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Outline

Outline. Energy flow versus chemical cycles Carbon Nitrogen Phosphorous Water Ecosystem services. Energy flow through ecosystems. Only 5% of the solar energy that arrives on earth is captured by photosynthesis. The energy captured powers life. Trophic levels. Energy flow versus

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Outline

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Presentation Transcript

  1. Outline • Energy flow versus chemical cycles • Carbon • Nitrogen • Phosphorous • Water • Ecosystem services

  2. Energy flow through ecosystems Only 5% of the solar energy that arrives on earth is captured by photosynthesis. The energy captured powers life.

  3. Trophic levels

  4. Energy flow versus Biogeochemical cycles

  5. A generalized biogeochemical cycle Consumers Producers Decomposers Abiotic reservoir Geological processes

  6. Picture of green plants

  7. Carbon cycle Carbon is the currency for energy flow!

  8. Carbon cycle Carbon is the currency for energy flow! Carbon cycles through the atmosphere, organisms, soils, and oceans (and rocks at very long time scales)

  9. Carbon cycle Carbon is the conduit for energy flow! Carbon cycles through the atmosphere, organisms, soils, and oceans (and rocks at very long time scales) Gaseous, mineral, organic

  10. Carbon cycle

  11. CO2, C leaching, erosion NPP Soil, plant growth (wood) Ecosystem carbon balance C in =  storage + C out C in >  storage + C out: accumulating C C in =  storage + C out: balanced C C in <  storage + C out: loosing C

  12. Carbon stocks Sedimentary rocks > deep oceans > atmosphere Only a small amount in organisms and soils!

  13. Picture of forest canopy

  14. Nitrogen cycle • N cycles through the atmosphere, organisms, soils and sediments

  15. Nitrogen cycle • N cycles through the atmosphere, organisms, soils and sediments • Organically bound N is one of the main constituents of organisms • enzymes for photosynthesis, metabolism • proteins • building blocks of DNA...

  16. Nitrogen cycle • N cycles through the atmosphere, organisms, soils and sediments • Organically bound N is one of the main constituents of organisms • enzymes for photosynthesis, metabolism • proteins • building blocks of DNA... • Gaseous, mineral, organic

  17. Nitrogen cycle • Although N2 gas makes up 72% of the atmosphere, few organisms can use it. • N is the element that is most likely to limit plant growth

  18. Nitrogen cycle • N enters system through biological fixation

  19. Picture of N accumulation over primary succession Nitrogen accumulates over primary succession

  20. Nitrogen cycle • N enters system through biological fixation • If organisms can fix N, why don’t they take over and fix enough N so that it is no longer limiting to plant growth?

  21. Why is N in short supply? • Only a few types of organisms can do it

  22. Why is N in short supply? • Only a few types of organisms can do it • Energetically expensive to fix N

  23. Why is N in short supply? • Only a few types of organisms can do it • Energetically expensive to fix N • Chemically expensive to fix N

  24. Why is N in short supply? • Only a few types of organisms can do it • Energetically expensive to fix N • Chemically expensive to fix N • N can be lost from the system • Leaching • Fire • Erosion

  25. Picture of ocean water

  26. Hydrological cycle Water cycles through the oceans, fresh waters, atmosphere, and land

  27. Hydrological cycle Water cycles through the oceans, fresh waters, atmosphere, and land Gaseous phase and liquid phase

  28. Hydrological cycle Evaporation: liquid to gas Transpiration: plant transport of water from the soil to the atmosphere Precipitation: gas to liquid

  29. Water inputs to ecosystems • Precipitation • THE major water input to ecosystems • Groundwater (in some ecosystems) • Fog deposition (in some ecosystems)

  30. Water balance in ecosystems Inputs = storage + outputs

  31. Water balance in ecosystems Soil is like a bucket

  32. Water balance in ecosystems Soil is like a bucket • Inputs • Mainly precipitation

  33. Water balance in ecosystems Soil is like a bucket • Inputs • Mainly precipitation • Storage • Plants, soil and water bodies

  34. Water balance in ecosystems Soil is like a bucket • Inputs • Mainly precipitation • Storage • Plants, soil and water bodies • Outputs • Evaporation • Transpiration • Drainage

  35. Hydrological cycle • Over oceans, evaporation >> precipitation • On land, evaporation << precipitation and transpiration • Lakes, rivers, streams, groundwater

  36. Ecosystem services Processes by which the environment produces fundamental life-support services enjoyed by humans

  37. Ecosystem services • Purification of air and water

  38. Ecosystem services • Purification of air and water • Detoxification and decomposition of wastes

  39. Ecosystem services • Purification of air and water • Detoxification and decomposition of wastes • Regulation of climate

  40. Ecosystem services • Purification of air and water • Detoxification and decomposition of wastes • Regulation of climate • Regeneration of soil fertility

  41. Ecosystem services • Purification of air and water • Detoxification and decomposition of wastes • Regulation of climate • Regeneration of soil fertility • Production and maintenance of biodiversity

  42. Ecosystem services Key ingredients of our agricultural, pharmaceutical, and industrial enterprises

  43. Ecosystem services We know that they are: • Essential to civilization

  44. Ecosystem services We know that they are: • Essential to civilization • So complex that they can’t be replaced by technology (???)

  45. Picture of biological machines

  46. Ecosystem services We know that they are: • Essential to civilization • So complex that they can’t be replaced by technology (???) • Impaired by human activities

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