energetics & remineralisation Flashcards
equation to calculate energy content of trophic level n
energy entering trophic level n + energy leaving trophic level n (respiration, predation, decomposition etc)
what is ecological efficient (EE) and its formula
- Amount of energy transfered between trophic levels
Energy present in current trophic level
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Energy in trophic level below x100
what 2 principles did Lindeman conclude after looking at energy in a complicated web of trophic interactions
- Predator = more active than herbivorous prey, which in turn are more active than plants - % energy loss to respiration is progressively greater for higher levels (Decreasing productivity)
- Consumers at higher levels are more efficient in using their food supply. (Increasing efficiency)
explain the Biomass pyramid patterns
- Generally need around 10x the animal to support the level above
- Size will decrease as going down the chain – phytoplankton = smallest (but most abundant)
- Bigger organisms at the top e.g. whales, cod, will have a smaller total biomass due to the amount of energy/biomass they need to support
whats the Second Law of Thermodynamics
“no process involving an energy transformation will spontaneously occur unless there is degradation of energy from a concentrated into a dispersed form”
what is Respiration (R)
Energy -> heat loss due to 2nd law of thermo
- Carbon -> break down of OM releasing CO2
what is Growth (G)
Energy amassed as matter i.e. net gain from ingested energy
equation for Energy budgets
I = G + R + Exc + Exu + D
what is Ingestion (I)
energy entering the gut
wat is Defecation (D)
energy not crossing the gut
what is Excretion (Exc)
energy never assimilated, but crosses gut wall
what is Excuvation (Exu)
energy once assimilated, but later secreted e.g. mucus
what’s the Lowest/most dispersed form of energy
heat
equation for growth
G = I – R – Exc – Exu – D
why is the Classic food chain more efficient than the microbial loop
fewer steps