Chapter 23 Lecture

1
Chapter 23 Lecture

• Sustaining Aquatic Biodiversity

2
What are the Major Types of U.S. Public Lands?

• Multiple Use Lands
• National Forest System
• National Resource Lands.
• Moderately Restricted-Use Lands
• National Wildlife Refuges
• Restricted-Use Lands
• National Park System
• National Wilderness Preservation System

3
How Should U.S. Public Lands Be Managed?

• The four following principles from environmental
  economists and free-market economists (Aldo
  Leopolds Land Ethics)
• Protect biodiversity, habitats, and ecological
  functioning should be number 1 goal.
• No one should receive subsidies or tax breaks for
  using or extracting resources on public lands.
• American people deserve fair compensation for the
  use of their property.
• All users of extractors of resources on public
  lands should be fully responsible for any
  environmental damage caused.

4
How Should U.S. Public Lands Be Managed?

• Economists, developers, and resource extractors
  view public lands in the following ways
• Their usefulness in providing mineral, timber,
  and other resources
• The ability to increase short-term economic
  growth
• Encourage the US Congress to pass a variety of
  anti-environmental laws

5
What Are the Major Types of Forests?

• Forests with 50 or more tree cover occupies
  about 32 of the earths land surface
• Can be classified as
• Old-Growth Forests uncut forests or regenerated
  forests that have not been seriously disturbed by
  human activities or nature disasters
• Second-Growth Forests stands of trees from
  areas where trees were once removed by human
  activities such as clear cutting or natural
  forces such as fire, hurricanes, or volcanic
  eruptions.
• Tree Plantations managed tracts with uniformly
  aged tress of one species.

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What Are the Major Types of Forest Management?

• Even-aged Management involves maintaining trees
  in a give stands at about the same size and age.
• Uneven aged Management involves the
  maintaining of a variety of species in a stand at
  many ages and sizes to foster natural
  regeneration.
• Goals of Biological diversity
• Long-term sustainable production
• Selective cutting of individual or mature trees
• Multiple use of the forest

7
How Are Trees Harvested?

• Build roads for access and timber removal
• Increased erosion and sediment runoff
• Habitat fragmentation and biodiversity loss
• Exposure of forests to invasion by nonnatives
• Opening of once-inaccessible forests to farmers,
  miners, etc.
• Logging roads cannot be protected as wilderness.

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How Are Trees Harvested?

• Selective cutting cut singly or in small groups
• Reduced crowding
• Encourages growth of younger trees
• Maintains an uneven-aged stand or different
  species.
• Allows natural regeneration from the surrounding
  trees
• Can be used to remove diseased tress
• Can protect the site for soil erosion and wind
  damage
• Allows a forest to be used for multiple purposed.
  
• High-grading the cutting and removing of only
  the largest and best.
• Reduces the forest canopy
• Causes the forest floor to become warmer, drier,
  and more flammable.
• Increases erosion of the forests thin and
  nutrient-poor soil

9
How Are Trees Harvested?

• Shelterwood Cutting - removes all mature trees in
  two to three cuttings over a period of ten yeas.
• Seed-tree Cutting harvests nearly all a stands
  trees in one cutting, leaving a few uniformly
  distributed seed-producing trees
• Clear-cutting removes all of the trees from an
  area in a single cutting.
• Strip-cutting clear-cutting a strip of trees
  along the contour of the land to allow natural
  regeneration within a few years

10
Positive and Negative Sides of Clear Cutting

• POSITIVE
• Increases timber yield per hectare
• Permits reforesting with genetically improved
  stocks
• Shortens time to establish a new stand of trees
• Takes less skill and planning
• Maximum economic return in the shortest time.
• If done carefully and responsibly is the best way
  to harvest tree plantations for some species.
• NEGATIVE
• Leaves moderate to large forest openings
• Eliminates most recreational value for decades
• Disrupts biodiversity destroys and fragments
  wildlife habitat
• Makes nearby trees more vulnerable to being blown
  down
• Leads to severe soil erosion, sediment water
  pollution, and flooding on steep slopes.

11
What Is Happening to the Worlds Forests?

• Forests are renewable resources as long as the
  rate of cutting and degradation does not exceed
  the rate of regrowth.
• How Can Forests Be Managed More Sustainably?
• Grows timber on long rotations
• Emphasizes selective cutting, strip cutting, not
  clear-cutting on steep slopes
• Minimize fragmentation
• Reduce road building in uncut forest areas
• Use road building and logging methods that
  minimize soil erosion and compaction.
• Leave most standing dead trees and fallen timber
• Timber grown by sustainable methods certified and
  labeled by outside certifying groups
• Includes the estimated ecological services in
  economic value.

