Role of Biology in Transferring Energy and Mass Through the Earth System

1. Role of Biology in Transferring Energy and Mass Through the Earth System Remember Conservation of Energy& Conservation of Mass

3. 3 Basic Steps in Photosynthesis • Light reactions- energy capture: chemiosmosis generation of ATP from harvested sunlight • Dark reactions- fixation of carbon: enzyme catalyzed reactions using the ATP formed in the light reactions to “fix” CO2 into sugars • Pigment regeneration- electron replacement from the splitting of H2O in oxygenic photosynthesis

4. Light Reactions: A very specific energy is required for photochemistry since only photons of a certain wavelength can dislodge electrons from an object Most common range of wavelength from the sun is the most sensitive range for photosynthesis

6. Carbon enters water leaves the plant through the same pore; thus the exchange of the two substances is linked. This processes is known as transpiration. Stoma

7. Chlorophyll

8. Nutrients Chemicals required for life processes but often in short supply and thus may limit growth

11. The Essential Elements Necessary for Plant Growth: 1. the bulk mass (95%)

12. The Essential Elements Necessary for Plant Growth: 2. minor constituents available from soil minerals or dissolved in water

17. Interactions Between Biology and Climate Climate Controls on Biology & Biology Controls on Climate

18. Climate Controls on Biology Temperature Light CO2 Water Climate variability

29. Levitus94 Annual Phosphate (micromolar) at Surface Blue lowest (~0); Pink highest (~2)

30. Source: SeaWiFS Project of the NASA Goddard Space Flight Center Data aquired between Noverber 1978 and June 1986

31. Climate variability and ecosystem structure (greater variability = lower diversity)

32. Biological Controls on Climate Albedo Interception of rainfall Cloud formation Surface roughness Greenhouse gasses Long-term atmospheric change

33. Albedos for Various Terrestrial Biomes • Equatorial forest 0.18 • Savannah 0.18-0.24 • Mid-latitude forest 0.14-0.46 • Tundra 0.18-0.80 • Desert 0.35 (In general vegetated surfaces reflect less than bare soil and rock. Tall vegetation prevents snow from making surface completely white)

35. Possible chain of events set off by overgrazing

36. Interception of Rainfall

40. Cloud Formation

41. Aerosols are cloud condensation nuclei Increased terrestrial vegetation leads to decrease dust (aerosol) Ocean plankton release a sulfur compound (aerosol)

42. Surface Roughness • Vegetation roughens the surface of the earth, causing air to flow less smoothly. • This increase in turbulence near the surface increases the efficiency of mixing of heat and moisture between the surface and rest of troposphere • Additionally, the rough surface causes surface winds to blow in a different direction from winds at high levels.

43. Greenhouse Gasses

45. Long-term Atmospheric Change The CO2 Content of the atmosphere is critical to maintianing the earth’s mean surface temperture. The CO2 content is controled by the biosphere. It has not always been as it is today.

48. Role of Biology • Photosynthesis • Respiration • Transpiration • Nutrient • Climate controls on Biology • Biology controls on Climate