John (Jack) Williams
Interests: Jack began his doctoral studies at Brown University in the fall of 1994 and defended his dissertation in July, 1999. His dissertation title is Biome-scale vegetation dynamics in North America since the Last Glacial Maximum Maps and reconstructions from fossil pollen data and the testing of biogeography models. In September, Jack moved to Santa Barbara to begin a 2-3 year research postdoc at the National Center for Ecological Analysis and Synthesis (NCEAS).
Research interests include paleoecology, paleoclimatology, biogeography, and carbon cycling. At Brown, Jacks research has centered upon mapping out the past distribution of biomes in boreal and eastern North America on the basis of fossil pollen evidence (A biome is an ecological community whose limits are primarily set by climate; biomes are mapped on sub-continental to global scales). Biome maps have been produced at 1,000-year intervals starting with the last glacial maximum (21,000 years before present) and moving forward to the present. These maps offer the opportunity to explore the effects of the independent migrations of plant taxa during the late Quaternary upon the stability and composition of plant communities. Selected biome maps have been applied to test paleo-vegetation simulations produced by biogeography models (BIOME3 and BIOME1). At NCEAS Jack will be attempt to estimate the amount of carbon stored in late-Quaternary terrestrial ecosystems of North America, using the pollen-derived biome maps in conjunction with the biogeochemistry model BIOME-BGC. Visit Jack's web page at NCEAS for more details on his current projects.
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