Author:
Bartlein P. J.,Webb T.,Fleri E.
Abstract
Mapping of Holocene pollen data in the midwestern United States has revealed several broadscale vegetational changes that can be interpreted in climatic terms. These changes include (1) the early Holocene northward movement of the spruce-dominated forest and its later southward movement after 3000 yr B.P. and (2) the eastward movement of the prairie/forest border into southwestern Wisconsin by 8000 yr B.P. and its subsequent westward retreat after 6000 yr B.P. When certain basic assumptions are met, multiple regression models can be derived from modern pollen and climate data and used to transform the pollen record of these vegetational changes into quantitative estimates of temperature or precipitation. To maximize the reliability of the regression equations, we followed a sequence of procedures that minimize violations of the assumptions that underlie regression analysis. Reconstructions of precipitation during the Holocene indicated that from 9000 to 6000 yr B.P. precipitation decreased by 10 to 25% over much of the Midwest, while mean July temperature increased by 0.5° to 2.0°C. At 6000 yr B.P. precipitation was less than 80% of its modern values over parts of Wisconsin and Minnesota. After 6000 yr B.P. precipitation generally increased, while mean July temperature decreased in the north, and increased in the south. The time of the maximum temperature varies within the Midwest and is earlier in the north and later in the south.
Publisher
Cambridge University Press (CUP)
Subject
General Earth and Planetary Sciences,Earth-Surface Processes,Arts and Humanities (miscellaneous)
Reference37 articles.
1. Postglacial climatic change
2. Transfer functions;Lofgren;Climate from Tree Rings,1982
3. Evidence of Stream Response to Holocene Climatic Change in a Small Wisconsin Watershed
4. Mean July temperature at 6000 yr B.P. in eastern North America: Regression equations for estimates from fossil pollen data;Bartlein;Syllogeus,1984c
5. The Contemporary Distribution of Pollen in Eastern North America: A Comparison with the Vegetation
Cited by
256 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献