1. The Water Cycle

2. Water The total amount of water on earth doesn’t change. The total amount of water on earth doesn’t change. Water in Earth’s oceans does not remain there indefinitely. Water is constantly recycled through the water cycle. Water in Earth’s oceans does not remain there indefinitely. Water is constantly recycled through the water cycle.

3. Energy for the Water Cycle The sun provides energy for the water cycle. The sun provides energy for the water cycle.

5. Evaporation Water is lost from the soil and from all surface water (lakes, streams, ponds, oceans) through evaporation or transpiration. Water is lost from the soil and from all surface water (lakes, streams, ponds, oceans) through evaporation or transpiration. 1.Evaporation – occurs when the sun’s energy heats the water, changing it from its liquid state into its gaseous state (known as water vapor) 2.Transpiration – loss of water vapor from the leaves of plants through the stomata (openings in leaves)

6. TRANSPIRATION EVAPORATION

7. Condensation Condensation – process of water vapor changing from water vapor into its liquid form Condensation – process of water vapor changing from water vapor into its liquid form –As warm humid air rises, it loses energy and cools. –As the air cools, the water vapor collects on small particles (such as dust or volcanic ash) in the atmosphere and forms clouds.

9. Precipitation When the droplets become too heavy to remain in the atmosphere they begin to fall. When the droplets become too heavy to remain in the atmosphere they begin to fall. –Precipitation – all moisture falling from the atmosphere The temperature of the air determines the form of precipitation: The temperature of the air determines the form of precipitation: 1. Rain 2. Sleet 3. Snow 4. Hail

10. Where Does The Precipitation Fall? 1. Ocean or Other Bodies of Water –Most precipitation falls here since most of the earth’s surface is covered by water. 2. Land –May flow over the surface as runoff, which flows into rivers or streams –May enter the soil and enter the plants roots

11. Infiltration Infiltration – process of precipitation entering the ground Infiltration – process of precipitation entering the ground –The water can move or percolate through the soil and rocks until it reaches a layer of impermeable rock or clay. –This layer of water is called groundwater. –This layer of permeable (porous) rock where the water is stored is called an aquifer.

12. Aquifer Aquifer – the layer of rock where the water is stored. Groundwater – the layer of water

13. The Carbon Cycle

14. Why is Carbon important? All living things are made of carbon!!! Calcium carbonate (CaCO 3 ) makes up animal skeletons Carbon Dioxide gas which makes photosynthesis and respiration work together

15. 1. 1. In the atmosphere, carbon is attached to some oxygen in a gas called carbon dioxide. 2. 2. Plants use carbon dioxide and sunlight to make their own food and grow. The carbon becomes part of the plant. 3. 3. Animals consume plants. The carbon becomes part of the animal. 4. 4. Plants that die and are buried may turn into fossil fuels made of carbon like coal and oil over millions of years. 5.. 5. When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide. Carbon Does Not Stay Still – It Is On the Move!

16. + → + + → + sunlight Using light energy, plants combine carbon dioxide (CO 2 ) from the atmosphere and water (H 2 0) to form sugar and oxygen in the process of photosynthesis. (CO 2 )(H 2 O) (C 6 H 12 O 6 ) (O 2 ) PHOTOSYNTHESIS What is Sugar (Glucose) Used For? 1. Source of energy 2. Building block for other compounds such as proteins, oils, and starches.

17. RESPIRATION In respiration, the compounds containing carbon (the organic compounds) are broken down, and carbon dioxide is released. Plants, animals, and microorganisms all carry out respiration!

19. IS THE CARBON-OXYGEN CYCLE BALANCED? The Carbon-Oxygen cycle is out of balance. There is more carbon dioxide being released into the atmosphere than is being removed.

20. COMBUSTION Most of the carbon dioxide is produced during the process of burning called combustion. When compounds containing carbon (wood, coal, or oil) are burned, the carbon is chemically combined with oxygen, and carbon dioxide is released.

21. The use of carbon dioxide by plants during photosynthesis is a much slower process. As a result of the imbalance between these two processes, the level of carbon dioxide in the atmosphere is increasing.

