Resurvey of the Corticolous Lichen flora of Epping Forest
Air quality in Epping is better and no AQMAs have been declared. However, health Objectives
apply only where people live and vegetation Objectives, at the present time, only apply at sites
away from industry, roads and urban agglomerations. Epping Forest is therefore mainly excluded
from the assessment procedure, but traffic flow rates on the major roads indicate that Objectives
for oxides of nitrogen are almost certainly exceeded in parts of the Forest.
Approach and Methodology
The approach adopted for the pilot survey was chosen to meet two objectives. The first was to
assess current diversity, the second to facilitate a comparative review of historical records. Four
days were allocated for the survey broadly following a north-south gradient, using selected parts of
the Centenary Walk. Occasional diversions away from the path occurred to encompass as many of
the areas identified in historical surveys as possible.
Four areas were designated and one day was spent recording at each. The areas were:
1. North: Wintry Wood, a non cSAC designated part of the Forest, but the most studied area
with the richest flora (Hawksworth et al. 1973,1992) and the site of a single remaining
ancient woodland indicator species, Enterographa crassa at Stump Ride.
2. Central (East): High Beech, Honey Lane Quarter and Woodridden Hill.
3. Central (West): Little Monk Wood, Great Monk Wood, Baldwins Pond and Blackweir.
4. South: Hollow Pond and Eagle Pond, A104 /A503/A406.
Trees in each area were examined at random and species on their boles were recorded. When a
new species record was identified the grid position was noted using a geographical positioning
system (Magellan). As many trees as possible were examined on each day. A limited number of
critical specimens were collected for microscopic examination and retained in the lichen herbarium
at the Natural History Museum (BM).
Results
A total of 64 species were recorded during the pilot study (Table 1, Appendix A). Of these 17 are
new records for Epping. The maximum diversity at each of the sites reached 44 (Great Monk
Wood), with similar totals of 42 at site 4 closest to London, and 41 at site 2. The most northerly site
(Wintry Wood) had the lowest diversity with 35 species.
The following species were recorded at all sites (those in bold were recorded in Epping before
1920 and those underlined are new records with the exception of Dimerella pineti for which there
is a single record in 1983): Amandinea punctata, Bacidia delicata, Candelariella reflexa, Cladonia
coniocraea, C. macilenta, Dimerella pineti, Flavoparmelia caperata, Flavoparmelia soredians,
Lepraria incana, Lepraria lobificans, Melanelia subaurifera, Micarea prasina, Parmelia sulcata,
Phaeophyscia orbicularis, Physcia adscendens, Physcia tenella, Punctelia subrudecta, Ramalina
farinacea, Xanthoria parietina, Xanthoria polycarpa. Opegrapha ochrocheila was recorded on
three different tree species: Hornbeam in Wintry Wood, Oak and Beech in Great Monk Wood.
The single ancient woodland indicator species found by Rose in 1970 and Hawksworth & McManus
in 1989-91, Enterographa crassa, was not recorded although not all sites previously surveyed by
these authors were revisited.
Essex Naturalist (New Series) 20 (2003)
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