6.3.1 (b) Biomass transfer Flashcards
what is each stage in a food chain called?
a trophic level
what is always the first trophic level?
a producer
what are each subsequent trophic level after the first one?
consumers
what is the order of consumers?
primary consumer eaten by secondary consumer eaten by tertiary consumer eaten by quaternary consumer
why are food chains not very long?
because there is not sufficient biomass and stored energy to support other organisms
what is biomass?
dry mass of living material present in a particular place or organism
biomass equation
biomass = biomass in each organism x number of organisms
what is the link between energy and biomass?
as biomass is transferred, energy is transferred
what energy to producers convert to biomass?
light energy
why do producers convert only a small amount of light energy into biomass?
- not all light energy is needed for photosynthesis
- some light is of different wavelengths which cannot be absorbed
- some light cannot be used if it hit’s parts of a plant like bark
- lack of water so less photosynthesis
what is gross production?
solar energy converted by a plant into organic matter
what is net production?
biomass available to the next trophic level
equation for net production
net production = gross production - respiratory losses
what causes the 10% rule?
- not all biomass of an organism is eaten
- some energy is transferred to the environment due to movement and respiration
- some parts of an organism are inedible
- energy can be lost during excretion
equation for ecological efficiency?
biomass available after transfer
——————————— x100
biomass available before transfer
