Approaches to Ecological Assessment

Models R Us

Handout # 5

2

Class Objective

1. Provide student with a understanding of the relationship of models to their job and to Corps projects.

2. Provide student with an overview of general approaches.

3. Review homework assignment.

4. Describe key procedures:

HEP, IFIM, IBI, HGM.

3

What is your job?

The Corps objective:

• to contribute to (NER) increases in net quantity and/or quality of desired ecosystem resources. – Measurement of NER is based on

changes in ecological resource quality as a function of improvement in habitat quality and/or quantity and expressed quantitatively in physical units or indexes (but not monetary units).

Discuss Homework

• Best professional judgment• WRAP• HEP• HGM• IBI

Which can be used as input to Incremental Cost Analysis?

5

General approachesHow to assess function?

1. Best professional judgment

(Descriptive narratives)

2. Measure specific criteria

(e.g., water quality input/output, biomass, fish and wildlife populations)

3. Assessment procedure

(structured bpj models) (Handout # 5)

6

1. Best Professional Judgment

• Simple statements or icons– Function present or absent– Screening tool

• Narrative (usually cite literature)

• Rating (e.g., index, score 1-5, low, moderate, high)Discuss example of bpj developed in the class exercise (i.e. WRAP Handout # 3 pg 1)

7

Comments: Best Professional Judgment

Advantages:• Usually more rapid and cost effective.• May reveal things overlooked by other

approaches.Disadvantages:• Generally lacks documentation to support

rating.• Lack of set criteria leads to different scoring

of same site by different observers. • Less defensible.

8

2. Specific Criteria2. Specific Criteria

Identify and measure specific Identify and measure specific structural orstructural orfunctional criteria based on areas offunctional criteria based on areas ofconcern.concern.Examples: Surveys for rare and endangered species Water quality (nutrient levels, oxygen

levels, turbidity, temperature) Sediment sampling for contaminants

9

3. Ecological Assessment Procedure3. Ecological Assessment Procedure• No models - best professional judgment.

with a Descriptive Approach; i.e. some structure.

(e.g.) WRAP.

• Models -that describe function based on ecological structure (minimal sampling of organisms if any).

(e.g., HEP, HGM).

• Models -that describe habitat based on population data (extensive sampling of organisms).

(e.g., IBI).

Scale/context differ: landscape, ecosystem (site level), community models, or species specific. (Handout #6)

Review of key procedures

• Habitat Evaluation Procedure (HEP)

• Instream Flow Incremental Methodology (IFIM)

• Index of Biological Integrity (IBI)• “Wetland assessment”: Many

including the Hydrogeomorphic Approach (HGM)

Handout # 5

11

All of These Procedures Require Field Sampling

• For small project visual recon is okay.

• Large projects need randomized sampling.

• The sample represents the quantification of a subset of the whole multiplied by the spatial extent.

A sampling exercise will be conducted with the cultural resources module.

12

HEP

Provides a numerical index incorporating food, cover and breeding relationships indicative of a habitat’s carrying capacity for a given species.

13

HEP

Habitats: Upland, wetland,and aquatic habitats

Measures: habitat suitability

Units: HSI and HUs

Handout #4 page 5

14

15

16

HEP Strengths:

Objective Quantitative Standardized

nationwide Models tested and

available Can compare

different habitats

Limitations:

Habitat only Can manipulate result by

changing species Time consuming Does not

address functions.

17

Instream Flow Incremental Methodology (IFIM)

Instream flow methodology deals with the amounts of streamflow necessary to sustain instream values at acceptable levels.

18

PURPOSE: To assesses stream flow and stream habitat utility utilizing macro-habitats variables including temperature, water quality, channel structure, and measures of micro-habitat variables such as velocity, depth, and cover.

IFIM (Instream Flow Incremental Methodology)

19

20

Stream Transects = Hydraulic Controls

*Hydraulic controls form upstream an downstream boundaries of each cell.

*

21

Use computer programs, e.g., PHABSIM* and

HABITAT

1

23

*

*

Habitat Cells

HydraulicCell

22

IFIM

23

IFIMStrengths

Looks holistically

at the species

year-round life

requirements Quantifies habitat

values at differing

flows

Limitations

Expensive Limited number

of models Cold Water

Origins

24

PURPOSE: To assess the biological integrity (level of disturbance) of a habitat through samples of living organisms to evaluate the consequences of human actions on biological systems.

