High-resolution peatland water-table changes for the past 200 years: the influence of climate and implications for management
2004
Hendon, Dawn | Charman, D. J.
Management of peatlands for conservation purposes is often directed at mitigation of damaging impacts of past and present human activity. Assessment of such impacts is often based on perspectives from short-term ecological data. Here we test a series of hypotheses for the causes of changes in mire hydrology and vegetation on the Border Mires in northern England using palaeoecological data for the last 200 years. Ecological data suggest peatlands surrounded by plantation forestry have become drier over the last 40 years. This could be caused by direct hydrological impacts of the growing trees and associated drainage or indirectly by the cessation of grazing and burning. A third hypothesis is that hydrological changes are the result of recent climatic change. High-resolution water-table reconstructions from testate amoebae analysis supported by plant macrofossil analysis and dated by 210Pb, spheroidal carbonaceous particles (SCPs) and pollen data demonstrate that a site outside the direct in‘ uence of forestry has also become drier during the twentieth century. This suggests that forestry is not the main cause of changes observed on other sites. Water-table declines began earlier than the main phase of forest planting and the magnitude of change appears to be similar to that on a site within the forest. Subjective comparisons of reconstructed water tables with meteorological data suggest that hydrological changes on the mires are primarily driven by summer temperature changes. If future regional climatic change predictions are correct, further water-table decline will follow and current management activities are unlikely to restore mires to their former condition.
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