Abrupt Climate Changes During the Holocene Across North America From Pollen and Paleolimnological Records

Abrupt Climate C Geophysical Mon Copyright 2011 b 10.1029/2010GM Databases of ecological and cultural records, especially of pollen diagrams, record climate variability of several time scales during the Holocene and late glacial. Results from lake and wetland ecosystems geographically extend the evidence of rapid climate change obtained from ice cores and ocean sediments. Continental and regional climate curves for North America, based on pollen diagrams from the North American Pollen Database, illustrate abrupt changes on the order of every ~1000 years during the past 12 kyr, and major times of change in North American pollen records are coherent with vegetation changes across Europe. Novel analyses of the database show that even taxa that are widespread and with presumably broad climate tolerances were affected by abrupt climate changes such as the Younger Dryas and illustrate the complexity of ecosystem response to these changes. Reconstructions of freshwater as well as terrestrial ecosystems across northern Canada also show how climate variability affects terrestrial and freshwater ecosystem-level properties such as nutrient cycling. These results can be used to reconstruct the spatial patterns of abrupt climate change, as well as the impacts of climate change on ecosystem and cultures.