Pollutants of Food Chains & Webs

1. Unfortunately, there is a hidden danger in many food chains and food webs. • When organisms take in nutrients and water from the environment, they may • also ingest chemical pollutants. • Some are excreted in urine (water soluble). • Some build up in tissues (fat soluble) Pollutants of Food Chains & Webs

2. For example, if a long lasting pollutant enters the environment, it may get passed on from one trophic level to the next. The level of the pollutant in each organism increases as it is moves along the food chain. While harmless at very low levels, a chemical pollutant may have serious effects at higher levels. Pollutants of Food Chains & Webs

3. This magnifying effect is called bioaccumulation. Pollutions of Food Chains & Webs

4. The following is an example showing how biomaccumulation takes place in nature: An anchovy eats many tiny zooplankton that have tiny amounts of mercury that the zooplankton has picked up from the water throughout its lifespan. A tuna eats many of these anchovies over its life, accumulating the mercury in each of those anchovies into its body. If the mercury stunts the growth of the anchovies, that tuna is required to eat more little fish to stay alive. Because there are more little fish being eaten, the mercury content is magnified, and so on up the trophic levels. FYI ~ Pollutions of Food Chains & Webs

6. DDT is an insecticide discovered in 1939. It has been especially useful in controlling mosquitos that carry malaria. DDT persists for a longtime in the environment and is disastrously toxic to birds, especially top-level predators such as hawks and eagles. The chemical interferes with the birds ability to metabolize calcium, and thus affected birds that lay eggs with fatally thin shells. DDT has been banned in most countries, but it is still widely used on crops in latinamerica. DDT almost destroyed populations of fish-eating eagles and ospreys, before its use was banned (1972) in the United States. FYI ~ DDT, A Bioaccumulant

7. FYI ~ DDT – A Bioaccumulant

9. Ecosystem Recycling Vocabulary Words to Know • evaporate • condense • transpiration • precipitation • greenhouse effect • nitrate • nitrogen fixation

10. Ecosystem Recycling • Energy is not the only thing that flows through an ecosystem. • Water and minerals such as carbon and nitrogen are also recycled and reused.

11. FYI ~ Ecosystem Recycling • Natural ecosystems have recycled materials since life began on Earth. In fact, life could not continue without this recycling of matter. • Of the dozens of elements that occur naturally, a few are found in significant amounts in organisms. • These include carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur.

12. FYI ~ Ecosystem Recycling • The amount of these elements on Earth today is about the same as when the planet first formed. • Because they are needed by living things and their supply does not increase, these elements have to be recycled again and again.

13. FYI ~ Ecosystem Recycling For example, think about the last time you had a glass of water. Now, think about where that water had been before you drank it. • Is it is possible that it could have been part of a swamp where alligators swam? • Could it have fallen as rain in Italy? • Could it have been given off by plants in Africa as water vapor?

14. FYI ~ Ecosystem Recycling The answer is “YES”! • The point is that all water is recycled. It is used over and over again. • The same is true for oxygen, carbon, and nitrogen. • These important life substances must be shared-used and reused-by all life on Earth.

15. <img src='http://b.scorecardresearch.com/p?c1=8&c2=6036211&c3=10600&c4=22135&c5=&c6=&c15=&cv=2.0&cj=1' /> The Water Cycle • Water is crucial to life. • The movement of water between the atmosphere, land and living things is known as the water cycle. • The Water cycle: • Evaporation • Transpiration • Precipitation

16. <img src='http://b.scorecardresearch.com/p?c1=8&c2=6036211&c3=10600&c4=22135&c5=&c6=&c15=&cv=2.0&cj=1' /> The Water Cycle • Evaporation is the process by which water is added to the air in the form of gas vapor. • The water vapor rises into the sky. Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapor or steam. The water vapor or steam leaves the river, lake or ocean and goes into the air.

17. <img src='http://b.scorecardresearch.com/p?c1=8&c2=6036211&c3=10600&c4=22135&c5=&c6=&c15=&cv=2.0&cj=1' /> The Water Cycle • Transpiration is the process by which water is released into the atmosphere by plants. Animals also release water through breathing, sweating and excreting

18. <img src='http://b.scorecardresearch.com/p?c1=8&c2=6036211&c3=10600&c4=22135&c5=&c6=&c15=&cv=2.0&cj=1' /> The Water Cycle • When water vapor rises, it cools, or condenses. • That means the gas turns back into a liquid. The water vapor condenses into tiny droplets that make clouds. Water vapor in the air gets cold and changes back into liquid, forming clouds. This is called condensation.

19. <img src='http://b.scorecardresearch.com/p?c1=8&c2=6036211&c3=10600&c4=22135&c5=&c6=&c15=&cv=2.0&cj=1' /> The Water Cycle • Precipitation is the process by which water falls to land from the atmosphere. • Precipitation occurs when so much water has condensed that the air cannot hold it anymore.  The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow

20. The Water Cycle

21. Check Your Understanding Fill in the blanks. • When liquid water turns into a gas, it ___________________ • When water vapor cools, it ___________________ • Plants release water vapor during ___________________ • Rain, hail, sleet, and snow are all forms of ___________________

22. Human Impact ACID RAIN Human activity can affect the cycles in nature. What we do to one part of the environment can affect many other parts. Acid rain is formed by air pollution. Sulfur and nitrogenous-oxide waste gas rises from autos and factories. These gases can join with water vapor in the air. This makes the water acidic. Later, the water falls as acid rain.

