Chapter 12 - Santa Rosa County School District

Lecture Outlines
Chapter 12
The Science behind the
4th Edition
© 2011 Pearson Education, Inc.
This lecture will help you understand:
• Ecological and economic
contributions of forests
• History and scale of
• Forest management and
harvest methods
• Major federal land
management agencies
• Types and design of
protected areas
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Central Case: Certified sustainable paper
• The paper in this book is made from trees sustainably
grown, managed, harvested, and processed
- This does not deplete mature trees or degrade
ecological functions
- The mill recycles chemicals and paper and burns
discarded lignin to help provide power
This paper is Forest
Stewardship Council (FSC)certified from sources that use
sustainable practices
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Many kinds of forests exist
• Forest = any ecosystem with a high density of trees
- Boreal forest = in Canada, Scandinavia, and Russia
- Tropical rainforest = South and Central America,
Africa, Indonesia, and southeast Asia
- Temperate deciduous forests, temperate rainforests,
and tropical dry forests also exist
- Woodlands = ecosystems with lower density of trees
• Plant communities differ due to soil and climate
- Forest types = are defined by predominant tree species
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Forests cover 31% of Earth’s surface
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Forest types
• The Eastern U.S. has 10
forest types
- Spruce-fir, oakhickory, longleaf-slash
• The Western U.S. holds
13 forest types
- Douglas fir, ponderosa
pine, pinyon-juniper
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Forests are ecologically complex
• Forests are some of the richest ecosystems for biodiversity
- They are structurally complex, with many niches
- They provide food and shelter for multitudes of species
- Fungi and microbes have parasitic and mutualistic
relationships with plants
• Plant diversity leads to greater overall organism diversity
- Succession changes species composition
• Old-growth forest diversity exceeds that of young forests
- They have higher structural diversity, habitats, and
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A cross-section of a mature forest
The scarlet tanager lives in
the eastern U.S. temperate
deciduous forest
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Forests provide ecosystem services
• Forests provide cultural, aesthetic, health, and
recreation values
• Forests also provide vital ecosystem services
- Stabilize soil and prevent erosion
- Slow runoff, prevent flooding, purify water
- Store carbon, release oxygen, influence weather
patterns, and moderate climate
• Roots draw minerals to surface soil layers
- Plants return organic material to the topsoil as
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Carbon storage helps limit climate change
• Carbon storage by forests is of great international interest
- Nations debate how to control climate change
• Trees absorb carbon dioxide and store carbon
- The world’s forests store 280 billion metric tons of C
• Cutting forests worsens climate change
- Dead plants decompose and release carbon dioxide
- Fewer trees soak up less carbon dioxide
• Preserving forests keeps carbon out of the atmosphere
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Forests provide us valuable resources
• Benefits: medicines, food,
fuel, shelter, ships, paper
• Help us achieve a high
standard of living
• Logging locations:
- Boreal forests: Canada,
- Rainforests: Brazil,
- Conifer forests/pine
plantations: U.S.
In 2010, 30% of all
forests were designated
for timber production
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Demand for wood leads to deforestation
• Deforestation = the clearing
and loss of forests
- Changes landscapes and
- Reduces biodiversity
- Worsens climate change
- Disrupts ecosystem
- Ruins civilizations
Although the rate of deforestation is slowing,
we still lose 12.8 million acres/year
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Deforestation fed the growth of the U.S.
