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Global Connections:


Global Connections: Forests of the World Activity 4 Analyzing Patterns of Forest Change * * Assessment Part A, write a paper describing first the observed differences ... – PowerPoint PPT presentation

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Title: Global Connections:

Global Connections Forests of the World
Activity 4 Analyzing Patterns of Forest Change
  • Identify global trends in a forest area.
  • Analyze maps of a particular forest to determine
    how and why its shape and size have changed over
  • Examine how people affect forest changes.
  • Investigate and present the reasons behind
    changes in a forest area observed in your own
    community or in another country.

Searchable Key Words
  • afforestation
  • deforestation
  • environmental change
  • environmental history
  • forest clearing
  • forest cover change map
  • forest history
  • landscape history
  • long-term ecological site
  • plantation forest
  • reforestation

  • Activity 4

Major factors determining the type and extent of
Activity 4 Background
  1. latitude
  2. climate
  3. terrain of a particular location
  4. altitude
  5. type of soil
  6. soil drainage or lack thereof
  7. fire intensity and frequency
  8. history of glaciers
  9. tree species that originated or were able to
    disperse to that area
  10. disease or insects
  11. frequency of hurricanes, earthquakes, volcanoes,
    mudslides, and other natural disturbances
  12. humans

Activity 4 Background
  • Fossil evidence suggests that hunter-gatherers
    living on the margins of forested land used fire
    to influence the mix of trees, shrubs, and
    grassesperhaps to attract game or to make it
    easier to travel through the landscape

Activity 4 Background
  • As humans began to raise sheep, goats, and other
    herd animals, they used fire to encourage the
    growth of new green grass shoots for their herds
    to graze.

Activity 4 Background
  • Scientists offer varied estimates of how much the
    worlds forest cover has been reduced by human
    activity throughout the past several millennia.
  • Those estimates put todays forest cover at
    between 50 and 80 percent of what it might be
    without human activities

Image http//
Three main human pressures on forests
Activity 4 Background
  • deforestation
  • forest fires
  • and fragmentation

Activity 4 Background
Definition the permanent removal of trees from a
forested area
  • Reasons Loss of forest land, usually from
    development, urbanization, conversion to
    agriculture, flooding land for hydroelectric
  • Conditions such as poverty, joblessness, and an
    unequal distribution of land lead to
    deforestation. These conditions force landless
    farmers to clear forests for farming or grazing
    because they have no other way to make a living.
  • Other activities indirectly lead to
    deforestation, including warfare, pollution, and
    human-caused global climate change.

Forest fires
Activity 4 Background
Definition natural or human-caused disturbance
that affect forest.
  • The number and intensity of human-caused forest
    fires greatly exceeds naturally occurring fires
  • Can cause significant damage even to those forest
    ecosystems that are adapted to a fire regime.
  • Routine fires set to burn debris, to clear
    fields, to clear underbrush to reduce fire
    potential near forested areas can escape control
    and cause extensive forest damage.
  • Routine fires are an increasing source of
    destruction in tropical moist forests
  • Example In the 1980s, and into the late 1990s,
    human-caused fires in Indonesia caused massive
    environmental and economic damage not only within
    that country, but also in neighboring countries
    such as Malaysia and Singapore, where the smoke
    led to health problems, disruption of shipping,
    and international airports being closed

Activity 4 Background
Definition division of a large or continuous
forest into smaller blocks, either by roads,
clearing for agriculture, urbanization, or other
human development.
  • This fragmentation diminishes species diversity
    because it creates different habitat conditions
    along the edges of the smaller blocks.
  • Example there may be less moisture and more
    sunlight and wind near the edges, making it hard
    for certain plant and animal species to survive
    and more difficult for animals to find food or
    shelter. Fragmentation may also block migration
    routes and open new areas for invasion by
    nonnative species. In addition, roads provide
    easier access into the forest for hunting, wood
    gathering, land clearing, and other activities
    that alter the forest ecosystem.

Image http//
Trying to increase forests
Activity 4 Background
  • Reforestation

Activity 4 Background
Definition renewing forest cover on a cut or
burned forest area by seeding or planting
  • Humans may plant trees to increase forests.
  • People may decide to reforest an area for
    commercial purposes, such as a plantation for
    forest products, or they may want to reestablish
    the natural forest environment for recreation or
    noncommercial purposes.
  • Example The Tijuca Forest in Rio de Janeiro,
    Brazil, is the largest urban forest in the world
    and was reforested in the 1800s when erosion
    threatened the city after the forest was cut for
    coffee plantations.

Tijuca Forest, Rio de Janeiro, Brazil
Activity 4 Background
Definition the planting of trees to create a
forest on lands that were not historically forest
  • Afforestation usually requires major human
    intervention and management.
  • Example Uruguay is one country that has an
    extensive afforestation program. With the goal of
    replacing unprofitable farming and livestock
    grazing on poor soils with profitable forests,
    those afforested plantations provide timber,
    pulpwood (for paper), and fuelwood.

Doing the activity
  • Activity 4

Now, time to work!
Activity 4 Doing the activity
  • Part A
  • The Duke Forest

Activity 4 Doing the activity
1. Discussion
  1. How have forests in our state changed over time?
  2. How do you think the extent of forests around the
    world have changed over time?
  3. Where is forest cover changing the most?

