Lake St. Clair Coastal Wetlands in 2050: Modelling Wetland Community Responses to Climate Change Water Level Scenarios Joel W. Ingram 1, Linda D. Mortsch 2, Susan E. Doka 3, Andrea J. Hebb 2, Shawn W. Meyer 1, Krista L. Holmes 1 1 Canadian Wildlife Service, Environment Canada - Ontario Region 2 Adaptation and Impacts Research Group, Environment Canada 3 Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada
Today s Presentation Climate change models and projected changes in Great Lakes water levels Climate Change Action Fund Project: Objectives, study sites, elevation, marsh bird, and plant surveys Modelling for coastal wetland margins methods and results Implications on current and future coastal wetland conservation
Range of Climate Change Scenarios Temp. & Precip. Conditions (2050) 20 Mean Precipitation Change (%) 15 10 5 0 Not Not as so Warm && Wet Wet Not so Not Warm as & Warm Dry & Dry 0 1 2 3 4 5 6 7 Mean Temperature Change ( o C) Warm Warm & Wet & Wet Warm Warm && Dry Dry CGCM2 A21 CGCM2 A22 CGCM2 A23 CGCM2 A2X CGCM2 B21 CGCM2 B22 CGCM2 B23 CGCM B2X CCSR A11 CCSR A1Fl CCSR A1T CCSR A21 CCSR B11 CCSR B21 ECHAM4 A21 ECHAM4 B21 HadCM3 A1Fl HadCM3 A21 HadCM3 A22 HadCM3 A23 HadCM3 A2X HadCM3 B11 HadCM3 B21 HadCM3 B22 NCAR-PCM A21 NCAR-PCM B21 GFDL-R30 A21 GFDL-R30 B21 *CGCM1 gax *HadCM2 gax * Included for comparison only. Based on IS92a emission scenarios and a 20-year average. Source: L. Mortsch, M. Alden & J. Klaassen, Env. Can.
2050 Climate Change Water Level Scenarios Lake Basin Warm & Dry Change in Mean Annual Water Levels (metres) Not-as-Warm & Dry Warm & Wet Not-as-Warm & Wet Lake Ontario -0.75-0.46-0.60 0.06 Lake Erie -0.81-0.55-0.67-0.15 Lake St Clair -0.99-0.63-0.81-0.21 Lake Huron / Michigan -1.18-0.73-0.98-0.29 Lake Superior -0.36-0.20-0.33-0.12 Source: David Fay & Yin Fan, Env. Can.
Modelling Wetland Community Response
Climate Change Action Fund Project 1. Assess the vulnerability of Great Lakes coastal wetland communities to climate change 2. Adaptation options: Managed wetlands Field Study: Assess plant, bird, and fish communities in managed and unmanaged wetlands to evaluate habitat quality Evaluate whether managed wetlands may be used as a potential adaptation strategy to alleviate the effects of climate change on these wetland communities
Climate Change Action Fund Project 3. Modelling wetland vegetation and bird community response Construct Elevation Models for each wetland site Construct a Rule-Based Vegetation Community Response Model Considers water depth and duration of hydrologic condition Validate with historical wetland data Apply climate change scenarios to model future response Apply vegetation output as input for bird and fish models
Study Sites
Modelling Adaptability of Coastal Wetlands to Climate Change Evaluate ecological resiliency of unmanaged wetlands to respond to water level changes Wetland elevation models Promark 2 (GPS) Rule-Based Vegetation Community 200 points Response per wetland
Wetland Vegetation Communities High water levels: landward migration of vegetation communities Low water levels: lakeward migration of vegetation communities Treed/Shrub Meadow Emergent Floating Submergent
Modelling Adaptability of Coastal Wetlands to Climate Change Evaluate ecological resiliency of unmanaged wetlands to respond to water level changes Wetland elevation models Rule-Based Vegetation Community Response Input variables: (1) Water depth (growing tolerance) & (2) duration of hydrologic condition (years since dewatering/flooding)
Vegetation Model Rules Wetland Communities Water (W) Exposed Substrate (Ex) Floating Emergent (EF) Emergent (E) Meadow Marsh (M) Treed/Shrub (T)
Elevation Models: Mitchell's Bay (Promark 2) Legend Lake/ Open Water Exposed Substrate Emergent/ Floating Mixed Emergent Meadow Marsh Shrub/Treed Swamp 2002 47.05 ha
Mitchell's Bay (Base Case) High Water Yr Legend Low Water Yr Lake/ Open Water 90.76 ha 59.16 ha Exposed Substrate Emergent/ Floating Mixed Emergent Meadow Marsh Shrub/Treed Swamp
Mitchell's Bay (Base Case) High Water Yr Legend Low Water Yr Lake/ Open Water 90.76 ha 59.16 ha Exposed Substrate Emergent/ Floating Mixed Emergent Meadow Marsh Shrub/Treed Swamp 53.79 ha CC1 Warm / Dry 4.84 ha
High Water Yr Mitchell's Bay (Base Case) Legend 90.76 ha 59.16 ha Lake/ Open Water Exposed Substrate Emergent/ Floating Mixed Emergent Meadow Marsh Shrub/Treed Swamp Low Water Yr 80.22 ha CC3 Warm / Wet 10.19 ha
Wetland Response expansion of wetland vegetation communities is possible (seed bank present = growing conditions)
Wetland Response emergent marsh expansion restoration of a shrub/treed swamp community marsh meadow expansion
