Reconstructing human impact on peatland development during the past 200 years in CE Europe through biotic proxies and X-ray tomography

Abstract

We present the past 200 years palaeoecology of a peatland located in W Poland. This site is very important from the point of view of regional nature conservation. Plant macrofossils, testate amoebae, peat microtomography and radiocarbon dating were used in high-resolution to reconstruct the recent human impact on the peatland. In this study, we hypothesise that recent disturbance associated with peatland drainage and forest transformation has affected the development of the peatland and its trophic states. We sought to answer several questions. I) How pristine is the Rzecin peatland? II) Did the outbreak of Panolis flammea and the deforestation of 90% of the area of the Noteć Forest affect the water table and the pH of the Rzecin peatland? III) Did the construction of the Rzecin Canal through the drainage of the peatland (in the 1880s and 1890s) strongly influence the changes in the ground water of the Rzecin peatland? Deforestation and the digging of the Rzecin drainage canal between AD 1880 and AD 1890 marked the beginning of major changes in the wetland ecosystem and caused habitat acidification. The next acidification event, connected with Sphagnum appearance, began ca AD 1990. Based on our quantitative reconstruction, the water table decreased during the years preceding P. flammea outbreak in AD 1923. Then, the water table increased after the outbreak correlated with the historical maps that show ephemeral lakes in the Noteć Forest. The wetland examined by the current study was formerly perceived as highly natural, but its state is far from pristine, being very unstable during the last 200 years. Catastrophic events in the catchment change wetlands to a greater extent than we suppose, and their pristine state may not have existed for centuries.