5.3 - Energy & Ecosystems Flashcards
What do pyramids of energy show?
Represent the total amount of energy that flows through each trophic level. They are always pyramid shaped as energy cannot be created.
What do pyramids of biomass represent?
Represent the total dry mass of living organisms each trophic level.
What do pyramids of numbers represent?
These show the numbers of organisms at each trophy level in a food chain.
The width of the bars represent the numbers and can be drawn to scale.
How is biomass determined?
Biomass is found by drying and weighing the organisms at each trophic level, or by counting the number of organisms and multiplying by an average individual mass.
What is biological control?
Involves using a predator or parasite of a pest to control, not eradicate its population.
How can chemical energy store be estimated?
Using calorimetry e.g. bomb calorimetry
How is energy minimised in intensive rearing of domestic livestock?
1) Kept inside in warm conditions to limit energy loss due to maintaining body temperature.
2) Kept in cramp conditions to limit energy loss due to movement.
3) Fed a concentrated and controlled diet, to maximise the amount of food used to create biomass.
What is the equation for net production in consumers?
N = I-(F+R)
N = net production
I = chemical energy
F = chemical energy lost to environment
R = respiratory losses
Why is leaching less common in natural fertilisers?
They are less soluble and need to be decomposed first by microorganisms.
What are saprobionts?
Micro organisms that digest the dead tissue and waste, releasing the elements back into the cycle.
What is the equation for Net Primary Production (NPP)?
NPP = GPP - R
net primary productivity = gross primary productivity - respiratory loses to the environment
What is Net Primary Productivity?
The chemical energy store in plant biomass after respiratory losses to the environment have been taken into account.
What is Gross Primary Productivity?
The chemical energy store in plant biomass, in a given area or volume.
What is a bomb calorimeter?
Drying out materials then burning it in oxygen.
How can biomass be measured?
Biomass can be measured in terms of mass of carbon or dry mass of tissue per given area.
