ARE PALAEOCLIMATIC RECORDS FROM PEATLANDS DRIVEN BY PRECIPITATION OR TEMPERATURE? HIGH-RESOLUTION PROXY RECORDS AND INSTRUMENTAL DATA FROM EUROPEAN MIRES

Peatland surface wetness records provide long Holocene palaeoclimate reconstructions at decadal to centennial resolution. These proxy records reflect changes in water balance but the relative strength of precipitation and temperature signals is not known. In common with other non-annually resolved records, there has been no calibration against instrumental climate data. In this paper high-resolution records of palaeohydrological change reconstructed from testate amoebae analysis are used to critically examine the relationships between reconstructed water table change and instrumental climate data. Data from three sites across Europe (UK, Sweden and Estonia) demonstrate that proxy surface wetness responses to climate are variable depending on the regional climate context. Under prevailing oceanic conditions, the proxy climate signal mainly reflects summer precipitation variability. Under more continental regimes, temperature plays a more important role, and both mean annual and summer temperatures may be important, depending on the period of water deficit. The results indicate we should expect to find spatially variable surface wetness – climate relationships in palaeoclimatic records. Considerable effort needs to be invested in understanding the proxy hydrological response to climate change within each region if palaeoclimatic records are to be interpreted more precisely in future. We should not necessarily expect similar proxy responses over very wide areas.