Journal of Paleolimnology

, Volume 17, Issue 4, pp 369–376

Human disturbance and trophic status changes in Crystal Lake, McHenry County, Illinois, USA

  • Yangdong Pan
  • Richard Brugam

DOI: 10.1023/A:1007952403488

Cite this article as:
Pan, Y. & Brugam, R. Journal of Paleolimnology (1997) 17: 369. doi:10.1023/A:1007952403488


The paleolimnology (sediment chemistry, 210Pb dating, pollen, and diatoms) of Crystal Lake, McHenry County, Illinois, USA was studied to investigate the impact of European settlement on lake trophic status. Pollen clearly indicates a vegetational shift from Quercus dominance to Ambrosia. 210Pb dating suggests that the Ambrosia rise likely occurs around the 1840's, which is consistent with historical records on the European settlement in this area. Coincident with the vegetational shifts, several diatom species, Cyclotella meneghiniana, Fragilaria crotenensis, Asterionella formosa and Tabellaria fenestrata, all increase while C. comta decreases after the settlement. However, C. comta and Aulacoseira ambigua, two dominant species, remain abundant throughout the entire core. Their relative abundances at the surface sediments reach presettlement levels. It is hypothesized that Crystal Lake, a glacial lake rich in CaCO3, may have been able to assimilate increases of phosphorus by coprecipitating phosphorus with CaCO3. Such a 'buffering mechanism’ may be responsible for the lake's resistance to trophic changes or recovery following disturbance.

Ambrosia CaCO3 diatom European settlement Illinois 210Pb lake trophic status pollen 

Copyright information

© Kluwer Academic Publishers 1997

Authors and Affiliations

  • Yangdong Pan
  • Richard Brugam

There are no affiliations available

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