Energy and Ecosystems Flashcards
How is the organic matter produced in photosynthesis used?
- respiratory substrate
- forms biological molecules (e.g starch and cellulose)
What is biomass?
mass of living material
What are the biological molecules made by producers (after photosynthesis)?
a chemical energy store
How can chemical energy store in dry biomass be estimated?
calorimetry
energy = specific heat capacity * volume * temp increase
(all of water)
Why is bomb calorimetry preferable to simple calorimetry?
reduces heat loss to the surroundings
What is Gross Primary Production?
total chemical energy in plant biomass within a given area/volume (usually the chemical energy converted from light energy in photosynthesis)
What is Net Primary Productivity?
Total chemical energy available for plant growth, plant reproduction, and energy transfer to other trophic levels after respiratory losses. It includes energy stored as biomass
What is the relationship between GPP and NPP?
NPP = GPP - R
When does energy transfer happen in ecosystems?
When organisms eat other organisms (chemical stores passed up/along food chain)
How could chemical energy from ‘food’ be lost?
- excretion; urine
- egestion; faeces
- respiratory losses
What is the NP of a consumer?
Net Production/ Productivity, how much chemical energy is stored and available for the next trophic level
What could the N of a primary consumer also be referred to?
secondary production
How would the dry mass of an organism be measured?
heat the organism in an oven, remove, weigh and reheat
repeat until mass reading is constant
How much of the recorded dry mass is usually assumed to be carbon?
50%
how can the Net production of consumers be calculated?
N = I - (F+R)