• Deforestation propelled the expansion and growth of
the U.S. and Canada
• Eastern deciduous forests were the first to be logged
- Timber companies moved south to the Ozarks, west
to the Rockies
• Primary forest = natural forest uncut by people
- Little remained by the 20th century
• Second-growth trees = grown to partial maturity after
old-growth timber has been cut
• Secondary forest = contains second-growth trees
- Smaller trees, very different species and structure
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Most primary forest is gone
The entire eastern half of the
continent used to be covered
in primary forest
Most primary forest was cut
for agriculture and timber
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Loggers lose their jobs with deforestation
• As each region is deforested, the timber industry declines
and timber companies move on
- Local loggers lose their jobs
• Once the remaining ancient trees of North America are
gone, loggers will once again lose jobs
- Companies will simply move to another area
- Most move to developing countries
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Rapid deforestation in developing nations
• Uncut tropical forests still remain in many developing
countries (Brazil, Indonesia, and West Africa)
- Technology allows for even faster exploitation
• Developing countries are so desperate for economic
development, they have few logging restrictions
• Concession = corporations pay the government for the
right to extract resources
- Temporary jobs are soon lost, along with the resources
- Wood is exported to North America and Europe
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Deforestation affects people
• In Malaysia, foreign corporations have deforested
millions of acres of tropical rainforest
- Affecting 22 tribes of hunter-gatherers
- The government did not consult the tribes
• Deforestation decreased game
- Oil palm agriculture’s pesticides and fertilizers killed
• The people peacefully protested
- The government wants to convert tribes to farmers
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Palm oil plantations
• Palm oil is used in snack
foods, soaps, cosmetics,
• Borneo has lost most of its
forest cover
• Clearing encourages further
development and illegal
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Solutions to deforestation are emerging
• Conservation concessions = organizations team up to
reduce deforestation and illegal logging
• Carbon offsets = curb deforestation and climate change
- Forest loss causes 12–25% greenhouse gas emissions
- The Kyoto Protocol does not address this
• REDD = Reducing Emissions from Deforestation and
Forest Degradation
- From the 2009 Copenhagen climate conference
- Wealthy nations would pay poor nations to conserve
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• The Copenhagen conference ended without a binding
- The REDD plan fell through
- But some of the $100 billion/year going to poor
nations may go to REDD
• Guyana is taking a leading role in REDD
- It is poor financially but rich in forests
- Cutting forests would provide $580 million/year
- Norway will pay $20 million in 2010 for conservation
and up to $250 million in 2015
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Forest management
• Forestry (silviculture) = forest management
- Sustainable forest management is spreading
• Foresters = professional managers who must balance
demand for forest products (short-term benefits) vs. the
importance of forests as ecosystems (long term)
• Resource management = strategies to manage and
regulate potentially renewable resources
- Sustainable management does not deplete resources
- Managers are influenced by social, political, and
economic factors
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Maximum sustainable yield
• Maximum sustainable yield = aims to achieve the
maximum amount of resource extraction without
depleting the resource from one harvest to the next
• Populations grow fastest at an intermediate size
- Population size is at half its carrying capacity
• Harvesting to keep the population at this size results
in maximum harvest
- While sustaining the population
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Maximum sustainable yield has problems
• Managed populations are much smaller than they would
naturally be
• Reducing populations so drastically affects other species
- Changing the entire ecosystem
• Trees are cut long before they grow to maximum size
- Changing forest ecology
- Eliminating habitats
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Ecosystem-based management
• Ecosystem-based management = managing resource
harvesting to minimize impacts on ecosystems and
ecological processes
• Sustainably certified forestry plans protect areas
- Restore ecologically important habitats
- Consider patterns at the landscape level
- Preserve the forest’s functional integrity
• It is challenging to implement this type of management
- Ecosystems are complex
- Our understanding of how they operate is limited
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Adaptive management
• Adaptive management = testing different approaches
and aiming to improve methods through time
- Monitoring results and adjusting methods as needed
- Time-consuming and complicated, but effective
• The 1994 Northwest Forest Plan resolved disputes
between loggers and preservationists over the last U.S.
old-growth temperate rainforests
- The plan let science guide management
- It allowed limited logging while protecting species
and ecosystems
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Fear of a “timber famine” spurred forest
• Depletion of eastern U.S. forests caused alarm
• National forest system = public lands set aside to grow
trees, produce timber, protect watersheds, and ensure
future timber supplies
- 77 million ha (191 million acres)—8% of U.S. land
• The U.S. Forest Service was established in 1905
- Manages forests for the greatest good of the greatest
number in the long run
- Management includes logging and replanting trees
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Federal agencies own land in the U.S.
