Fen Management Handbook - Scottish Natural Heritage

5.4 Site survey to establish what is there now
5.4.1 Ecological survey
Having established the historical and wider context for the fen, the next stage is
to determine what is there now on the site in the way of wildlife. This requires an
up-to-date survey. The aim is to identify and map:
– Presence, location, distribution and population of species, habitats and features
of conservation interest within and around the site.
– Rare and protected species and habitats.
– Presence, location and distribution of invasive and non-native species.
– NVC plant communities within each wetland type and ways in which any differ
from published descriptions.
Clearly record the limits of accuracy for any mapping.
Designated sites such as SSSIs, ASSIs, SACs and sites of county importance
normally have written descriptions and recorded reasons for selection which
provide an important baseline measure of what the site contained at the time of
its listing or designation. There may be a statutory requirement to restore any lost
features for which the site was originally chosen. Citations do not necessarily
contain detailed habitat information so it may be necessary to infer the habitat type
from the species listed. For example, a plant list including the moss Scorpidium
cossonii and common butterwort (Pinguicula vulgaris) is likely to indicate nutrientpoor
base-rich groundwater-fed fen. The loss of these plants, and replacement by
tall species like great willowherb (Epilobium hirsutum) will require the reinstatement
of suitable conditions.
For both designated and non-designated sites, recent and historical species
records should be available from local biological record centres, which are usually
maintained by the county or unitary authority. Vice-county recorders (or their
equivalents in Scotland and Northern Ireland), and local wildlife groups (including
specialist local ornithological, herpetological, bat, moth or mammal groups) may
also be able to provide useful information. The county or local wildlife trust may
hold species records and be able to provide useful contacts.
Species locations should then be plotted on a site map which will help to pinpoint
areas of particular interest for further survey. Presence of a species or group of
species should be linked with the fundamental habitat characteristics. As outlined in
Section 2: Fen Flora and Fauna, classification of habitats for birds or invertebrates
may differ from those provided by plant ecologists. For example, the breakdown
of niches for invertebrates found in acid bogs is far less detailed, and reflects the
structure provided by a combination of substrate and vegetation. Absence of data
for a particular species is not necessarily evidence that a species is absent.
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