Wetland Breeding Bird Habitat Guilds Emergent Marsh Obligates Emergent Marsh Generalists Meadow Marsh Treed/Shrub Swamp Pied-billed Grebe Red-winged Blackbird Swamp Sparrow Yellow Warbler American Coot Yellow-headed Blackbird Common Snipe Song Sparrow Common Moorhen Common Grackle Savannah Sparrow Common Yellowthroat Black Tern Sand Hill Crane Sedge Wren Great Crested Flycatcher Forster's Tern Common Yellowthroat Willow Flycatcher Least Bittern Virginia Rail American Bittern Least Flycatcher Alder Flycatcher
Bird Abundance Models 12.0 16.0 Abundance (per hectare) Abundance (per hectare) 10.0 8.0 CCAF IJC 6.0 CCAF IJC 4.0 14.0 12.0 10.0 8.0 6.0 4.0 Emergent Marsh Marsh Nesting Obligates Generalists y = -1.586x 2 + 1.8744x + 3.853 y = -1.9654x 2 + 3.5718x + 1.1686 2.0 2.0 0.0 0.0-1.0-1.5-1.0-0.5-0.5 0.0 0.0 0.5 0.5 1.0 1.0 1.5 1.5 2.0 2.0 2.5 Water Depth (metres)
Bird Abundance Estimates in Meadow and Swamp Habitats For the purposes of this study fixed density estimates are being used to estimate habitat supply. Meadow marsh bird abundance, 3.7 birds/ha Tree and shrub swamp bird abundance, 5.6 birds/ha
High Water Yr 9.72 mno / ha Mitchell's Bay (Base Case) Low Water Yr 5.15 mno / ha
High Water Yr 9.72 mno / ha Mitchell's Bay (Base Case) Low Water Yr 5.15 mno / ha 5.79 mno / ha CC1 Warm / Dry 2.55 mno / ha
High Water Yr 9.72 mno / ha Mitchell's Bay (Base Case) Low Water Yr 5.15 mno / ha 6.51 mno / ha CC3 Warm / Wet 4.79 mno / ha
Coastal Wetland Conservation Considerations Proactive planning and policy Increased focus on conservation of physical integrity, natural processes and pathways
Coastal Wetland Conservation Considerations Natural resiliency to hydrologic change
Coastal Wetland Conservation Considerations Proactive planning and policy Increased focus on conservation of physical integrity, natural processes and pathways Long term costs to maintain values
Results Managed / Unmanaged Study Lake St. Clair: Managed wetlands = Unmanaged wetlands Marsh Nesting Obligates Maximum Abundance / Cumulative Species Richness per station 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 Managed Maximum Abundance Cumulative Species Richness Unmanaged Wetland Type
Results Emergent Vegetation Managed wetlands had: Lower exotic species richness Higher native species coverage Mean Species Richness 6.0 180.0 5.0 160.0 Mean Aerial Coverage per metre squared 140.0 4.0 3.0 100.0 2.0 1.0 120.0 80.0 60.0 40.0 20.0 * Native Species Native Exotic Species * 0.0 0.0 Managed Managed Wetland Type Wetland Type Unmanaged Unmanaged
Adaptation Options Evaluate the ability of managed wetland infrastructure to operate under low mean lake levels Elevation surveys Bathymetry data for channels and pumping infrastructure Engineering blueprints
Water Levels in Lake St. Clair Base Case Not-as-Warm/Wet Scenario Water Elevation (m) 176.10 176.00 175.90 175.80 175.70 175.60 175.50 175.40 175.30 175.20 175.10 175.00 174.90 174.80 174.70 174.60 174.50 174.40 174.30 174.20 174.10 174.00 173.90 173.80 173.70 173.60 1980 1985 1990 1995 2000 2005 Historic Threshold for water intake pipes Threshold for dredging channel 0 50 Projected 50 Year Hydrological Cycle Not-as-Warm/Dry Scenario WarmWet Scenario WarmDry Scenario Threshold for water intake pipes Threshold for dredging channel Year
Coastal Wetland Conservation Considerations Proactive planning and policy Increased focus on conservation of physical integrity, natural processes and pathways Long term costs to maintain values Restoration and management designs that are robust to variable hydrology
Preliminary Conclusions Potential Wetland for geomorphologic significant type alteration Predicted study of current site responses wetland are plant community distribution and abundance Wetland geomorphology strongly influenced wetland community response Marsh nesting obligate birds were vulnerable to predicted habitat changes
Modelling Limitations and Future Considerations Climate and water supply models Other climate change impacts Resolution, accuracy and extent of elevation data Constant bathymetry Generalized communities Additional environmental inputs Landscape/Basin level response
Additional Coastal Wetland Research Needs Nearshore data Shoreline mapping of habitats (biotic and abiotic) Coastal processes Nearshore bathymetry St. Clair / Detroit Rivers Ecological processes and habitat associations Multi-scale research Landscape models
Project Partners Adaptation Impacts Research Group, Environment Canada Canadian Wildlife Service, Environment Canada Maggie Galloway Paul Watton Lesley Dunn Nancy Patterson Fisheries and Oceans Canada Ken Minns Lynn Bouvier Carolyn Bakelaar Nick Mandrak Andrew Doolittle Charlene Rae University of Waterloo Peter Deadman
http://www.fes.uwaterloo.ca/research/airg/wetlands