Carrying Capacity and LAC

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Carrying Capacity and LAC
course website
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Carrying capacity ... How many people can be
in a wilderness and still have wilder-ness
conditions and experiences?
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Concept developed for grazing animals. Carrying
capacity is the maximum number of animals that
can be sustained indefinitely.
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Numb.
Time
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limiting factor
Numb.
Time
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Numb.
Time
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Thomas Malthus - population will outrun food
production, 1798
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• For wilderness, limiting factors are
• quality of experiences
• integrity of ecosystems
• Many technological fixes prohibited

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Biologically-trained people adopted carrying
capacity model for grazing animals.
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Grazing Wilderness Objective sustained
sustained benefit, profit
ecol. integrity Product meat, milk.
experiences, hides, etc.
naturalness Basis forage psychol. of
users Owner rancher public(s) Manager
rancher public servants
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Carrying capacity is a means to and end or
objective. Makes no sense until objective is
specified
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Grazing Wilderness Objective sustained
sustained benefit, profit
ecol. integrity Product meat, milk.
experiences, hides, etc.
naturalness Basis forage psychol. of
users Owner rancher public(s) Manager
rancher public servants
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Can quality of experience increase with
crowding? Depends on preferences and
expectations.
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... the maximum degree of the highest type ...
use ... a wilderness can receive, consistent with
its long-term preservation Lowell Sumner, NPS
1942
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... to conserve the scenery and the natural and
historic objects and the wildlife therein ... in
such manner and by such means as will leave them
unimpaired for the enjoyment of future
generations. NPS Organic Act, 1916
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... to secure for the American people of present
and future generations the benefits of an
enduring resource of wilderness. Wilderness
Act, 1964
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For grazing animals, carrying capacity a matter
of nutrition
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• Options for maintaining wilderness quality
• Designate more wilderness
• Change definition of wilderness
• Go elsewhere
• Increase efficiency
• Allocate

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Built a stomping machine
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People do not eat grass!
Issues are cultural and social.
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Ecological research can define how much change
occurs with various use Social research
guidance on how much change is acceptable. No
change would mean no use.
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USFS originally very reluctant to impose
constraints NPS seemed more comfortable with
constraints.
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Possible increase in efficiency distribute use
in time, in space.
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Because use so uneven, setting area-wide carrying
capacity makes little sense. Amount of use does
not correlate well with either visitor
experiences or condition of area. Carrying
capacity - a great concept, awkward to apply
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So, Limits of Acceptable Change (LAC). Not
perfect but best yet. NPS Visitor Experience and
Resource Protection (VERP) system essentially the
same.
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Rule of the tool
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LAC focuses on acceptable conditions. Indicators
(physical social) Standards As contrasted with
carrying capacity approach, LAC focuses on
desired conditions and management to get there.
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Focus on process, not detail
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Acceptable largely social issue. Public
involvement built in. Advisory group (stakeholder
reps). Identify concerns and issues. Define
opportunity classes (such a pristine, primitive,
semi-primitive.
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Select indicators of resource and social
conditions.
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Inventory wilderness in terms of the indicators.
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Specify standards. Probabilistic, as 90 percent
of the time during heavy use season. Develop
alternative allocation or zoning schemes.
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Zoning has many management implications, for
example, action to bring an area up to
standards. Translated into workloads and cost
figures for budget preparation.
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Select preferred alternative. Public review
input Final allocation plan Monitoring
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What do we have? (inventory) What do we want?
(concerns issues, public input) How do we get
it? (defining indicators, standards for
opportunity classes, allocation of classes to
wilder-ness, management actions) Did we get it?
(monitoring)