Energy Flow Flashcards
What is primary production?
The amount of light energy converted to chemical energy by autotrophs during a given time period
What is Gross Primary Production (GPP)
total primary production
Gross Primary Production is measured as
conversion of chemical energy from photsynthesis per unit time
What is Net Primary Production (NPP)
GPP minus Energy used by primary producers for respiration
What is Net Ecosystem Production (NEP)
measure of the total biomass accumulation during a given period
GPP - total respiration of all organisms in an ecosystem
What are the most productive ecosystems per unit area?
Tropical rain forests, estuaries, coral reefs
What is the efficiency of energy transfer between trophic levels?
10%
What is secondary production of an ecosystem?
The amount of chemical energy in food converted to new biomass during a given period of time
What is organism’s production efficiency?
fraction of energy stored in food that is not used for respiration
How do you calculate production efficiency?
(net secondary production/assimilation of primary production) x 100%
What is a food web?
a branching food chain with complex tropic interactions
What are the two hypotheses that explain food chain length?
Energetic Hypothesis - length is limited by inefficient energy transfer (supported by most data)
Dynamic Stability Hypothesis - long food chains are less stable than short ones
