Field stratigraphy

Vegetation communities present at each mire were assessed by traversing the sites, noting dominant species. General descriptions are included in the site descriptions where appropriate. Peat stratigraphy was rapidly assessed using a 30mm bore gouge auger and recording the sediments in the field. Peat humification (degree of decomposition) was recorded in the field using the 10-point scale of Troels-Smith (1955) ranging from 0 -the least to 10-the most. (0 = not humified: plant remains are not decomposed at all, 10 = well humified: individual plant remains are not recognisable). The humification value gives a crude measure of the comparative 'dryness' of the mire surface and growth rate of peat at the time the specific peat layer it refers to was formed (i.e. the higher the value, the more decomposed, the 'drier and slower growing the mire). The information is displayed in a series of tables in each site report.

An optical level was used for determination of relative surface levels of core positions where practicable. This information was then used to draw a series of stratigraphic sections through each major mire system surveyed. Different peat types are represented by different colour codes in each peat column. A key accompanying the diagrams explains the colour codes. Lines are used to link stratigraphical units between individuals cores where appropriate.

Macrofossil analysis

Field descriptions of stratigraphic elements were occasionally complemented by more detailed analysis in the laboratory from core samples. These were examined using a stereozoom microscope and helped to check and add detail to field determinations of material.

Cores were sub-sampled into blocks of ca. 25ml volume at varying intervals depending on the site investigated and marked variation in stratigraphy noted in the field. Sample volumes were measured by water displacement and samples were disaggregated by soaking in water for a minimum of 24 hours. Dispersed samples were washed through a sieve with a mesh size of 500 microns. Material retained from sieving and was systematically examined for plant macrofossil content low power stereozoom microscope (x6-40 magnification). Plant material was identified using a reference collection and the keys of Beijerinck (1974), Berggren (1969, 1981), Grosse-Brauckmann (1972), Jessen (1955) and Katz, Katz, and Kipani (1965).

The results are presented as a series of histograms indicating frequencies of vegetative remains per unit volume and seeds from each level sampled. In the diagrams and descriptions the word "seed" is used to describe both fruits and seeds in order to simplify the presentation. The results display relative abundance of plant remains assessed on a semi-quantitative five-point scale

1= rare
2=occasional
3=frequent
4=very frequent
5=abundant

where: