Chapter 13: Forests, Parks an
Landscapes
Modern Conflicts over Forestland
and Forest Resources
• In recent decades forest conservation has
become an international cause
– NA Pacific Northwest
– Tropical rain forest
• Forestry has a long history
– Silviculture- professional growing of trees
• What should forest be used for?
– Resources vs. conservation
Modern Conflicts over Forestland
and Forest Resources
• Forest and civilization closely linked
– Wood major building material and source of
fuel
– Spiritual and aesthetic value
Modern Conflicts over Forestland
and Forest Resources
• Public service functions
– Indirect benefits that people and the
environment receive from forests
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Improving watersheds
Wildlife habitat
Recreation
Climate
The Life of a Tree
• How a tree grows
– Leaves of a tree take up CO2 and absorb
sunlight
– Water transported up from roots
– Leaves carry out photosynthesis
• Products = simple sugar and oxygen
– Roots have symbiotic fungi that help extract
minerals from the soil
How a Tree Grows
• Leaves and roots connected by two
transport systems
– Phloem- on the inside of the living side of bark,
transports sugars and other organic compounds
down to stems and roots
– Xylem- farther inside, transports water and
inorganic molecules upward to the leaves
• Sun-powered pump
Tree Niches
• Each species of tree has its own niche and
adapted to specific environmental
conditions
– E.g., water content of the soil
– Tolerance of shade
– Some adapted to early succession, others to
later stages
A Forester’s View of a Forest
• Traditionally managed in stands
– Stand- an informal term foresters use to refer to a group
of trees
• Usually the same specie and successional age
• Even- aged stands
• Uneven-aged stands
• Forest that has never been cute is virgin forest
– Old growth forest
• A forest cut and regrown is secondary growth
forest
A Forester’s View of a Forest
• Rotation time- the time between cuts of a stand
• Foresters and forest ecologists group the trees
in a forest into
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Dominants
Codominants
Intermediate
Suppressed
• Site quality- max timber crop the site can
produce in a given time
Approaches to Forest
Management
• Managing forests can involve
– removing poorly formed and unproductive trees
to permit larger trees to grow
– Planting genetically controlled seedlings
– Controlling pests and diseases
– Fertilizing the soil
Clear-cutting
• Clear-cutting- the cutting of all trees in a
stand at the same time
Alternatives to Clear-Cutting
• Selective cutting- individual trees are marked and
cut (thinning)
• Strip-cutting- narrow rows of forest are cut, leaving
wooded corridors whose trees provide seeds
• Shelterwood-cutting- practice of cutting dead and
less desirable trees first and later cutting mature
trees.
• Seed-tree cutting- removes all but a few seed trees
to promote regeneration of the forest
Experimental Test of ClearCutting
• Scientist have tested the effects of clear
cutting
• Hubbard Brook experimental forest in NH
– Erosion increased and pattern of water runoff
changed substantially
– Exposed soil decayed more rapidly
– Stream water exceeded public health standards
for nitrates
Experimental Test of ClearCutting
• HJ Andrews Experimental Forest in OR
– Increase in the frequency of landslides after
clear cutting
• C-c also changes chemical cycling in forests
and causes the soil to lose chemical
elements necessary for life
Experimental Test of ClearCutting
• Experiments show
– Clear-cutting can be a poor practice on steep
slopes in areas of moderate to heavy rainfall
– Clear-cutting on an appropriate spatial scale
may be useful to regenerate desirable species
• Where ground is level, rainfall moderate, and
desirable species require open ground to grow
Plantation Forestry
• Plantation- a stand of a single species
typically planted in straight rows
– Much like agriculture
– Fertilizers added, mechanized harvesting
• Offer a solution to the pressure on natural
forests.
– High-yield forests could provide all the world’s
timber
Sustainable Forestry
• A sustainable forest is one from which a
resource can be harvested at a rate that does
not decrease the ability of the forest
ecosystem to continue to provide that same
rate of harvest indefinitely.
What is Sustainability and How
is it Applied to Forests
• Two basic kinds of ecological sustainability
– Sustainability of the harvest of a specific
resource w/in an ecosystem (harvest of timber)
– Sustainability of the entire ecosystem (forest as
an ecosystem)
• Lack scientific data to demonstrate that
either type ever achieved in forests
Certification of Forest Practices
• Compare the actual practices of a specific
corporation or government agencies w/
practices that are believed to be consistent
w/ sustainability.
– Don’t know if beliefs are correct or practices
really sustainable
– Movement to call them “well-managed forests”
or “improved management”
A Global Perspective on Forests
• Vegetation of any kind can affect the
atmosphere in four ways
– 1. By changing the color of the surface and
therefore the amount of sunlight reflected and
absorbed.
