Recent changes in soil properties and carbon stocks in fen peatlands adjacent to open‐pit lignite mines

Abstract

AbstractThe simultaneous impact of climate change and human activities on soil organic carbon content (SOC) in peatlands is insufficiently recognized, especially in relation to peatlands affected by open‐pit lignite mining. Given their importance in climate change feedback loops, long‐term observations of SOC changes in peatlands are essential. The aim of the study was to determine recent changes in the properties and SOC content/stock of agro‐managed fen peatlands located adjacent to open‐pit lignite mines. We studied two soil layers (0–20 and 20–40 cm) within 12 sampling plots in the Grójec Valley (Central Poland). Soil sample collection and field measurements took place in 2005 and again in 2015. The largest negative changes in soil properties (e.g. SOC content drop from 208 to 318 g kg−1 in 2005 to 125–263 g kg−1 in 2015 and SOC stock decrease from 12.1–16.2 kg m−2 in 2005 to 9.22–14.5 kg m−2 in 2015), as well as the largest variability of watertable level were recorded in the northern part of the study area, affected by long‐term lignite mining (1982–2009). While such a strong changes were not observed in the plots from central and southern part of the valley (230–439 g kg−1 in 2005 and 228–396 g kg−1 in 2015; 11.5–29,2 kg m−2 in 2005 and 13.4–36.1 kg m−2, respectively). Our results showed that depletion of SOC content in lowland peatlands in the temperate climate zone (due to human activity and changeable weather conditions) will proceed unless we implement sustainable management practices or apply restoration plans at these sites.