Tropical rainforests are found in areas with high temperatures between 20-30 degrees Celsius and high rainfall between 1000-2000 mm annually. They have 3 main layers - the emergent layer with the tallest trees up to 50m high and buttress roots, the canopy layer 15-30m tall that blocks 70% of sunlight, and the undergrowth layer that receives very little sunlight. Rainforests are threatened by deforestation for agriculture, logging and development which causes extinction of plants and animals. Singapore once had more rainforests but they were cleared for population and industry growth, though reserves like the Bukit Timah Nature Reserve protect some remaining forest.

1. Tropical Rainforests Workbook pg. 105 & 106

2. Where is tropical?

3. Rainforests are found in places with High temperatures 20 0 C to 30 0 C High rainfall 1000 mm to 2000 mm

6. Layers of rainforests Have 3 layers Emergent Canopy undergrowth

7. Emergent 40m to 50m in height. Buttress root to support the heavy and tall trunk. Broad leaves to absorb as much sunlight as possible.

8. Emergent

10. What can you tell about the roots?

11. Buttress root

12. Buttress root

13. Buttress root

15. Canopy 15m to 30m tall. Top of the trees interlock to form a continuous layer. Block out at least 70% of sunlight. E.g. ferns, lianas and epiphytes

16. Canopy

17. Canopy

18. Undergrowth Consist of small trees, bushes, fern and herbs Sparse Receives very little sunlight.

19. Undergrowth

20. Undergrowth

21. Undergrowth

22. Layers of a tropical rainforests

23. Features of rainforests Trees grow very close to each other. Broad leaves to absorb maximum sunlight. Drip tip leaves Evergreen due to heavy rainfall Tall, straight and thin trunk to reach the top.

24. Drip tip / broad leaves

25. Evergreen

27. Can you identify what are hanging down from the branches?

31. Can you identify what is growing on the tree?

32. Epiphytes Bird nest fern

33. Future of rainforests Deforestation / commercial logging Raw materials Make way for buildings and agriculture. Extinction of animals and plants

34. Rainforests in Singapore

35. Bukit Timah Nature Reserve

36. Bukit Timah Rainforest

37. Sungei Buloh Wetland Reserve

38. Rainforests in Singapore Rainforests in Singapore were cleared due to Growing population Industrial development

39. Central Catchment Nature Reserve Bukit Timah Nature Reserve Features 164 hectares Trees 30 m in height Buttress root Interlocking crowns Forest floor dark and damp.

40. Uses of rainforests in Singapore Water catchment areas MacRitchie Seletar Upper Pierce Lower Pierce Natural heritage Recreational activities