Tim Asplund, Buzz Sorge (WI DNR) The Importance of Healthy Riparian Areas and their Current Status in Wisconsin Tim Asplund, Buzz Sorge (WI DNR) Advanced Lake Leaders – Green Lake Sept. 26, 2013 Courtesy of MN DNR
Lakeshore zone Shallow zone Complexity: The degree to which both lakeshore and shallow zones are intact. Complex habitats facilitate movement of food into and out of lakes, provide shelter and nesting areas for fish an wildlife, and buffer human impacts. Disturbance:
Shorelands and Shallows
Shorelands and Shallows
Shorelands and Shallows
Shorelands and Shallows
SHORELINE DEVELOPMENT
Shoreland Assessments Riparian Habitat Vegetation cover Shoreline and bank Trees and shrubs Littoral Habitat Bottom substrate Aquatic plants Fish habitat Human Influences Docks, piers, seawalls Buildings, lawns, driveways
Data: U.W. BioComplexity project
Fish grow ~3X faster in lakes with lots of woody habitat Undeveloped Undeveloped log Growth Rate (mm/yr) Low Development Low Development High Development High Development Woody Habitat (no./km) From Schindler et al. 2000
FLOATING-LEAF VEGETATION Jennings et al 2003
Shorelands and Shallows
Shorelands and Shallows
Shorelands and Shallows
2007 National Lake Assessment 15
Poor Biology is Three Times More Common when Lakeshore Habitat is Poor Regional summary: Northern Plains, Coastal Plains and Xeric have highest proportion of lakes with poor habitat conditions While Northern Appalachian exhibits the highest proportion of lakes with high-quality habitat, > 25% of lakeshores are in poor condition 16
National Lake Assessment (P-Hab) method
Habitat assessment plot (P-hab) Benthic Sampling
1. Littoral Habitat
Canopy Understory Groundcover 2. Riparian Zone
3. Shoreline
4. Human Development Building Pier Lawn
55 individual habitat metrics captured at each site (550/lake).
NLA Physical Habitat and Human Disturbance Indices Riparian (Lakeshore) Vegetation Cover Index Littoral Habitat Cover Index Littoral Habitat and Lakeshore Vegetation Complexity Index Riparian Disturbance Intensity and Extent Index
Protocol Littoral Zone Riparian Zone Both Bottom substrate Aquatic macrophytes Fish cover Canopy Understory Ground cover Shoreline substrate Human influence Bank features Invasive species Riparian Zone Both
Condition of the Nation’s Lakes: Habitat * *) NLA Primary indicator is Lakeshore Habitat
Condition of the Nation’s Lakes: Habitat
Stressors to the Nation’s Lakes: Extent, Relative Risk, and Attributable Risk #1 – Lakeshore vegetation: Poor biology is three times more common when lakeshore vegetation cover is in poor condition. This affects 36% of lakes. #2 – Nutrients: Poor biology is 2.5 times more common when nutrients are high. This affects about 20% of lakes. 28
Riparian Disturbance
Littoral Cover Index
Lakes sampled for shore habitat in 2012 and 2013
Goals of 2013 National Lake Assessment Lakeshore Sampling expand the assessment of lakeshore habitat condition across Wisconsin analyze lakeshore habitat condition in terms of lake area and surrounding land use Compare macrophyte survey methods: point-intercept vs. transect develop ecoregion-specific lakeshore habitat metrics for Wisconsin Incorporate lakeshore habitat metrics into WisCALM and Citizen Lakes Monitoring use lakeshore habitat metrics in addition to trophic status to assess lake health
Putting it together – Setting lake specific objectives and management strategies Poor Impaired/ UAA Fair Watch List Good Maintain Condition Excellent Consider for O/ERW TSI LittRipVeg AMCI Objective Box plots: All lakes in a given natural community and/or ecoregion Lake Condition Metrics (Water Quality, Plants, Shorelands, etc )
Lakes sampled for shore habitat in 2012 and 2013
Restoring Complexity and Functional Values of Shorelands
Reference Developed/Control Developed/Treated Found – Post Crystal – Post Total Number Figure 3. Initial habitat structure at vegetation plots along reference shorelines on undeveloped lakes (n=5) as compared to vegetation plots at control shorelines on developed lakes (n=5) and treated shorelines (shorelines selected for habitat restoration) on developed lakes (n=5). Also, conditions at 2 “treated” lakeshores, two to three years after planting (Found and Crystal). \ Figure 4. Initial forest canopy closure at vegetation plots along reference shorelines on undeveloped lakes (n=5) as compared to canopy closure at vegetation plots at control shorelines on developed lakes (n=5) and treated shorelines (shorelines selected for habitat restoration) on developed lakes (n=5). Starrett/Crystal Escanaba/Found White Sand/Lost L. St. Germain/Star Moon/Jag % Canaopy Closure