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Energy conversions:. Driving the system…. From last lesson…. Continuous process = cycle. The Energy cycle?. The Producers: p. 345. Photosynthetic efficiency. http://wps.pearsoned.com.au/sd3/46/11967/3063571.cw/content/index.html. Efficiency and productivity.
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Energy conversions: Driving the system…
The Producers: p. 345 Photosynthetic efficiency
http://wps.pearsoned.com.au/sd3/46/11967/3063571.cw/content/index.htmlhttp://wps.pearsoned.com.au/sd3/46/11967/3063571.cw/content/index.html
Efficiency and productivity • Environmental factors influence photosynthetic efficiency • Productivity can differ between seasons, ecosystems – p.346 • We like to measure these things – how?
Gross Primary Productivity (GPP) Net Primary Productivity (NPP) Like salary after tax… NPP = GPP – energy used for respiration Can be measured by mass (g/m2/year) or energy (kJ/m2/year We’ll take this idea further when we talk about trophic efficiency. • = total organic matter in an ecosystem made during photosynthesis • BUT not all of this is available to consumers – producers need some of it too! • SO we measure…
The consumers: p. 350 • Primary consumers • Secondary consumers • Top consumers • Omnivores • Scavengers • Detrivores (aka detritivores) • Decomposers
Recap Mindmap eg. Efficiency vs. production GPP NPP
Next time: • More on trophic levels and trophic efficiency • Read: pp.344-353 • Look at questions on p.348 and 354
Trophic efficiency • Photosynthetic efficiency = the percentage of light energy that a producer converts to chemical energy (carbohydrates) during photosynthesis • Trophic efficiency = the percentage of chemical energy that is transferred from one trophic level to the next
Trophic efficiency The 10% Rule: • Approximately 90% of energy is lost as we move up each trophic level!