– 2. By increasing the amount of water transpired
and evaporated from the surface to the
atmosphere.
A Global Perspective on Forests
• 3. By changing the rate at which greenhouse
gases are released from Earth’s surface into
the atmosphere.
• 4. By changing “surface roughness”, which
affects wind speed at the surface.
World Forest Area, Global Production
and Consumption of Forest Resources
• Countries differ greatly in their forest
resources
– Potential of their land and climate for tree
growth
– History of land use and deforestation
World Forest Area, Global Production
and Consumption of Forest Resources
• Developed countries account foe 70% of
world’s total production and consumption
of industrial wood products
• Developing countries produce and consume
about 90% of wood used as firewood
• 90% of world timber trade
– Construction, pulp and paper
– NA is the dominant supplier
World Forest Area, Global Production
and Consumption of Forest Resources
• In recent years world trade in timber has not
grown substantially.
• The fundamental questions are
– Whether forests can continue to produce at least
this amount of timber for an infinite period
– Whether they can produce even more as the
population grows
Deforestation: A Global
Dilemma
• Deforestation is estimated to have increased
erosion and caused the loss of 562 million
hectares of soil.
• Deforestation in one country can affects
countries downstream
– E.g. Nepal and India
Deforestation: A Global
Dilemma
• Is forested area increasing or decreasing?
– Information is lacking on which to base an
accurate evaluation
– Forest cover is large, often remote
– Difficult to assess the total amount of forest
area
– Estimates suggest an annual loss each year of
7.3 million hectares
History of Deforestation
• Has occurred in all societies from
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Early Greece and Roman Empire
Prehistoric farmers in Denmark
Medieval Great Britain
Upon colonization of the New World
• The greatest losses in the present century
taken place in South America
Causes of Deforestation
• Two most common reasons
– Clear land for agriculture and settlement
– To use to sell timber for lumber, paper
products, or fuel
The World Firewood Shortage
• In many parts of the world, wood is a major
energy source.
• As the human population grows, use of
firewood increases.
– Management is essential
Indirect Deforestation
• The death of trees from pollution or disease
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Acid rain
Ozone
Other air pollutants
All can increase susceptibility to disease
• Global climate change may lead to
– Major die-off and shift in areas of potential
growth
Parks, Nature Preserves, and
Wilderness
• Landscapes may be protected in different
ways
– Government established parks, nature
preserves, and wilderness areas
– Private organizations buying land and
maintaining it as nature preserves
Parks and Preserves
• Park- an area set aside for use by people
• Nature preserve- may be use by people but
primary purpose the conservation of some
resource
• Both create ecological islands
– Island biogeography used in design and
management
Parks and Preserves as Islands
• The size of the park and the diversity of
habitats determine the # of species that can
be maintained.
• The further the park is from other parks or
sources of species, the fewer species are
found.
Parks and Preserves as Islands
• Most park boundaries have been arbitrarily
set.
• E.g., Lake Manyara National Park in
Tanzania
– Original boundaries did not include elephants
entire yearly range
– Elephants and farmer came into direct conflict
– Boundary shifted
Brief History of Parks
• The French work parc once referred to an
enclosed area for keeping wildlife to be
hunted.
• E.g., Coto Donana National Park on the
coast of Spain
– Once country home of nobles
– Now a stop over for 80% of birds migrating
between Europe and Africa
Brief History of Parks
• First public park
– Victoria Park in Great Britain, 1842
• Concept of national park originated in NA
in the 19th century
– Yosemite designated in 1864
– Preserve unique awesome landscapes
• 20th century emphasis more ecological
Conflicts in Managing Parks
• Major conflicts generally have to do with
– Size
– What kinds and levels of access and activities
will be available
How Much Land Should be in
Parks
• What percentage of the landscape should be
in parks or nature preserves?
• If parks are to function as biological
preserves, they must be adequate in size and
habitat diversity.
Conserving Wilderness
• As a modern legal concept, wilderness is an
area undisturbed by people.
– New idea introduced in the second half of the
20th century
– US Wilderness Act of 1964
• First time wilderness recognized by national law
– “land retaining its primeval character and
influence”
Conserving Wilderness
• Wilderness
– 1. Imprint of human work is unnoticeable
– 2. There are opportunities for solitude and
primitive and unconfined recreation
– 3. There are at least 5,000 acres
• “Wilderness” vs “Wildness”
Conflicts in Managing
Wilderness
• Legal definition given rise to several
controversies
– Desire to include more land as wilderness
– Desire to develop this land and its natural
resources
• Can view goal of managing
– 1. To preserve nature undisturbed by people
– 2. To provide people w/ a wilderness
experience