The DAFOR scale

The following is a quantitative definition of frequency, intended to assist with the assessment of several of the saltmarsh attributes. This is a version of the well known DAFOR scale, which has been adapted to the particular characteristics of vegetated shingle as follows:

• Dominant: the species appears at most (>60%) stops and it covers more than 50% of each sampling unit;
• Abundant: species occurs regularly throughout a stand, at most (>60%) stops and its cover is less than 50% of each sampling unit;
• Frequent: species recorded from 31-60% of stops;
• Occasional: species recorded from 11-30% of stops;
• Rare: species recorded from up to 10% of stops.
  

Having completed the rapid assessments for the quality of the main vegetated shingle 'zones' it should then be relatively straightforward to do the one or more transects required to assess the width of the saltmarsh zones. If there is no prior data on the width of these habitats for your site, this assessment can form a crude baseline.

The routes followed for the structured walk and the start and finish points for the transects, should be marked on a map for future comparative use. Ideally these should be traced over aerial photos of the site using GIS, to enable comparisons on future visits. Permanent markers could be used to aid orientation in this respect. Comparisons could be made using set bearings from a given permanent marker - the owner/occupier could be asked not to destroy or remove particular makers (pill boxes etc.) that could be used (although loss due to erosion will have to be accepted). Some landmarks may already be used as permanent markers for surveys by local authorities, the Environment Agency or universities.