IBI (Index of Biological Integrity)

25

IBI (Index of Biological Integrity)

Habitats: streams, mud flats, wetlands, anddeepwater habitats

Measures: biological integrity

Units: IBI

IBI = sum of metric* scores

* A parameter with predictable and empirical patterns when plotted against a gradient of human disturbance.

26

Disturbed –DamagedDisturbed –Damaged

HealthyHealthy

Same Habitats Type

Same Habitat Type

27

Collecting organisms from selected assemblage (e.g., macroinvertebrates)

Activity TrapActivity Trap

Fixed Area SampleFixed Area Sample

Dip NetDip Net

Dip NetDip Net

28

0

10

20

30

40

50

Human Disturbance

Nu

mb

er

of

Ta

xa

MostLeast

Example of a Metric

29

0

10

20

30

40

50

Human Disturbance

Nu

mb

er

of

Ta

xa

MostLeast

5

3

1

Scoring a Metric

30

Example of Multiple MetricsValue Score Value Score

Number of Taxa 27 5 12 1% Water Boatmen 15% 5 60% 3% Erpodella 5% 5 40% 1% 3 Dominants 40% 5 70% 3# Midge Taxa 12 3 4 1# ETSD 6 5 1 1# Intolerant Taxa 4 3 0 1# Leech Taxa 4 5 1 1# Odonata Taxa 5 5 2 1# Snail Taxa 6 5 3 3

WIBI 46 16

A B

Wisconsin IBI

31

Different assemblages

AmphibiansAmphibians FishFish

MacroinvertebratesMacroinvertebrates

BirdsBirds

AlgaeAlgae

Vascular Vascular PlantsPlants

32

IBIStrengths:

Direct measurement of biological integrity

Accounts for multiple stressorsChemical, physical, &

biologicalHelps to diagnose

stressor(s) impacting biota

Limitations:

Shortage of most models

Non-biological functions not assessed e.g., flood storage, erosion control

Time consumingCannot compare

different habitat types

33

HGM (Hydrogeomorphic Approach)

Purpose: The HGM Approach utilizes reference wetlands as the means for establishing a scale, or index, against which other wetlands of the same type in a particular geographic area (reference domain) can be compared to determine their functional capacity.

34

HGM (Hydrogeomorphic Approach)

Habitats: Wetland

Measures: Functional capacity UnitsUnits: FCI and FCU

1 FCI x 1 acre = 1 FCU Functional Capacity Index: A comparison of

how well other wetlands in the region perform a particular function.

35

HGM Approach

Strengths:

ObjectiveQuantitativeSeveral functionsStandardized

nationwideRapid once

models ready

Limitations:

Model development time consuming

Cannot compare different wetland classes

Need to develop most models

36

Different purposes establish the basis for

different approaches ...

... thus leading to separate procedures.

37

Some of the Many Wetland Assessment Procedures

• AREM• Coastal Method• CT Method• Descriptive App. • EPW• HAT• HEP• HGM Approach• Hollands-Magee• IBI• Interm HGM• IVA• Larson Method• MDE Method

ME Tidal Method MN RAM MT Form NBM NC-CREWS NC Guidance NEFWIBP NH Method NJ Watershed Method OFWAM PAM HEP PFC RA

Rapid Assess Meth. Synoptic Approach VIMS Method WAFAM WCHE WET WEThings WHAMS WHAP WIRAM WQI WVA WRAP

38

Approaches used by other DistrictsApproaches used by other Districts Elizabeth River, Norfolk: - One HEP species (clapper rail) and best professional judgment for 7 functional values

DesPlains River, Chicago - floristic quality index, HEP, HGM, ……

South River, New York – HEP and EPW

St. Louis District – WHAG and AHAG.

East St. Louis project - HEP, tried HGM

New River, Huntington –IFIM

Whitney Point, Baltimore District – IFIM

39

Sage AdviceSage Advice

• Many ways to assess (bpj and beyond…).

• Carefully define your objectives.

• See what is used in your division.

• Always explore other possibilities.

• Finally note that environmental windows also apply to field data collection.