Modeling and Measuring the Process of Watershed Change, and Implications for

FisheriesKarin E. Limburg

SUNY College of Environmental Science & Forestry

Supported by the Hudson River Foundation and National Science Foundation

Modeling and Measuring the Process andModeling and Measuring the Process andConsequences of Land Use ChangeConsequences of Land Use Change

Jon Erickson, Caroline HermansJon Erickson, Caroline Hermans University of VermontUniversity of VermontJohn Gowdy, Audra Nowosielski, John PolimeniJohn Gowdy, Audra Nowosielski, John Polimeni Rensselaer Polytechnic InstituteRensselaer Polytechnic InstituteKarin Limburg, Karen Stainbrook, Bongghi HongKarin Limburg, Karen Stainbrook, Bongghi Hong SUNY College of Environmental Science and ForestrySUNY College of Environmental Science and Forestry

CollaboratorsCollaborators::

David BurnsDavid Burns Dutchess County Environmental Management CouncilDutchess County Environmental Management CouncilEileen SassmanEileen Sassman Wappinger Creek Watershed Intermunicipal CouncilWappinger Creek Watershed Intermunicipal Council

The two paradigms…

The natural landscape (watershed) perspective vs the socio-economic perspective…

Separate, but in need of linkage!

EconomistAlfred Kahn

“The Tyranny of Small Decisions”

Bill Odum applied this to ecological

systems

“Connecting the dots”: linking economy, land use, and ecological effects

Watershed HealthLand-Use andDemographic Change

Biophysical

Land Use

Society

Community

Economy

Business

HouseH

EconomicStructure and Change

Individuals

• How does human activity create the demand for land use change?

• How does this demand change the spatial pattern of land use?

• How does land use change affect ecosystem health?

Research Questions

What does all this mean for coastal fisheries?

The Hudson River Watershed – site of

case study

Hudson River estuary

Geographic SettingGeographic SettingDutchess County, NY

3 assessment approaches, followed by integrative model

GOVERMENTGOVERMENT

OUTSIDEOUTSIDEWORLDWORLD

CAPITALCAPITALExportsExports

ImportsImports INDUSTRYINDUSTRY

HOUSEHOLDSHOUSEHOLDS

DepreciationDepreciation

InvestmentInvestment

ConsumptionConsumptionGoodsGoodsLaborLabor

Private GoodsPrivate Goods& Services& Services

PublicPublicServicesServices

County-Wide Stakeholder Workshop:

• Semi-Conductor Industry• Suburbanization• Loss of agriculture• Commuting (↑ traffic)

a) Model the economy with a Social Accounting Matrix

#1 in Value-Added#2 in Employment

Dutchess County

Semiconductor and relateddevices industry

b) Land use and demographic change

Quantifying Past & Present Condition

- Satellite maps, followed by…

- Ortho-rectified photos

- Land use interpretation

- Tax parcel maps

-Developed land use change model

Quantifying past & present condition, continued

c) Ecosystem health (and watershed

health) maintenance of biotic integrity, resistance and/or resilience to change in the face of anthropogenic disturbance (Rapport, 1992)

includes

physical and chemical environmental quality (e.g., stream temperature, conductivity, and element concentration), biotic condition (e.g., status of fish and macroinvertebrate communities)

Assessing watershed health:

The idea: organisms and ecosystems integrate and reflect the insults (or lack thereof) resulting from watershed-level processes

Some techniques have proven robust after 25+ years of testing; others in development

Indicators of ecosystem health can (should?) evaluate changes at levels of

•Ecological population•Community/habitat•Whole-system

Metrics may not all be additive, although many schemes designed that way

What we looked at:• physical habitat characterizations

• water chemistry

• biotic community structure (fish and macro-invertebrates)

• ecosystem function

Some results: how “healthy” are the Wappinger and Fishkill Creek watersheds?

(Fishkill is closer to NY City, more urbanized…)

Let’s look at a few diagnostics…

Land use patterns

Environmental quality patterns

Biological indicators

…includes changes over time

Assessments at different spatial scales(relates to the degree of influence)

Amount of land in different uses varied at different spatial scales

Per

cent

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Water quality – an example

Conductivity – a measure of the ionic strength of water

Correlates strongly with human disturbance (population density, road density, nitrates, etc.)

Getting recognition as a bellwether of aquatic disturbance

Hudson Valley, New York

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Wappinger Creek

Biotic responses

Fish Index of Biotic Integrity (IBI)

Use fish community characteristics to assess aquatic health – composed of 12 metrics, including

• Species richness & abundance

• Indicator species (of degradation, e.g.)

• Functional role ID

• Condition and health indices

IBIs originally worked out for Ohio streams – but are gaining popularity worldwide now

However, have to be regionally calibrated

We tested the relatively new northern Mid-Atlantic IBI (Daniels et al. 2002. Trans. Amer. Fish. Soc. 131: 1044-1060)

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Fishkill Wappinger

IBIs over time…

Similar results w/ macroinvertebrate

analyses

Stable Isotope Analysis.

A big field of research in everything from meteorology to archaeology, geology to food science, ecology to physiology

Basically a way to trace how elements move from one compound to another, or from one chemical state to another

In ecology, we often use Carbon and Nitrogen stable isotope ratios as tracers of matter in food webs – and can also be used to trace migrating animals – and things like pollution…

Less urbanized More urbanized

Stable isotope analysis of a “sentinel species” blacknose dace

Evidence of any threshold effects?

less urban more urban

Social Accounting Matrix(Input-output Model)

Binary Logit Regression Model

Integrating through models

Multiple Linear Regression Model

Nowosielski (2002) Polimeni (2002) Stainbrook (2004)

Simulation Result from Socio-economic Sub-model:2292 new jobs (1000 direct + 1292 indirect)

expected number of new jobs

124,549 “Tax Parcels” within Dutchess County

Land Use Change Sub-model

Properties of Tax Parcels

Reclassified: Residential vs Vacant

Input Spatial Dataset(Independent Variables for Binary Logit Model)

NeighborhoodIndex

Distance to Central Business District

Total Assessment

Value

Change in Income

Change in Population

Minimum Lot Size Requirement

Protected LandsSteep AreaWetlandsHydric Soils

Possible Restriction to Development

Predicted Conversion of Vacant Lands to Residential Usein Response to Economic Impact (%)

Expected Change in Land Use due to Economic Impact

NAWQA (National Water Quality Assessment) Dataset:Correlation with Percent Urban Land Use

correlation coefficient

Result from Ecosystem Health Sub-model:Reduced Stream Water Quality and Species Diversity

We are able to track the effects of economic activity in the watershed…but

what does this mean for coastal fisheries?

Chesapeake Bay

Mississippi R. watershed and “The Dead Zone”

It’s a matter of scale…

Image sources: NOAA and Virginia Inst. of Marine Science

Fish & Fisheries declines

Diaz, et al. 2004

Hypoxia increasing

Year1840 1860 1880 1900 1920 1940 1960 1980 2000 2020

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Nitrogen

Hypoxia

Eutrophication severity (chl)Pela

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Caddy 2000, de Leiva Moreno 2000

System-wide effects?

Eutrophication severity

Fish

eri

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Caddy 1993

hypoxia

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Nixon 2002

1850 1900 1950 2000

*not including dams missing dates

Dams Over Time*

Data from BASINS software

Is a new paradigm needed?

We (all of us!) need a new way of VALUING the environment.

Not just the $$$...

Connecting the dots…de rode draad

Evaluate ecosystem services…

Evaluate the trade-offs…

Thank you!