gas, that comes from the remains of organisms that lived millions of years ago

30. Click on image to see animation Sulfur and nitrogen compounds that are produced when fossil fuels burn can combine with moisture in the atmosphere. This producesacid rainrain that is more acidic than normal.

31. Click on image to see animation global warming; a increase in Earth's average surface temperature caused by an increase in greenhouse gases such as carbon dioxide (CO2 )

32. loss ofozone layer; the layer of ozone gas in the upper atmosphere that protects Earth from some of the sun's radiation skin cancer skin layers

33. Actions being taken by humans to reduce or repair damage to the environmentinclude: • Recycling wastes • Conserving available resources nonrenewable; any resource, such as fossil fuels and minerals, that cannot be replaced and renewable; resources, such as our food supply and solar energy, which, given time, can be replaced • Using cleaner resources (ex: solar over fossil fuels) • Protection of habitats and endangered species • Use of biological controls instead of pesticides and herbicides • Farming native plants (ex: cocoa in the rainforest) • Planting trees to replace those cut down. • Rotating crops or planting cover crops to reduce soil loss.