Question 1
Paper 2Medium16 marksTwo rabbit populations were monitored in separate fenced grassland enclosures, each with an area of 2.0 ha. The enclosures had similar vegetation and water supplies. At year 0, each enclosure contained 20 rabbits. From year 1 onwards, supplementary food was added to enclosure B each year; no supplementary food was added to enclosure A. Other management was kept the same.
| Year | Rabbits in enclosure A | Rabbits in enclosure B |
|---|---|---|
| 0 | 20 | 20 |
| 1 | 39 | 44 |
| 2 | 55 | 67 |
| 3 | 65 | 85 |
| 4 | 70 | 96 |
| 5 | 69 | 101 |
| 6 | 71 | 99 |
Calculate the approximate rabbit population density at carrying capacity in enclosure A. Give your answer with a unit.
Describe the changes in rabbit population size in enclosures A and B over the seven years.
Define carrying capacity and give two examples of resources that may limit it.
Explain how competition for limited resources affects a rabbit population as it approaches carrying capacity.
Use the data to explain what the comparison between enclosures A and B suggests about the effect of food availability on carrying capacity. State one limitation of this comparison.