AN ASSESSMENT OF TERRESTRIAL LIMING STRATEGIES IN UPLAND WALES

Five terrestrial liming strategies are compared in forested and moorland subcatchments monitored under the Llyn Brianne Acid Waters Project in Wales. Lime was applied to a moorland whole catchment, to a forested and to a moorland water source area, to a forest buffer zone and to a hillslope within a moorland catchment. In terms of the long-term behaviour of stream chemistry, in particular calcium, pH and aluminium, at each site, addition of limestone to hydrological source areas has raised stream chemistry above proposed biological thresholds in the long term and has changed, chemically, the short-term storm event response in these catchments significantly. Buffer zone liming and standard agricultural improvement have not affected streamwater chemistry.