The table below describes four different ecosystems and the amount of energy converted into plant biomass each year in each ecosystem:
| Ecosystem | Description | Energy converted into plant biomass (kJ m−2 yr−1\text{kJ m}^{-2}\text{ yr}^{-1}kJ m−2 yr−1) |
|---|---|---|
| A | Boreal coniferous forest | 22 500 |
| B | Lowland peat bog | 11 200 |
| C | Semi-arid natural shrubland | 7 400 |
| D | Pivot-irrigated alfalfa monoculture | 39 800 |
Name three abiotic (non-living) factors, other than water availability, likely to affect the rate of photosynthesis in these ecosystems.
Ecosystems C (semi-arid natural shrubland) and D (pivot-irrigated alfalfa monoculture) experience the same climate. Suggest two reasons, other than the selective breeding of alfalfa, why more energy is converted into plant biomass in ecosystem D than in ecosystem C.
What is meant by the term selective breeding?
Describe how you could use a quadrat to estimate the total dry plant biomass in Ecosystem C, which has a total area of 850 m2\text{m}^2m2.