2. What factors might have influenced these
changes in the worlds forest area?
Activity 4 Doing the activity
  • Which factors are forces of nature?
  • ______________
  • ______________
  • ______________
  • ______________
  • Which factors are human forces?
  • ______________
  • ______________
  • ______________
  • ______________
  1. Which forces do you think have the biggest
    influence on forests today?
  2. How about in the past or the future?

3. In groups of 3 or 4, look at the cards and
Activity 4 Doing the activity
  1. What are the main ways that humans change
  2. How does each of those ways influence the extent
    of forests?

4. Lets look closely at one forest
Activity 4 Doing the activity
  • Material
  • One Forest Over Time
  • Map Analysis Tool

Activity 4 Doing the activity
a. What are the differences and similarities
between them (size and shape of the forest)?
Activity 4 Doing the activity
b. Trace the map onto the Map Analysis Tools
5. In small groups
Activity 4 Doing the activity
  • Discuss the causes of the changes
  • Read the From Forest to Farm to Urban Forest
    (student page)
  • Discuss the questions
  • What factors influenced the size of this forest
    over time?
  • What factors have influenced its extent and
  • Do you think those factors are similar to what
    might be found in other places on Earth? Why or
    why not?

(No Transcript)
Activity 4 Doing the activity
  • Part B
  • Change over time

1. Lets check this interview
Activity 4 Doing the activity
  • Planting Trees in Kenya
  • http//
  • Discussion
  • What are the benefits of planting trees in Kenya
    and the challenges or barriers that Maathai and
    other Kenyans have faced?

(No Transcript)
2. Challenge
Activity 4 Doing the activity
  • Search records on forest cover change in your
    own community or in another country to find out
  • what changes have occurred over time,
  • the causes of the changes,
  • whether anything is being done or could be done
    to slow or reverse the changes,
  • what people in the community have been agents of
    change, and
  • what students can do to effect changes.

Potential information sources
Activity 4 Doing the activity
  • Aerial photographs or satellite images from the
    local planning department.
  • Maps of forest cover from the local forestry
  • GIS (geographic information systems) digital
    data. http//, http//,
  • The Food and Agriculture Organization (FAO) of
    the United Nations (check the TEMS - Terrestrial
    Ecosystems Monitoring Sites - database at
  • Maps, photos, or logs housed at the local
    historical society.

3. Discuss
Activity 4 Doing the activity
  • whether the factors involved in the changes are
    still issues and whether actions can or should be
    taken to slow or reverse those changes.

  • Part A, write a paper describing first the
    observed differences in the Duke Forest over time
    and answer the questions
  • What factors influenced the size of this forest
    over time?
  • What factors have influenced its extent and
  • Do you think those factors are similar to what
    might be found in other places on Earth? Why or
    why not?
  • Express your understanding of the various factors
    that play into the Duke Forest story climate,
    family farming, Indian management, research
    forestry, tobacco farming, and urban development.
  • Part B, students presentations

  • Activity 4

Forests change in your area over geologic time
Activity 4 Enrichment 1
  • Research how forests have changed in your area
    over geologic time.
  • For example where there is now a dry,
    cactus-studded desert in central Arizona, 225
    million years ago the area was a lush forest with
    conifer trees towering almost 200 feet tall. The
    area was once located near the equator and on the
    southwestern edge of the super-continent
    Pangea, which broke up to create our present

Forest data in your state or region
Activity 4 Enrichment 2
  • Look for information about a forest in your state
    or region.
  • For example Many states and universities have
    research forests similar to the one at Duke
    University. Harvard University has long-term data
    on its Harvard Forest (http//harvardforest.fas.

Activity 4 Enrichment - Technology
  • Explore how forests relate to the topic of
  • What are the differences between traditional
    methods for modifying plants (such as selective
    breeding) and genetic modification?
  • How are forests affected when humans modify the
    DNA of trees to make them (a) adapted to local
    conditions, (b) more resistant to insects or
    disease, or (c) grow faster and bigger to meet
    the needs of the growing human population?
  • What trade-offs are involved?
  • As a place to start Genetically Modified Trees
    From Stone Age to Modern Biotechnology by Rowland
    D. Burdon and William J. Libby (Forestry History
    Society 2006).

Activity 4 Enrichment - Careers
  • Interview a local planner (or other person who
    uses maps and mapping in their job) to find how
    mapping and other tools enhance the work being
    done in your community.

  • Americas Ancient Forests From the Ice Age to
    the Age of Discovery by Thomas M. Bonnicksen (New
    York Wiley, 2000)
  • Deforesting the Earth From Prehistory to Global
    Crisis by Michael Williams (Chicago University
    of Chicago Press, 2002)
  • The Duke Forest at 75 A Resource for All Seasons
    by Ida Phillips Lynch (Durham, NC Office of the
    Duke Forest, Duke University, 2006)
  • A Forest Journey The Role of Wood in the
    Development of Civilization by John Perlin
    (Cambridge, MA Harvard University Press, 1991)
  • The Last Forest The Story of Hatfield Forest by
    Oliver Rackham (London Weidenfeld and Nicholson,