JACK WILLIAMS

Research Associate
PhD, 1999, Brown University
 

Limnological Research Center
Department of Geology and Geophysics
University of Minnesota
310 Pillsbury Drive SE
Minneapolis, MN 55455

Office: 212 Pillsbury Hall
Phone: (612) 626-0401
Fax: (612) 625-3819
Email: willi477@umn.edu   

My general area of interest is vegetation dynamics and the couplings between the terrestrial biosphere and other components of the earth system at timescales of decades to millennia.  Much of my recent work has focused on mapping vegetation history and land cover change in North America, using networks of paleoecological records, with the goal of developing benchmark datasets for refining and testing earth system models.  The Quaternary is a particularly interesting time to study because 1) it included large variations in climate, atmospheric CO₂, insolation, and ice sheet extent that transformed the distribution of plant taxa and the structure and function of terrestrial ecosystems, 2) numerous well-dated paleoclimatic and paleoecological records enable spatially explicit reconstructions of vegetation and climate history, and 3) Quaternary history sets the context for present-day biogeographic patterns and current challenges in global change research. 

At present my colleagues and I are investigating the effect of Holocene land-cover change in eastern North America upon regional atmospheric dynamics and climate variability.  Other research interests include the ecophysiological effects of reduced atmospheric CO₂ concentrations, vegetation responses to abrupt climate change, and understanding how novel communities arise from species-level responses to climate change. 

Webb, T., Shuman, B. N., Williams, J. W. (2004)  Climatically forced vegetation dynamics in eastern North America during the late Quaternary period.  The Quaternary Period in the United States.  Edited by Gillespie, A. R., Porter, S. C., Atwater, B. F.  Elsevier, pp. 459-478.  (Introduction)

Williams, J. W., Shuman, B. N., Webb, T., III, Bartlein, P. J., Leduc, P.(2004) Quaternary vegetation dynamics in North America:  Scaling from taxa to biomes.  Ecological Monographs 74: 309-334.   (Abstract and Figure PDFs) (Request Reprint)

Jackson, S. T. and Williams, J. W. (2004) Modern analogs in Quaternary paleoecology:  Here today, gone yesterday, gone tomorrow? Annual Review of Earth and Planetary Sciences 32: 495-537. (Request Reprint)

Williams, J. W. (2003)  Needleleaved and broadleaved tree cover distributions in North America since the Last Glacial Maximum.  Global and Planetary Change 35:  1-23. (Request reprint)

Williams, J. W., Post, D. M., Cwynar, L. C., Lotter, A. F., Levesque, A. J.  (2002) Rapid vegetation responses to past climate change.  Geology 30:  971-974. (Request reprint)

Williams, J. W., Shuman, B. N., Webb III, T. (2001) No-analog conditions and rates of change in the climate and vegetation of eastern North America.  Ecology 82:  3346-3362.  (Request reprint)

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