Lecture 35


Most productivity is in the canopy, not on the ground due to lots of sunlight being taken by trees.

Temperate Deciduous Forest

  • Mid-latitude forests in EU, east china, east north america
  • Deciduous trees lose leaves and go dorment during winter
  • Temp 30to+30C−30to+30C
  • Precipitation 75150cm/yr−75−150cm/yr evenly distributed
  • Soil \rightarrow Fertile; decaying litter
  • Canopy - Allows some light to penetrate; well-developed understory

Temperate Rainforest

  • Mild (412C4−12C )
  • Wet (140cm/yr→140cm/yr)
  • Fertile soil
  • Closed canopy
  • Confirs moss

Central Case - Clayoquot Sound

  • UN biomass conservation
  • We logged it
  • Largest trees in the world
  • Now is desert
  • BC has 14\frac{1}{4} of the world's remaining coastal temperate rainforest, over 50% has been logged
  • Only 6% is protected
  • We did not do much to protect such a great resource

The War of the Woods

  • 1993, largest act of civil disobedience in Canadian history
  • Province announced plans to open 23\frac{2}{3} of the sound to unrestricted logging (against recommendations of federal government scientists)
  • 12,000 protesters
  • International response was huge
  • The science panel for sustainable forest practices in clayoquot sound formed in 1993 - scientists, environmentalists, First nations
  • Made stringent recommendations which macmillan bloedel promised to abide by
  • Sold to weyehouser in 1999, decided to maintain commitment


  • Phase out clear cutting
  • Conserve old growth
  • Selective logging to preserve habitats and streams
  • Invite scientists to monitor progress
  • Develop non-timber resources

IISAAK - "respect"

  • Created in 1998 \rightarrow joint venture between the Nuu-chah-nulth Central Region First Nations and weyerhaouser
  • In 2005 First nations took 100% ownership of IISAAK

Deforestation is not new

  • Principle form of land conversion
  • Clearing forest for farming was one of the first human environmental impacts
  • Ireland is covered in peat bogs due to neolithic deforestation

Deforestation has Proximate and Root Causes.


  • Slash and burn agriculture
  • Clearcut logging
  • Pollution
  • Fuelwood use

Ultimate (root)

  • Poverty
  • Debt
  • Bad policies
  • Environmental change

Agriculture is the Major Cause of Conversion of Forests

  • Agriculture now covers more of the planet's surface than forest
  • Principle driver of land conversion today
  • Swidden agriculture \rightarrow Small area of forest cleared and crops planted

Clearing rainforests is bad, because the soil has such low nutrients that you would require so much more land to grow less.

Plantation Forestry has Grown in North America

  • Reforestation - Planting of trees after logging
  • Afforestation - Planting of trees where forested cover has not existed for some time
  • Even-aged trees - All trees are the same age

Timber Harvesting Clear Cutting


  • Cost efficient


  • Leads to erosion
  • Destroys age structure, ecosystem function

Selective Harvest


  • Mimics natural disturbances; maintains ecosystems function and resilience


  • Expensive

Maximum Sustainable Yield

  • MSY - Max resource extraction without depleting resource
  • Pops grow most rapidly at an intermediate size
  • Pop size must be maintained below carrying capacity
  • Target pop size is at the point of inflection

Adaptive and Ecosystem-Based Management are Guiding Principles

  • Managing the harvesting of resources to minimize impacts on ecosystems and ecological processes
  • Adaptive management

Sustainable forestry is gaining ground.

Conserving Forests

  • Canada ~ 9.8% land protected
  • Costa Rica ~25%

Non-Governmental Entities also Protect Land

  • Each province has agencies that manage resources on provincial crown land

Human Activities can Coexist with Sustainability

  • No knowledge
  • Connect ideas
  • Systems, basic science
  • Look at all topic and look to see what it can connect to
  • EG what is the connection between biodiversity and systems thinking?
  • Read through the textbook quickly, so you see the overview, not the fine details
  • Then touch up on things you need to touch up on

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