Pteridophytes as primary colonisers after catastrophic events through geological time and in recent history

Abstract

Pteridophytes reproduce by producing vast numbers of spores that may be dispersed over considerable distances, helping the plants colonise new areas. Being resistant to desiccation, fern spores can often survive for many years as spore banks in soil. After disturbance, such spores can germinate and subsequently colonise the area. These factors help pteridophytes to become primary colonisers on barren land, such as volcanic islands or land that has been devastated by some cataclysmic event. A further method of rapid colonisation is provided through the preservation and possible scattering of fragments of rhizomes in particular of horsetails. Similar rapid colonising by pteridophytes has been documented in the geological record following several major extinction events. These distinct, but short-lived, fern populations are recognisable by fern spikes in the microfossils. This paper brings together information on the reasons for pteridophyte success in colonising barren land, and examples taken from both the historic and geological records.