The Time Factor in the Development of Dune Soils at South Haven Peninsula, Dorset

Abstract

The history and physiography (including recent developments) of these maritime dunes are briefly described, and changes in dune soil pH and organic content are correlated with the characteristic plant succession and the historical evidence of dune growth. The dune-building sand has a very low CaCO3 (about 0.015%): young dunes are dominated by Agropyron junceiforme and Ammophila arenaria, have a surface reaction near pH 7 and an organic content about 0.2%. After about 240 years they tend to an apparently fairly stable Calluna vulgaris heath with a surface pH of 3.8-4.4 and a mean surface organic content of about 13%. The course of these changes is discussed in comparison with those which have been described for other dune systems of comparable age (Blakeney Point, Norfolk and Southport, Lancs.) where the initial CaCO3 contents of the dune-building sands are significantly higher and subsequent leaching is less extreme.