Topic 5B: Energy Transfer and Nutrient Cycles Flashcards
1
Q
What are biotic factors?
Give an example
A
- Living
e.g. predators, food availability, pathogens
2
Q
What are abiotic factors?
Give an example
A
- Non-living
e.g. temperature, light availability, water availability, pH, salinity
3
Q
Define ecosystem
A
- All organisms and the biotic & abiotic factors in an area
4
Q
Define population
A
- All organisms of one species in a habitat
5
Q
Define community
A
- All organisms of all species in a habitat
6
Q
Define habitat
A
- The place an organism lives
7
Q
Define niche
A
- The role of a species in an ecosystem
8
Q
Define trophic level
A
- Each stage of a food chain
9
Q
What productivity values do plants have?
A
- GPP -> total amount of energy made by a producer (units = given area per unit time - kJ/m^2/yr)
- NPP -> biomass accumulated
- R -> respiratory losses
10
Q
How is NPP calculated?
A
NPP = GPP - R
11
Q
What productivity values to animals have?
A
- I -> total energy ingested
- R -> respiratory losses
- F -> faeces and urine
- N -> net productivity
12
Q
How is net productivity (N) calculated?
A
N = I - (R + F)
13
Q
How do you calculate energy transfer efficiency?
A
- N/I x100
14
Q
How is energy lost from the sun to a producer?
A
- Light reflected
- Not all light shines on photosynthetic areas
15
Q
How is energy lost between producers and primary consumers?
A
- Respiration
- Heat
- Not all of the producer eaten - e.g. deep roots
- Some not digested - e.g. cellulose
16
Q
How is energy lost between consumers?
A
- Respiration, heat
- Not all eaten - e.g. bones
17
Q
How do you make dry biomass?
A
- Put in an oven on a low temperature - prevent combustion
- Regularly measure the mass
- When the mass remains constant - all the water has been removed - now dry
18
Q
What unit do you measure dry biomass in?
A
kg/m^2
19
Q
Describe calorimetry
A
- Estimates the amount of energy stored in dry biomass
- Burn a sample of dry biomass completely to heat a known volume of water
- Change in temperature is used to calculate the chemical energy of the dry biomass