Movement of Energy Flashcards
Conservation of energy
Energy is neither created or destroyed.
Gross primary productivity
rate at which energy (E) is captured and converted into chemical bonds by photosynthesis or chemosynthesis.
Most energy enters biosphere via
photosynthesis
Great Oxygenation Event
Photosynthetic bacteria came to be 2.3 billion years ago. This caused the extinction of more than 90% of earths species (anaerobic) at the time.
Photosynthesis is not efficient because
Only 1% of solar energy is captured by the plant and the rest is either reflected or not absorbed by plant
Net Primary Productivity
60% of gross primary productivity is respired. Only 40% of gross primary productivity is used for producer growth and reproduction. This is net primary productivity.
Respiration
Uses oxygen to release chemical energy to drive cellular processes.
Secondary production relies on
primary production
Assimilated energy
energy that a consumer digests and absorbs. NOT EGESTS
Net secondary production (NSP)
Energy converted to first order consumer biomass. (assimilated energy left after respiration by first order consumer)
NSP=GSP - R
Net secondary production = (Food eaten-feces)-respiration
Factors involved in estimating primary production
Change in producer biomass, CO2 exchange, remote-sensing
Change in Producer Biomass
Estimate NPP by harvesting plants to determine mass of growth over a period of time. Underestimation due to herbivory, below ground biomass, and mutualistic exchanges
Co2 uptake
Light/dark bottle experiments measure NPP and GPP. (because plants respire in the dark)
How can remote sensing help us detect biomass?
Measure the absorption of blue and red light and reflection of green light from satellite images. Calculate indices indicating vegetation biomass. Changes in spectral reflectance over time give information on seasonal and annual variation.
