Describe the relationship between the level of poverty and the level of soil degradation shown on the diagram.

Explain one strategy that has been successful in reducing soil degradation.

Explain the importance of maintaining biodiversity in tropical rainforests.

Possible descriptions might include:

• low levels of poverty have lower levels of high soil degradation/high levels of poverty have higher levels of high soil degradation
• low levels of poverty have the most improving soil
• low levels of poverty appear to suffer the most from moderate soil degradation.

Accept other valid descriptions.

Reserve the final [1 mark] for some attempt at quantification/use of the data.

Award [1 mark] for a valid choice, [1 mark] for its description, and [1 mark] for its explanation. Identification of a valid specific location may also receive [1 mark], up to a maximum of [3 marks].

There are many possible choices including reforestation, shallow plowing, the use of ground covers during fallow periods, planting of wind breaks, controlled grazing, etc.

Example:

“One strategy is reforestation [1 mark] where the planting of trees on degraded soil can help stabilize the surface [1 mark] because their roots bind the soil together and make it less likely that erosion can occur [1 mark].”

Award [1 mark] for a definition, or clear or implied understanding of the term “biodiversity”.

Award [1 mark] for each valid statement linking a reason to the importance of biodiversity, and [1 mark] for each development/exemplification, up to a maximum of [2 + 2 marks].

Possible reasons include: climate regulation; flood control/protection; gene bank maintenance; food/timber; soil conservation; value to indigenous people; tourism value; research opportunities; keeping food chains intact; value of medicinal products.

A relatively straightforward question, most candidates were able to give two valid descriptions with quantification/use of the data.

Again a very straightforward question where most candidates achieved the full marks. Some very good answers with clear valid choices often illustrated with accurate and specific geographical locations.

On the whole well answered, although some responses did not reflect the question posed and instead focused their answer on why we should maintain tropical rainforests as opposed to why we should maintain their biodiversity. This was self-limiting. On the whole most candidates demonstrated a solid knowledge and understanding of biodiversity and tropical rainforests.