Yellowstone hot spring environments and the palaeo-ecophysiology of Rhyniechert plants: towards a synthesis
Channing A and Edwards D. 2009. Yellowstone hot spring environments and the palaeo-ecophysiology of Rhyniechert plants: towards a synthesis. Plant Ecology and Diversity. 2(2):111-143
Background: The Rhynie chert, Aberdeenshire, encapsulates the ecophysiological and anatomical information on allcomponents, including plants, animals and micro-organisms, of an early terrestrial ecosystem as it existed some 400 millionyears ago (Early Devonian), as preserved by siliceous waters emanating from a hot spring system.Aims: This paper concentrates on the higher plants (tracheophytes) and brings together information on the habitats of theplants and the environmental pressures that they endured to answer issues relating to their endemism and their ecophysiology.Methods & Results: The synthesis includes detailed information on the palaeo-environments recorded in the chert, plusanatomical and autecological data from the plants themselves, and makes comparisons with the abiotic and biotic dataobtained from an extant analogue, the alkali–chloride geothermal systems at Yellowstone National Park. Particular attentionis paid to the physiological basis and evolution of osmotic and chemical tolerance of halophytes, the dominant colonisers ofYellowstone’s wetlands and, to a lesser extent, metallophytes.Conclusions: The Rhynie plants colonised wetlands at the low temperature fringes of a hot spring system and were versatile,but physiologically highly specialised, capable of withstanding osmotic and chemical stresses in a dynamic environment,but were probably out-competed by mesophytic vegetation elsewhere.
- Type
- Journal Article
- Authors
- Channing, Alan; Edwards, Dianne
- Units
- GRYN
- Keywords
- fossilisation, geothermal wetland, permineralisation, silicification, Taphonomy