Deep Time Ecosystem Engineers: The Correlation between Palaeozoic Sedimentation, Vegetation, and Habitats in Riverine Environments
Event details
| Date | 18.09.2012 |
| Hour | 16:15 › 17:15 |
| Speaker | Dr Neil Davies, Department of Geology and Soil Science, Ghent University (BE) |
| Location | |
| Category | Conferences - Seminars |
Evidence from the deep time geological record attests to the fundamental importance of plant life to the construction of physical habitats within fluvial environments. Data from an extensive literature review and original fieldwork demonstrates that many landforms and geomorphic features present in modern river systems appear in the Palaeozoic stratigraphic record once terrestrial vegetation had adopted certain evolutionary advances: for example, stable point bars are associated with the development of deep rooting in the Siluro-Devonian and avulsive anabranching fluvial systems appear at the same time as extensive arborescent vegetation in the Carboniferous. Many extrinsic factors have been considered when attempting to identify controls on the evolutionary timelines of terrestrialization for various different organisms. Factors such as O2 and CO2 levels in the atmosphere, climatic events, global tectonic organisation, sea-level changes, extinction events, weathering rates and nutrient supply are all known to have played a role. However, a fundamental prerequisite for achieving terrestrial biodiversity was the variety of physical habitats available for newly evolved organisms, especially riparian systems. In the Carboniferous, the evolution of the anabranching habit within alluvial systems created further new physical landforms for colonization and would have promoted increasingly complex hyporheic flow regimes. Furthermore the associated increase in arborescent vegetation and supply of large woody debris to rivers would have created a wealth of new microhabitats for continental organisms. We argue that the expanding extent and diversity of physical alluvial niches during the Palaeozoic is an underappreciated driver of the terrestrialization of early continental life. The study of the deep-time fossil and stratigraphic record also illustrates that vegetation is a fundamental prerequisite for the creation of biogeomorphic alluvial landforms and physical habitats and microhabitats. In this presentation we illustrate new evidence for the interplay of vegetation, fluvial sediments and novel organism habitats using data from original field investigations into Carboniferous alluvium from extensive outcrop successions in eastern Canada and the United States.
Practical information
- General public
- Free
- This event is internal
Organizer
- IIE
Contact
- Professor Paolo Perona, AHEAD