Forest Resources

1

• Forest Resources

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Clear Cutting

• forest harvesting that removes all trees from an
  area.
• Includes desirable AND undesirable species
• the land is left uncovered.

3
Clear Cutting

• Advantages
• faster
• more economical
• and least dangerous

• Disadvantages
• Leaves behind a poor looking landscape.
• impossible to duplicate the biodiversity of
  forest.
• Soil is defenseless to erosion.
• Wildlife habitats are disturbed.

4
Clear Cutting
5
Selective Cutting

• harvesting that removes only mature trees and
  leaves the other trees in place. 
• Immature trees, undesired species and underbrush
  is all left intact. 

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Selective Cutting

• Advantages
• Leaves the biggest portion of the forest intact.
• Causes the least ecological disruption.

• Disadvantages
• Most expensive method.
• Yields are lower.
• Care must be taken to avoid damaging unharvested
  trees.
• Roads must be maintained longer to keep
  harvesting mature trees.

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Deforestation p. 163

• The removal of a forest stand by cutting and/or
  burning,
• the land is put to a non-forest use
• Ex. agricultural purposes, residential or
  industrial sites, roads, etc..

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Deforestation

• Approx. 1/3 of the earth's land masses are
  covered in forest.

• Some values of our worlds forests are
• biodiversity
• medicine/pharmaceuticals
• animal habitats
• air purification
• water retention
• soil maintenance

• Forests can be used for things like
• building materials
• home heat
• recreation
• paper.

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Deforestation Reasons!?!?

• Reasons for extensive deforestation include
• Expanding needs in agriculture (1)
• Urbanization
• Mining operations
• Hydroelectric operations - flooding the land
• Logging, lumber, building materials

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Rates of Deforestation World Wide (pg.164)
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Deforestation - Latin America

• clearing the forests for hydroelectric projects
  to provide electricity to an increasing number of
  people.
• Large scale cattle ranches and urbanization have
  also contributed to deforestation.
• The cost of modernization!!!!

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Deforestation - Latin America
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Deforestation - Africa

• forests are being cleared to make room for
  subsistence farming to support the growing
  hungry population.

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Deforestation Asia

• A growing population means that more forest is
  cleared for housing and for agricultural land to
  feed the people.

15
Sustainable Forestry

• Sustainable means to manage or maintain something
  so that it remains and provides benefits over the
  LONG term.
• Sustainable forestry is a method of harvesting
  or using the forests so that the resource is not
  depleted or permanently damaged.
• FACT
• If we cut trees faster than they grow back, we
  will run out of trees.

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• However, as the world's population increases, the
  demand for forestry products increases and the
  demand for forestry land to be converted to
  housing, mining, and hydro-electricity projects.

• We must manage the forest, taking into
  consideration biodiversity, hunting, hiking,
  camping, habitat protection and many other things.

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Sustainable Forestry

• From a Systems Model perspective
• Improve what we input into forestry (replanting
  seeds)
• Improve processes like
• road construction
• harvesting techniques
• environmental protection actions
• reducing losses (use all of the tree)
• Reduce the need of output product
• Recycle
• Use of alternate building materials

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• Clear Cutting Controversy
• (handout)

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Forests and Climate

• Seasons
• The type of trees and forest
• present in a region is determined
• by the climate. 
• Trees have adapted to climate
• just as animals have.
• Temperate regions of the world often have
  broad-leaf, deciduous trees to help them deal
  with the lack of water availability in winter.
  (ex lose leaves so moisture does not freeze). 
• Some regions have dry seasons and they have
  deciduous trees even though it does not get
  "cold."

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• Seasons
• The needle leaf trees of the coniferous forests
  are adapted to deal with winter and the lack of
  available water. (ex tall and narrow, grow close
  together, waxy coating on needles)
• Both the tropical regions of the world and the
  sub arctic regions of the world have evergreen
  trees.

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Forests and Climate

• Precipitation
• Forests require a large
• amount of water. 
• Therefore, the amount
• of precipitation in a
• region will determine whether a forest will
  grow.

• Tropical areas with high rainfall have tropical
  rain forests (meaning lots of trees/vegetation). T
  ropical areas that have alternating rainfall
  amounts have Savannas because there is not enough
  water to support trees and a forest. 

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Forests and Climate

• Diversity
• Colder regions tend to have less biodiversity
  while tropical regions tend to have greater
  biodiversity. 
• The same is true of trees. Tropical forests tend
  to be a blend of many different species, while
  coniferous forests tend to be "pure stands" of
  one type of tree.

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Case Study

• Tree Harvesting in Various
• Ecosystems
• Pg. 166
• Question 9