1. Rangelands & Forestry

2. USDA
Rangelands
Rangelands are large, undeveloped areas populated by grasses, grass-like plants and scrub.
Rangelands are usually semi-arid to arid and include grasslands, tundra, scrublands, coastal scrub, alpine areas, and savanna.
Rangelands cover about 50% of the Earth’s land surface.
Rangelands are often used for grazing livestock, but because they often occur in low rainfall areas they do not regenerate quickly.

3. Managing Rangelands
Grasses grow continuously from a meristem close to the ground, so the leaf can be cropped without causing growth to stop.
OVERGRAZING is the theme of Tragedy of the Commons!
Overgrazing occurs when too many animals are grazed for too long on an area and there is not enough time for regrowth between cropping.

4. Stock Rotation
Rotating stock through rangelands can prevent overgrazing.
Rotating livestock between different parts of the range gives ungrazed areas a chance to regrow.
Rotating stock helps to prevent animal parasites, such as ticks, from establishing.
Rangelands are ecologically important areas. They need to be managed carefully to maintain their biodiversity.
Reducing grazing times and rotating through three areas over a three year cycle can leave each area ungrazed for a total of two years in every full cycle.
Area 1
Grazed first half
Grazed second half
Ungrazed
Area 2
Grazed second half
Ungrazed
Grazed first half
Area 3
Ungrazed
Grazed first half
Grazed second half
First year
Second year
Third year

5. North American Forests
In the United States
alone there are 749
million acres of forest.
Of this 67.5% is
timberland (potentially
able to be logged)
7% is reserve land
25.5% are non commercial
forest types
Deciduous forest
Desert
Mediterranean
Grassland
Coniferous forest
Rainforest
Alpine
Tundra

6. Countries with the Largest Forested Areas

7. Forest Ecosystem Services
Provide wildlife habitats
Reducing soil erosion
Carbon Sinks
Affect local climate patterns
Purifying air and water
Provide energy and nutrient cycling
Oxygen!

8. A Forest Watershed This diagram shows the effects of trees in:
evaporating water
preventing erosion
providing habitats for wildlife.
What happens when the trees are gone?
Should all streams have “stream-protection zones” where no logging etc. is allowed? If so how wide should this buffer be?

9. Old Growth Forests
Old growth forests are climax communities that have remained undisturbed by large scale natural events (e.g. fire) or human interference for hundreds of years.
Old growth forests are ecologically significant because of their high and often unique biodiversity.
Photo: COR

11. Forest Products
Removal of timber from both private and national forest in the U.S. has remained steady since the middle of the last decade.
16.0
14.0
12.0
10.0
8.0
6.0
4.0
2.0
0.0
1952
1962
1976
1986
1996
2001
Billion cubic feet
Sawlogs
Veneer logs
Pulp
Other products
Data source: US Dept Agriculture

12. Goal: Sustainable Forests
Sustainable forests occur when a forest is managed so that a resource in it can be harvested at a rate that does not decrease the ability of the forest ecosystem to continue to provide that same rate of harvest indefinitely.
The “certification of sustainable forestry” developed where organizations certify forest practices
This involves:
Determining which methods appear most consistent with sustainability
Comparing the management of a specific forest with those standards

13. PROBLEM: A series of harvests is necessary to prove sustainability and the proof therefore lies in the future.

14. Deforestation
History
Forests have been being cut down since times of the Roman Empire onward
The greatest losses in the present century have occurred in South America 4.3 million acres a year are being lost since the year 2000!
Human population growth is the largest cause 

15. Causes of Deforestation
As populations grow we cut for two main reasons
Clear land for agriculture & housing
For goods, such as lumber, paper, fuel etc.
World Firewood Shortage
63% of all wood produced is used for firewood
Indirect Deforestation
Killing of forests due to pollution or disease.

16. Different logging methods have different effects on the structure of a forest ecosystem. The two common methods used are:
Clear-cutting (or clear-felling) exposes soil to erosion and results in less diverse regrowth.
Selective logging has many variations, including a focus on particular species or thinning of small trees.
Types of selective logging include harvesting:
Single scattered trees
Trees above a specified girth
Selected groups of trees

17. Forestry Skits
You will work in a small group to create & present a skit on a forestry topic.
One group member must give a short introduction; another a short conclusion.
All group members must be included in the presentation.
You may use props as necessary. You may use other class members for non-speaking roles.
Your skit must thoroughly explain your topic. Focus on the basic purpose of the method, pros, and cons.