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 structureEcosystem function

Structure water quality Biotic diversity & abundance habitat diversity Ecological Metrics Function nutrient uptake primary production decomposition Ecosystem structureEcosystem function

Ecological model development This project: Ecological structure – Habitat Models Proposed project: Ecological Function – P rimary production – Decomposition

Primary Production InvertsFish Decomposition Riparian Vegetation Sediments Nutrients LightTemperature Climate Change Land Use Change Light Flow PP I F D I F D D 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 Suitability 1 Estimates of “Suitability” of various conditions e.g., –Current velocity –Depth –Percent riffles, pools –Substrate composition –Temperature –Percent cover –pH, oxygen –Turbidity 0 Suitability 1 Avg water temp

Example: Longnose Dace cm/s Avg current velocity 1 m Max riffle depth 50 % % riffles Avg max temp in riffles 50 % % appropriate substrate 50 % % cover HSI = minimum score = 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