Goals• Develop models to relate “stream health”

to land use change and climate change• Parameterize models using data from study sites,

past work, and newly proposed experiments

What do we mean by stream health?

Includes human values: ecosystem services clean water for drinking, agriculture, recreation, etc. (fishable/swimmable waters)

supported by biota and ecological processes

Ecosystem structure Ecosystem function

Structure water quality

Biotic diversity & abundance

habitat diversity

Ecological Metrics

Function nutrient uptake

primary productiondecomposition

Ecosystem structure

Ecosystem function

0

5

10

15

20re

ach

up

take

/ flu

x

nwb pb hr cc

nwb 7.126518474 2.884044033

pb 8.407912416 4.611403302

hr 4.78378811 6.592018536

cc 12.63783059 4.290335524

N reach uptake/flux P reach uptake/flux

Ecological model development

• This project: Ecological structure

– Habitat Models

• Proposed project: Ecological Function– Primary production

– Decomposition

Primary Production

Inverts Fish

Decomposition

Riparian Vegetation

Sediments

Nutrients

LightTemperature

Climate Change Land Use Change

Light

Flow PP I F D

PP I F D

PP

PP D

PP I F D

I D

The Big Picture

Three Modelling Tasks

• Step 1: Model the inputs– Temperature, substrate, siltation, – High flows, low flows, nutrients, organic matter

• Step 2: Use the inputs to model habitat

• Step 3: Simulate spatial linkages– One-way flow– Hierarchical structure– Watershed and Buffer inputs

Umbrella Suite of Species

• Siltation: Rosyside Dace

• Algae: Central Stoneroller

• Inverts: Tessellated Darter

Lambeck 1997: “Focal Species: a Multi-Species Umbrella for Nature Conservation”

Habitat Suitability Models

Turbidity

0 Suit

abili

ty 1

Estimates of “Suitability” of various conditionse.g., – Current velocity – Depth– Percent riffles, pools– Substrate composition– Temperature – Percent cover– pH, oxygen– Turbidity

0 Suit

abili

ty 1

Avg water temp

Example: Longnose Dace

40 75cm/s

Avg current velocity

1m

Max riffle depth

50%

% riffles

10 20 30

Avg max temp in riffles

50%

% appropriate substrate

50%

% cover

HSI = minimum score = 0.5

1

SI

0

1

SI

0

Siltation

Flood events: frequency, intensity, timing, refuges

impose mortality

Particle Size: gravel

constrains spawning

Baseflow: velocity distributions

determines energetic costs and feeding success

Temperature

affects growth rate and reproduction

Riparian zone:

Leafy Debris inputs

Wood / Roots / Flow obstructions

Rosyside Dace

A drift-feeder, sensitive to siltation and flooding

Going beyond Habitat Suitability Models

• Want to evaluate habitat in a spatial context (land use change)

• Want to evaluate habitat over time (climate change)

• Want to estimate uncertainty / risk(chaining models)

Spatially Explicit Index Models (SESI)

Three Modelling Tasks

• Step 1: Model the inputs– Temperature, substrate, siltation, – High flows, low flows, nutrients, organic matter

• Step 2: Use the inputs to model habitat

• Step 3: Simulate spatial linkages– One-way flow– Hierarchical structure– Watershed and Buffer inputs

Spatial Structure of a Stream

• One way flow

Spatial Structure of a Stream

• One way flow

• Hierarchical structure

Spatial Structure of a Stream

• One way flow

• Hierarchical structure

• Watersheds

Spatial Structure of a Stream

• One way flow

• Hierarchical structure

• Watersheds

• Riparian Buffers

Spatial Structure of an Urban Stream

• One way flow

• Hierarchical structure

• Watersheds

• Riparian Buffers

• Pipe network