1. 1 http://bellaonthebeach.files.wordpress.com/2009/01/water.jpg BIOL 3240 Plant and Animal Ecology – Water

2. 2 Water Availability The tendency of water to … determine whether an organism tends to lose or gain water from its environment. – ____________ important factor! BIOL 3240 Plant and Animal Ecology – Water

3. 3 Water Content of Air ___________ accounts for much of water lost by terrestrial organisms. – As water vapor in the air increases, the water concentration gradient from organisms to air is __________, thus evaporative loss is decreased. – Would you buy a “swamp cooler” to help you keep cool in the cypress swamps of southern U.S.? BIOL 3240 Plant and Animal Ecology – Water

4. 4 Water Content of Air Relative Humidity: ________________ is measured as the water vapor per unit volume of air. _____________________________ is measured as the quantity of water vapor air can potentially hold. – BIOL 3240 Plant and Animal Ecology – Water

5. 5 Water Content of Air Total Atmospheric Pressure – Water Vapor Pressure – Saturation Water Vapor Pressure – Vapor Pressure Deficit – BIOL 3240 Plant and Animal Ecology – Water

6. 6 Evaporative Water Loss BIOL 3240 Plant and Animal Ecology – Water A high vpd indicates that the H2O vapor content of air is… Where the vpd is high, the rate of evaporative H2O loss by organisms is… A low vpd indicates that the H2O vapor content of air is… Where the vpd is low, the rate of evaporative H2O loss by organisms is…

7. 7 Water Movement in Aquatic Environments Water moves down concentration gradient. – Water is more concentrated in … Aquatic organisms can be viewed as an ______________ bounded by a _______ _______________ floating in an another ______________________. BIOL 3240 Plant and Animal Ecology – Water

8. 8 Water Movement in Aquatic Environments If two environments differ in water or salt concentrations, substances will tend to move… – Diffusion Osmosis: BIOL 3240 Plant and Animal Ecology – Water

9. 9 Water Movement in Aquatic Environment ____________: Body fluids and external fluid are at the same concentration. ____________: Body fluids are at a higher concentration than the external environment. ____________: Body fluids are at a lower concentration than the external environment. BIOL 3240 Plant and Animal Ecology – Water

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13. 13 Water and Salt Balance in Aquatic Environments Freshwater Fish and Invertebrates – Hyperosmotic organisms that … Replace ________ by absorbing sodium and chloride at base of gill filaments and by ingesting food. BIOL 3240 Plant and Animal Ecology – Water

14. 14 Osmoregulation by Freshwater Organisms BIOL 3240 Plant and Animal Ecology – Water

15. 15 Osmoregulation by Marine Organisms BIOL 3240 Plant and Animal Ecology – Water What happens with H 2 O in hypoosmotic bony fish? What happens with salts in hypoosmotic bony fish? How do hypoosmotic bony fish compensate?

16. 16 Water and Salt Balance in Aquatic Environments Marine Fish and Invertebrates – __________ organisms do not have to expend energy overcoming osmotic gradient. Sharks, skates, rays - – Slowly gain water osmotically. Marine bony fish are strongly hypoosmotic, thus need to… BIOL 3240 Plant and Animal Ecology – Water

17. 17 Water Movement Between Soils and Plants Water moving between soil and plants flows... ______________ (Ψ) is the capacity to perform work. – Dependent on free energy content. – Pure Water ψ =. Ψ in nature generally ____________. Ψ solute measures the reduction in Ψ due to… BIOL 3240 Plant and Animal Ecology – Water

18. 18 BIOL 3240 Plant and Animal Ecology – Water ? ? ? ? ? ?

19. 19 Water Movement Between Soils and Plants – Ψ plant = Ψ solute + Ψ matrix + Ψ pressure – ______________: Water’s tendency to adhere to container walls. – Ψ pressure is the reduction in water potential due to negative pressure created by… – As long as Ψ plant < Ψ soil, water flows from… BIOL 3240 Plant and Animal Ecology – Water

20. 20 Water Regulation on Land Terrestrial organisms face (2) major challenges: – – BIOL 3240 Plant and Animal Ecology – Water

21. 21 Water Regulation on Land - Animals BIOL 3240 Plant and Animal Ecology – Water

22. 22 Water Regulation on Land - Animals W ia = W d + W f + W a - W e - W s W ia = W d = W f = W a = W e = W s = BIOL 3240 Plant and Animal Ecology – Water

23. 23 Water Acquisition by Animals Most terrestrial animals satisfy their water needs via… – Can also be gained via ______________ through oxidation of glucose:  – ________________________ refers to the water released during cellular respiration. BIOL 3240 Plant and Animal Ecology – Water

24. 24 Water Regulation on Land - Plants BIOL 3240 Plant and Animal Ecology – Water Water is lost via what mechanism(s)? How might Water be gained? Water is lost via what mechanism(s) due to wind? How might Water be gained?

25. 25 Water Regulation on Land - Plants Wip= Wr + Wa - Wt - Ws W ip = W r = W a = W t = W s = BIOL 3240 Plant and Animal Ecology – Water

26. 26 Water Acquisition by Plants Extent of plant root development often reflects differences in water availability. – Deeper roots often help plants… Park found supportive evidence via studies conducted on common Japanese grasses, Digitaria adscendens and Eleusine indica. BIOL 3240 Plant and Animal Ecology – Water

27. 27 Water Conservation by Plants and Animals Many terrestrial organisms equipped with _______________________. Concentrated _______________. __________________________ in breath. __________________________ to avoid stress times. ___________________ in response to drought. BIOL 3240 Plant and Animal Ecology – Water

28. 28 BIOL 3240 Plant and Animal Ecology – Water How is heat gain reduced? How is H 2 O loss decreased? How is heat gain reduced?

29. 29 Dissimilar Organisms with Similar Approaches to Desert Life Camels – Can withstand water loss up to ___%. Saguaro Cactus – Trunk / arms act as... – Dense network of shallow roots. WHY? – BIOL 3240 Plant and Animal Ecology – Water

30. 30 Two Arthropods with Opposite Approaches to Desert Life Scorpions – – – BIOL 3240 Plant and Animal Ecology – Water

31. 31 Cicadas (Diceroprocta apache) – – – How? http://www.learnnowonline.net/nucpan/wp-content/uploads/2007/08/cicada2.JPG http://www.canyouseethesunset.com/uploaded_images/cicada-2.jpg BIOL 3240 Plant and Animal Ecology – Water

32. 32 BIOL 3240 Plant and Animal Ecology – Water