The Fen that vanished: The untold story of drainage and peat extraction in Bagno Chlebowo peatland with implications for nature conservation

Peatlands have been among the world's fastest-disappearing ecosystems, facing human pressure, especially over the last two centuries. The drainage of peatlands has long been pursued to expand agricultural and forestry areas as well as for peat extraction. One of the most degraded peatlands in western Poland is the Bagno Chlebowo, of which a small part is legally protected, having a raised bog status. The peatland has been undergoing drainage and peat mining since the 19th century, and regardless of its partial protection since 1959, it continues to be subjected to drainage, further compromising the function of the nature reserve. Our research focuses on reconstructing the impact of anthropogenic pressure on the state of the peatland over the last 600 years. We applied palaeoecological methods to reconstruct changes in water table levels, acidity (pH) and local plant cover over time. Additionally, we utilized historical maps to gather data on the area's land use and land cover changes. Our findings reveal that drainage and peat harvesting significantly increased the pH level of the peatland, consequently promoting Sphagnum expansion. These recent changes in vegetation cover and increased acidity have led to inaccuracies in correctly identifying peatland type. Therefore, the palaeoecological record makes us question its current protection status as a true raised bog, suggesting that the site was a fen for most of the time of its functioning. We demonstrate that long-term reconstructions are, therefore, substantial for nature conservation to (1) properly assess the status of wetlands, (2) identify baseline conditions, and (3) plan suitable restoration and protection methods.