Reversing Desertification in Africa
Erosion and the Environment
Jan Weber
Grade 8 Lesson Plan
OBJECTIVES: Students will be able to:
1. Explain the unintended consequences of harvesting natural resources from an
ecosystem.
2. Identify natural and human activities that impact the cycling of matter and
the flow of energy through ecosystems.
3. Compare over time the impact of human activity on the cycling of matter and
energy through ecosystems.
4. Explain how the climate in regions throughout the world is affected
by seasonal weather patterns, as well as other factors, such as the
addition of greenhouse gases to the atmosphere and proximity to
mountain ranges and to the ocean.
5. Assess how the natural environment has changed since humans have
inhabited the region.
6. Explain that people respond to incentives to preserve scarce resources
PRIOR KNOWLEDGE Required:
Human impact on natural resources
Sustainable grazing, logging, mining
Public land management
INTRODUCTORY NARRATIVE:
I would like you to think about two very different countries. One you have
heard about a lot on the news, Haiti. It is a Caribbean island that is almost
completely devoid of trees. According to a recent UNESCO report,
The island's coastal plains, where the bulk of agricultural activity normally
occurs, are bordered on one side by mountain slopes which are denuded of trees
by the production of charcoal (the country's main source of domestic energy)…
As well, the uncontrolled exploitation of land resources results in excessive
erosion and sedimentation in the watershed areas as well as along the coastline,
where such practices in turn affect the development of coastal resources. The
pressures of industrial development and increasing tourism are likely to increase
in the near future. (http://www.unesco.org/csi/act/haiti/project7.htm)
The other country is the Dominican Republic, also in the Caribbean, but it
is a lush tropical island with extensive trees and forests.
From 1992 to 1999 the Dominican Republic was among the fastest growing
economies in the world, registering annual GDP growth rates in excess of 6
percent. (http://www.usaid.gov/our_work/crosscutting_programs/wid/pubs/DominicanRepublic_Economic_Snapshot_Dec2005.p
df)
What are some possible reasons these two countries could be so
different?
[talk about all possible reasons then...] Now I want to tell you that these two
countries are physically just two halves of the same Island ! ...
PROCEDURE:
1. Research the following vocabulary words and write their definitions:
Arable Land
Fertile Soil
Top soil
Soil conservation
Biodiversity
Scarcity
Erosion
Desertification
2. Explore the following websites:
a. http://www.greenfacts.org/en/desertification/index.htm#4
b. http://pubs.usgs.gov/gip/deserts/desertification/
3. For each of the following categories, list 2 factors that impact or influence
the spread of desertification:
a. Social
b. Political
c. Economic
d. Natural
4. WHAT DO YOU THINK? How can countries with limited resources prevent
or reverse desertification?
a. Describe 2 short-term approaches
b. Describe 2 long-term approaches
5. READ THE NY TIMES ARTICLE, “IN NIGER, TREES AND CROPS TURN
BACK THE DESERT.”
http://www.nytimes.com/2007/02/11/world/africa/11niger.html?pagewanted=all
Answer the following questions:
a. What relatively small social factor changes helped to restore
biodiversity and land productivity in Niger?
b. What political factors (government actions) influenced the
conservation of trees in Niger?
c. Provide an example of the economic impact on Niger communities
of property rights enforcement.
d. How do climate variations affect soil erosion?
CONCLUSIONS
Role-Play Project