List of Plates (Only the most important plates are included in the text. For others see the appendix.) Text figures are not included in this list. Following page Ordinance Survey map of Skokholm Island……………………………………………………...Frontispiece
Part I 1. Map showing the position of the South Pembrokeshire Islands………………..………………4 2. Simplified map of the vegetation of Skokholm Island, October 1948………….…………..15 3. Distribution of the freshwater habitats of Skokholm………………………………………………39 4. Percentage cover histograms and soil profiles in seven freshwater communities on Skokholm……………………………………………………………………………………………………42 5. Vegetation map of Grassholm Island, June 1950…………………………………………………..44 6. “Fetch” diagram for the South Pembrokeshire Islands and three maps showing the direction of wind waves and swell around Skokholm shores……………………………..52 7. Simplified map of the chief breeding birds of Skokholm Island, summer 1949. (After Conder and Keighley)……………………………………………………………………………….65
Part II 8. Soil profiles in the boulder clay of the North and South Ponds on Skokholm to show types of soil and vegetation…………………………………………………………………….90 9. Representative belt transects showing the vegetation of cliffs suffering slight, intermediate and severe exposure to spray-bearing winds……………………………………..120 10. Morphological variation in Armeria maritima arising largely as a result of excessive exposure……………………………………………………………………………………………149 11. Soil profiles showing wind and water erosion in Armerietum………………………………..152 12. Illustrations to show the effect of grazing on Festuca rubra and Plantago maritima…..199 13. Morphological variation in Samolus valerandi dependent upon fluctuations in the environment………………………………………………………………………………………………201 14. Illustrations of the dwarf plants growing on 2 square inches of ground in a heavily grazed Plantago coronopus sward……………………………………………………………202 15. Morphological variation in Plantago coronopus var. vulgaris according to differences in the environment…………………………………………………………………………..202 16. Morphological variation in the large succulent variety of Plantago coronopus…………202 17. Morphological differences between grazed and ungrazed plants of Littorella uniflora in a terrestrial habitat………………………………………………………………206