Assessment of wetland plant communities at Isle Royale National Park
Meeker J, Harris A, Hofman V, Judziewicz E, Marr J. 2007. Assessment of wetland plant communities at Isle Royale National Park. Great Lakes Network Reports. GLKN/2008/04. Great Lakes Inventory & Monitoring Network. Ashland, WI
Isle Royale National Park (ISRO) contains numerous named and unnamed lakes, stretches of protected Lake Superior coves, open peatlands, and miles of stream – all with a variety of wetland habitat. Over the 2003-2006 field seasons, we assessed these diverse wetlands guided by four main objectives. We sought to: 1) describe and establish a monitoring benchmark for the aquatic and shoreline communities of all named lakes, 2) characterize the floristic composition in open peatlands, 3) give the island a ‘bill of health’ relative to aggressive wetland invaders especially cattails (Typha spp.) and common reed (Phragmites australis), and 4) expand the known flora of the island by locating plant taxa likely but not yet documented. Relative to goal 1, we described three aquatic plant assemblages; the aquatic assemblages of Lake Superior bays differed from that of lakes less than 20 ha in size, and these, in turn, were different from lakes larger than 20 ha. For goal 2, we determined that peatland communities differed, as expected, along nutrient and water depth gradients, separating sedge meadow habitat from that of fens and bogs. For goal 3, we assessed 308 km of interior lake and Lake Superior bay shoreline, and determined that 1.2% was occupied by aggressive taxa. Finally for goal 4, thirteen new taxa were added to the flora of ISRO, including the aquatic lake cress (Armoracia lacustris) and Farwell’s water milfoil (Myriophyllum farwellii), both ranked as Threatened in Michigan. We believe that this snapshot in time of the wetland plant communities will better enable the parks to begin monitoring programs for these important wetland resources.
- Type
- Published Report
- Authors
- Meeker, Jim; Harris, Al; Hofman, Valena; Judziewicz, Emmet; Marr, Janet
- Date of Issue
- 2007-02
- Publisher
- Great Lakes Inventory & Monitoring Network
- Units
- GLKN , ISRO
- Keywords
- Absence (Biodiversity), Abundance (Biodiversity), Aquatic Plants, Distribution (Biodiversity), Isle Royale, Lake Superior, moose browse, Observations, peatland, phragmites, Presence (Biodiversity), Typha, Vegetation Inventory