Collaborative Research: A Late-Glacial Model System for Studying Fine-Scale Vegetational Responses to Abrupt Climate Change

点击翻译按钮获取中文摘要

Because of rising concentrations of greenhouse gases, climate models predict future climates that are different from anywhere on Earth today, in other words, they have no modern analog. Such predictions greatly confound efforts to predict vegetation response because most climate-vegetation models rely on analog climates. The late-glacial period in the Midwestern United states, approximately 15,000 to 11,500 years ago, was also a time of non-analog climate and vegetation. Relative to today, plant communities with unusual associations of species dominated the landscape. These "non-analog" communities present an ideal opportunity to investigate fine-scale response to rapid climate change under conditions outside the modern envelope and to test models designed to predict vegetation responses to climate change. This project will employ a multiproxy approach to environmental reconstruction, involving fossil pollen for vegetation reconstruction, vegetation modeling to elucidate climatic drivers, and hydrologic reconstruction as an independent check on moisture balance.This study will establish the temporal correlation of late-glacial ecosystem change in the upper Midwest with the North Atlantic region, a subject of long debate. It tackles one of the outstanding problems in paleoecology, non-analog fossil assemblages. The modeling techniques proposed are designed to predict biotic response to climates outside the modern envelope, climates that greenhouse warming may well produce and for which predictive modeling is crucial.