Response of Diatoms and Other Siliceous Indicators to the Developmental History of a Peatland in the Tiksi Forest, Siberia, Russia

Abstract

Diatoms and other siliceous microfossils were examined from a 386-cm-long peat core, covering the last ca. 7200 yr, from north-central Siberia to gain insights into peatland developmental history, and to explore the potential of diatoms as proxy indicators in arctic peats. Diatom analyses of arctic peatlands are rare, and so one aspect of this study was to examine the sensitivity of diatom taxa in relation to independent paleoindicators already described from this core. Changes in the relative abundances of diatom taxa divided the core into four zones that closely tracked the ontogeny of the peatland from an open water environment (Zone I: benthic, alkaliphilic taxa), followed by fen environments (Zones II and III; epiphytic, acidophilic taxa), and finally to a better-drained, high-centered bog (Zone IV; aerophilic taxa). In addition to the diatom taxa, observations were made on the relative abundances of siliceous protozoan plates, chrysophyte cysts, and phytoliths. Both the diatoms and these other siliceous microfossils appeared to respond to changes in hydrology and moisture, as well as to fire episodes likely triggered by climatic change. This study demonstrates that diatoms and other siliceous microfossils from arctic peat deposits provide an important source of paleoenvironmental information that can strengthen interpretations derived from other commonly used indicators.