Preparation of testate amoebae samples affects water table depth reconstructions in peatland palaeoecological studies

In peatland palaeoecological studies, the preparation of peat samples for testate amoebae (TA) analysis involves boiling of samples and microsieving them through a 15-mu m sieve. We studied the effect of these preparation stages on the estimation of TA assemblages and on the reconstruction of water table depths (WTD). Our results indicate that the TA assemblages of boiled and unboiled samples are not significantly different, while microsieving reduces the concentration of small TA taxa and results in significantly different TA assemblages. The differences between microsieved and unsieved TA assemblages were reflected also in predicted values of WTD, which indicated drier conditions in case of unsieved samples than in microsieved samples. We conclude that the boiling of samples might be omitted if TA are extracted from the fresh peat samples. Microsieving may lead to erroneous palaeoecological WTD reconstructions and should be avoided if small TA taxa are present in samples.