3.5.3 Energy and ecosystems Flashcards
1
Q
Why is dry mass used instead of fresh mass?
A
- dry mass measures increase in organic material
- Water content varies
2
Q
Units for gross productivity
A
Unit of energy or mass per area per year
3
Q
What is used to measure the chemical energy store in dry biomass?
A
Calorimeter
4
Q
What is gross primary production GPP?
A
Chemical energy store in plant biomass, in a given area or volume
5
Q
What is net primary production NPP?
A
Chemical energy store in plant biomass after respiratory losses to the environment have been taken into account
6
Q
What is the equation for NPP?
A
NPP = GPP - R
R is respiratory losses to environment
GPP is gross primary production
7
Q
What is the equation for net production of consumers?
A
N = I - (F+R)
- I is chemical energy store in ingested food
- F is chemical energy lost to environment in faeces and urine
- R is respiratory losses to environment
8
Q
Describe how an ecosystem may be established (succession)
A
- pioneer species
- change in abiotic conditions, more habitats and ecological niches created
- increase in number and diversity of species
9
Q
What is productivity?
A
Rate of production of new biomass
