Comparing Cost, Risk, and Benefit Trade-offs Under Uncertainty: Cheatgrass Case Study

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Comparing Cost, Risk, and Benefit Trade-offs
Under Uncertainty Cheatgrass Case Study

• Lisa Wainger and Dennis King,
• University of MarylandRichard Mack, Washington
  State University
• Jim Opaluch, University of Rhode Island

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Decision Framework
Establish Management Priorities
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Decision analysis components to examine with case
study

• Benefits of Treatment
• How do measures of damage avoided vary with
  location and scale of analysis?
• Probability of Successful Restoration
• How do site, location and characteristics of
  invasion influence whether ecosystem services
  will be restored?
• Costs of Treatment
• How do costs vary by location and scale of
  treatment?

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Columbia Basin Study Area
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Bromus tectorum (cheatgrass) distribution through
time
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Federal Land Ownership
Source data USGS
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Risks created by cheatgrass invasion
Increasing scale
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Measuring Benefits
Benefits
E
D
Time
i service, t time period
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Risk-Adjusted Benefits as a Function of Site and
Landscape Conditions
Performance Risk
Service Value Index
Service Capacity
Service Scarcity
Service Loss Risk
Treatment effectiveness
X
Site Qualities
E f(sr,lr) p f(sd,ld) (1- p) s
site qualities l location factors r
restored conditions d degraded conditions p
probability of restoring service
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Does the Site Provide a Valued Service?

• Site has features necessary to produce service
• Site has capacity to produce service because
  users have access and complementary inputs are
  available
• Service value is enhanced because service is
  scarce and substitutes are unavailable or
  expensive
• The risk that the stream of services will end due
  to factors beyond the control of restoration is
  low.

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Fire Risk
Source data USDA FS ICBEMP
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Fire Risk with Population
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Treatment Scenarios

• Preventive reseeding following fire
• Apply to uninvaded sites
• Spread seeds aerially or use drill-seeding
• Sometimes follow aerial seeding with chaining
• Herbicide treatment of existing stands
• Applied to heavily invaded sites
• Multi-step process of burning, herbicide, seeding

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Treatment Decision Tree
Cheatgrass Dominant
B1
native
Natives Dominant
B3
Type of Seed
treat
Cheatgrass Dominant
B1
Treat / No-treat
forage
Forage Species Dominant
B2
No-treat
Cheatgrass Dominant
B1
(p 0.90)
Natives Dominant
B3
(p 0.10)
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Restorability Model
Cheatgrassregrowth
Site Variables
Probability of Success
Landscape Variables
New cheatgrassinfestation
Stochastic Variables
Native / Forage regrowth
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Comparing Restorability
sparse
dense
Contagion Index 0.30
Contagion Index 0.85
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Evaluating Costs

• Trying to supply treatment effort to multiple
  sites for minimum cost
• How do costs vary over infested area?
• How many sites to treat?
• How much area to treat in each location?
• Is it worth treating?

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Minimum-Cost Network Flow
Initial Costjk Fixed Costk Travel Costjtimej
Search Costjarea
Treatment Costjkarea j
location ktreatment method
SC f(site factors) TC g(site factors)
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Equipment Sources and Treatment Destinations
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Cost Per Unit Distance
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Cumulative Travel Cost Map
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Evaluating Marginal Costs of Treatment
Cell Costjk Travel Cjtimej Search Cjarea
Treat Cjkarea j location
ktreatment method
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Marginal Cost Surface(time-dependent costs)
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Comparing Costs and Kill Efficiency
sparse
dense
Sparse Infestation   Dense Infestation
8.8 Total Cost 31.2
0.5 Marginal Cost 1.4
227.4 Total Treatment (m2) 6,628.0
73.1 Marginal Treatment 366.0
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Uncertainty of Returns from Treatment Reversibilit
y of Decline
Ecosystem Service Benefits
Site A
p
Risk of Treatment Failure
Intensity of Invasion
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Transferring Results to Risk Analysis for Recent
Invasions

• How well do GIS databases perform for doing this
  type of modeling?
• What were the main factors contributing to cost
  of control and degree of impact?
• How does an evaluation of cost-effectiveness
  change with the scale of analysis?
• How do costs of control and level of impact
  change through time?
• How have transitions in land uses (e.g.,
  recreation vs. rangeland) changed our perception
  of the impacts of cheatgrass?
• Given our current values, when, in the
  progression of the cheatgrass invasion, would
  treatment have been the most cost-effective?