QUESTION 41 (4 marks)
An investigator uses the supplied simplified Holdridge excerpt. A site has annual biotemperature 20 °C and a potential evapotranspiration-to-precipitation ratio of 0.70. Treat boundaries exactly as listed.
a) Classify its temperature belt and forest moisture class. [2 marks]
b) Predict its moisture class if annual precipitation halves while potential evapotranspiration stays unchanged. Show the new ratio. [2 marks]
Practice marking scheme
Answer
a) Subtropical moist forest. b) Ratio 1.40; dry forest.
Working
A biotemperature of 20 °C lies within the subtropical belt in the supplied excerpt. A ratio 0.70 lies in , giving moist forest. Since , halving doubles to 1.40, which falls in the dry-forest interval. This is a simplified lookup exercise; it does not reproduce every life zone in the full Holdridge diagram.
Marking criteria
- Identifies the subtropical belt. [1 mark]
- Identifies moist forest. [1 mark]
- Calculates the changed ratio as 1.40. [1 mark]
- Predicts dry forest. [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.