Response of diatoms and other siliceous indicators to the developmental history of a peatland in the Tiksi forest, Siberia, Russia

Diatoms and other siliceous microfossils were examined from a 386-cm-long p ear 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 pears. Diatom analyses of arctic peatlands are rare, and so one aspect of this study was to examine the sens itivity of diatom taxa in relation to independent paleoindicators already d escribed from this core. Changes in the relative abundances of diatom taxa divided the core into four zones that closely tracked the ontogeny of the p eatland from an open water environment (Zone I: benthic, alkaliphilic taxa) , followed by fen environments (Zones EI and In; epiphytic, acidophilic tax a), and finally to a better-drained, high-centered bog (Zone IV; aerophilic taxa). In addition to the diatom tars, observations were made on the relat ive abundances of siliceous protozoan plates, chrysophyte cysts, and phytol iths. Both the diatoms and these other siliceous microfossils appeared to r espond to changes in hydrology and moisture, as well as to fire episodes li kely triggered by climatic change. This study demonstrates that diatoms and other siliceous microfossils from arctic peat deposits provide an importan t source of paleoenvironmental information that can strengthen interpretati ons derived from other commonly used indicators.