22. “Even if human emissions of CO2 magically dropped to zero, the gas already in the air would linger for many centuries, trapping heat. Global temperatures would continue to creep upward until the ocean depths reached equilibrium with the heated air, until biological systems finished adapting to the new conditions, and until Arctic icecaps melted back to their own equilibrium”

24. When organisms die, decomposers break down the carbon compounds in their bodies, and carbon dioxide is returned to the atmosphere. During decomposition (decay), other chemicals are also returned to the soil or released into the air. One of these chemicals is nitrogen. Decomposers

25. The Nitrogen Cycle

26. NITROGEN Plants and animals need nitrogen to make amino acids (proteins) The atmosphere is about 78% nitrogen gas, but plants and animals cannot use nitrogen directly from the air.

27. How Do Plants Get Nitrogen? Special bacteria, in the soil and water, must change or “fix” nitrogen gas (N 2 ) into nitrogen fertilizers (NO 3 - ) or ammonium ions (NH 4 + ) that plants can use. These bacteria are called nitrogen-fixers. N=N → 2NH 3

28. Nitrogen Fixers Legumes - members of a large family of plants that include peas, beans, alfafa, and clover. Convert nitrogen gas to ammonia Most nitrogen-fixing bacteria live in little houses, or nodules, on the roots of plants called legumes.

29. Nitrogen Fixers Mutualistic Relationship – –The plants provide food and cover for the bacteria, and the bacteria convert nitrogen gas into fertilizer for the plant.

30. How Do Animals Get Nitrogen? Animals get nitrogen from plants or from other plant-eating animals, in the form of protein. Animals must eat protein to get our nitrogen requirements! We can’t breathe in nitrogen.

31. Nitrogen is recycled by special bacteria (legumes) that break down the nitrogen compounds (proteins) in dead plants and animals, and in animal wastes. How is Nitrogen Recycled?

32. If plants do not use the nitrogen compounds as fertilizer, special forms of bacteria may recycle it. These bacteria convert the unused fertilizer into nitrogen gas and release it into the atmosphere.

33. All natural ecosystems depend upon bacteria to keep the nitrogen cycle going!

34. Lightning and the Nitrogen Cycle Lightning plays a small role in the nitrogen cycle. The high temperature and pressure from lightning combines nitrogen and oxygen (nitrogen oxides) in the atmosphere. – –The “fixed” nitrogen, (which is dissolved in the rain making nitrates) enters the soil

35. Combustion: Another source of Nitrogen The burning of fossil fuels is another source of nitrogen. – –Combustion causes nitrogen and oxygen to combine creating nitrogen oxides (NOx). These lead to acid rain and smog

36. The Phosphorus Cycle

37. Where is Phosphorus found? Phosphorus is important to living organisms because it makes up Phosphorus is important to living organisms because it makes up DNA and RNA. DNA and RNA. Found in enamel of teeth (calcium phosphate) Found in enamel of teeth (calcium phosphate) It is not very common in the biosphere. It is not very common in the biosphere. Phosphorus exists as inorganic phosphorus (does NOT contain carbon). Phosphorus exists as inorganic phosphorus (does NOT contain carbon). Phosphorus stays on land in rock, soil, and ocean sediments never entering the atmosphere. Phosphorus stays on land in rock, soil, and ocean sediments never entering the atmosphere.

38. Rocks and sediments wear down releasing phosphates Rocks and sediments wear down releasing phosphates On land this phosphate washes into rivers dissolving and eventually makes its way to oceans where marine animals use it On land this phosphate washes into rivers dissolving and eventually makes its way to oceans where marine animals use it When plants absorb phosphate they bind it making it organic instead of inorganic  organic phosphate can move through the food web from producers to consumers When plants absorb phosphate they bind it making it organic instead of inorganic  organic phosphate can move through the food web from producers to consumers

39. Nutrient Limitation If a nutrient is in short supply, it will limit an organism's growth. If a nutrient is in short supply, it will limit an organism's growth. When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient. When an ecosystem is limited by a single nutrient that is scarce or cycles very slowly, this substance is called a limiting nutrient. Farmers are aware of this so they apply fertilizers that contain nitrogen, phosphorus, and potassium. Farmers are aware of this so they apply fertilizers that contain nitrogen, phosphorus, and potassium.