Early Plant responses to Large Igneous Province Activity: the Devonian of Angarida, Siberia.

Devonian plants in Siberia present protracted pioneer succession. During the Devonian Angarida was a large and semi-isolated continent within warm, arid zones of the northern hemisphere. Early plants in the Devonian did not originate upon Angarida, instead they are known to migrate to Angarida allowing a unique opportunity to study their changing biogeography and their influence upon the virgin landmass. In the Late Devonian, the Viluy-Yakutsk Large Igneous Province had two active phases and dramatically altered the physical and chemical environment of both the early plants and the marine systems. Our research into the survivourship dynamics of early plant communities upon the palaeocontinent Angarida have demonstrated that transgression and volcanogenic nutrient influx were key to the survival of colonising plants. Taxic proportions show that migrating taxa entered Angarida from the southwest, Kuznetsk and Minusinsk basins, dispersing across the continent in waves through central areas northwards. The patterns of dispersal are consistent throughout the Devonian and into the Early Carboniferous. Increased nutrient load from the active pulses of the Viluy-Yakutsk Large Igneous Province, biogeomorphic ecosystem engineering, and the increased biomass of Angaridan plants are assisted by Late Devonian transgression. These cumulative factors can be linked to the Late Devonian marine extinctions observed in Siberia.