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WATER RELATIONS (Chapter 6). Terrestrial. WATER RELATIONS (Chapter 6). Saltwater. Freshwater. 23 o C. 23 o C. Water Saturation of Air. Saturation Water Vapor Density (g/m 3 ) Saturation Water Vapor Pressure (kPa). Fig. 6.2 in Molles 2010. Fraction of Water Saturation in Air I.
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WATER RELATIONS (Chapter 6) Terrestrial
WATER RELATIONS (Chapter 6) Saltwater Freshwater
23oC 23oC
Water Saturation of Air Saturation Water Vapor Density (g/m3) Saturation Water Vapor Pressure (kPa) Fig. 6.2 in Molles 2010
Fraction of Water Saturation in Air I Relative Humidity http://upload.wikimedia.org/wikipedia/commons/8/84/Relative_humidity.jpg Actual Water Vapor Density Rel. Humidity = X 100 Saturation Water Vapor Density
Fraction of Water Saturation in Air II Vapor Pressure Deficit Vapor Pressure Deficit = Saturation Vapor Pressure – Actual Vapor Pressure
Potential for Evaporation Fig. 6.3 in Molles 2010
WATER MOVEMENT: OSMOSIS Hypotonic, Isotonic, Hypotonic
Osmotic Stress in Marine Organisms Fig. 6.4 in Molles 2010
Strategies for Coping with Hyperosmotic Environments I (Osmoregulation) Fig. 6.27 in Molles 2010
Strategies for Coping with Hyperosmotic Environments II (Osmoregulation) http://www.kcl.ac.uk/ip/christerhogstrand/courses/hb0223/images/water&8.jpg
Osmotic Stress in Freshwater Organisms Fig. 6.4 in Molles 2010
Strategies for Coping with Hypoosmotic Environments I (Osmoregulation) Fig. 6.28 in Molles 2010
Strategies for Coping with Hypoosmotic Environments I I (Osmoregulation) http://www.emc.maricopa.edu/faculty/farabee/biobk/contractilevac.gif
Water Potential (ψ ) = Ability to Do Work (Measured in pressure units: MPa) Fig. 6.5 in Molles 2010
Water Potential (ψ ) = Ability to Do Work (Measured in pressure units: MPa)
Which soil has greater Water Potential? (Matric Forces) Wet Sand Wet Clay ψ1 ψ2
Which has Higher Water Potential? (Effect of Dissolved Substances) 5
Which has Higher Water Potential? (Effect of Dissolved Substances)
Which root has greater Water Potential? (Effect of Dissolved Substances) = Salt
Predicting Direction of Water Flow: Soil Water Potential and Root Water Potential Roots ψ1 Soil ψ2
Which root has greater Water Potential? (Effect of Relative Humidity) ψ1 ψ2
In Which System is there a Greater Difference in Water Potential 8 10 9 Dry Air Moist Air
Plant Water Relations Fig. 7.7 in Molles 2008
Animal Water Relations Fig. 6.7 in Molles 2008