1. Do Now: Movie Clip While watching the clip answer the following:
1) Identify and describe at least 2 causes/impacts of deforestation in the Amazon.

2. Turn and Talk
Why is it important to preserve natural lands and sustain Earth’s biodiversity?

3. Aim: What are the major threats to forest ecosystems?

4. Forests Vary in Their Make-Up, Age, and Origins
Make up 30% of earths land surface.
What are the three types of forests?
½ are tropical rain forests.
Classified based on their age and structure

6. Old Growth or Primary Forests
Represents 36% of all forested land
Uncut or not disturbed for several hundred years
Rich in biodiversity
Niches for many animals
Top 5: Russia, Canada, Brazil, Indonesia, and Papua New Guinea.

7. Redwood Forest

8. Natural Capital: An Old-Growth Forest
Washington State
Olympic National
Forest
Figure 10.2: Natural capital.
This old-growth forest is located in the U.S. state of Washington’s Olympic National Forest.
Fig. 10-2, p. 219

9. Second Growth Forest Represents 60% of forested land
Trees in an area were removed. Ex: clear cutting, forest fires, hurricanes, volcanic erruptions.
Secondary ecological succession:
- naturally or when trees are planted

10. Tree Plantation
Tree farm, commercial forest represent 4% of forested land
1-2 species all the same age.
Violates sustainability and biodiversity
Depletion of nutrients from topsoil
Harvested by clear cutting when trees are commercially valuable. Then replanted.
May supply most industrial wood in the future.
Top 5: China, India, US, Russia, and Canada

11. Rotation Cycle of Cutting and Regrowth of a Monoculture Tree Plantation
Figure 10.3: This diagram illustrates the short (25- to 30-year) rotation cycle of cutting and regrowth of a monoculture tree plantation. In tropical countries, where trees can grow more rapidly year-round, the rotation cycle can be 6–10 years. Most tree plantations (see photo, right) are grown on land that was cleared of old-growth or second-growth forests. Question: What are two ways in which this process can degrade an ecosystem?
What are two ways in which this process can degrade an ecosystem?
Fig. 10-3, p. 219

12. Weak trees removed 25 yrs Clear cut 30 yrs 15 yrs Years of growth
Figure 10.3: This diagram illustrates the short (25- to 30-year) rotation cycle of cutting and regrowth of a monoculture tree plantation. In tropical countries, where trees can grow more rapidly year-round, the rotation cycle can be 6–10 years. Most tree plantations (see photo, right) are grown on land that was cleared of old-growth or second-growth forests. Question: What are two ways in which this process can degrade an ecosystem?
Seedlings planted
5 yrs
10 yrs
Fig. 10-3a, p. 219

13. Forests Provide Important Ecological Services
Support energy flow and chemical cycling
Reduce soil erosion
Absorb and release water
Purify water and air
Influence local and regional climate
Store atmospheric carbon
Habitats

14. Forests Provide Important Economic Services
Wood for fuel
Lumber
Pulp to make paper
Mining
Livestock grazing
Recreation
Employment
Medicine

15. Natural Capital: Major Ecological and Economic Services Provided by Forests
Figure 10.4: Forests provide many important ecological and economic services (Concept 10-1a). Question: Which two ecological services and which two economic services do you think are the most important?
Fig. 10-4, p. 220

16. Read A Loud
Science Focus: Putting a price tag on natures ecological services.

17. Science Focus: Putting a Price Tag on Nature’s Ecological Services
Forests valued for ecological services
Nutrient cycling
Climate regulation
Erosion control
Waste treatment
Recreation
Raw materials
$4.7 trillion per year

18. Pause…Write…Discuss
Some analysts believe that we should not try to put economic values on the world’s irreplaceable ecological services because their value is infinite? Do you agree with this view? Explain. What is the alternative?

19. Deforestation Step by Step
Step 1: Build roads to access and remove timber
Problems:
- Increased erosion
- Sediment runoff into waterways
- Habitat fragmentation
- Loss of biodiversity

20. Natural Capital Degradation: Building Roads into Previously Inaccessible Forests
Figure 10.5: Natural capital degradation.
Building roads into previously inaccessible forests is the first step to harvesting timber, but it also paves the way to fragmentation, destruction, and degradation of forest ecosystems.
Fig. 10-5, p. 221

21. Deforestation Step by Step
Step 2: Timber Harvesting; 3 methods
Selective cutting
Clear Cutting: All trees in an area are removed. Most efficient/most harm.
Strip cutting: removes a narrow strip of trees.

22. Selective cutting: middle aged/mature trees are removed individually or in small groups.
Figure 10.6: This diagram illustrates the three major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why?
Clear stream
Fig. 10-6a, p. 222

23. Clear-cutting: All trees in an area are removed
Clear-cutting: All trees in an area are removed. Most efficient/most harm.
Figure 10.6: This diagram illustrates the three major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why?
Muddy stream
Fig. 10-6b, p. 222

24. Strip cutting: removes a narrow strip of trees
Cut 1 year ago
Uncut
Dirt road
Cut 3–10 years ago
Uncut
Figure 10.6: This diagram illustrates the three major tree harvesting methods. Question: If you were cutting trees in a forest you owned, which method would you choose and why?
Clear stream
Fig. 10-6c, p. 222

25. Clear-Cut Logging in Washington State
Figure 10.7: This aerial photograph shows the results of clear-cut logging in the U.S. state of Washington.
Fig. 10-7, p. 222

26. Trade-offs: Advantages and Disadvantages of Clear-Cutting Forests
Figure 10.8: Clear-cutting forests has advantages and disadvantages. Questions: Which single advantage and which single disadvantage do you think are the most important? Why?
Fig. 10-8, p. 223

27. Summary: If you were cutting trees In a forest you owned,
(a) Selective cutting
(c) Strip cutting
Clear stream
Summary:
(b) Clear-cutting
Muddy stream
Uncut
Cut 1 year ago
Dirt road
Cut 3–10 years ago
Clear stream
If you were cutting trees
In a forest you owned,
Which method would
You choose and why?
Stepped Art
Fig. 10-6, p. 222

28. Fire, Insects, and Climate Change Can Threaten Forest Ecosystems (1)
Surface fires
Usually burn leaf litter and undergrowth
May provide food in the form of vegetation that sprouts after fire
Crown fires
Extremely hot: burns whole trees
Kill wildlife
Increase soil erosion

29. Fire, Insects, and Climate Change Can Threaten Forest Ecosystems (2)
Introduction of foreign diseases and insects
Accidental
Deliberate
Global warming
Rising temperatures
Trees more susceptible to diseases and pests
Drier forests: more fires
More greenhouse gases

30. Surface and Crown Fires
Figure 10.9: Surface fires (left) usually burn only undergrowth and leaf litter on a forest floor. They can help to prevent more destructive crown fires (right) by removing flammable ground material. In fact, carefully controlled surface fires sometimes are deliberately set to prevent the buildup of flammable ground material in forests. Surface fires also recycle nutrients and thus help to maintain the productivity of a variety of forest ecosystems. Question: What is another way in which a surface fire might benefit a forest?
Fig. 10-9, p. 223

31. Nonnative Insect Species and Disease Organisms in U.S. Forests
Figure 10, Supplement 8