movement of energy Flashcards
Primary productivity
Definition?
rate at which energy (E) is captured and
converted into chemical bonds by photosynthesis or
chemosynthesis
* Most energy enters biosphere via
photosynthesis
* Exception: chemosynthesis near deep
ocean vents
2.3 billion years ago photosynthetic
cyanobacteria caused the…
“Great
Oxygenation Event”
Gross primary productivity (GPP)
Definition?
Total energy acquired via photo- or
chemosynthesis
Respiration (R)
Definition?
uses oxygen to release chemical energy to drive cellular processes
Net primary productivity (NPP)
What is the definition and equation?
energy converted to producer biomass
NPP = GPP - R
Assimilated energy
Definition?
energy that a consumer digests and absorbs (consumed minus egested energy)
Net secondary production (NSP)
What is the definition and equation?
energy converted to consumer biomass
(assimilated energy left after respiration by the first order consumer)
NSP = GSP - R
Net primary production is…
Definition?
the amount that can be “passed” up the food chain
Estimating primary
production
What 3 processes?
- Change in producer biomass
- CO2 exchange
- Remote-sensing
Assimilation efficiency
Equation?
Assimilated energy/Consumed energy
Net production efficiency
Equation?
Net production energy/Assimilated energy
* Lower for homeothermic and mobile animals
than poikilothermic and sedentary ones
Ecological efficiency
Equation?
Net production energy of a trophic level/Net production energy of the next lower trophic level
A meat-based diet requires
——– more land than a
plant-based diet
7 times
Decomposers release energy as…
heat during respiration
Brown Food Webs =
Decomposer Food Webs
