The main features of the vegetational history revealed by study of two sets of cores from Dubh Lochan, near Loch Lomond are as follows:
- 1 There was a brief pioneer phase during the end of the Younger Dryas period after the disappearance of the Loch Lomond glacier. Dwarf shrubs and herbs, including arctic-alpines and pteridophytes, predominated.
- 2 There followed a brief phase of Empetrum and Juniperus in the earliest Flandrian.
- 3 Next came the expansion of tree Betula and then Corylus at 9350 years B.P. Together these dominated for up to 3000 years, with the arrival of Ulmus and Quercus and expansion of the latter, towards the end of the period.
- 4 There followed a temporary expansion of Pinus and the development of mixed Quercus forest with Alnus before 6000 years B.P. The Ulmus decline at 4900 years B.P. was well marked.
- 5 Major differences in the pollen spectra of the two cores in terms of the regional, extra local and local components occur during the last 4000 to 5000 years B.P. A hydroseral succession from open water through a Salix carr to a Myrica carr was noted only from the marginal core.
- 6 Though pollen indicative of human disturbance occurs from the Ulmus decline onwards and expands towards the top of the sequences, the area has stayed under Quercus forest with Alnus and Betula, there having been no substantial disforestation until the last 1000 years.