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Timber is extracted from public and private
• Private companies extract timber
from public land
- The Forest Service plans
and manages timber sales
and builds roads
- Companies log and sell
the timber for profit
Taxpayers subsidize
private timber
harvesting on public
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Logging on private vs. public land
• Most U.S. logging occurs on private land owned by
timber companies or small landowners
- Companies use the maximum sustained yield approach
• Management on public lands reflects social and political
factors that change over time
- Public concern, changing management philosophies,
and economics have caused harvests to decrease
- But the secondary forests that replace primary forests
are less ecologically valuable
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Plantation forestry
• The timber industry focuses on timber plantations
- Fast-growing, single-species monocultures
• Even-aged stands= all trees are the same age
• Rotation time = trees are cut after a certain time
- The land is replanted
• Uneven-aged stands = mixed ages of trees and species
Tree plantations are
crops, not ecologically
functional forests
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Harvesting timber: clear-cutting
• All trees in the area are cut
- Most cost-efficient
- Greatest ecological
- May mimic some natural
disturbance (e.g., storms)
- Leads to soil erosion
• Public outrage caused
companies to use other
harvesting methods
Clear-cutting destroys
entire communities
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Harvesting: other methods
• Seed-tree approach = a few seed-producing trees are left
standing to reseed the logged area
• Shelterwood approach = some trees are left to provide
shelter for the seedlings as they grow
• Selection systems = only select trees are cut
- Single tree selection = widely spaced trees are cut
- Group tree selection = small patches of trees are cut
• All methods disturb habitat and affect species
- Change forest structure and composition
- Increased runoff, flooding, erosion, siltation, landslides
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Harvesting forests
Clear-cut logging
Selection logging
Seed-tree and shelterwood logging
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Managing public forests
• Increased public awareness caused people to urge that
forests be managed for recreation, wildlife, and
ecosystem integrity, instead of only for logging
- Critics protest federal subsidies of logging companies
• Multiple use policy = national forests are to be managed
for recreation, habitat, minerals, and other uses
- In reality, timber production is the primary use
The Forest Service loses $100 million/year of taxpayer
money and increased harvest by selling timber below cost
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The National Forest Management Act (1976)
• Every national forest must formulate plans for renewable
resource management that:
- Consider both economic and environmental factors
- Provide for and protect regional diversity
- Ensure research and monitoring of management
- Permit only sustainable harvest levels
- Ensure that profit alone does not guide harvest
- Protect soils and wetlands
- Assess all impacts before logging to protect resources
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New forestry
• U.S. Forest Service programs:
- Manage wildlife, non-game animals, endangered
- Push for ecosystem-based management
- Run programs for
ecological restoration
• New forestry = timber cuts
that mimic natural events
- Sloppy clear-cuts mimic
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Politics influences forestry management
• The Bush administration rolled back regulations in 2004
- Freed managers from requirements of the National
Forest Management Act
- Loosened environmental protections
- Restricted public oversight
- Repealed President Clinton’s roadless rule, which
protected 31% of national forests from logging
- State governors had to petition the federal government
to protect areas
- Court rulings reinstated the roadless rule in 2009
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Fire policy also stirs controversy
• For over 100 years, the Forest Service suppressed all fires
- But many ecosystems depend on fires
- Excess vegetation produces kindling for future fires
• In the wildland-urban interface, housing developments
that are near forests are vulnerable to forest fires
Catastrophic fires have become more numerous recently
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Prescribed fires are misunderstood
• Prescribed (controlled) burns = burning areas of forests
under carefully controlled conditions
- Clear away fuel loads, nourish soil, encourage growth
of new vegetation
- Are time-intensive
- Are impeded by public misunderstanding and political
• Healthy Forests Restoration Act (2003) = promotes
removal of small trees, underbrush, and dead trees
- Passed in response to forest fires
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Salvage logging
• Removal of dead trees following a natural disturbance
• It seems logical, but is really destructive
- Snags (standing dead trees) provide nesting and
roosting cavities for countless animals
- Removing timber from recently burned areas increases
erosion and soil damage
- Impedes forest regeneration and promotes future fires
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Climate change is altering forests
• The U.S. is warming and getting drier and will get worse
• Pests kill huge areas of trees, particularly plantations
• Dead trees do not remove carbon dioxide
- Intensifying climate change
• Woodlands, shrublands. or grasslands may replace forests
Increased fires and pests destroy large areas of the U.S.
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Progress toward sustainable forestry is
• The world is still losing forested land
- But advances are being made toward sustainable
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Sustainable forestry is gaining ground
• Sustainable forest certification = products produced
sustainably can be certified by organizations
- The Forest Stewardship Council (FSC) has the
strictest standards
- Companies such as Home Depot sell sustainable
wood, encouraging better logging practices
- Consumers look for logos to buy sustainably
produced timber
Strong certification standards
drive sustainability
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Why create parks and reserves?
• People establish parks and reserves to:
- Preserve areas with enormous or unusual scenic
features, such as the Grand Canyon
- Offer recreational value: hiking, fishing, hunting, etc.