12
How Can Pathogens and Insects Affect Forests

• Ways to reduce the impact of tree diseases and of
  insects on forests
• Preserve biodiversity
• Ban imported timber
• Remove infected and infested trees, clearing,
  burning
• Treating diseased trees with antibiotics
• Developing tree species that are
  disease-resistant
• Applying pesticides
• Using integrated pest management.

13
How Can Fires Affect Ecosystems?

• Fires can be important
• Maintain the vegetations of many ecosystems at a
  certain stage of ecological succession fires
  burn away the low-lying vegetation and small
  trees a burst of new vegetation follows.
• Surface fires usually burn only undergrowth and
  leaf litter on the forest floor. Kill seedlings
  and small trees but spare most mature trees and
  allow most wild animals to escape.
• Crown fires extremely hot fires might start on
  the ground, but eventually burn whole trees and
  leap from top to top.

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How Can We Protect Forests From Fire?

• Prevention
• Requiring burning permits
• Closing all parts of a forest and camping during
  periods of drought and high fire danger
• Educating the public
• Smokey Bear! prevent forest fires, save lives,
  prevent billions in losses
• Prescribed burning setting controlled ground
  fires
• Presuppression early detection and control of
  fires
• Suppression fighting fires once they have
  started.

15
How Do Air Pollution and Climate change Threaten
Forests?

• At high elevations and those downwind from urban
  and industrial centers are exposed to a variety
  of air pollutants that can harm trees
• Reduce emissions of the offending pollutants
• Regional climate change brought about by global
  warmning
• Increase the threat of forest fires in areas that
  may get less precipitations
• Cause some types of tree species to die out in
  some areas.

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Why Should We Care About National Forests?

• Economic
• Supply timber
• Serve as grazing lands
• Provide minerals, oil, and natural gas
• Contain network of roads
• Ecological
• o Provide habitat for almost 200 threatened and
  endangered species
• o Principle habitats for pollinator species
• o Provide some of the cleanest drinking water.
• Recreational
• Recreation, hunting, fishing

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How Should U.S. National Forests Be Managed?

• Sustainable Yield trees cant be harvested or
  used faster than they are replenished
• Multiple Use each of the forests should be
  managed for a variety of uses such as sustainable
  timber harvesting, recreation, livestock grazing,
  watershed protection, and wildlife.
• In 2001, Bush increased the sale of timber in
  national forests by 40, moved to block road
  construction in roadless areas of the national
  forest eliminated the requirement that the
  forest service manage national forests to protect
  the viability of wildlife and ecological
  sustainability. Created the idea of charter
  forests.

18
Battle Between Environmentalists and Timber
Companies

• Environmentalists
• Timber-cutting program Loses Money
• Logging in national forests causes more harm than
  good to local communities near such forests
  Communties relying on national forest timber
  sales experience economic slumps.
• Costs the taxpayers in logging subsidies and
  cleaning of pollutions It would save taxpayers
  money.
• Only provides about 3 of the countries wood is
  from National Forests
• Ample private forestland is available to meet the
  countries demand for wood
• Below costs is not good for other forests and has
  little effect on the consumer
• Recreation in national forests provides more
  jobs.
• Timber Companies say
• Helps satisfy the countrys demand for food
• Provides cheap timber that benefits consumers
• Improves forest health, fires
• Provides jobs and stimulates economic growth.

19
How Can We Cut Fewer Trees by Using Wood More
Efficiently?

• 60 of the wood consumed is wasted
• o inefficient use of construction materials
• o excess packaging
• o Overuse of junk mail
• o Inadequate paper recycling
• Failure to reuse wooden shipping containers
• o Packaging (50)
• o Writing and printing (30)
• o Newsprint (12)
• o Paper tissues and towels (8)
• Only 3 of softwood production comes from
  national forests

20
How Can We Cut Fewer Trees by Making Paper from
Tree-Free Fibers?

• Tree-free fibers
• From agricultural residues from crops
• From fast growing crops
• Account for 7 of the worlds fiber supply for
  paper
• less than 1 in the US
• China uses tree-free pulp makes 60 of paper
• Made from kenaf in the US
• 3 5X the cost however, supply and demand

