On the North Gower saltmarshes soil samples were collected (at a series of depths) from 40 pits, these being arranged in linear transacts at right angles to the shoreline. From the samples, data for the following were obtained: soil pH, calcium carbonate content, total and hygroscopic soil moisture contents, loss on ignition, particle size analysis, clay mineral fractions, water soluble sodium and chloride, and degree of soil ripeness. Percent cover data were also collected for the plant species present along the transacts. Field examination and the analytical results show that distinct vertical and horizontal (i.e.-seaward) gradients exist in the saltmarsh soils. It was also established that 8 of the factors studied were strongly related to geographical location on the saltmarsh. Statistical analysis revealed a high degree of interrelationship between these factors. Using the plant data, Ward's agglomerative clustering technique produced species clusters. These were found to represent plant communities occurring on the saltmarsh. It was possible to describe these communities in terms of the soil factors measured. Multiple discriminant analysis showed that the soil factor most important in terms of vegetation distribution in the North Gower saltmarshes, was pH. The soils and vegetation of adjacent reclaimed and open saltmarsh sites, were also studied. Here, seawall construction had imposed a new set of environmental conditions upon an area of enclosed saltmarsh. As a result, soil development at these adjacent sites had diverged, and the soils studied on either side of the seawall were found to differ greatly. This difference was reflected in the vegetation present. It was concluded that the saltmarsh soils of North Gower represent the interplay of a complex set of factors along a land to sea continuum. This graded interplay is expressed visually in the vegetation zonation observed on the saltmarsh. Soil salinity may determine which plants grow on the saltmarsh, but pH was the factor which accounted for the actual distribution of the vegetation present. Enclosure was shown to constitute a truncation of the soil continuum described.