23. The Carbon Cycle • Carbon is a key element to all life. • The most abundant substance in living things is water. The second most abundant substance is carbon. • Carbon is cycled between the air, water, and organism. • Together, photosynthesis and cellular respiration form the basis of the carbon cycle.

24. The Carbon Cycle • In photosynthesis, plants and other autotrophs extract carbon dioxide from the air and combine it with other elements to form sugar molecules. Glucose (sugar) molecules contain carbon. • Oxygen, a byproduct, is released into the air.

25. The Carbon Cycle • Both plants and animals use the glucose from photosynthesis for cellular respiration. • In cellular respiration, oxygen and glucose are used to release energy. The byproducts are carbon dioxide and water, which is released into the air.

26. The Carbon Cycle • Some of this carbon dioxide dissolves in water. • Some carbon dioxide is reused during photosynthesis. • Some carbon is returned to the atmosphere as dead organisms decompose - This is done by decomposers. They break down wastes and dead organisms and return carbon to the air. Remember: Decomposers (mainly bacteria and fungi) are organisms that break down and absorb nutrients from dead organisms and waste.

27. The Carbon Cycle

28. The Carbon Cycle • Every so often, a plant or animal does not decompose right away. Their bodies are trapped, in locations where decomposition can simply not take place. • This is most common at the bottom of oceans and seas, where the life forms become buried by sand.

29. The Carbon Cycle • Instead of returning to the atmosphere, the carbon from these life forms is trapped within the Earth. • Over millions of years more and more of the carbon on Earth has been trapped in this manner. • Today, almost 99% of all the carbon on Earth has been locked up deep within the Earth as fossil fuels..

30. The Nitrogen Cycle All living things need nitrogen. Nitrogen is one of the most important nutrients as it helps to form cell proteins and nucleic acids. Almost 80 percent of the air is nitrogen.

31. The Nitrogen Cycle However, plants and animals cannot use nitrogen from the air. So the nitrogen must be changed into a form that plants and animals can use. To do this, special kinds of bacteria called nitrogen-fixing bacteria change nitrogen gas into another form called ammonia. Then, other bacteria change the ammonia into compounds called nitrates.

32. The Nitrogen Cycle Nitrogen fixation allows organisms to get the nitrogen they need.

33. The Nitrogen Cycle Nitrogen-fixing bacteria live in the soil and on the roots of some plants. Once the ammonia has been changed into nitrogen compounds, they can be used by plants. Plants use nitrates to make proteins. Animals eat the plants to make their own proteins. In this way, nitrogen compounds are transferred from plants to animals.

34. The Nitrogen Cycle The bacteria fix nitrogen which they share with the plant. In exchange, the plant supplies the bacteria with a source of carbon and energy for growth. What type of relationship is this?

35. The Nitrogen Cycle Decomposers such as bacteria and fungi change animal waste and decayed matter back into nitrogen in the air or nitrates in the soil.

36. The Nitrogen Cycle Atmospheric nitrogen can also be converted into nitrates in the soil by lightening storms. Lightening creates so much energy in the atmosphere that the atmospheric nitrogen reacts and enters the soil as nitrates. This completes the nitrogen cycle.

37. The Nitrogen Cycle

38. Check Your Understanding Answer the questions in complete sentences 1. Which cell processes are involved in the carbon cycle? 2. What is the greenhouse effect? 3. CRITICAL THINKING Why do you think scientists want to find more information on global warming?

39. What Cycle does this picture represent?

40. What Cycle does this picture represent?

41. What Cycle does this picture represent?

42. lajhsslab.com Terrestrial Ecosystems • BIOMES • Biomes are very large ecosystems that contain a number of smaller, but related ecosystems.

44. A large region of Earth that has a characteristic climate and kinds of organisms is called a biome. The Major Land Ecosystems

45. There are seven major land biomes found on Earth. • Tundra • Taiga/Coniferous forest • Temperate forest (deciduous) • Tropical rain forest • Temperate grassland • Savanna • Desert The Major Land Biomes

46. The Major Land Biomes

47. The Major Land Biomes The climate plays a big part on the type of biomes that exist in a given area. Both temperature and average rainfall are part of the climate of an area.

48. The tundra is a very cold, dry biome. Much of the ground is permanently frozen. This layer of permanently frozen soil is called permafrost. Only very small plants can grow in the tundra. Tundra Many animals and plants live in the Tundra. Some include Arctic foxes, hares, caribou, musk oxen, polar bears, porcupines, Arctic shrews, squirrels, weasels, wolves, arctic loons, snowy owls, falcons, ravens, snow buntings, snow birds, snow geese, sandpipers, tundra swans, many species of gulls cod, flatfish, salmon, trout, Arctic bumblebees, black flies, flies, grasshoppers, mosquitoes, and moths.

49. The taiga has warmer temperatures and receives more rainfall than the tundra. Cone-bearing trees grow in the taiga. Taiga Many animals and plants live in the Taiga. Some include the Arctic fox, Arctic hare, wolf, badger, Bald eagle, Beaver, Black bear, Brown bear, Canada goose, Caribou, sheep, Deer, Earthworms, Fox, moose, Musk ox, Malamute, Muskrat, Mosquito, Red tailed hawk, Reindeer, Scorpion, Short tailed weasel and Squirrel.

50. Temperate forests are warmer and wetter than the taiga. They differ in the types of trees they have. The leaves on most of the trees in this biome change colors in fall and drop off from the tree. This type of tree is called deciduous. Temperate Forest Many animals and plants live in the temperate forest. Some include American Bald Eagle, American Black Bear, Coyote, Duckbill Platypus, Eastern Chipmunk, European Red Squirrel , Fat Dormouse Least Weasel, White-tailed Deer