An Analysis of the Effects of Fluctuating Water Levels on Littoral Zone Macrophytes in the Namakan Reservoir/Rainy Lake System, Voyageurs National Park and The Flora of Voyageur National Park
Monson PH. 1986. An Analysis of the Effects of Fluctuating Water Levels on Littoral Zone Macrophytes in the Namakan Reservoir/Rainy Lake System, Voyageurs National Park and The Flora of Voyageur National Park. University of Minnesota, Duluth. Duluth, MN
In the Rainy Lake / Namakan Reservoir System in Voyageurs National Park, Minnesota, annual water level fluctuations average 3.6 feet in Rainy Lake and 9.3 feet in Kabetogama, Namakan and Sand Point Lakes. To study the effects of these fluctuations on littoral zone macrophytes, biomass samples were obtained from eleven selected sites during the summers of 1982 and 1983. The data available as the result of these field studies includes site characteristics and above-substrate biomass for each species of plant in each of four 0.25 square meter quadrat samples of emergent, floating-leaf, and submerged zone macrophytes at each site. Data were examined in comparison with previously published records of the effects of fluctuating water levels on aquatic macrophytes, by a standard analysis of variance, in an adaptation of Morisita's Index of Community Similarity, and by Detrended Correspondence Analysis. The picture which emerges includes a number of inconsistencies but there is little to suggest that the aquatic macrpohytes in these four lakes are responding differentially to the annual water level fluctuations. It is suggested that the inconsistencies which occur might be explained on the basis of inadequacies in the sampling effort and by the fact that there is no consistency in either the magnitude or timing of the annual water level fluctuations. This a final report (US DOI, NPS Contract #CX-6000-2-0039). Appendices contain field data summary for each site including 1) site location and physical characterisitics, 2) biomass values for each species and zone, 3) calculated importance value for each species, and 4) basic statistics.
- Type
- Unpublished Report
- Authors
- Monson, Paul
- Date of Issue
- 1986-06
- Publisher
- University of Minnesota, Duluth
- Units
- VOYA
- Keywords
- Algae, Checklist, Flora, Herbaria, Impacts, Littoral Zone, macrophytes, Minnesota, Voyageurs National Park, Water Level