Aligning Methods for Assessing Wetland Ecosystem Services

Anthony DvarskasNOAA Assessment and Restoration Division/IMSG

CNREP 2010New Orleans, LA

Presentation Outline 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 Ecological element

Structure and function of ecosystem Human element

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 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) 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 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 Developed by Army Corps of Engineers Uses reference wetlands (e.g., natural in region of

interest) Evaluates set of wetland functions through field

assessment 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 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)

Time

Resource

Services

BaselineServiceLevel

Incident Full NaturalRecovery

A

Compensatory

Resource Services

CompensatoryRestoration

Begins

BInterim Lost

Resource Services

Indices of Biological Integrity 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 States also develop mitigation ratios Different ratios for different wetland enhancements

(e.g., creation vs preservation), types of wetlands impacted

Virginia DEQ example: 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 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) 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? 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 Need to define area for assessment

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 What does the baseline trajectory look like?

Research Needs and Questions How to take information from assessments using different scales

and translate to a common method? Boyd and Banzhaf (Ecol Econ 2007) argued for standardized

methods of ecosystem service measurement How can information from an “aligned” method translate into

policy-relevant tradeoff information? Making the leap between the functional analysis and the benefits

Need to consider intergenerational aspect of ecosystem service valuation What is appropriate discount rate, if any?

Research Needs and Questions Metrics for policy decisions need to be in readily understandable

terms Many wetland evaluation procedures rely on subjective evaluations

Additional data monitoring at wetland sites Increased understanding of links between level of function and

societal values 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 Work by EPA ESRP, USDA ERS and Natural Capital Project

Consistency vs Specificity 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 How does this limit potential size of an ecosystem services market?

Carbon markets have developed frameworks and guidance with formalized accounting procedures

Summary 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