Productivity

What is primary productivity?

The amount of energy converted from light energy into chemical energy in 1 m2 over a year in kJ/m2/year
What is an alternate measurement for primary production?

Amount of new plant biomass in 1m2 in one day measured in g/m2/day
What is the GPP?

The gross primary productivity: the rate at which the products of photosynthesis accumulate
What is the NPP?
- The net primary productivity: the amount of biomass available as food
- Plants use some of the products of their photosynthesis for respiration
Write a word equation for Net primary productivity

NPP = GPP - respiratory loss
Name 5 biotic and abiotic factors that affect productivity
- Light intensity
- Availability of minerals
- Competition from other species
- Damage by pests
- Water availability
What is the energy input for a natural ecosystem?

Solar energy
What is the energy input for a farm ecosystem?
- Solar energy
- Chemical energy as food for workers
- Fossil fuels for machinery
Describe the productivity of a natural ecosystem
- Low due to:
- Higher rates of competition
- Increased damage by pests
- Reduced availability of minerals
Describe the productivity of a farm ecosystem
- High due to:
- Pesticides removing competition and pests
- Fertilisers increasing the availability of minerals

Author

camturnbull

274628

Card Set

Productivity

Description

AQA BIOL4 Energy flow

Updated

2014-05-17T09:12:31Z

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