Food Webs, Energy Flow, Structure

biomass

total mass of all organisms in a habitat

trophic structure

feeding relationships between organisms; the position an organism occupies in a food chain

energetic hypothesis

idea that the length of a food chain is limited by the inefficiency of energy transfer along the chain

1st law of thermodynamics

energy cannot be created or destroyed

2nd law of thermodynamics

every exchange of energy increases the entropy of the universe

law of conservation of mass

matter cannot be created or destroyed

detritivores

feeds on detritus (ex. prokaryotes & fungi)

gross primary production (GPP)

amount of energy from light converted to chemical energy of organic molecules per unit time

net primary production (NPP)

equal to GPP minus energy used by primary producers

eutrophication

excessive nutrients

potential energy

stored energyk

kinetic energy

energy in use

average net primary productivity

amount of energy accumulated by producers during photosynthesis in a region (energy available for all trophic levels

heterotroph

cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly matter from other organism