Analysis

The final stage of the project was to classify woods, using a combination of the historical data and field survey data.

This was done using a key, rather like the botanical keys used to identify plants. The key enabled a consistent approach to assigning woods to one of five classes:

• Recent Woodland
• Long-established Woodland
• Ancient Woodland (3)
• Ancient Woodland (2)
• Ancient Woodland (1)

For definitions of these classifications, click here. A sample of 129 woods was selected: these were the sites with the best available historical evidence, which could be classified using archive evidence alone. They included 61 Long-established sites and 68 Ancient (1 or 2).

Statistical analysis of the species lists for these sites produced a list of 63 flowering plants and bryophytes that were strongly associated with ancient woodland rather than long-established woodland (woods classified as Ancient (1) and (2) were both treated as ancient for the purposes of the analysis).

In the sample, the number of these species in a wood was found to vary signifcantly with the size of the site.

The trend line for number of ancient woodland plants and bryophytes plotted against woodland size was used as a threshold in the key to help classify the remaining woods.