1. Topic Two Biogeochemical Cycles

2. 2-2 Water Cycle

3. Water Cycle Water cycle  path of water through the environment From the earth to the atmosphere and back to the earth Importance of water: Absorbs and releases water-stable global weather patterns Medium for reactions Solvent 60% of cell’s mass

6. Water’s Role Moves from atmosphere to earth through precipitation Surface runoff and groundwater flows to other bodies of water Water enters the atmosphere through transpiration evaporation Transpiration: loss of water thru leaves of plants

7. Role of living things Plants: Return water to the atmosphere through transpiration and evaporation Animals: Return water to the atmosphere through gas exchange, perspiration, evaporation, excretion

9. Acid Rain Caused by release of nitrogen and sulphur compounds into the atmosphere Change into acidic compounds and rain down lowers pH causing aquatic life to experience chemical "shock" effects EG. Success of trout eggs is decreased when pH falls below 5.5 reduces crop productivity and forest growth rates Increases amount of metals water from soil accelerates weathering of limestone surfaces on buildings and monuments; corrodes metals

12. Acid Rain

13. Water Cycle

14. 1 Water in clouds 2 Rain and snow 3 Water drains into river and soil 4 Water taken up by plants and animals 5 Water loss by transpiration 6 Water loss by respiration 7 Evaporation