transfer of biomass Flashcards
name the two elements that constantly cycle within an ecosystem
nitrogen and carbon
draw a simple food chain
what do the arrows represents
plankton -> fish -> seal -> polar bear
-energy transfer
where is energy captured what is the reaction and products and what are they used for
-producer capture light energy by photosynthesis = glucose and oxygen
glucose used for respiration and other reactions in plants
what else do plants need to take in to produce biomass
nitrates from soil
what is a trophic level
what is biomass transfer
-level of feeding
-amount of biomass 9total living mass) that passes from one organism to another
how is biomass lost from each trophic level in a food chain
-energy is lost as heat during movement or respiration
-lost in excretory materials such as urine and faeces
-not all parts are edible or digestible by consumers e.g bones. hair
-dead organisms available for consumers
what is biomass measured in
-grams per square metre (g m ^-2) for land animals
-grams per cubic metre (g m ^-3) for marine animals
how are pyramids of number a better representation than food chains of relationships within an ecosystem
what do the blocks in pyramids need to be proportional to
-give numerical/ quantitative information
-to the number of organisms at each trophic level
how can you measure the energy stored in biomass?
-collect and kill sample
1. dry the biomass sample in an oven until its mass remains constant to obtain dry mass
2. weigh dry mass
3. burn the dry mass ina calorimeter
4.measure the volume and temp change of surrounding water
5. use these values to calculate an estimate of heat energy released from burnt biomass
how can you calculate the efficiency of biomass transfer
(biomass at higher trophic level/ biomass at lower trophic level) x 100
what is gross primary production (GPP)
what is net primary production (NPP)
-Total amount of energy that plants convert into organic matter, storing it as chemical energy within their biomass NPP + respiratory losses
-chemical energy that is available to next trophic level after accounting for respiratory losses (R) - energy converted into biomass
NPP = GPP-R
