Transcript Logging Forests - Leo Hayes High School

LOGGING FORESTS
Chapter 3.10
Logging Forests
• Forests regulate climate by recycling
water and carbon dioxide.
• On hot days a large tree may absorb 5.5
tons of water from the soil and release it
into the atmosphere through its leaves in
a process called transpiration.
FORESTRY PRACTICES
• Forests are logged by two different
methods:
• CLEAR CUTTING – every tree is cut
down whether it has value or not and the
unnecessary trees are left
• SELECTIVE CUTTING – only certain
trees are cut down depending on what
they are needed for ( firewood, paper,
furniture or lumber)
EVALUATING A CLEARCUT
• Company’s point of View
• 1. Less expensive – provide timber or pulp
at a more competitive price
• 2. safer for workers
• 3. Company can choose which trees to
plant – get better price for when the area
is logged again in the future.
EVALUATING A CLEARCUT
• Ecological Point of View
• 1. Soil erosion and runoff into local streams
increases – increasing growth of algae
• 2. Eroded soil forms sediment in streams,
affecting spawning areas of fish.
• 3.Removal of vegetation on the ground exposes
the soil, increasing the warming of the area in
summer and cooling in winter
• Exposure also increases water loss from the
soil.
EVALUATING A CLEARCUT
• Clear-cut creates completely different
abiotic and biotic conditions in the area.
• Ecosystem must change – therefore the
community must change.
• Loss in forest plants – loss of forest
animals
• Ecotones are also created between the
remaining forest and the newly cut area.
DEFORESTATION
• Is any removal of trees from the area of
land.
• Deforestation affects the environment in
many ways:
• 1. Erosion – tree roots hold soil in place
during heavy rains
• 2. Nutrient Loss – nutrients are washed
away with the rain instead of being
absorbed by the trees
DEFORESTATION
• 3. Temperature Change – the ground will
absorb more energy (albedo effect?) and
affect organism functions
• 4. Carbon Cycle Change - no trees to take
in CO2 and to make O2
• 5. Food Web Changes – less producers at
the beginning of food chains
• 6. Habitat loss – nesting areas and ground
cover disappears
HANDOUT
• Read the handout “The Forests of the
Temagami Region”
• Answer the questions at the bottom.