Renewable Resource: timber

1. Renewable Resource: timber

2. Importance of timber to human (1)For industustrial propose --Construction --Making furniture --Manufacturing of paper (2)As the principal source--fuel

3. Resource of timber --Mainly large-diameter old growth pine

4. Effect of exploitation of timber(For the conifer forest) --Number of large diameter tree(pine tree) decrease --Number of small diameter tree increase --The species composition of the forest change

5. Effect of exploitation of timber(for animal) Since animals require the special habitats for survival,the destruction or modification of habitats lead to the loss of shelters and food sources of the animals.This has a devastating impact on bio diversity and many species will be pushed towards extinction.

6. Effect of exploition of timber(about nutrient availablity) Trees are removed The nutrients can’t be locked up and loss The entire ecosystem is affected by the disruptive effects on nutrient availability

7. Effect of exploitation of timber(about soil) No roots of trees hold the topsoil The topsoil is washed away by heavy rain or blown by strong wind The nutrient of soil loss The exposed soil become infertile and abandoned & soil erosion occur

8. Effect of expoitation of timber(about human) As forests are destroyed, human communities lose vital services such as protecting the soil, maintaining productive water cycles, and mediating both floods and drought at a local and a regional level.

9. Effect of expiotation of timber(about climate) Forests is removed No evaporation of water through the leaves and amount of carbon dioxide increase The air can’t be cool down and moistened The condition become hotter and drier Global warming

10. How fast do the forests be destructed? Ten thousands years ago,about half of the world’s land surface was covered in trees. About a third of these forests have completely disappeared today. The extent of global tropical deforestation through the 1980’s was estimated to be 16.9millon hectares a year. This means that an area of half the total size of Hong Kong is lost every day. Over 40% of all tropical forests have been destroyed in the last 50 years.

11. What can we do to maintain the present state of the tropical rainforest? The things we can do are simple. We just need to remember to 3R. (1)Reduceto use the wood product, e.g.paper (2)Reusethe wood product as possible (3)Recyclethe wood waste and produce new wood product