A conservation researcher investigates the impact of off-trail mountain biking on the density of wild bluebell shoots in a protected ancient woodland.
She uses a 0.5 m×0.5 m0.5\text{ m} \times 0.5\text{ m}0.5 m×0.5 m quadrat to sample the vegetation from two distinct zones:
She records the number of bluebell shoots in multiple quadrat samples across both zones.
The mean densities calculated from her data are shown below:
| Zone | Mean number of bluebell shoots per m2\text{m}^2m2 |
|---|---|
| Zone A (on-trail) | 222 |
| Zone B (undisturbed) | 868686 |
Name the independent variable in this investigation.
Suggest an explanation for the difference in the mean number of bluebell shoots between the two zones.
Suggest how the researcher ensured that her data collection was both valid and reliable.
The researcher suggests that constructing raised wooden boardwalks over all high-traffic trails would be the best way to protect the woodland floor.
Discuss the advantages and disadvantages of installing raised wooden boardwalks in protected woodland areas.
