Out of the Icehouse into the Greenhouse: A Late Paleozoic Analogue for Modern Global Vegetational Change

A change to global greenhouse conditions following deglaciation occurred during the late Paleozoic. The deep-past data set preserved in the stratigraphic record can serve as a model system to understand vegetational responses during this kind of climatic change, especially in the tropics. No other time in Earth history so mimics the late Cenozoic or provides the long-term data set from which generalizations can be deduced. Two long-term glacial cycles have been identified in Permian-Carboniferous time. The waxing and waning of glaciers during the height of either ice age resulted mainly in spatial displacement of vegetation, and also in minor variations in tropical climate. Brief intervals of rapid deglaciation at the end of the Middle Pennsylvanian (Westphalian) and mid–Early Permian (Sakmarian) were accompanied by major changes in plant assemblages, including extinctions, changes in the spatial distribution of plants in the tropics and temperate zones, and nearly synchronous changes in the structure of vegetation throughout the globe. Although the plants of the late Paleozoic and the geography of that time differed entirely from those of today, the rates, geographic distribution, and nature of vegetational changes can serve as portents of similar patterns in the transition to a modern greenhouse world. INSIDE • First International Secretary Named, p. 22 • 1996 Honorary Fellows, p. 23 • Call for Award Nominations, p. 26 • Southeastern Section 1997 Meeting, p. 32 Vol. 6, No. 10 October 1996