Earth’s Environmental Systems

1. Earth’s Environmental Systems 3 CHAPTER

2. Talk About ItDo you think the distance between the source of the nitrogen and phosphorus and the dead zones themselves makes it difficult to manage this problem? Why or why not? The Gulf of Mexico’s Dead Zone • Nutrient-rich runoff causes plankton blooms and hypoxia—low oxygen levels—in the Gulf of Mexico. • Hypoxia kills or displaces marine organisms, causing a decline in the fisheries and the fishing industry. • U.S. government and farmers debate the need to cut down on fertilizer use.

3. Lesson 3.1 Matter and the Environment Water’s abundance is a primary reason there is life on Earth.

4. Lesson 3.1 Matter and the Environment Atoms and Elements • Atoms are the basic unit of matter. • Nucleus: Contains protons and neutrons • Electrons: Move around the nucleus • An element is a substance that cannot be broken down into other substances. Did You Know?There are 92 elements that occur naturally, and scientists have created about 20 others in labs.

5. Lesson 3.1 Matter and the Environment Bonding • Atoms combine by bonding: • Covalent bonds: Electrons are shared. • Ionic bonds: Electrons are transferred. • Molecule: Two or more atoms joined by covalent bonds • Compound: Substance composed of atoms of two or more different elements Covalent bonding Ionic bonding

6. Lesson 3.1 Matter and the Environment Organic and Inorganic Compounds • Organic compounds: Consist of covalently bonded carbon atoms and often include other elements, especially hydrogen • Hydrocarbons: Organic compounds, such as petroleum, that contain only hydrogen and carbon • Inorganic compounds: Lack carbon-to-carbon bonds Organic compounds include natural gas, petroleum, coal, and gasoline.

7. Lesson 3.1 Matter and the Environment Solutions • A mixture is a combination of elements, molecules, or compounds that are not bonded chemically. • Solutions are mixtures in which all ingredients are equally distributed. • Mixtures can be solids, liquids, or gases. Blood, sea water, plant sap, and metal alloys, such as brass, are all solutions.

8. Lesson 3.1 Matter and the Environment Macromolecules • Large organic compounds that are essential to life • Proteins: Serve many functions; include enzymes • Nucleic Acids: Direct protein production; include DNA and RNA • Carbohydrates: Provide energy and structure; include sugars, starch, and cellulose • Lipids: Not soluble in water; many functions; include fats, waxes, and hormones

9. Lesson 3.1 Matter and the Environment Water • Water is required by all living things for survival. • Hydrogen bonding gives water many unique properties: • Cohesion • Resistance to temperature change • Less dense when frozen • Ability to dissolve many other molecules

10. Lesson 3.1 Matter and the Environment Acids, Bases, and pH • The separation of water molecules into ions causes solutions to be acidic, basic, or neutral. • The pH scale measures how acidic or basic a solution is. • pH of 7—Neutral: Equal concentrations of H+ and OH- • pH below 7—Acidic: Relatively high concentration of H+ • pH above 7—Basic: Relatively high concentration of OH-

11. Lesson 3.2 Systems in Environmental Science Positive feedback loops can help erosion turn a fertile field to desert in just a few years. Dust storm, Stratford Texas, 1930s

12. Interacting Systems Lesson 3.2 Systems in Environmental Science • Inputs into Earth’s interconnected systems include energy, information, and matter. • Feedback loops regulate systems. • Negative feedback loops: Result in stabilization of a system • Positive feedback loops: Result in a system moving to an extreme Negative feedback loop Did You Know?Predator-prey cycles are negative feedback loops. If prey populations rise, predator populations can rise in response, causing prey populations to fall. Then predator populations may decline, allowing prey populations to rise again, and so on.

13. Lesson 3.2 Systems in Environmental Science Spheres of Function • Earth can be divided into spheres that are defined according to their location and function.

14. Lesson 3.3 Earth’s Spheres The Geosphere • Rocks and minerals on and below Earth’s surface: • Crust: Thin, cool, rocky outer “skin” • Mantle: Very hot and mostly solid • Core: Outer core is molten metal, inner core is solid metal Rock formation, Ouray National Wildlife Refuge, Utah

15. Lesson 3.3 Earth’s Spheres The Biosphere and Atmosphere • Biosphere: The part of Earth in which living and nonliving things interact • Atmosphere: Contains the gases that organisms need, such as oxygen; keeps Earth warm enough to support life Earth’s atmosphere, seen from space

16. Lesson 3.3 Earth’s Spheres The Hydrosphere • Consists of Earth’s water • Most of Earth’s water (97.5%) is salt water. • Only 0.5% of Earth’s water is unfrozen fresh water usable for drinking or irrigation. • Earth’s available fresh water includes surface water and ground water. Greenlaw Brook, Limestone, Maine Did You Know?If it is depleted, groundwater can take hundreds or even thousands of years to recharge completely.

