The primary control on ancient land plant diversity is climate
- Texas A M Univ., College Station, TX (United States). Dept. of Geology
Reproductive strategy and competition have been proposed as determinants of ancient land plant diversity. However climate is the primary control on modern plant productivity and diversity and may be the primary control on ancient diversity. For Silurian through Mid-Carboniferous land plants, the most profound diversity collapse and the greatest diversity increase occurred during times of global climate change. In the middle to late Frasnian, land plant diversity fell precipitously and remained low through the middle Famennian. Global warming probably triggered this event. Climate models suggest global warming at the end of Frasnian; the cosmopolitan faunas and floras of the Famennian indicate a uniform global climate. The diverse floras of the late Givetian and early Frasnian show pronounced latitudinal differentiation which disappeared after the diversity collapse. The depauperate floras of the late Frasnian--middle Famennian fall into two or three biogeographic units, each of which spans a large paleolatitudinal range. Land plant diversity remained constant during the Early Carboniferous and rose dramatically at the Mid-Carboniferous boundary at the onset of, and perhaps in response to, Southern Hemisphere glaciation. Polar glaciation contributes to ever wet, ever warm tropical climate because polar high pressure zones confine the intertropical convergence zone to a narrow latitudinal belt near the equator. As land plant diversity rose, the paleoequatorial coal belt of the Late Carboniferous became established, suggesting a correlation between increases in land plant diversity and tropical precipitation.
- OSTI ID:
- 7271679
- Report Number(s):
- CONF-9303210--
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Journal Name: Geological Society of America, Abstracts with Programs; (United States) Vol. 25:3; ISSN GAAPBC; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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