Exam 2 - Victorian Curriculum and Assessment Authority

ENVSC EXAM 2 6
Use the following information to answer Questions 15–17.
Environmental management strategies must be developed to ensure the ecological sustainability of the
environment. These are developed by regulatory agencies such as national parks services.
A species of shrub in a national park will not reproduce successfully unless there is sufficient viable* seed
when a fire occurs. The amount of viable seed initially increases with time since the last fire and then declines.
This is shown in Figure 2 below.
The national park is managed with the aim of ensuring that there is an appropriate ‘fire interval’ in places where
the shrub exists. A fire interval is the time in years between two successive fires.
* viable = capable of living
viable seeds
per hectare
100 000
80 000
60 000
40 000
20 000
O 20 40
fire interval (in years)
60 80
Figure 2. Number of viable shrub seeds per hectare versus time (in years) since last fire
Question 15
Studies show that the shrub needs at least 20 000 viable seeds per hectare for the species to reproduce successfully.
Using the data in the above graph (Figure 2), which of the following fire intervals would allow the species to
reproduce successfully?
A. 15 years
B. 30 years
C. 55 years
D. 65 years
SECTION A – continued