Lecture 18 Flashcards
Primary productivity
“rate at which energy is captured and concerted into organic compounds by photosynthesis or chemosynthesis”
What are the organisms responsible for primary production?
Primary producers or autotrophs
Extremophiles
Organisms that are able to live in extreme conditions
Productivity
“rate at which energy is converted into organic matter”
Production
“biomass produced by organisms in an ecosystem over a given period of time”
Standing crop
“biomass of producers present in an area at a particular moment in time”
Units for productivity
kg C/m^2/year
Units for production
kg C/m^2
Units for standing crop
kg C/m^2
OR
kg C
Gross primary productivity (GPP)
“rate at which energy is captured and assimilated by producers in a given area”
Net primary productivity (NPP)
“rate at which energy is assimilated by producers and converted into biomass in a given area”
Equation for NPP
NPP = GPP - respiration
What factors change net primary production among ecosystems?
- Latitude
- Region
- Ecosystem type
Food chain
linear sequence of energy flow between organisms
- each group is the source of energy/nutrients for the next
Trophic level
“position in food chain that represents a group of organisms sharing the same primary source of nutrition and energy”
