An assessment of lentic ceratopogonids, ephemeropterans, trichopterans and oribatid mites as indicators of past environmental change in Finland

I studied a dataset of surface sediment samples from 80 lakes with zoological macroremain analysis to assess the potential of fossil ceratopogonids (Diptera: Ceratopogonidae), ephemeropterans (Insecta: Ephemeroptera), trichopterans (Insecta: Trichoptera) and oribatid mites (Acarina: Oribatida) as palaeolimnological indicators in Finland. Results showed that late-winter hypolimnetic oxygen and climatic variables were most important in influencing the occurrence and abundance of these taxa. Of the ceratopogonids, the Bezzia type was an indicator of elevated hypolimnetic oxygen conditions, warm climate and oligotrophy, while the Dasyhelea type indicated low hypolimnetic oxygen conditions, moderately cool climate and mild acidity. Ephemeropterans, trichopterans and oribatids indicated warm climatic conditions and oribatids were also indicative of elevated oxygen conditions and small oligotrophic lakes. Results of this study can be useful in palaeolimnological studies because the fauna examined provides a valuable supplementary data source for multiproxy studies.