Cycles of Matter

1. Cycles of Matter How does matter move among the living and nonliving parts of an ecosystem?

2. Cycles of Matter • Energy is crucial to an ecosystem. • All organisms need more than energy to survive: • -water • -minerals • -other life-sustaining compounds. • In most organisms, more than 95 percent of the body is made up of just four elements: oxygen, carbon, hydrogen, and nitrogen. • Although these four elements are common on Earth, organisms cannot use them unless the elements are in a chemical form that cells can take up.

3. Recycling Matter • Energy and matter move through the biosphere very differently. • Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Matter = recycled Energy = 1 way

4. Biogeochemical Cycles Matter moves through the biosphere in what are called biogeochemical cycles. Bio = life Geo = Earth Chemical = well…chemical Matter can cycle through the biosphere because biological systems do not use up matter, they transform it.

5. Cycles of Matter • Cycles of Matter • -Water • -Carbon • -Nitrogen • -Phosphorous • -Oxygen* *Oxygen participates in all these cycles by combining with these elements and cycling with them during various parts of their journey.

6. All living things require water to survive Water moves between the ocean, atmosphere, and land Water Cycle

7. Water Cycle • Includes • Evaporation (Liquid Gas Vapor) • Condensation (Gas Vapor  Liquid) • Precipitation (Liquid falls from clouds) • Transpiration (evaporation from leaves  atmosphere)

8. How are nutrients important in living systems? • Nutrients are chemicals needed by an organism to sustain life. • Every living organism needs nutrients to build tissues and carry out essential life functions. • Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.

9. Three Nutrient Cycles Important to the Biosphere Phosphorous Cycle Nitrogen Cycle Carbon Cycle

10. Carbon Cycle • Carbon is a key ingredient of all organic compounds. • Biological processes, such as photosynthesis, respiration, and decomposition, take up and release carbon and oxygen. • Geochemical processes, such as erosion and volcanic activity, release carbon dioxide to the atmosphere and oceans.

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

12. Carbon Cycle

13. Three Nutrient Cycles Important to the Biosphere Phosphorous Cycle Nitrogen Cycle Carbon Cycle

14. Nitrogen Cycle All organisms require nitrogen to make amino acids, which in turn are used to build proteins. DNA  RNA  Protein

15. Nitrogen Cycle • Nitrogen Gas (Free nitrogen) • Most common form of nitrogen (78% of Earth’s atmosphere). • Cannot be used by organisms like us that need nitrogen • Must be converted into usable form. • Nitrogen Fixation • Process of changing nitrogen gas from the air into nitrogen compounds (ammonia) plants can use. • Performed by bacteria (some live in roots of plants—called legumes)

16. Nitrogen Cycle • Decomposers • Decomposers return nitrogen to the soil as ammonia by breaking down proteins from dead remains. • Denitrification • Bacteria further break down nitrogen into nitrogen gas

17. Three Nutrient Cycles Important to the Biosphere Phosphorous Cycle Nitrogen Cycle Carbon Cycle

18. Phosphorous Cycle • Phosphorus is essential to organisms because it helps form important molecules like DNA and RNA. • It is not very common in the biosphere. • Most phosphorus exists in the form of inorganic phosphate. • Inorganic phosphate is released into the soil and water as sediments wear down.

19. Phosphorous Cycle • Does not enter the atmosphere. • Remains mostly on land; in rock and soil minerals, and in ocean sediments as inorganic phosphate.

20. Phosphorous Cycle • As the rocks and sediments gradually wear down, phosphate is released. • -Can dissolve in rivers and streams, make its way to the oceans, and be used by marine organisms. • -Or, it can stay on land and cycle between organisms and the soil.

21. Phosphorous Cycle • When plants absorb phosphate from the soil or from water, the plants bind the phosphate into organic compounds. • Organic phosphate moves through the food web, from producers to consumers, and to the rest of the ecosystem.

22. Nutrient Limitation • The primary productivity of an ecosystem is the rate at which organic matter is created by producers. • One factor that controls the primary productivity of an ecosystem is the amount of available nutrients. • When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient.

23. Nutrient Limitation • When an aquatic ecosystem receives a large input of a limiting nutrient: • —Runoff from heavily fertilized fields (excess nitrogen) • —Over fishing (reduces the number of organisms that feed on algae) • Result is often an immediate increase in the amount of algae and other producers. • This result is called an algal bloom. • Algal blooms can disrupt the equilibrium of an ecosystem.