Does peatland drainage damage the palaeoecological record?

Abstract

Upland peatlands in the UK are important sources of palaeoenvironmental information, providing context to human land use in upland areas. Land management practices, particularly over the last 150years have resulted in damage to the integrity of this palaeoenvironmental record. This study focuses on the effects of drainage on the condition of pollen remains within upland peat deposits using a case study from Exmoor, southwest England. Water-table monitoring and coring across three mires enabled the effects of water-table draw-down on the condition of pollen remains within the peat matrix to be assessed. Our results show that peatland drainage, which has taken place over the last 60–150years, caused significant localised water-table draw-down. A detailed pollen condition survey across seven coring sites demonstrates that pollen within the peat is damaged as a consequence. However, pollen is rarely so damaged that counted pollen assemblages are unreliable. Correspondence between pollen condition and past climate shifts and periods of enhanced human activity, suggests that recent damage to pollen caused by peatland drainage is superimposed on damage caused by other factors throughout the period of peat accumulation.