Pearson Edexcel GCSE Geography A (1GA0) · Spec 3.4 and 3.5
Tropical rainforests
Read the notes, then try the questions. Each one is marked the moment you press Check, and shows the right answer and why.
Key ideas
- A tropical rainforest has a monthly mean temperature above 18 degrees C all year and rainfall of typically 1,750 to 3,000 mm a year.
- In the nutrient cycle, most nutrients are held in the biomass store. The litter store is small because warm, wet conditions bring fast decomposition.
- Plants and animals are adapted. Buttress roots support tall trees in thin soil, drip tips shed heavy rain, epiphytes grow on branches to reach light and lianas climb to the canopy.
- Economic causes of deforestation include logging, cattle ranching, mining, plantations and roads.
- Management can include reserves, ecotourism, selective logging and replanting. Good answers use a named rainforest region.
Key terms
- Biomass
- The total mass of living things. In a rainforest it holds most of the nutrients.
- Buttress roots
- Roots that spread out to support very tall trees.
- Epiphyte
- A plant that grows on a branch, with no roots in the soil.
- Deforestation
- Cutting down large areas of forest.
- Niche
- The role a species plays in its habitat, including what it eats and where it lives.
Common mistakes
- Saying buttress roots take in nutrients. They support tall trees in thin soil.
- Saying rainforest soil is the main nutrient store because it is rich. Most nutrients are in the biomass.
- Listing population growth or conflict as economic causes of deforestation. Economic causes are commercial, such as logging, ranching and mining.
Exam tip
A named-region item wants place detail: the name of a reserve, a scheme or a project. A third mark for a general answer such as 'ecotourism' is not enough.
Free practice questions
6 questions, 11 marks. Answer, then press Check. The marking guide explains how the marks are worked out. Nothing is saved.
- Question 1 · Multiple choice[1 mark]
Which statement defines a niche in a rainforest ecosystem?
- Question 2 · Choose more than one[2 marks]
Which TWO of these are economic causes of tropical deforestation?
Choose 2.
- Question 3 · Sort into groups[3 marks]
Sort each rainforest benefit into goods (products taken) or services (functions provided).
Water regulation
Carbon storage
Timber
- Question 4 · Multiple choice[1 mark]
In a tropical rainforest nutrient cycle (Gersmehl model), which store holds most of the nutrients?
- Question 5 · Matching[3 marks]
Match each rainforest adaptation to its job.
- Question 6 · Multiple choice[1 mark]
Which statement best explains how buttress roots help a rainforest tree?