Lecture 35

Arboreal

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


Reforms

  • 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.

Proximate

  • 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

PROS

  • Cost efficient

CONS

  • Leads to erosion
  • Destroys age structure, ecosystem function


Selective Harvest

PROS

  • Mimics natural disturbances; maintains ecosystems function and resilience

CONS

  • 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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