Cycling of Matter

1. Cycling of Matter

2. Recycling in the Biosphere • In most organisms 95% of the body is made up of just four elements. • Oxygen • Carbon • Hydrogen • Nitrogen

3. The Cycle of Matter • Matter changes form, but it does not disappear. It can be used over and over again in a continuous cycle.

4. The Water Cycle

5. The Water Cycle • All living things need water to survive. • Water moves between the ocean, atmosphere, and land.

6. The Water Cycle • Water molecules enter the atmosphere as water vapor (a gas), when they evaporate from the ocean or other bodies of water. • Evaporation • The process by which water changes from liquid form to an atmospheric gas.

7. The Water Cycle • Transpiration • Water can enter the atmosphere by evaporating from the leaves of plants.

8. The Water Cycle • Sun heats the atmosphere. • Warm, moist air rises, and cools. • Water vapor condenses into droplets that form clouds. • As droplets become large enough, they return to the Earth’s surface in the form of precipitation.

9. The Water Cycle • Most precipitation runs along the surface of the earth until it enters a river or stream that carries the runoff back to a lake or ocean. • Rain also seeps into the soil, some deeply enough to become ground water.

10. The Water Cycle

11. Nutrient Cycles

12. Nutrient Cycles • Nutrients • All the chemical substances that an organism needs to sustain life. • Every living organism needs nutrients to build tissues and carry out essential life functions. • Nutrients are passed between organisms and the environment through biogeochemical cycles.

13. Elements essential for life also cycle through ecosystems. • Biogeochemical cycles • A biogeochemical cycle is the movement of a particular chemical through the biological and geological, or living and non-living, parts of an ecosystem. • Many substances will change states, from solid, to liquid, to gas, as they move through their cycles.

14. The Oxygen Cycle • Plant, animals, and most other organisms need oxygen for cellular respiration.

15. The Oxygen Cycle

16. The Carbon Cycle • Carbon is a key ingredient of living tissue. • Calcium carbonate (CaCO3) is an important component of animal skeletons, and is found in several kinds of rocks. • Carbon dioxide (CO2) is an important part of the atmosphere. • CO2 is taken up by plants during photosynthesis, and given off by both plants and animals during cellular respiration.

17. The Carbon Cycle • Biological processes, such as photosynthesis, respiration, and decomposition, take up and release carbon and oxygen.

18. The Carbon Cycle • Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans.

19. The Carbon Cycle • Mixed biogeochemical processes, such as the burial and decomposition of dead organisms and their conversion under pressure into coal and petroleum (fossil fuels), store carbon underground.

20. The Carbon Cycle • Human activities, such as mining, cutting and burning forests, and burning fossil fuels, release carbon dioxide into the atmosphere.

21. The Carbon Cycle • Plants take in CO2 and use carbon to build carbohydrates during photosynthesis. • The carbohydrates are passed along food webs to animals and other consumers.

22. The Carbon Cycle • In the ocean, carbon is found along with calcium and oxygen in the form of calcium carbonate. • Calcium carbonate is formed by marine organisms. • This accumulates in marine sediments and in the bones and shells of organisms.

23. The Carbon Cycle • Not all carbon molecules move freely thorough the cycle. • Areas that store carbon over a long period of time are called carbon sinks. • Example: Forest land, where large amounts of carbon are stored in the cellulose of wood.

24. The Carbon Cycle

25. The Nitrogen Cycle • All organisms require nitrogen to make amino acids, which in turn are used to make proteins. • Many different forms of nitrogen are found in the biosphere.

26. The Nitrogen Cycle • Nitrogen gas (N2) makes up 78% of Earth’s atmosphere.

27. The Nitrogen Cycle • Ammonia (NH3), nitrate (NO3-), nitrite (NO2-), are found in wastes produced by many organisms and in dead and decaying organic matter.

28. The Nitrogen Cycle • Nitrogen exists in several forms in the ocean and other large bodies of water.

29. The Nitrogen Cycle • Human activity adds nitrogen to the biosphere in the form of nitrate—a major component of plant fertilizers.

30. The Nitrogen Cycle • Although nitrogen gas is the most abundant form of nitrogen on Earth, only certain types of bacteria can use this form directly. • These bacteria live in the soil and on the roots of legumes, convert nitrogen gas into ammonia. • The process is called NITROGEN FIXATION.

31. The Nitrogen Cycle • Now, other bacteria can convert the ammonia into nitrates and nitrites. • Producers (plants) can use nitrates and nitrites to make proteins.

32. The Nitrogen Cycle • Consumers then eat the producers and reuse the nitrogen to make their own proteins.

33. The Nitrogen Cycle • When the consumers die, decomposers return nitrogen to the soil as ammonia. • This process is called DENITRIFICATION.

34. The Nitrogen Cycle

35. The Nitrogen Cycle

36. The Phosphorus Cycle • Phosphorous is essential to living organisms because it forms part of important life-sustaining molecules such as DNA and RNA. • Phosphorous is not very common in the biosphere.

37. The Phosphorous Cycle • Phosphorous is found mainly on land in rocks and soil minerals, and in ocean sediments. • As the rocks and sediments wear down, phosphate is released.

38. The Phosphorous Cycle • On land, some of the phosphate washes into rivers and streams, where it dissolves. • The phosphate eventually makes its way to the ocean, where it is used by marine organisms.

39. The Phosphate Cycle • Some phosphate stays on land and cycles between organisms and the soil. • When plants absorb phosphate from the soil or from water, the plants bind the phosphate into organic compounds.

40. The Phosphate Cycle

41. Nutrient Limitation • Primary Productivity • The rate at which organic matter is created by producers. • One factor that controls primary productivity of an ecosystem is the amount of available nutrients. • If a nutrient is in short supply, it will limit an organisms growth.

42. Nutrient Limitation • Limiting nutrient • When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly. • These ecosystems are considered to be nutrient-poor environments.

43. Nutrient Limitation • Oceans can be considered to be nutrient-poor. • Sea water contains only .00005 % nitrogen (1/10,000 of the amount typically found in soil). • In sea water and other saltwater environments, nitrogen is often the limiting nutrient. • In streams, lakes, and freshwater environments, phosphorous is typically the limiting nutrient.

44. Nutrient Limitation • Farmers are aware of nutrient limitation and apply fertilizer to their crops. • Fertilizer contains nitrogen, phosphorous, and potassium.

45. Nutrient Limitation • As rain comes down on fertilized fields, runoff will flow into the oceans and freshwater lakes and ponds. • The results are ALGAL BLOOMS.