Western Great Lakes regional paleoenvironmental changes: island and inland contrasts
Winkler MG, Sanford PR, Cole KL, Flakne RL. 1997. Western Great Lakes regional paleoenvironmental changes: island and inland contrasts. Bulletin of the Ecological Society of America. 78(4):208
Pollen, charcoal, diatom, and cladoceran analyses of radiocarbon-dated lake sediment cores from Voyageurs National Park, MN, Apostle Islands National Lakeshore, WI, Lac du Flambeau Tribal Lands, Wisconsin, and Isle Royale, Michigan, provide information on spatial and time transgressive vegetation and climate changes since deglaciation. Microfossil stratigraphies demonstrate that island sites are younger and have changed less during the Holocene than inland sites. At inland lakes, proximity to the Great Lakes also moderates Holocene fluctuations and imposes a lake-climate signal different from that interpreted from sites farther south and west of the Great Lakes. Changes in upland vegetation and within-lake biota are most dramatic and more frequent during the late-glacial and at the late-glacial/Holocene transition at inland sites. Diatom changes, including Fragilaria-rich and more alkaline earliest sediments (between 10 and 9 ka) identify the early Holocene expansion of large pro-glacial lakes in the region. Subsequent hiatuses in diatom deposition are possibly due to turbulence during times of transition and/or changes in groundwater input in some lakes. Post-European settlement changes in species composition and increased soot and metal deposition are found in all lakes.
- Type
- Journal Article
- Authors
- Winkler, Marjorie; Sanford, P; Cole, Kenneth; Flakne, Robyn
- Units
- ISRO
- Keywords
- Ecology, Global Climate Change, Paleoenvironment