Effectiveness of turf stripping as a measure for restoring species-rich fen meadows in suboptimal hydrological conditions

Most species-rich fen meadows in nature reserves in The Netherlands are acidified due to weaker upwelling of base-rich groundwater. The present study investigated whether and why turf stripping combined with superficial drainage might promote the long-term recovery of such meadows and restore the nutrient-poor, buffered conditions they require. In a field experiment, we analyzed changes in vegetation composition, soil parameters, and soil water chemistry in stripped plots of degraded Cirsio-Molinietum vegetation over 12 years. After the first five years, many species from the target communities occurred in stripped plots. Both vegetation and soil data showed positive effects of turf stripping on the acid-buffering capacity. Because sulfate concentration in the soil water decreased over time, whereas the bicarbonate concentration increased, we inferred that there was internal alkalinization driven by sulfate reduction in low-lying stripped plots. However, the succession toward more acidophilus plant communities, in both control and stripped plots, indicated gradual acidification. This may be caused by a continuing weakening of the upward seepage of base-rich groundwater as shown by declining calcium concentrations in the soil water. Though turf stripping exposed a nutrient-poor soil layer with a greater acid-buffering capacity, these positive effects might not be sufficient to combat the ongoing acidification in the long term