Predicting Pleistocene climate from vegetation

C. Loehle
2006 Climate of the Past Discussions  
Climates at the Last Glacial Maximum have been inferred from fossil pollen assemblages, but these inferred climates are colder than those produced by climate simulations. Biogeographic evidence also argues against these inferred cold climates. The recolonization of glaciated zones in eastern North America following the last ice age 5 20 gave an advantage to pine and spruce, which are the dominant trees in the BPZ, and to herbaceous species over trees, which also fits the observed pattern. Most
more » ... rved pattern. Most temperate species could have survived across their current ranges at lower abundance by retreating to moist microsites. These would be microrefugia not easily detected by pollen records, especially if most species became rare. These results mean that cli-25 mate reconstruction based on terrestrial plant indicators will not be valid for periods with markedly different CO 2 levels. 980 CPD Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU 25 colder than the likely actual climates. Then these various types of evidence are shown to reconcile with effects of low ambient CO 2 . The focus of this study is largely eastern North America for the sake of concreteness, but no-analog vegetation found elsewhere 981 CPD Abstract Introduction Conclusions References Tables Figures Back Close Full Screen / Esc Printer-friendly Version Interactive Discussion EGU at the LGM can be explained by similar mechanisms.
doi:10.5194/cpd-2-979-2006 fatcat:na4unx3kt5cu5crhqe3rumbhle