No abstract

Abstract:Fine-scale dynamics of groundwater¯ow were studied in a 1 . 5 ha peatland in central New York. Measurements of the hydraulic head throughout a detailed network of piezometer clusters revealed spatial and temporal variability in the direction of groundwater¯ow at a very ®ne (within a few metres) scale of analysis. Within the small wetland, there were areas of groundwater recharge, discharge and lateral¯ow. Such patterns of groundwater¯ow frequently reversed or changed due to¯uctuations of only a few centimetres in hydraulic head. Speci®c conductance, deuterium signatures and calcium concentrations of groundwater corroborated the groundwater¯ow patterns determined with hydraulic head measurements and illustrated the in¯uence of source water chemistry and evaporation on dierent layers in the peat column. The control of peat chemistry by such ®ne-scale groundwater¯ow may have important implications for plant community composition and diversity in groundwater-fed peatlands.