QUESTION 40 (4 marks)
In a forest, trees 16 m tall form the highest vegetation stratum. Their foliage projective cover falls from 55% to 22% after a cyclone. Shrub cover remains 80%. Use the supplied Specht excerpt.
a) Classify the ecosystem before and after the cyclone. [2 marks]
b) Explain why shrub cover does not determine these classifications. [2 marks]
Practice marking scheme
Answer
a) Open-forest before; woodland after. b) Classification uses the growth form, height and cover of the tallest stratum, which remains the trees.
Working
The 16 m trees lie in the 10–30 m height category. Their initial 55% cover gives open-forest; their later 22% gives woodland. The shrubs have higher cover, but are not the tallest stratum. Classifying by total or shrub cover would therefore apply the excerpt incorrectly.
Marking criteria
- Classifies the original community as open-forest. [1 mark]
- Classifies the later community as woodland. [1 mark]
- Identifies the trees as the tallest stratum. [1 mark]
- Explains that the system uses the cover of that stratum rather than shrub/total cover. [1 mark]
Practice question aligned to the current QCAA syllabus; review the worked solution and marking criteria.
View the QCAA syllabusCompare your working with the guide above.