17. Lesson 3.3 Earth’s Spheres The Water Cycle

18. Lesson 3.4 Biogeochemical Cycles A carbon atom in your body today may have been part of a blade of grass last year, or a dinosaur bone millions of years ago. Fossilized bones in a Colorado dig.

19. What is a nutrient? • What molecular nutrients are needed by all living things?

20. Biogeochemical Cycles • In a self sustaining ecosystem - Nutrients cycle endlessly between living and nonliving realms of the environment

21. 4 Components of a self sustaining ecosystem • Abiotic Factors sun, wind, water, minerals,light • Biotic Factors living things, their products /wastes • Energy flow begins with sun as primary source • Nutrient cycles

22. Lesson 3.4 Biogeochemical Cycles What is matter? • Matter is made of atoms and has mass. • Matter may be transformed, but cannot be created or destroyed. • .

23. Lesson 3.4 Biogeochemical Cycles What are nutrients? • Matter that is required to support life. • Macronutrients – required in large amounts. C, N, P, Ca • Micronutrients – molybdenum, magnesium • Small deficiencies in either is very harmful • . Did You Know?Organisms require several dozen nutrients, such as nitrogen, phosphorus, and carbon, to survive.

24. Nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter between the biosphere, atmosphere, hydrosphere and lithosphere back into the production of living matter.

25. Nutrient Cycle = Biogeochemical Cycle • BIO – Life • GEO – EARTH • CHEMICAL – MOLECULES These cycles rely on interactions between abiotic and biotic factors

26. Carbon Cycle • Basis of all the Organic molecules found in living things. • These include: • Proteins • Carbohydrates • Lipids • Nucleic Acids

27. Lesson 3.4 Biogeochemical Cycles The Carbon Cycle

28. Human Impacts on Carbon Cycle • Burning of fossil fuels has released large amounts of stored carbon from the lithosphere into atmosphere • Burning of rainforests to clear land for ranching/farming/other development also has increased the release of stored carbon to atmosphere

29. Phosphorus Cycle • Basis for phospholipid molecules needed to form cell membranes • Needed to form the important biological molecules of ATP (E source), DNA, RNA, Proteins

30. Human Impacts on Phosphorus Cycle • Important component of fertilizer – must be mined • Added to detergents to increase sudsing and released in wastewater

31. It is bound up in rock and thus often not easily dissolved by roots of plants making it a limiting factor to plant and algae growth. When added to a water body it can lead to eutrophication.

32. As these producers die, bacteria and fungi act as decomposers a process which requires them to use dissolved oxygen. This reduces the amount of available oxygen to other organisms, a condition known as hypoxia

33. Large areas of hypoxia are known as dead zones. • Ex. Gulf of Mexico Dead Zone

34. Lesson 3.4 Biogeochemical Cycles The Phosphorus Cycle

35. Lesson 3.4 Biogeochemical Cycles The Nitrogen Cycle

36. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition.

37. Nitrogen Cycle • Process by which nitrogen is converted between its various chemical forms. This transformation is carried out through both biological and physical processes.

38. Important transformations in Nitrogen cycle. • Nitrogen Fixation, • Ammonification, • Nitrification, • Denitrification.

39. Nitrogen Fixation – Conversion of nitrogen gas into usable ammonia and nitrates by physical (lightning) or biological (Rhizobium bacteria) processes

40. Legumes- family of plants such as beans and clover that form a relationship with Rhizobium bacterial species. Bacteria form colonies in plant roots and the plant responds to the Infection by swelling . The swollen areas are called root nodules. This symbiotic relationship is mutualism as both species benefit. Bacteria obtain a safe place to live and a “free” meal as they absorbs nutrients stored in plant roots. Plant obtain fixed nitrogen through the action of the bacteria.

41. Ammonification – Nitrogen in organic waste products /detritus is converted to Ammonia(NH3)by decomposers (specific bacteria and fungal species) (Think cat urine…) Ammonia buildup in soil is toxic to plants

42. Nitrification – Conversion of Ammonia(NH3) to Nitrates – a 2 step process. Step 1: Ammonia to Nitrites NO2- by Nitrosomonas Step 2: Nitrites toNitrates NO3- by Nitrobacter bacteria

43. Denitrification – Conversion of Nitrates NO3-to N2 gas which is released to atmosphere. Carried out by denitrifying bacterial species Pseudomonas and Clostridium