21
Why Is It Difficult to Determine Deforestation?

• Interpretation of satellite images
• Different ways of defining forests
• Political and economic factors
• Why Should We Care About Tropical Forests?
• Economic and ecological services
• Their instrumental values
• Chemicals
• Uses

22
Case Study Madagascar

• 85 of the plant and animals species re endemic
  species unique to the island
• Lost of habitat due to slash and burn agriculture
  and rapid population growth
• Many species face extinction
• Large erosion

23
What Is Cultural Extinction?

• Indigenous cultures who used the land sustainably
  are vanishing
• This is an irreplaceable loss of ecological
  knowledge and cultural diversity
• They know how to live sustainably
• They know which plants are useful as food and
  medicines.

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Solutions to Deforestation and Degradation

• Solutions
• New settlers who know how to practice small-scale
  sustinable agriculture and forestry
• Debt for Nature Swaps
• Conservation Easements
• Conservation Concessions
• International System for Evaluating Timber
  produced by sustainable methods
• Gentler methods for harvesting trees
• National and global efforts to reforest and
  rehabilitate

25
Fuelwood Crisis

• Developing countries use wood to meet their
  energy needs
• They have not had enough to meet their needs
• They burn charcoal because it is lighter and
  cheaper
• They must travel far distances, expensive, more
  disease, burn dung and crop residues
• Solutions
• Plant more fast growing fuelwood trees
• Switch to other fuels (root-fuel plants)

26
How are Parks Threatened?

• Only 1 of the parks in developing countries
  receive protections - become paper parks
• Popularity
• Lack of Funds
• Lack of law enforcement
• Suffer from nonnative specie
• Nearby human activity threatens wildlife and
  recreational values

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How Can Management of US Parks Be Improved?

• Currently under the principle of Natural
  Regulation - managed as if they are wilderness
  ecosystems that can adapt and sustain themselves.
  
• Goals and Ideas
• Preserve nature
• Make parks available to the public, but limit
  visitors and raise entry fees
• Require integrated management plans for parks
• Increase the budget - more maintenance and
  repairs, more park rangers at higher pay
• Encourage donations, ask for volunteers
• Provide transportation
• Give private concessionaries

28
What Principles Should Be Used to Establish and
Manage Nature Reserves?

• Ecosystems are rarely stable
• Ecosystems and communities that experience fairly
  frequent but moderate disturbances have the
  greatest diversity of species
• We should view most at habitat islands.

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How Should Nature Reserves Be Designed?

• Shape - Circular or Elongated?
• Single Large or Several Small Reserves?
• Heterogenous or Homogeneous?
• Isolated or Connected
• What about Buffer Zones?

30
What is Gap Analysis?

• Gap Analysis - determines whether existing
  networks or nature reserves provide enough
  protection for native plant and animal species.
• Maps of topography
• Databases of biological information
• Superimpose the species data onto the maps
• Use this information to close gaps
• Conservation Gaps - where there is a lack of
  adequate protection.

31
What Areas Should Receive Top Priority for
Establishing Reserves?

• 25 Hot Spots
• Mostly tropical forests
• Contain 60 of the biodiversity

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Wilderness - Why Preserve It?

• Wilderness - areas of undeveloped land affected
  primarily by the forces of nature, where man is a
  visitor who does not remain.
• Why preserve?
• Beauty of nature!
• Just to know it is there is comforting
• Centers of evolution
• Undisturbed areas
• A natural laboratory
• Wild species have a right to exist and play their
  roles in earth.

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Fixing Ecosystems

• Restoration - trying to return it to its
  predegraded state
• Let nature do most of the work
• Remove pollutants, add nutrients, add topsoil,
  remove nonnative species
• Reintroduce species
• Prevention from further damage
• Monitor area
• Difficulties include
• Lack of knowledge about previous composition
• Changes in climate
• Ecosystem is changing
• Rehabilitation - an attempt to restore some of
  the degraded systems species and ecosystem
  functions.
• Replacement - replace a degraded ecosystem
• Create Artificial Ecosystems

34
What Are The Next Steps?

• Preserve hot spots
• Keep forests intact
• Cease all logging of old-growth forests
• Concentrate on protecting lakes and river systems
• Determine marine hot spots
• Continue to map the worlds biodiversity
• Make conservation profitable