- Generate revenue from ecotourism
- Offer peace of mind, health, exploration, wonder, etc.
- Protect areas that provide ecosystem services
- Use sites that are otherwise economically not valuable
and are therefore easy to protect
- Preserve biodiversity
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Federal parks and reserves began in the U.S.
• National parks = public lands protected from resource
extraction and development
- Open to nature appreciation and recreation
- Yellowstone National Park
was established in 1872
• The Antiquities Act (1906) lets
the president declare public
lands as national monuments
- Which may later become
national parks
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The National Park Service (NPS)
• Created in 1916 to administer parks and monuments
- 392 sites totaling 34 million ha (84 million acres)
- Includes national historic sites, national recreation
areas, national wild and scenic rivers
- 285 million visitors in 2009
• These parks are “the best idea we ever had”
• There are also 3,700 state parks across the U.S.
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National Wildlife Refuges
• Begun in 1903 by President Theodore Roosevelt
- 39 million ha (96 million acres) in 550 sites
- The Pacific Remote Islands Marine National
Monument added 22 million ha (55 million acres)
• U.S. Fish and Wildlife Service (USFWS)
- Administers wildlife refuges, serving as havens
- But allows hunting, fishing, wildlife observation,
photography, education
- Managed for waterfowl and non-game species
- Restores marshes and grasslands
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Wilderness areas are on federal lands
Wilderness areas = are off-limits to development
• For hiking, nature study, etc.
- Must have minimal impact
• Grazing and mining were
allowed as political
• Established in federal lands
- Overseen by the agencies
that administer those areas Wilderness is necessary
• 756 areas, 44 million ha (109 to ensure that humans
million acres)
don’t occupy and
modify all natural areas
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Not everyone supports land set-asides
• Some western states want resource extraction and
• The wise-use movement = individuals and industries
opposed to environmental protection want:
- To protect private property, oppose government
- Federal lands transferred to state or private hands
- Motorized recreation on public lands
- Farmers, ranchers, loggers, mineral, and fossil fuel
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Opposition to wilderness protection
• President George W. Bush weakened wilderness
- Federal agencies shifted policies and enforcement
away from preservation and conservation toward
recreation and resource extraction
• Indigenous people often oppose land protection
- Recreational areas are often sacred to Native cultures
• But protected areas can help indigenous people
- In Brazil and other Latin American nations, these areas
protect tribes from miners, farmers, and settlers
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Nonfederal entities also protect land
• Each U.S. state has agencies that manage resources on
public lands
- So do counties and municipalities
• Land trusts = local or regional organizations that
purchase land to protect it
- The Nature Conservancy is the world’s largest land
- Trusts own 690,000 ha (1.7 million acres) and protect
an additional 4.1 million ha (10.2 million acres)
- Jackson Hole, Wyoming is protected by a land trust
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Parks and reserves are increasing
• Many nations have established national parks
- Benefit from ecotourism
- Protected areas cover 12% of the world’s land area
• Parks do not always receive necessary funding
- Paper parks = areas protected on paper but not in
• Biosphere reserves = land with exceptional biodiversity
- Couple preservation with sustainable development
- Benefit local people
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Biosphere reserves have several zones
• Are designated by UNESCO (the UN Educational,
Scientific, and Cultural Organization)
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World heritage sites
• Another type of international protected area
- 890 sites in 148 countries are listed for their natural or
cultural value
• Transboundary parks = protected land overlapping
national borders
- Over 100 nations, 10% of protected land
• Peace parks = transboundary parks that ease tensions by
acting as buffers between quarreling nations
- Costa Rica and Panama
- It may work for Israel and its neighbors
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Habitat fragmentation makes preserves vital
• Contiguous habitat is chopped into small pieces
- Species suffer
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Effects of habitat fragmentation
• Logging, agriculture, and residential development
fragment habitat
• Edge effects = conditions along a fragment’s edge are
different than conditions in the interior
- Interior bird species can’t reproduce when forced near
the edge of a fragment
- Parasites and predators attack nests
• Fragmentation is the main reason populations of North
American songbirds are declining
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Islands warn us of habitat fragmentation
• Island biogeography theory = explains how species
come to be distributed among oceanic islands
- It also applies to “habitat islands” = patches of one
habitat within “seas” of others
• The number of island species results from a balance
between species added (immigration) versus lost
- Predicted by the island’s size and distance from the
• Area effect = large islands have more species than small
- They have more habitats, environments, and variety
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The theory of island biogeography
• Distance effect: the farther
an island is from the
continent, the fewer species
find and colonize it
• Larger islands have higher
immigration rates – they are
fatter targets
• Larger islands have lower
extinction rates – more
space allows for larger
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The species-area curve
• Species-area curves = the number of species on an island
doubles as island size increases tenfold
• Protected parks are small “islands” surrounded by
development (farms, roads, cities)
- Many parks are missing species
and are too isolated to be
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Reserve design has consequences
• With habitat fragmentation, the size and placement of
protected areas are key to protecting biodiversity
• The SLOSS dilemma = which is better to protect
species: a single large or several small reserves?
