Natural Shoreline Landscapes on Michigan Inland Lakes

Transcription

1 Natural Shoreline Landscapes on Michigan Inland Lakes Excerpts from Chapters 2 and 3 Session topics Characteristics of natural and altered shorelines Lakes, shorelines, habitat and water quality Considerations when designing a natural shoreline Photo by Jane Herbert Photo by Jane Herbert Design ideas Michigan Natural Shoreline Partnership Did you know? Twenty-four species of amphibians, 25 species of reptiles, 87 species of birds and 19 species of mammals are supported by Michigan inland lakes. (O Neal & Soulliere, et.al., 2006) 1

2 2013 Lake and Stream Leaders Institute - Session 2 Three tiers of vegetation Tree canopy Shrub understory Herbaceous plants Aquatic, wetland and upland Natural Shorelines are stable shorelines Horizontal roots stabilize lake-bottom sediments Modified from: University of Minnesota Natural Resources Research Institute PROFUNDAL PROFUNDAL ZONE ZONE 2

3 Provides critical habitat for at least 65 native fish species. Spawning Nursery Feeding Predator avoidance Entire life cycle or seasonal use Twenty of these 65 fishes are considered to be Species of Greatest Conservation Need 1 1Michigan Wildlife Action Plan (2005) Lawn to the water s edge Loss of fish and wildlife habitat Nuisance animal habitat Shoreline erosion and hardening Loss of shade Deadwood removal Sandy beach maintenance Polluted stormwater Excessive plant growth and algae blooms Oxygen loss Recreation impacts Chemical treatment Results of a study of 44 Minnesota lakes indicate (on average) a 66% reduction in emergent and floating-leaf vegetation in the presence of shoreline development. Results of the same study indicate a positive relationship between the occurrence of emergent and floating-leaf vegetation and the abundance and size of certain fishes including: Northern pike Bluegill Pumpkinseed (Radomski and Goeman, 2001) Loss of tiered vegetation and shade 3

4 Reduce pollutants entering the lake Home Sweet Home Adapted From: Wisconsin DNR Runoff Volume Phosphorus Inputs Sediment Inputs 4x 5x Adapted From: Wisconsin DNR 6x In freshwater aquatic systems 1 unit of phosphorus can produce 500 times its weight in algae. (Wetzel, Limnology, 2nd Edition) 18x Identify the causes and sources at water s edge: Identify upland cause(s) and source(s): Cause: overland runoff Source: stormwater collecting on impervious surfaces Cause: Undercut bank and bank failure Source: Removal of long-rooted native vegetation plus prolonged and repeated high water levels (level controlled lake) 4

5 2013 Lake and Stream Leaders Institute - Session 2 Consequences on inland lakes PROFUNDAL ZONE Modified from: University of Minnesota Natural Resources Research Institute Wave energy flanking from neighboring sea wall MDNR IFR density development density development N = 250 Wave energy at vertical sea wall Littoral zone vegetation provides wave attenuation. 5

6 2013 Lake and Stream Leaders Institute - Session 2 Depends on: Fetch = Maximum uninterrupted distance across the lake from your location Water Depth Wind Speeds Other factors Wisconsin On-line Erosion Calculator Lake types 12 inches How high does the water get? Source: Four Townships Water Resources Council 6

7 Ice action along the shoreline Intensity and frequency can vary from year to year. Factors include: Freeze/thaw expansion and contraction Lack of snow cover and/or Spring ice-out (break-up) Rate of warm up Orientation of site to spring winds Shapes and reshapes natural shorelines Ice ridges: Lakes and shorelines come to a dynamic equilibrium Removal of ice ridge give the lake the advantage Result is shoreline recession Water Table Chapter 4: Design Ideas June 2009 Late Summer 2009 Lakefront Landscape: different approach. The upland and aquatic zones are outlined. (Source: MSU Extension) High Impact Lake Front Landscape. (Source: MSU Extension) Lake Front Landscape integrating a more manicured approach with buffers. (Source: MSU Extension) Summer 2010 Photos: Allegan Conservation District 7

8 Pop Quiz Video: Restoration of a low to moderate energy shoreline property Naturalize shorelines to restore habitat AND improve curb appeal Naturalize shorelines to restore habitat AND fix problem areas Photo: Jane Herbert 8

9 2013 Lake and Stream Leaders Institute - Session 2 Restore natural shorelines to restore habitat (for people, too) Questions? Natural shorelines can preserve and/or restore ecological benefits to our lakes. Photo: Jane Herbert 9