Space, Relativity, and Uncertainty in Ecosystem Assessment of Everglades

Restoration Scenarios

Michael M. Fuller, Louis J. Gross,

Scott M. Duke-Sylvester, and Mark Palmer

Background and Need

General Approach to Scenario Comparison

Specific Example: Everglades Restudy Area

Multi-Species Approach

Methodology

Results of Analysis

Summary & Conclusions

Relative Assessment of Management Scenarios

Balancing the needs of multiple stakeholders

Policy decisions based on inputs from:

• Urban Resource Agencies (water districts, air quality depts, etc)• Farmers and Industry (fisheries, timber companies, etc).• Conservation Organizations (Audubon, NRDC, etc.)• Governing Bodies (municipal, county, state, federal - politcal)• Natural Area Managers (National Parks, etc)

Natural systems are complex; Uncertainty is highProblem:

Solution: use models to:

Better understand natural systems.

Test sensitivity of system to different variables.Forecast future state of system.

Models can have complex structure

EXAMPLE: SESI ModelAlligator & Everglades Hydrology

• Many potential sources of error

• Reproduction: nesting, mating

• Many parameters

• Spatially Explicit Species Index

• Several alternative hydrology plans

Evaluate variation in input data or parameter settings

Incorporate uncertainty into analyses using hypothetical data

SA used to rank alternative management plans.

Scenario Analysis

Predict effects of alternative management plans.

Investigate changes in conditions or environmental impacts.

Evaluate variation in input data or parameter settings

Incorporate uncertainty into analyses using hypothetical data

SA used to rank alternative management plans.

Scenario Analysis

PROJECT (forecast) effects of alternative management plans.

Investigate changes in conditions or environmental impacts.

SA assumes that interactions between model components, and error propagation, is similar for different scenarios,

Uncertainty in how models respond toalternative scenarios can expose policydecisions to unexpected system behavior.

How can we reduce uncertainty?

A tool for testing the assumptions about model behavior.

Relative Assessment

Does rank order of management plan change with different Input data or parameter scenarios?

Reduce uncertainty of model behavior

Comparison requires a specific assessment criterion

A metric for ranking alternatives in order of preference

Using relative assessment for Everglades Restoration

• Does rank order of alternatives change?

• Compare alternative hydrology plans under consideration.

• Scenario analysis used to rank alternatives

• Relative assessment to reduce uncertainty.

General Approach

• Vary the input data and parameter settings.

• Multi-species comparison.

Central and South Florida Project Comprehensive Review Study

Three natural areas in southern Florida:

Two management alternatives: F2050 & D13R

Study System

• Everglades National Park• Big Cypress• Restudy area

F2050 = Baseline

4 Species + 2 wading bird guilds

ATLSS Spatially Explicit Index Models

Study System

Assessment Criterion

Species and Geographic Subregions

Subregion Species Affected Subregion Description

R1American alligator

and Snail kiteWater Conservation areas 3A and 3B

R2 Snail kite Water Conservation areas 1, 2A, 2B

R3 American alligator Shark River, NE Shark River, and Taylor Sloughs

R4 Wading Birds Central Rookeries

R5 Wading Birds Southern Rookeries

R6 Cape Sable seaside sparrow Core area

R7 Cape Sable seaside sparrow Western area

R8 Cape Sable seaside sparrow Eastern area

R9 White- tailed deer Everglades National Park

R10 White- tailed deer Big Cypress

Constructing Alligator Nest Parameter Scenarios

x 100

Average SESI ValueRepeat for

each subregion

Spatially ExplicitHabitat Index

(SESI)

Repeat for each hydrology scenario (F2050 & D13R)

HydrologyScenario

GeographicSubregion

SESI Model

Test Values

30 years of Historic Water Levels

Change values ±20 percent

9 nesting parameters

Baseline Values

Average over space & time

Constructing Climate I Data

30 year historic base pattern

Select 5 wettest years

Randomly reorder selected years

Repeat 5 more times

Combine into 30 year sequence

Repeat 27 more times

Calculate a mean SESI value for each 30 year sequence, for eachhydrologic plan, and a global mean for eachplan.

1

2

28

Calculate a differencein global means. -0.0428

D13R F2050

0.13660.13660.1367

0.1366

0.15350.15340.1534

0.1535

123

28

Count

Hydrologic Plan

Long Wading Bird SESI

0.2291 0.2719Grand Mean

All species groups.

Criterion: SESI Value

Difference between F2050 & D13R

Average over space & time

Constructing Climate II Data

Simulate 30 years of water level data.

1) Increase rainfall by 25 percent

2) Decrease rainfall by 25 percent

Baseline Data: 30 year historic pattern.

Experimental Data

Comparison for all species groups.

Criterion: SESI Value

Difference between F2050 & D13R D = F2050 - D13R

Summary of Scenarios and Treatments

Scenario Taxon Treatment

Nesting Parameter

VariationAlligator

Parameters randomly changed in the range of ±20% and

±30% of standard settings.

Climate Change I All 6 TaxaResampling and permutation of historical climate data to

create 3 climate themes: wet, dry, and average climate.

Climate Change II All 6 Taxa Baseline ±25 percent random variation in water levels.

Effect of Random Variation in Model Parameters30 Percent Variation

Difference between Alternative Scenarios (SESI)

20 Percent Variation

R1 R1

R3

10

20

30

40

10

20

30

40

.026 .028 .030 .032 .034 .036 .038

R1 = Water conservation areas 3A and 3B

R3 = Shark river, NE Shark river, and Taylor slough

No rank reversals

D = F2050 - D13R

Climate Change Effects

Difference between F2050 & D13RCriterion: SESI Value

D = 0 (No difference)

Baseline

Increase level

D = F2050 - D13RD13RF2050

Decrease level

For each species:D < 0D > 0

Effect of Simulated Climate on Scenario Ranking

Difference in SESI (D13R - F2050)

White-TailedDeer

AmericanAlligator Snail Kite

Cape Sable Seaside Sparrow

Long-LeggedWading Birds

Short-LeggedWading Birds

Effect of Simulated Climate Shift on Scenario Ranking

Difference in SESI (D13R - F2050)

White-TailedDeer

AmericanAlligator Snail Kite

Cape SableSeaside Sparrow

Long-LeggedWading Birds

Short-LeggedWading Birds

Summary of Effect on Rank Order of Hydrologic Scenarios

Taxon Scenario Type

Percent of scenarios

that rank

F2050 > D13R

Percent of scenarios that reverse

the rank order of F2050 & D13R

relative to base scenario.

Alligator ≤20% Parameter Variation None None

Alligator ≤30% Parameter Variation None None

All Ta xa Climate Change I 54.17% 25.93%

All Ta xa Climate Change II 53.71% 30.55%

Substantial variation in parameters = no reversals in rank order

Substantial variation in rainfall pattern = reversals in rank order

American Alligator

All Species Groups

Recap

• Compare rank order of alternatives.

• Compare alternative hydrology plans.

• Scenario analysis useful for ranking alternatives

• Relative assessment helps reduce uncertainty.

Summary

• Construct hypothetical climate patterns from historic data.

General Approach

• Change in climate patterns caused some rank reversals.• Alligator SESI not affected by parameter variation

Results

• Randomly vary nesting parameters (alligator).