- Depends on the species: tigers vs. insects
• Corridors = protected land that allows animals to travel
between islands of habitat
- Animals get more habitat
- Enables gene flow between populations
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Climate change threatens protected areas
• Global climate change threatens to undo our efforts to
design, establish, and guard protected areas
• Species shift northward with warmer temperatures
- Species can’t move in a fragmented habitat
• High-elevation species are most at risk
- There is no place for them to go
• Corridors to allow movement become very important
- Preserving biodiversity must go beyond parks and
protected areas
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• We are losing ecologically and environmentally valuable
• Resource management policies first emphasized
extraction; then shifted to sustained yield and multiple
• Sustainable forest certification provides economic
incentives for responsible conservation of forests
• Public support for land preservation resulted in parks and
protected areas in the U.S. and abroad
• Development fragments habitats and subdivides
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If an area with 100 organisms is managed for Maximum
Sustainable Yield, how many organisms will be harvested
from the area?
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Erosion prevention, decreased flooding, and storing
carbon are all _________ services that forests provide.
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Which of the following is NOT a result of deforestation?
Changes in landscape structure
Reduced biodiversity
Worsened climate change
All of these are results of deforestation
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Tree harvesting by shelterwood cutting:
Cuts all trees in an area, leaving only stumps
Cuts most trees, but leaves some to produce seeds
Cuts most trees, but leaves some to shelter seedlings
Produces uneven-aged tree stands
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Which agency manages wilderness?
U.S. Fish and Wildlife Service
U.S. Forest Service
Bureau of Land Management
Any of these, depending on the federal land the
wilderness is located within
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People create parks and reserves for many reasons.
Which of the following is NOT a reason to protect land?
Preserve an area with scenic features
Protect areas that provide ecosystem services
Offer recreational opportunities
Maximize profit for the federal government
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The Wise-Use Movement:
a) Pays farmers subsidies to drain wetlands
b) Believes in preserving natural areas against
c) Opposes government regulations and protection of
natural areas
d) Wants to prevent motorized recreation on public
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Biosphere reserves are:
Very large areas
Areas with exceptional biodiversity
Heavily developed
Completely protected from all development
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Which areas are off limits to all development?
National forests
National parks
Wilderness areas
BLM lands
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According to the island biogeography theory, a large
island close to the mainland will:
Have low rates of extinction
Have high rates of extinction
Have few species colonize it
Be without species, since most can’t make it to
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QUESTION: Viewpoints
Some states manage their natural resources (i.e.,
forests) based strictly on profit maximization. Is this
the best way to manage natural resources?
a) Yes, anytime profit can be made, that should be
the type of management used.
b) Yes, but only if more jobs are created than lost.
c) No, natural resources are far more important than
their economic value suggests.
d) I don’t care, I just want to be able to buy what I
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QUESTION: Viewpoints
Should a wilderness area be drilled for petroleum or
natural gas, or mined for minerals?
a) Absolutely yes; we are in a crisis and need every
resource we can get.
b) Maybe, if the resource results in jobs and income.
c) No, we need to preserve some nature – we can find
alternatives ways of satisfying our needs.
d) No, but only if I can benefit from going there.
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QUESTION: Interpreting Graphs and Data
Which type of land ownership supplies the most timber?
a) National forests
b) Other public
c) Forest industry
d) Private land
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QUESTION: Interpreting Graphs and Data
What does this graph say about the incidence of fires?
They have decreased.
They have increased recently.
They have nothing to do with temperature.
Cooler temperatures cause more fires.
© 2011 Pearson Education, Inc.
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