THE RESTORATION OF COASTAL SHINGLE VEGETATION - EFFECTS OF SUBSTRATE COMPOSITION ON THE ESTABLISHMENT OF CONTAINER-GROWN PLANTS

1. The use of container-grown plants in restoring shingle beach vegeta tion was investigated at Sizewell, Suffolk, UK, where the vegetation h ad been destroyed by the construction of a power station. Six species, Crambe maritima, Eryngium maritimum, Glaucium flavum, Honckenya peplo ides, Lathyrus japonicus and Rumex crispus, were selected to counter e rosion and assist the development of a more complex and natural commun ity. Plants were raised from stored seed, indigenous to the site, by h orticultural techniques. 2. Shingle substrates are dry, nutrient-poor and heterogeneous in their physical composition. Field experiments inv estigated the efficacy of organic matter and fertilizer treatments as ameliorants, and examined the influence of position on the beach profi le and substrate composition on the establishment of container-grown p lants. 3. Neither organic matter nor fertilizer additions had any sign ificant effect on mean plant size in any species after one field seaso n. Planting location on the beach profile was the most important facto r influencing establishment. Crambe maritima, G. flavum, H. peploides and R. crispus plants all grew significantly larger in the seaward plo ts, with more coarse shingle. Only G. flavum produced many reproductiv e plants during the first year, and these were more frequent and more fecund in the seaward plots. 4. The establishment of container-grown p lants of four of the species was also compared at two sites at similar distances from the sea, but with sandy or shingle-dominated substrate s, respectively. Again, greater growth on the coarser shingle substrat e by three of the most characteristic shingle beach species reflected an apparent selective advantage. Thus, substrate physical composition was probably the primary determinant of differences in performance acr oss the beach profile. 5. The use of container-grown plants to establi sh shingle vegetation resulted in low mortality, with rapid plant grow th and establishment. Fertilizer and organic matter treatments were no t generally cost-effective in establishing shingle beach vegetation fr om container-grown plants. The use of resources to recreate an appropr iate substrate composition is of far greater importance.