Fen Management Handbook - Scottish Natural Heritage

Case Study 5.3
Fen Management and Restoration
– Wybunbury Moss
Wybunbury Moss is a small basin fen, 18ha in extent, approximately 9km south-east
of Nantwich in Cheshire (SJ697502). The fen has formed in one of the many glacial
hollows found in this part of the country. At its centre is an oligotrophic, floating
mire or schwingmoor, which has been formed through the solution and subsidence
of underlying salt-bearing strata. The peat raft is surrounded by open fen, mixed
woodland and wet grassland.
The site is notified as a SSSI for its raised mire, bog pool and fen communities,
vascular plant assemblages and its invertebrate assemblage, the latter being
arguably the most important in Cheshire. The Moss also forms part of the Midlands
Meres and Mosses Ramsar site and the West Midlands Mosses SAC (transition
mires and quaking bogs).
Flora and fauna
The central oligotrophic area contains much Sphagnum fallax, S. capillifolium
and S. papillosum, upon which grow round-leaved sundew Drosera rotundifolia,
bog rosemary Andromeda polifolia and white beak-sedge Rhynchospora alba.
Radiating out from this, Sphagnum recurvum becomes the dominant and often, only
Sphagnum species, generally occurring with common cotton-grass Eriophorum
angustifolium, hare’s-tail cotton-grass E. vaginatum, cross-leaved heath Erica
tetralix, cranberry Vaccinium oxycoccos, crowberry Empetrum nigrum and heather
Calluna vulgaris.
Fen woodland is characteristic of those parts of the mire where the peat is wet and
unstable and the mire waters are eutrophic. The principal canopy species is alder
with lesser amounts of rowan (Sorbus aucuparia), downy birch (Betula pubescens),
oak (Quercus robur and Q. petraea), common sallow (Salix cinerea) with alder
buckthorn (Frangula alnus) and guelder rose (Viburnum opulus) in the shrub layer.
This community has the most diverse ground flora on the reserve with species
including greater and lesser bulrush, common reed and saw sedge.
A rich invertebrate fauna includes two Red Data Book (RDB) species of spider, the
increasingly rare argent and sable moth (Rheumaptera hastata) and the RDB2 leaf
beetle (Cryptocephalus decemmaculatus).
Past management
Although Wybunbury has been an NNR since 1954, significant habitat
management did not take place until the mid 1980s. Since then, management
has concentrated on reversing the adverse effects of tree encroachment and
eutrophication, whilst at the same time maintaining suitable habitats for the
invertebrate assemblage.
The plant communities for which the site is notified are those which occupy the
wetter, treeless parts of the Moss. However, attempts to drain parts of the Moss
for peat cutting and the gradual encroachment of Scots pine (Pinus sylvestris) have
led to a reduction in the extent of these communities. Management work since the
1980s has centred on restoring water levels and removing trees and scrub from
these areas – the generic guidance for conservation objectives gives a guideline of