Aligning Methods for Assessing
Wetland Ecosystem Services
Anthony Dvarskas
NOAA Assessment and Restoration Division/IMSG
CNREP 2010
New Orleans, LA
Presentation Outline
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Components for ecosystem service assessment
Current methods available
Components of available approaches
Research needs, policy questions and next steps
Intermediate and Final Ecosystem Services
Figure from: Fisher B, et al. Ecological Applications. 2008; 18: 2050-2067.
Components of a Wetland Ecosystem
Services Assessment Tool
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Ecological element
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Human element
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Structure and function of ecosystem
Benefits to humans from given ecosystem structure and
level of function/provision of intermediate services
Ability to evaluate tradeoffs within and across
categories
Wetland Assessment Approaches
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Several procedures available for assessing ecological
components (physical and biological functions) from
multiple Federal agencies
Different contexts for use of techniques
Not all techniques consider both ecologic and human
elements
Biological assessment vs physical/functional assessment
Approaches generally do not assign a monetary value (is
this always necessary?)
Wetland Evaluation Technique (WET)
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Developed in 1980s (Adamus 1988)
Evaluates multiple functions (e.g., sediment stabilization,
nutrient removal/transformation)
Considers social significance, effectiveness, opportunity,
and habitat suitability of evaluated wetland
Arrive at probability that selected wetland function will
occur
Habitat Evaluation Procedure
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Developed by Fish and Wildlife
Service
Can compare areas in terms of
wildlife habitat
Relies on understanding of
species and habitat interaction
(use of Habitat Suitability Index
(HSI))
HSI X AREA HABITAT =
Habitat Unit
Habitat Evaluation Procedures. ESM 102. USFWS. 1980.
Habitat Evaluation Procedure (cont’d)
Habitat Evaluation Procedures. ESM 102. USFWS. 1980.
Hydrogeomorphic Method
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Developed by Army Corps of Engineers
Uses reference wetlands (e.g., natural in region of
interest)
Evaluates set of wetland functions through field
assessment
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Functional capacity index (FCI) – 0-1, 1 equals function at
same level as reference wetland
FCI X acres of habitat assessed = FCUs
Habitat Equivalency Analysis
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Developed by NOAA
Used in assessing ecological service gains and losses
resulting from injuries to natural resources
Metric(s) selected as proxy for habitat services
Discounting used to aggregate injuries over time
Output of discounted service acre-year (DSAY)
Interim Lost
Resource Services
Compensatory
Resource Services
B
Baseline
Service
Level
A
Resource
Services
Incident
Compensatory
Restoration
Begins
Time
Full Natural
Recovery
Indices of Biological Integrity
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Used in stream assessments
Have been applied in wetlands
Similarities to HEA approach
Identify assemblages, select set
of metrics, combine metrics into
index
Demonstrate change in index
with changing human disturbance
http://www.epa.gov/Wetlands/wqual/bio_fact/fact5.html
State Wetland Mitigation Ratios
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States also develop mitigation ratios
Different ratios for different wetland enhancements
(e.g., creation vs preservation), types of wetlands
impacted
Virginia DEQ example:
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2:1 forested wetlands
1.5:1 for scrub-shrub wetlands
1:1 for emergent wetlands
http://www.deq.state.va.us/wetlands/mitigate.html
Economic Analyses of Wetland Values
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Economic literature provides attempts to value
wetland ecosystem services
Benefit of using the metric of currency – widely
understood and consistent across areas
Challenge remains in transfer of monetary values from
one wetland to another (benefit transfer)
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Since values based on human perception and behavior,
can vary from region to region
Summary of Selected Methods
Method
Units Produced
Habitat Equivalency Analysis
DSAYs
Habitat Evaluation Procedure
HUs
Hydrogeomorphic Method
FCU
Wetland Evaluation Technique
Probability rating
Economic Valuation Methods
$$
Where do we stand?
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Range of methods that assess wetland ecosystem
functions/intermediate services
Different units produced from each assessment
method
No prescribed translation of those functions and
services described to final ecosystem
services/benefits to humans
Common Characteristics of Assessment
Methods
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Need to define area for assessment
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At baseline and under future conditions
Role of GIS in ecosystem services evaluation
Habitat types play key role
Selection of indicator metrics for analysis
Assessment of changes over time from impacts other
than policy
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What does the baseline trajectory look like?
Research Needs and Questions
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How to take information from assessments using different
scales and translate to a common method?
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How can information from an “aligned” method translate into
policy-relevant tradeoff information?
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Boyd and Banzhaf (Ecol Econ 2007) argued for standardized
methods of ecosystem service measurement
Making the leap between the functional analysis and the benefits
Need to consider intergenerational aspect of ecosystem service
valuation
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What is appropriate discount rate, if any?
Research Needs and Questions
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Metrics for policy decisions need to be in readily understandable
terms
Many wetland evaluation procedures rely on subjective evaluations
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Increased understanding of links between level of function and
societal values
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Additional data monitoring at wetland sites
How does assessment of function inform the value tradeoff determinations?
Ecological production functions?
How to link ecological and human components?
Mapping of relationship between ecosystem functions and human
well-being
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Work by EPA ESRP, USDA ERS and Natural Capital Project
Consistency vs Specificity
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Consistent and similar framework aids in accounting of
credits/potential expansion of markets
Consistent framework may create broad metrics that do not
capture specific regional characteristics
Will likely always be some tradeoff between consistency and
specificity
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How does this limit potential size of an ecosystem services market?
Carbon markets have developed frameworks and guidance with
formalized accounting procedures
Summary
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Multiple techniques available to assess wetland functions and,
in some cases, values
Ongoing need to link assessment of function and collected
ecological metrics to policy-relevant values
Need for further collaboration across Federal and non-Federal
entities that calculate restoration uplift
How to develop consistent tool that works across regions?
Contact info: Anthony.Dvarskas@noaa.gov